Frontiers of Environmental Science & Engineering

ISSN 2095-2201

ISSN 2095-221X(Online)

CN 10-1013/X

Postal Subscription Code 80-973

2018 Impact Factor: 3.883

   Online First

Administered by

Top Read Articles
Published in last 1 year |  In last 2 years |  In last 3 years |  All
Please wait a minute...
For Selected: View Abstracts Toggle Thumbnails
Review on design and evaluation of environmental photocatalysts
Xin Li, Jun Xie, Chuanjia Jiang, Jiaguo Yu, Pengyi Zhang
Front. Environ. Sci. Eng.    2018, 12 (5): 14-.
Abstract   HTML   PDF (8528KB)

Fundamentals on the photocatalytic degradation were systematically summarized.

Charge carrier dynamics for the photocatalytic degradation were reviewed.

Adsorption and photodegradation kinetics of reactants were highlighted.

The mechanism aspects, including O2 reduction, reactive oxidation species and key intermediates were also addressed.

Selectivity and stability of semiconductors for photodegradation were clarified.

Heterogeneous photocatalysis has long been considered to be one of the most promising approaches to tackling the myriad environmental issues. However, there are still many challenges for designing efficient and cost-effective photocatalysts and photocatalytic degradation systems for application in practical environmental remediation. In this review, we first systematically introduced the fundamental principles on the photocatalytic pollutant degradation. Then, the important considerations in the design of photocatalytic degradation systems are carefully addressed, including charge carrier dynamics, catalytic selectivity, photocatalyst stability, pollutant adsorption and photodegradation kinetics. Especially, the underlying mechanisms are thoroughly reviewed, including investigation of oxygen reduction properties and identification of reactive oxygen species and key intermediates. This review in environmental photocatalysis may inspire exciting new directions and methods for designing, fabricating and evaluating photocatalytic degradation systems for better environmental remediation and possibly other relevant fields, such as photocatalytic disinfection, water oxidation, and selective organic transformations.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(33) WebOfScience(36)
Designing an in situ remediation strategy for polluted surface water bodies through the specific regulation of microbial community
Boran Wu, Xiaoli Chai, Youcai Zhao, Xiaohu Dai
Front. Environ. Sci. Eng.    2019, 13 (1): 4-.
Abstract   HTML   PDF (236KB)

Remediation of polluted water body via microbial community regulation is proposed.

EAS-induced microbial growth can enhance self-purification of polluted water body.

Principle of EAS is elaborated by the conceptual model description.

This paper proposes an in situ restoration strategy, ecosystem activation system (EAS), for self-purification abilities of polluted water ecosystems through the specific regulation of microbial community. EAS utilizes polyhydroxyalkanoates (PHA) to modify indigenous microbial communities of polluted water bodies. Microorganisms preferentially utilizing PHA as the carbon source for their enhanced growth are defined as specific, and those with no special selectivity to PHA and raw-water dissolved organic matter are defined as non-specific and can be phased out during EAS operation. As a result, the microbial community can be regulated to the specific structure, which is beneficial for the water quality improvement. The developed model described the above principle with accounting for the growth kinetics of specific microorganisms, competitive inhabitation of specific microorganisms on non-specific microorganisms, and coupled EAS-induced self-purification of polluted water bodies. The conceptual model is believed to be a primary step toward quantitative design, operation, and optimization of EAS.

Table and Figures | Reference | Related Articles | Metrics
Effect of chemical dose on phosphorus removal and membrane fouling control in a UCT-MBR
Guangrong Sun, Chuanyi Zhang, Wei Li, Limei Yuan, Shilong He, Liping Wang
Front. Environ. Sci. Eng.    2019, 13 (1): 1-.
Abstract   HTML   PDF (1281KB)

Phosphorus removal was enhanced effectively by dosing aluminum sulfate and effluent phosphorus concentration was lower than 0.5 mg/L.

Sludge activity was not inhibited but improved slightly with addition of aluminum sulfate.

EPS concentrations both in mixed liquid and on membrane surface were decreased, contributing to the effective mitigation of membrane fouling.

To enhance phosphorus removal and make the effluent meet the strict discharge level of total phosphorus (TP, 0.5 mg/L), flocculant dosing is frequently applied. In this study, the performance of aluminum sulfate dosing in a University of Cape Town Membrane Bioreactor (UCT-MBR) was investigated, in terms of the nutrients removal performance, sludge characteristics and membrane fouling. The results indicated that the addition of aluminum sulfate into the aerobic reactor continuously had significantly enhanced phosphorus removal. Moreover, COD, NH4+-N and TN removal were not affected and effluent all met the first level A criteria of GB18918-2002. In addition, the addition of aluminum sulfate had improved the sludge activity slightly and reduced trans-membrane pressure (TMP) increase rate from 1.13 KPa/d to 0.57 KPa/d effectively. The membrane fouling was alleviated attributed to the increased average particle sizes and the decreased accumulation of the small sludge particles on membrane surface. Furthermore, the decline of extracellular polymeric substance (EPS) concentration in mixed sludge liquid decreased its accumulation on membrane surface, resulting in the mitigation of membrane fouling directly.

Table and Figures | Reference | Related Articles | Metrics
Effective removal of Cd2+ and Pb2+ pollutants from wastewater by dielectrophoresis-assisted adsorption
Qinghao Jin, Chenyang Cui, Huiying Chen, Jing Wu, Jing Hu, Xuan Xing, Junfeng Geng, Yanhong Wu
Front. Environ. Sci. Eng.    2019, 13 (2): 16-.
Abstract   HTML   PDF (353KB)

Dielectrophoresis (DEP) process could enhance the removal the Cd2+ and Pb2+ with less absorbent.

The removal rates of both Cd2+ and Pb2+ increased with the increase of voltage.

The overall removal rate of Cd2+ and Pb2+ in the binary system is higher than that of Cd2+ or Pb2+ in the single system.

DEP could cause considerable changes of the bentonite particles in both surface morphology and microstructure.

Dielectrophoresis (DEP) was combined with adsorption (ADS) to simultaneously and effectively remove Cd2+ and Pb2+ species from aqueous solution. To implement the process, bentonite particles of submicro-meter size were used to first adsorb the heavy metal ions. These particles were subsequently trapped and removed by DEP. The effects of the adsorbent dosage, DEP cell voltage and the capture pool numbers on the removal rate were investigated in batch processes, which allowed us to determine the optimal experimental conditions. The high removal efficiency, 97.3% and 99.9% for Cd2+ and Pb2+, respectively, were achieved when the ions are coexisting in the system. The microstructure of bentonite particles before and after ADS/DEP was examined by scanning electron microscopy. Our results suggest that the dielectrophoresis-assisted adsorption method has a high capability to remove the heavy metals from wastewater.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(1)
A review on application of dielectric barrier discharge plasma technology on the abatement of volatile organic compounds
Wenjing Lu, Yawar Abbas, Muhammad Farooq Mustafa, Chao Pan, Hongtao Wang
Front. Environ. Sci. Eng.    2019, 13 (2): 30-.
Abstract   HTML   PDF (565KB)

• Applications of non-thermal plasma reactors for reduction of VOCs were reviewed.

• Dielectric barrier discharge (DBD) plasma was considered.

• Effect of process parameters was studied.

• Effect of catalysts and inhibitors were evaluated.

Volatile organic compounds (VOCs) released from the waste treatment facilities have become a significant issue because they are not only causing odor nuisance but may also hazard to human health. Non-thermal plasma (NTP) technologies are newly developed methods and became a research trend in recent years regarding the removal of VOCs from the air environment. Due to its unique characteristics, such as bulk homogenized volume, plasma with high reaction efficiency dielectric barrier discharge (DBD) technology is considered one of the most promising techniques of NTP. This paper reviews recent progress of DBD plasma technology for abatement of VOCs. The principle of plasma generation in DBD and its configurations (electrode, discharge gap, dielectric barrier material, etc.) are discussed in details. Based on previously published literature, attention has been paid on the effect of DBD configuration on the removal of VOCs. The removal efficiency of VOCs in DBD reactors is presented too, considering various process parameters such as initial concentration, gas feeding rate, oxygen content and input power. Moreover, using DBD technology, the role of catalysis and inhibitors in VOCs removal are discussed. Finally, a modified configuration of the DBD reactor, i.e. double dielectric barrier discharge (DDBD) for the abatement of VOCs is discussed in details. It was suggested that the DDBD plasma reactor could be used for higher conversion efficiency as well as for avoiding solid residue deposition on the electrode. These depositions can interfere with the performance of the reactor.

Table and Figures | Reference | Related Articles | Metrics
Effect of 2-butenal manufacture wastewater to methanogenic activity and microbial community
Guangqing Song, Hongbo Xi, Xiumei Sun, Yudong Song, Yuexi Zhou
Front. Environ. Sci. Eng.    2018, 12 (5): 10-.
Abstract   HTML   PDF (450KB)

The inhibition ratio sharply increased with the increasing COD.

The absorbance of UV-vis at 420 nm showed a linear correlation with the SMA.

The molecular structure of EPS has changed when COD was 9585 mg/L.

Illumina Miseq sequencing was employed to reveal the microbial composition.

The synthesis of 2-butenal, which is a vital raw material for the production of sorbic acid as a food preservative, generates some toxic by-products, so it is urgent to seek better detoxification strategies for the treatment of 2-butenal manufacture wastewater. In this study, batch experiments were carried out to investigate the inhibition effect of wastewater on the methanogenic activity. To understand the wastewater toxicity to anaerobic granular sludge, variations of the specific methanogenic activity (SMA) and extracellular polymeric substance (EPS) constituents at various wastewater CODs were investigated. Ultraviolet-visible (UV-vis) spectra and Fourier transform infrared (FT-IR) spectra were employed to analyze the structure of the EPS. The results showed that the inhibitory ratio of 2-butenal manufacture wastewater was less than 8.4% on the anaerobic granular sludge when the CODs were less than 959 mg/L. However, the inhibitory ratio increased from 36.4% to 93.6% when CODs increased from 2396 mg/L to 9585 mg/L, with the SMA decreasing from 39.1 mL CH4/(gVSS·d) to 3.2 mL CH4/(gVSS·d). The diversity of the microbial community under various CODs was researched by Illumina 16S rRNA Miseq sequencing and the results demonstrated that ProteiniphilumPetrimonas and Syntrophobacter were the dominant bacteria genera in all sample. Regarding archaea, Methanobacterium was the most dominated archaea genera, followed by the Methanosaeta group in all samples. Moreover, the bacterial communities had changed obviously with increasing CODs, which indicated high CODs played a negative impact on the richness and diversity of bacterial community in the sludge samples.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Relations between indoor and outdoor PM2.5 and constituent concentrations
Cong Liu, Yinping Zhang
Front. Environ. Sci. Eng.    2019, 13 (1): 5-.
Abstract   HTML   PDF (762KB)

Factors impacting indoor-outdoor relations are introduced.

Sulfate seems a fine tracer for other non-volatile species.

Particulate nitrate and ammonium desorb during outdoor-to-indoor transport.

OC load increases during the transport due to sorption of indoor SVOCs.

Outdoor PM2.5 influences both the concentration and composition of indoor PM2.5. People spend over 80% of their time indoors. Therefore, to assess possible health effects of PM2.5 it is important to accurately characterize indoor PM2.5 concentrations and composition. Controlling indoor PM2.5 concentration is presently more feasible and economic than decreasing outdoor PM2.5 concentration. This study reviews modeling and measurements that address relationships between indoor and outdoor PM2.5 and the corresponding constituent concentrations. The key factors in the models are indoor-outdoor air exchange rate, particle penetration, and deposition. We compiled studies that report I/O ratios of PM2.5 and typical constituents (sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), elemental carbon (EC), and organic carbon (OC), iron (Fe), copper (Cu), and manganese (Mn)). From these studies we conclude that: 1) sulfate might be a reasonable tracer of non-volatile species (EC, Fe, Cu, and Mn) and PM2.5 itself; 2) particulate nitrate and ammonium generally desorb to gaseous HNO3 and NH3 when they enter indoors, unless, as seldom happens, they have strong indoor sources; 3) indoor-originating semi-volatile organic compounds sorb on indoor PM2.5, thereby increasing the PM2.5 OC load. We suggest further studies on indoor-outdoor relationships of PM2.5 and constituents so as to help develop standards for healthy buildings.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(2) WebOfScience(2)
Detection of oxidative stress and DNA damage in freshwater snail Lymnea leuteola exposed to profenofos
Daoud Ali, Huma Ali, Saud Alifiri, Saad Alkahtani, Abdullah A Alkahtane, Shaik Althaf Huasain
Front. Environ. Sci. Eng.    2018, 12 (5): 1-.
Abstract   HTML   PDF (802KB)

Freshwater snail (Lymnea luteola L.) is good bio indicator of water pollution.

Profenofos is tested for its molluscicidal activity against Lymnea luteola L. snail.

Deleterious effects on some oxidative stress were detected.

Profenofos has a genotoxic effect on Lymnea luteola L. snails.

Extensive production and use of organophosphate pesticide in agriculture, has risen concerned about its ecotoxicity and risk assessment of insecticides, which are more important. Therefore, the present investigation was aimed to study the induction of oxidative stress and DNA damage by organophosphate insecticide profenofos (PFF) in freshwater snail Lymnea luteola (L. luteola). The median lethal value (96 h LC50) of PFF was estimated as 1.26 mg/L for L. luteola in a semi-static system and on the basis of LC50 value three concentrations viz., 0.126 (1/10 of LC50, Sublethal I), 0.63 (1/2 of LC50, Sublethal II) and 0.84 mg/L (2/3 of LC50, Sublethal III) were determined. Snails were exposed to above-mentioned concentrations of PFF along with solvent control (acetone) and negative control for 96 h. The haemolymph was collected at 24 and 96 h of after treatment. In heamolymph of PFF exposed snail, lipid peroxide, glutathione reduced glutathione S transferase and superoxide dismutase activities at the tested concentrations significantly differ from those in the control. The genotoxicity induced in hemocytes of treated snails was measured by alkaline single cell gel electrophoresis assay. The data of this experiment demonstrated significantly enhancement of oxidative stress and DNA damage in the treated snails as compared to controls. Also, we observed statistically significant correlations of ROS with DNA damage (% tail DNA) (R2 = 0.9708) for 24 h and DNA damage (R2 = 0.9665) for 96 h.

Results of the current experiment can be useful in risk assessment of PFF among aquatic organisms. The study confirmed the use of comet assay for in vivo laboratory experiments using freshwater snail for selecting the toxic potential of industrial chemicals and environmental contaminants.



Table and Figures | Reference | Related Articles | Metrics
Cited: WebOfScience(1)
Optimization of denitrifying phosphorus removal in a pre-denitrification anaerobic/anoxic/post-aeration+ nitrification sequence batch reactor (pre-A2NSBR) system: Nitrate recycling, carbon/nitrogen ratio and carbon source type
Weihua Zhao, Meixiang Wang, Jianwei Li, Yu Huang, Baikun Li, Cong Pan, Xiyao Li, Yongzhen Peng
Front. Environ. Sci. Eng.    2018, 12 (5): 8-.
Abstract   HTML   PDF (2825KB)

A novel two sludge pre-A2NSBR system was developed.

Advanced N and P removal was optimized to treat real domestic wastewater.

Nitrifiers and PAOs were enriched with 19.41% and 26.48%, respectively.

Acetate was demonstrated as the high-quality carbon source type.

Because the efficiency of biological nutrient removal is always limited by the deficient carbon source for the low carbon/nitrogen (C/N) ratio in real domestic sewage, the denitrifying phosphorus removal (DNPR) was developed as a simple and efficient method to remove nitrogen and phosphorous. In addition, this method has the advantage of saving aeration energy while reducing the sludge production. In this context, a pre-denitrification anaerobic/anoxic/post-aeration+ nitrification sequence batch reactor (pre-A2NSBR) system, which could also reduce high ammonia effluent concentration in the traditional two-sludge DNPR process, is proposed in this work. The pre-A2NSBR process was mainly composed of a DNPR SBR and a nitrifying SBR, operating as alternating anaerobic/anoxic/post-aeration+ nitrification sequence. Herein, the long-term performance of different nitrate recycling ratios (0–300%) and C/N ratios (2.5–8.8), carbon source type, and functional microbial community were studied. The results showed that the removal efficiency of total inorganic nitrogen (TIN, including NH4+-N, NO2 -N, and NO3 -N) gradually increased with the nitrate recycling ratios, and the system reached the highest DNPR efficiency of 94.45% at the nitrate recycling ratio of 300%. The optimum C/N ratio was around 3.9–7.3 with a nitrogen and phosphorus removal efficiency of 80.15% and 93.57%, respectively. The acetate was proved to be a high-quality carbon source for DNPR process. The results of fluorescence in situ hybridization (FISH) analysis indicated that nitrifiers and phosphorus accumulating organisms (PAOs) were accumulated with a proportion of 19.41% and 26.48%, respectively.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(1)
A pulsed switching peroxi-coagulation process to control hydroxyl radical production and to enhance 2,4-Dichlorophenoxyacetic acid degradation
Yaobin Lu, Songli He, Dantong Wang, Siyuan Luo, Aiping Liu, Haiping Luo, Guangli Liu, Renduo Zhang
Front. Environ. Sci. Eng.    2018, 12 (5): 9-.
Abstract   HTML   PDF (386KB)

• A new pulsed switching peroxi-coagulation (PSPC) system was developed.

• The ECT for 2,4-D removal in the PSPC was lower than that in the EF.

• The iron consumption for 2,4-D removal in the PSPC was lower than that in the PC.

The aim of this study was to develop a new pulsed switching peroxi-coagulation system to control hydroxyl radical (?OH) production and to enhance 2,4-Dichlorophenoxyacetic acid (2,4-D) degradation. The system was constructed with a sacrifice iron anode, a Pt anode, and a gas diffusion cathode. Production of H2O2 and Fe2+ was controlled separately by time delayers with different pulsed switching frequencies. Under current densities of 5.0 mA/cm2 (H2O2) and 0.5 mA/cm2 (Fe2+), the ?OH production was optimized with the pulsed switching frequency of 1.0 s (H2O2):0.3 s (Fe2+) and the ratio of H2O2 to Fe2+ molar concentrations of 6.6. Under the optimal condition, 2,4-D with an initial concentration of 500 mg/L was completely removed in the system within 240 min. The energy consumption for the 2,4-D removal in the system was much lower than that in the electro-Fenton process (68±6 vs. 136±10 kWh/kg TOC). The iron consumption in the system was ~20 times as low as that in the peroxi-coagulation process (196±20 vs. 3940±400 mg/L) within 240 min. The system should be a promising peroxi-coagulation method for organic pollutants removal in wastewater.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(1) WebOfScience(1)
Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil
Yu Miao, Nicholas W. Johnson, Kimberly Heck, Sujin Guo, Camilah D. Powell, Thien Phan, Phillip B. Gedalanga, David T. Adamson, Charles J. Newell, Michael S. Wong, Shaily Mahendra
Front. Environ. Sci. Eng.    2018, 12 (5): 2-.
Abstract   HTML   PDF (1984KB)

Groundwater microbial community was altered after catalysis and chemical oxidation.

The coupled treatment train removed 90% 1,4-dioxane regardless of co-contaminants.

Dynamics of microbial populations varied along with different treatment stages.

Many microbial taxa exhibited resilience against oxidative and catalytic treatments.

Metagenomic analysis will be valuable for long-term management of polluted sites.

Post-treatment impacts of a novel combined hydrogen peroxide (H2O2) oxidation and WOx/ZrO2 catalysis used for the removal of 1,4-dioxane and chlorinated volatile organic compound (CVOC) contaminants were investigated in soil and groundwater microbial community. This treatment train removed ~90% 1,4-dioxane regardless of initial concentrations of 1,4-dioxane and CVOCs. The Illumina Miseq platform and bioinformatics were used to study the changes to microbial community structure. This approach determined that dynamic shifts of microbiomes were associated with conditions specific to treatments as well as 1,4-dioxane and CVOCs mixtures. The biodiversity was observed to decrease only after oxidation under conditions that included high levels of 1,4-dioxane and CVOCs, but increased when 1,4-dioxane was present without CVOCs. WOx/ZrO2 catalysis reduced biodiversity across all conditions. Taxonomic classification demonstrated oxidative tolerance for members of the genera Massilia and Rhodococcus, while catalyst tolerance was observed for members of the genera Sphingomonas and Devosia. Linear discriminant analysis effect size was a useful statistical tool to highlight representative microbes, while the multidimensional analysis elucidated the separation of microbiomes under the low 1,4-dioxane-only condition from all other conditions containing CVOCs, as well as the differences of microbial population among original, post-oxidation, and post-catalysis states. The results of this study enhance our understanding of microbial community responses to a promising chemical treatment train, and the metagenomic analysis will help practitioners predict the microbial community status during the post-treatment period, which may have consequences for long-term management strategies that include additional biodegradation treatment or natural attenuation.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(1) WebOfScience(1)
Static and dynamic characteristics of SO2-O2 aqueous solution in the microstructure of porous carbon materials
Shi Yin, Yan-Qiu Chen, Yue-Li Li, Wang-Lai Cen, Hua-Qiang Yin
Front. Environ. Sci. Eng.    2018, 12 (5): 12-.
Abstract   HTML   PDF (577KB)

To derive liquid fuel from waste engine oil and plastics thorough pyrolysis process.

To make equal blend of waste engine oil and plastics with diesel fuel.

To find the suitability of fuel from waste in diesel engine through performance, emission and combustion characteristics.

Porous carbon material facilitates the reaction SO2 + O2 + H2O → H2SO4 in coal-burned flue gas for sulfur resources recovery at mild conditions. It draws a long-term mystery on its heterogeneous catalysis due to the complicated synergic effect between its microstructure and chemical components. To decouple the effects of geometric structure from chemical components, classical molecular dynamics method was used to investigate the static and dynamic characteristics of the reactants (H2O, SO2 and O2) in the confined space truncated by double-layer graphene (DLG). Strong adsorption of SO2 and O2 by the DLG was observed, which results in the filling of the solute molecules into the interior of the DLG and the depletion of H2O. This effect mainly results from the different affinity of the DLG to the species and can be tuned by the separation of the two graphene layers. Such dimension dependence of the static and dynamic properties like distribution profile, molecular cluster, hydrogen bond and diffusion coefficient were also studied. The conclusions drawn in this work could be helpful to the further understanding of the underlying reaction mechanism of desulfurization process in porous carbon materials and other applications of carbon-based catalysts.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Isolation and application of an ibuprofen-degrading bacterium to a biological aerated filter for the treatment of micro-polluted water
Bingjie Xu, Gang Xue, Xing Yang
Front. Environ. Sci. Eng.    2018, 12 (5): 15-.
Abstract   HTML   PDF (597KB)

• An ibuprofen-degrading strain, Serratia marcescens BL1, was isolated and identified.

• The effects of various factors on ibuprofen degradation by BL1 were evaluated.

• Strain BL1 was applied to a laboratory-scale biological aerated filter system.

• Strain BL1 was stable in both static tests and in the biological aerated filter system.

Ibuprofen (IBU) is widely used in the world as anti-inflammatory drug, which posed health risk to the environment. A bacterium capable of degrading IBU was isolated from activated sludge in a sewage treatment plant. According to its morphological, physiologic, and biochemical characteristics, as well as 16S rRNA sequence analysis, the strain was identified as Serratia marcescens BL1 (BL1). Degradation of IBU required the presence of primary substrate. After a five-day cultivation with yeast powder at 30℃ and pH 7, the highest degradation (93.47%±2.37%) was achieved. The process of BL1 degrading IBU followed first-order reaction kinetics. The BL1 strain was applied to a small biological aerated filter (BAF) device to form a biofilm with activated sludge. IBU removal by the BAF was consistent with the results of static tests. The removal of IBU was 32.01% to 44.04% higher than for a BAF without BL1. The indigenous bacterial community was able to effectively remove CODMn (permanganate index) and ammonia nitrogen in the presence of BL1.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(1) WebOfScience(1)
Influence of hydraulic retention time on behavior of antibiotics and antibiotic resistance genes in aerobic granular reactor treating biogas slurry
Jie Liao, Chaoxiang Liu, Lin Liu, Jie Li, Hongyong Fan, Jiaqi Ye, Zhichao Zeng
Front. Environ. Sci. Eng.    2019, 13 (3): 31-.
Abstract   HTML   PDF (1385KB)

Longer HRT can enhance degradation rate of sulfamethoxazole in granular reactor.

Longer HRT can reduce accumulated concentrations of TCs and QNs in sludge.

Longer HRT may have increased relative abundances of ARGs in aerobic granules.

The behavior of antibiotics and the corresponding resistance genes in aerobic granular reactors for treating biogas slurry under different hydraulic retention times (10.7 h, R1; 8 h, R2) was investigated in this study. The results indicated that the hydraulic retention time could affect the effluent concentrations and removal efficiencies of sulfonamides. The average removal rates of tetracyclines, fluoroquinolones, and sulfonamides were 63%, 46%, and 90% in R1, and 62%, 46%, and 86% in R2, respectively. Although the removal efficiencies of tetracyclines and fluoroquinolones were similar in both reactors, the respective accumulated concentrations of tetracyclines and fluoroquinolones in R1 were 7.00 and 11.15 µg/g SS, which were lower than those in R2 (8.92 and 13.37 µg/g SS, respectively). The difference in the relative abundance of target antibiotic resistance genes between both reactors was not significant, yet the average relative abundances of all target resistance genes in R1 were higher than those in R2 after 45 days of operation. The results of this study suggested that a longer hydraulic retention time could enhance the antibiotic removal ability of aerobic granular sludge, yet it may also increase the risk of surplus sludge utilization from a resistance genes point of view.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Inverse uncertainty characteristics of pollution source identification for river chemical spill incidents by stochastic analysis
Jiping Jiang, Feng Han, Yi Zheng, Nannan Wang, Yixing Yuan
Front. Environ. Sci. Eng.    2018, 12 (5): 6-.
Abstract   HTML   PDF (718KB)

Uncertainty rules of pollution source inversion are revealed by stochastic analysis

A release load is most easily inversed and source locations own largest uncertainty

Instantaneous spill assumption has much less uncertainty than continuous spill

The estimated release locations and times negatively deviate from real values

The new findings improve monitoring network design and emergency response to spills

Identifying source information after river chemical spill occurrences is critical for emergency responses. However, the inverse uncertainty characteristics of this kind of pollution source inversion problem have not yet been clearly elucidated. To fill this gap, stochastic analysis approaches, including a regional sensitivity analysis method (RSA), identifiability plot and perturbation methods, were employed to conduct an empirical investigation on generic inverse uncertainty characteristics under a well-accepted uncertainty analysis framework. Case studies based on field tracer experiments and synthetic numerical tracer experiments revealed several new rules. For example, the release load can be most easily inverted, and the source location is responsible for the largest uncertainty among the source parameters. The diffusion and convection processes are more sensitive than the dilution and pollutant attenuation processes to the optimization of objective functions in terms of structural uncertainty. The differences among the different objective functions are smaller for instantaneous release than for continuous release cases. Small monitoring errors affect the inversion results only slightly, which can be ignored in practice. Interestingly, the estimated values of the release location and time negatively deviate from the real values, and the extent is positively correlated with the relative size of the mixing zone to the objective river reach. These new findings improve decision making in emergency responses to sudden water pollution and guide the monitoring network design.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: WebOfScience(1)
Feasibility assessment of up-flow anaerobic sludge blanket treatment of sulfamethoxazole pharmaceutical wastewater
Yi Chen, Shilong He, Mengmeng Zhou, Tingting Pan, Yujia Xu, Yingxin Gao, Hengkang Wang
Front. Environ. Sci. Eng.    2018, 12 (5): 13-.
Abstract   HTML   PDF (1205KB)

The UASB system successfully treated sulfamethoxazole pharmaceutical wastewater.

High concentration sulfate of this wastewater was the main refractory factor.

UASB recovery performance after a few days of inflow arrest was studied.

The optimal UASB operating conditions for practical application were determined.

Treatment of sulfamethoxazole pharmaceutical wastewater is a big challenge. In this study, a series of anaerobic evaluation tests on pharmaceutical wastewater from different operating units was conducted to evaluate the feasibility of using anaerobic digestion, and the results indicated that the key refractory factor for anaerobic treatment of this wastewater was the high sulfate concentration. A laboratory-scale up-flow anaerobic sludge blanket (UASB) reactor was operated for 195 days to investigate the effects of the influent chemical oxygen demand (COD), organic loading rate (OLR), and COD/SO42? ratio on the biodegradation of sulfamethoxazole in pharmaceutical wastewater and the process performance. The electron flow indicated that methanogenesis was still the dominant reaction although sulfidogenesis was enhanced with a stepwise decrease in the influent COD/SO42? ratio. For the treated sulfamethoxazole pharmaceutical wastewater, a COD of 4983 mg/L (diluted by 50%), OLR of 2.5 kg COD/(m3·d), and COD/SO42? ratio of more than 5 were suitable for practical applications. The recovery performance indicated that the system could resume operation quickly even if production was halted for a few days.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(2) WebOfScience(1)
Investigate of in situ sludge reduction in sequencing batch biofilm reactor: Performances, mechanisms and comparison of different carriers
Yonglei Wang, Baozhen Liu, Kefeng Zhang, Yongjian Liu, Xuexin Xu, Junqi Jia
Front. Environ. Sci. Eng.    2018, 12 (5): 5-.
Abstract   HTML   PDF (914KB)

Microbial metabolism uncoupling, sludge decay is the main mechanism to promote in situ sludge reduction on this biofilm system.

The main reduction mechanism inside the biofilm is sludge decay in the longitudinal distribution of biofilm.

Mizugakiibacter and Azospira anaerobic fermentation bacterium dominate the FSC organisms indicating the dominant mechanism on the biofilm is sludge decay.

The floating spherical carriers with compound of the polyurethane and two fiber balls can effectively blocking suspended sludge, improving Biofilm formation efficiency significantly.

Biofilm is an effective simultaneous denitrification and in situ sludge reduction system, and the characteristics of different biofilm carrier have important implications for biofilm growth and in situ sludge reduction. In this study, the performance and mechanism of in situ sludge reduction were compared between FSC-SBBR and SC-SBBR with constructed by composite floating spherical carriers (FSC) and multi-faceted polyethylene suspension carriers (SC), respectively. The variation of EPS concentration indicated that the biofilm formation of FSC was faster than SC. Compared with SC-SBBR, the FSC-SBBR yielded 0.16 g MLSS/g COD, almost 27.27% less sludge. The average removal rates of COD and NH4+ -N were 93.39% and 96.66%, respectively, which were 5.21% and 1.43% higher than the average removal rate of SC-SBBR. Investigation of the mechanisms of sludge reduction revealed that, energy uncoupling metabolism and sludge decay were the main factors for sludge reduction inducing 43.13% and 49.65% less sludge, respectively, in FSC-SBBR. EEM fluorescence spectroscopy and SUVA analysis showed that the hydrolytic capacity of biofilm attached in FSC was stronger than those of SC, and the hydrolysis of EPS released more DOM contributed to lysis-cryptic growth metabolism. In additional, Bacteroidetes and Mizugakiibacter associated with sludge reduction were the dominant phylum and genus in FCS-SBBR. Thus, the effect of simultaneous in situ sludge reduction and pollutant removal in FSC-SBBR was better.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(2) WebOfScience(3)
Impacts of n-alkane concentration on soil bacterial community structure and alkane monooxygenase genes abundance during bioremediation processes
Yueqiao Liu, Aizhong Ding, Yujiao Sun, Xuefeng Xia, Dayi Zhang
Front. Environ. Sci. Eng.    2018, 12 (5): 3-.
Abstract   HTML   PDF (480KB)

Soil microbial community is not significantly shaped by alkane concentrations

Alkane concentrations alter dominant alkane degraders in soils

Different alkanes are preferentially degraded at different contamination level

Different types of alkane monooxygenase genes responsible for alkane degradation

Petroleum hydrocarbons, mainly consisting of n-alkanes and polycyclic aromatic hydrocarbons (PAHs), are considered as priority pollutants and biohazards in the environment, eventually affecting the ecosystem and human health. Though many previous studies have investigated the change of bacterial community and alkane degraders during the degradation of petroleum hydrocarbons, there is still lack of understanding on the impacts of soil alkane contamination level. In the present study, microcosms with different n-alkane contamination (1%, 3% and 5%) were set up and our results indicated a complete alkane degradation after 30 and 50 days in 1%- and 3%-alkane treatments, respectively. In all the treatments, alkanes with medium-chain length (C11-C14) were preferentially degraded by soil microbes, followed by C27-alkane in 3% and 5% treatments. Alkane contamination level slightly altered soil bacterial community, and the main change was the presence and abundance of dominant alkane degraders. Thermogemmatisporaceae, Gemmataceae and Thermodesulfovibrionaceae were highly related to the degradation of C14- and C27-alkanes in 5% treatment, but linked to alkanes with medium-chain (C11-C18) in 1% treatment and C21-alkane in 3% treatment, respectively. Additionally, we compared the abundance of three alkane-monooxygenase genes, e.g., alk_A, alk_P and alk_R. The abundance of alk_R gene was highest in soils, and alk_P gene was more correlated with alkane degradation efficiency, especially in 5% treatment. Our results suggested that alkane contamination level showed non-negligible effects on soil bacterial communities to some extents, and particularly shaped alkane degraders and degrading genes significantly. This study provides a better understanding on the response of alkane degraders and bacterial communities to soil alkane concentrations, which affects their biodegradation process.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(1)
Transferral of HMs pollution from road-deposited sediments to stormwater runoff during transport processes
Qian Wang, Qionghua Zhang, Mawuli Dzakpasu, Nini Chang, Xiaochang Wang
Front. Environ. Sci. Eng.    2019, 13 (1): 13-.
Abstract   HTML   PDF (438KB)

Ratio of turbidity and TSS (Tur/TSS) was used to characterize PSD of stormwater particles.

Pb and Zn preferred to accumulate in finer RDS, while Cu, Cr and Ni in coarser RDS.

HMs pollution in stormwater particles increased linearly with Tur/TSS.

Dissolvability of HMs and PSD variations contribute to the differences between RDS and stormwater.

Stormwater runoff, derived from the wash-off of road-deposited sediments (RDS), contains elevated heavy metal (HM) concentrations and, thus, imposes an increasing threat to urban aquatic ecosystems. In-depth understanding of the variations of HMs pollution from RDS to stormwater during transport processes facilitates the development of effective RDS and stormwater control strategies. Toward this end, the distribution of HMs (Cu, Pb, Zn, Cr, and Ni) in RDS and stormwater were investigated simultaneously. The results show a preferential accumulation of Pb and Zn in the finer (<38.5 μm) RDS, and Cu, Cr and Ni in the coarser (38.5–150 μm) RDS. For stormwater, n.d.~48.6% of HMs fractionated into the dissolved phase, and stormwater particles constitute the primary carriers of HMs. Furthermore, the accumulation of HMs in stormwater particles increased linearly with finer particle size distributions (PSD). Geoaccumulation index (Igeo) highlighted the predominant pollution of both RDS and stormwater particles by Cu, Pb and Zn. Nonetheless, Cu, Pb, and Ni mostly contributed the potential ecological risk of RDS, whereas Cu, Pb, and Zn mainly contributed that of stormwater particles. Moreover, contamination by Cu, Pb and Zn was significantly higher in stormwater particles than that in RDS. These differences are attributable to the solubility and size-dependent accumulation of HMs in RDS, as well as the PSD variations during transport processes. The study outcomes highlight the importance of very fine (nano- and submicron- scale) RDS in stormwater pollution and the necessity of control.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(1) WebOfScience(1)
Development of combined coagulation-hydrolysis acidification-dynamic membrane bioreactor system for treatment of oilfield polymer-flooding wastewater
Xue Shen, Lei Lu, Baoyu Gao, Xing Xu, Qinyan Yue
Front. Environ. Sci. Eng.    2019, 13 (1): 9-.
Abstract   HTML   PDF (3619KB)

• We created a combined system for treating oilfield polymer-flooding wastewater.

• The system was composed of coagulation, hydrolysis acidification and DMBR.

• Coagulant integrated with demulsifier dominated the removal of crude oil.

• The DMBR proceed efficiently without serious membrane fouling.

A combined system composed of coagulation, hydrolysis acidification and dynamic membrane bioreactor (DMBR) was developed for treating the wastewater produced from polymer flooding. Performance and mechanism of the combined system as well as its respective units were also evaluated. The combined system has shown high-capacity to remove all contaminants in the influent. In this work, the coagulant, polyacrylamide-dimethyldiallyammonium chloride-butylacrylate terpolymer (P(DMDAAC-AM-BA)), integrated with demulsifier (SD-46) could remove 91.8% of crude oil and 70.8% of COD. Hydrolysis acidification unit improved the biodegradability of the influent and the experimental results showed that the highest acidification efficiency in hydrolysis acidification reactor was 20.36% under hydraulic retention time of 7 h. The DMBR proceeded efficiently without serious blockage process of membrane fouling, and the concentration of ammonia nitrogen (NH3-N), oil, chemical oxygen demand and biological oxygen demand in effluent were determined to be 3.4±2.1, 0.3±0.6, 89.7±21.3 and 13±4.7 mg/L.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: WebOfScience(1)
Source attribution for mercury deposition with an updated atmospheric mercury emission inventory in the Pearl River Delta Region, China
Jiajun Liu, Long Wang, Yun Zhu, Che-Jen Lin, Carey Jang, Shuxiao Wang, Jia Xing, Bin Yu, Hui Xu, Yuzhou Pan
Front. Environ. Sci. Eng.    2019, 13 (1): 2-.
Abstract   HTML   PDF (686KB)

Estimated anthropogenic Hg emission was 11.9 tons in Pearl River Delta for 2014.

Quantifying contributions of emission sources helps to provide control strategies.

More attentions should be paid to Hg deposition around the large point sources.

Power plant, industrial source and waste incinerator were priorities for control.

A coordinated regional Hg emission control was important for controlling pollution.

We used CMAQ-Hg to simulate mercury pollution and identify main sources in the Pearl River Delta (PRD) with updated local emission inventory and latest regional and global emissions. The total anthropogenic mercury emissions in the PRD for 2014 were 11,939.6 kg. Power plants and industrial boilers were dominant sectors, responsible for 29.4 and 22.7%. We first compared model predictions and observations and the results showed a good performance. Then five scenarios with power plants (PP), municipal solid waste incineration (MSWI), industrial point sources (IP), natural sources (NAT), and boundary conditions (BCs) zeroed out separately were simulated and compared with the base case. BCs was responsible for over 30% of annual average mercury concentration and total deposition while NAT contributed around 15%. Among the anthropogenic sources, IP (22.9%) was dominant with a contribution over 20.0% and PP (18.9%) and MSWI (11.2%) ranked second and third. Results also showed that power plants were the most important emission sources in the central PRD, where the ultra-low emission for thermal power units need to be strengthened. In the northern and western PRD, cement and metal productions were priorities for mercury control. The fast growth of municipal solid waste incineration were also a key factor in the core areas. In addition, a coordinated regional mercury emission control was important for effectively controlling pollution. In the future, mercury emissions will decrease as control measures are strengthened, more attention should be paid to mercury deposition around the large point sources as high levels of pollution are observed.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(2) WebOfScience(1)
Effect of nitrobenzene on the performance and bacterial community in an expanded granular sludge bed reactor treating high-sulfate organic wastewater
Jun Li, Wentao Li, Gan Luo, Yan Li, Aimin Li
Front. Environ. Sci. Eng.    2019, 13 (1): 6-.
Abstract   HTML   PDF (1066KB)

Less than 50 mg/L nitrobenzene brought little effect on anaerobic sulfate reduction.

Kinetics of sulfate reduction under different nitrobenzene contents was studied.

Increased nitrobenzene contents greatly changed the bacterial community structure.

Genus Desulfovibrio played the key role in anaerobic sulfate reduction process.

Nitrobenzene (NB) is frequently found in wastewaters containing sulfate and may affect biological sulfate reduction process, but information is limited on the responses of sulfate reduction efficiency and microbial community to the increased NB contents. In this study, a laboratory-scale expanded granular sludge bed reactor was operated continuously to treat high-sulfate organic wastewater with increased NB contents. Results successfully demonstrated that the presence of more than 50 mg/L NB depressed sulfate reduction and such inhibition was partly reversible. Bath experiments showed that the maximum specific desulfuration activity (SDA) decreased from 135.80 mg SO42?/gVSS/d to 30.78 mg SO42?/gVSS/d when the NB contents increased from none to 400 mg/L. High-throughput sequencing showed that NB also greatly affected bacterial community structure. Bacteroidetes dominated in the bioreactor. The abundance of Proteobacteria increased with NB addition while Firmicutes presented an opposite trend. Proteobacteria gradually replaced Firmicutes for the dominance in response to the increase of influent NB concentrations. The genus Desulfovibrio was the dominant sulfate-reducing bacteria (SRB) with absence or presence of NB, but was inhibited under high content of NB. The results provided better understanding for the biological sulfate reduction under NB stress.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(1)
Permitted emissions of major air pollutants from coal-fired power plants in China based on best available control technology
Xiaohui Song, Chunlai Jiang, Yu Lei, Yuezhi Zhong, Yanchao Wang
Front. Environ. Sci. Eng.    2018, 12 (5): 11-.
Abstract   HTML   PDF (574KB)

We proposed the SO2 and NOx emission performance standards for coal-fired power plants based on the best available control technology.

The CFPGUs’ SO2 emission performance reference values should be 0.34 g/kWh for active units in general areas and 0.13 g/kWh for newly built units and active units in key areas.

The CFPGUs’ NOx emission performance standard reference values should be 0.35 g/kWh for active units in general areas and 0.175 g/kWh for new units and active units in key areas.

Based on the activity level and technical information of coal-fired power-generating units (CFPGU) obtained in China from 2011 to 2015, we, 1) analyzed the time and spatial distribution of SO2 and NOx emission performance of CFPGUs in China; 2) studied the impact of installed capacity, sulfur content of coal combustion, and unit operation starting time on CFPGUs’ pollutant emission performance; and 3) proposed the SO2 and NOx emission performance standards for coal-fired power plants based on the best available control technology. Our results show that: 1) the larger the capacity of a CFPGU, the higher the control level and the faster the improvement; 2) the CFPGUs in the developed eastern regions had significantly lower SO2 and NOx emission performance values than those in other provinces due to better economic and technological development and higher environmental management levels; 3) the SO2 and NOx emission performance of the Chinese thermal power industry was significantly affected by the single-unit capacity, coal sulfur content, and unit operation starting time; and 4) based on the achievability analysis of best available pollution control technology, we believe that the CFPGUs’ SO2 emission performance reference values should be 0.34 g/kWh for active units in general areas, 0.8 g/kWh for active units in high-sulfur coal areas, and 0.13 g/kWh for newly built units and active units in key areas. In addition, the NOx emission performance reference values should be 0.35 g/kWh for active units in general areas and 0.175 g/kWh for new units and active units in key areas.

Table and Figures | Reference | Related Articles | Metrics
Cited: Crossref(1) WebOfScience(1)
Influence of reclaimed water discharge on the dissemination and relationships of sulfonamide, sulfonamide resistance genes along the Chaobai River, Beijing
Ning Zhang, Xiang Liu, Rui Liu, Tao Zhang, Miao Li, Zhuoran Zhang, Zitao Qu, Ziting Yuan, Hechun Yu
Front. Environ. Sci. Eng.    2019, 13 (1): 8-.
Abstract   HTML   PDF (620KB)

Reclaimed water threatens the ecological safety of the Chaobai River.

SMX, TMP, and SDZ were the first three abundant antibiotics in the research area.

SRGs and intI1 were widespread with high abundance after reclaimed water recharge.

The SRGs values followed the sequence: Summer>autumn>spring>winter.

Strong correlations were detected between SRGs and environmental factors.

Reclaimed water represents an important source of antibiotics and antibiotic resistance genes, threatening the ecological safety of receiving environments, while alleviating water resource shortages. This study investigated the dissemination of sulfonamide (SAs), sulfonamide resistance genes (SRGs), and class one integrons (intI1) in the surface water of the recharging area of the Chaobai River. The three antibiotics sulfamethoxazole, trimethoprim, and sulfadiazine had the highest abundance. The highest absolute abundances were 2.91×106, 6.94×106, and 2.18×104 copies/mL for sul1, sul2, and intI1 at the recharge point, respectively. SRGs and intI1 were widespread and had high abundance not only at the recharging point, but also in remote areas up to 8 km away. Seasonal variations of SRGs abundance followed the order of summer>autumn>spring>winter. Significant correlations were found between SRGs and intI1 (R2 = 0.887 and 0.786, p<0.01), indicating the potential risk of SRGs dissemination. Strong correlations between the abundance of SRGs and environmental factors were also found, suggesting that appropriate environmental conditions favor the spread of SRGs. The obtained results indicate that recharging with reclaimed water causes dissemination and enrichment of SAs and SRGs in the receiving river. Further research is required for the risk assessment and scientific management of reclaimed water.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(1) WebOfScience(1)
Social media and mobility landscape: Uncovering spatial patterns of urban human mobility with multi source data
Yilan Cui, Xing Xie, Yi Liu
Front. Environ. Sci. Eng.    2018, 12 (5): 7-.
Abstract   HTML   PDF (4240KB)

Check-in and survey data are explored to identify personal activity-specific places.

Ways for detecting and moderating sample bias of Weibo check-in data is proposed.

A graphic representation of urban activity intensity in Beijing, China is presented.

The potential application of Weibo check-in data for urban analysis is introduced.

In this paper, we present a three-step methodological framework, including location identification, bias modification, and out-of-sample validation, so as to promote human mobility analysis with social media data. More specifically, we propose ways of identifying personal activity-specific places and commuting patterns in Beijing, China, based on Weibo (China’s Twitter) check-in records, as well as modifying sample bias of check-in data with population synthesis technique. An independent citywide travel logistic survey is used as the benchmark for validating the results. Obvious differences are discerned from Weibo users’ and survey respondents’ activity-mobility patterns, while there is a large variation of population representativeness between data from the two sources. After bias modification, the similarity coefficient between commuting distance distributions of Weibo data and survey observations increases substantially from 23% to 63%. Synthetic data proves to be a satisfactory cost-effective alternative source of mobility information. The proposed framework can inform many applications related to human mobility, ranging from transportation, through urban planning to transport emission modeling.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Characterization of a phenanthrene-degrading methanogenic community
Quanhui Ye, Chengyue Liang, Chongyang Wang, Yun Wang, Hui Wang
Front. Environ. Sci. Eng.    2018, 12 (5): 4-.
Abstract   HTML   PDF (811KB)

The mixed samples of contaminated soil, sludge and coke wastewater showed great phenanthrene methanogenic degradation potential.

Comamonadaceae, Nocardiaceae and Methanobacterium were dominant members.

Hexane, hexadecane and benzene could enhance phenanthrene degradation.

Polycyclic aromatic hydrocarbons (PAHs) often occur in oil-contaminated soil, coke wastewater and domestic sludge; however, associated PAH degraders in these environments are not clear. Here we evaluated phenanthrene degradation potential in the mixed samples of above environments, and obtained a methanogenic community with different microbial profile compared to those from sediments. Phenanthrene was efficiently degraded (1.26 mg/L/d) and nonstoichiometric amount of methane was produced simultaneously. 16S rRNA gene sequencing demonstrated that bacterial populations were mainly associated with Comamonadaceae Nocardiaceae and Thermodesulfobiaceae, and that methanogenic archaea groups were dominated by Methanobacterium and Methanothermobacter. Substances such as hexane, hexadecane, benzene and glucose showed the most positive effects on phenanthrene degradation. Substrate utilization tests indicated that this culture could not utilize other PAHs. These analyses could offer us some suggestions on the putative phenanthrene-degrading microbes in such environments, and might help us develop strategies for the removal of PAHs from contaminated soil and sludge.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(2) WebOfScience(1)
FESE’s Best Papers of 2018
Front. Environ. Sci. Eng.    2019, 13 (3): 48-null.
Abstract   HTML   PDF (30KB)
Reference | Related Articles | Metrics
Upgrading VFAs bioproduction from waste activated sludge via co-fermentation with soy sauce residue
Yanqing Duan, Aijuan Zhou, Kaili Wen, Zhihong Liu, Wenzong Liu, Aijie Wang, Xiuping Yue
Front. Environ. Sci. Eng.    2019, 13 (1): 3-.
Abstract   HTML   PDF (426KB)

SSR addition upgraded VFAs production from WAS.

Structure modification by pretreatments led to performance distinctions.

Distinctions in microbial community was observed by pretreatments selection.

Up to 0.49‒0.65 billion €/year of market value potential was preliminary estimated.

Conditioning of extra carbon sources has been widely reported to facilitate fermentation of waste activated sludge (WAS). Soy sauce residue (SSR) was a relatively untapped carbon source for sludge conditioning. This batch study aimed to evaluate the possible implementation of SSR for volatile fatty acids (VFAs) production from WAS. To upgrade the bioavailability of feedstock, three typical pretreatment methods were conducted, i.e., ammonium hydroxide (AH), sulfuric acids (SA) and thermal assisted alkaline (TA). AH pretreated test (AH-PT) outperformed due to a relatively strong structure decomposition of cellulosic materials as revealed by infrared spectroscopic analysis and crystal index. As a result, performed a high hydrolysis rate of 4449 mg COD/d, 1.12-1.23-fold higher than that in TA and SA pretreated tests (TA-PT and SA-PT), and 7.8-fold higher than that in the Control test. Meanwhile, a volatile fatty acids (VFAs) contribution of 401.2 mg COD/g SSR∙L and a maximum acidification rate of 3.59 d-1 was recorded, with a high sum proportion of mall molecular acetic and propionic 82.2%, 11% ‒70% increase over the other three tests. Besides, speciation process characterized with functional genus differentiation was identified by microbial diversity and distribution investigation and canonical correspondence analysis (CCA). Finally, a potential market value of 0.49‒0.65 Billion €/year was preliminary estimated, showing promise of resource recovery from both WAS and SSR instead of extensive disposal.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(1) WebOfScience(2)
Effect of biological activated carbon filter depth and backwashing process on transformation of biofilm community
Wanqi Qi, Weiying Li, Junpeng Zhang, Xuan Wu, Jie Zhang, Wei Zhang
Front. Environ. Sci. Eng.    2019, 13 (1): 15-.
Abstract   HTML   PDF (1803KB)

We studied BAC biofilm during the process of initial operation and backwash.

Microbial diversity decreased gradually with the increase of BAC filter depth.

Proteobacteria dominated at the phylum level among the BAC biofilm samples.

α-proteobacteria increased about 10% in all carbon filter depth after backwash.

The biological activated carbon (BAC) is a popular advanced water treatment to the provision of safe water supply. A bench-scale device was designed to gain a better insight into microbial diversity and community structure of BAC biofilm by using high-throughput sequencing method. Both samples of BAC biofilm (the first, third and fifth month) and water (inlet water and outlet water of carbon filter, outlet water of backwashing) were analyzed to evaluate the impact of carbon filter depth, running time and backwash process. The results showed that the microbial diversity of biofilm decreased generally with the increase of carbon filter depth and biofilm reached a steady-state at the top layer of BAC after three months’ running. Proteobacteria (71.02%–95.61%) was found to be dominant bacteria both in biofilms and water samples. As one of opportunistic pathogen, the Pseudomonas aeruginosa in the outlet water of device (1.20%) was about eight times higher than that in the inlet water of device (0.16%) at the genus level after five-month operation. To maintain the safety of drinking water, the backwash used in this test could significantly remove Sphingobacteria (from 8.69% to 5.09%, p<0.05) of carbon biofilm. After backwashing, the operational taxonomic units (OTUs) number and the Shannon index decreased significantly (p<0.05) at the bottom of carbon column and we found the Proteobacteria increased by about 10% in all biofilm samples from different filter depth. This study reveals the transformation of BAC biofilm with the impact of running time and backwashing.

Table and Figures | Reference | Related Articles | Metrics
PPCPs in a drinking water treatment plant in the Yangtze River Delta of China: Occurrence, removal and risk assessment
Xinshu Jiang, Yingxi Qu, Liquan Liu, Yuan He, Wenchao Li, Jun Huang, Hongwei Yang, Gang Yu
Front. Environ. Sci. Eng.    2019, 13 (2): 27-.
Abstract   HTML   PDF (1810KB)

• 39 PPCPs were investigated at a DWTP using the Yangtze River as its water source.

• Grab and continuous sampling were conducted for the comparison of data consistency.

• Ketoprofen & carbamazepine can be risk management indicators because of the high RQ.

The occurrence and removal of 39 targeted pharmaceuticals and personal care products (PPCPs) from source water, through a drinking water treatment plant (DWTP) to the water supply station, were investigated around the central part of Yangtze River Delta in China using both grab sampling and continuous sampling. Totally 24 of the 39 targeted PPCPs were detected in raw water, and 12 PPCPs were detected in the finished water. The highest observed concentration was enrofloxacin (85.623 ng/L) in raw water. Removal efficiencies were remarkably negative correlated with log Kow (r = -0.777, p<0.01) after calibration control of concentration, indicating that more soluble PPCPs are easier to remove by the combined process (prechlorination and flocculation/precipitation), the concentration level also had a great impact on the removal efficiency. The normal process in the pilot DWTP seems to be ineffective for PPCPs control, with the limited removal efficiency of less than 30% for each step: pre-chlorination, flocculation and precipitation, post-chlorination and filter. There were notable differences between the data from continuous sampling and grab sampling, which should be considered for different monitoring purposes. The chlorination and the hydrolytic decomposition of PPCPs in the water supply pipe may attenuate PPCPs concentration in the pipeline network. The PPCPs examined in the effluent of DWTP do not impose a potential health risk to the local consumers due to their RQ value lower than 0.00067.

Table and Figures | Reference | Supplementary Material | Related Articles | Metrics
Cited: Crossref(2)