1. School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China 2. National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China 3. School of Chemical Engineering and Technology, Zhengzhou University, Zhengzhou 450001, China
• The sustainable approaches related to Fenton sludge reuse systems are summarized.
• Degradation mechanism of Fenton sludge heterogeneous catalyst is deeply discussed.
• The efficient utilization directions of Fenton sludge are proposed.
The classical Fenton oxidation process (CFOP) is a versatile and effective application that is generally applied for recalcitrant pollutant removal. However, excess iron sludge production largely restricts its widespread application. Fenton sludge is a hazardous solid waste, which is a complex heterogeneous mixture with Fe(OH)3, organic matter, heavy metals, microorganisms, sediment impurities, and moisture. Although studies have aimed to utilize specific Fenton sludge resources based on their iron-rich characteristics, few reports have fully reviewed the utilization of Fenton sludge. As such, this review details current sustainable Fenton sludge reuse systems that are applied during wastewater treatment. Specifically, coagulant preparation, the reuse of Fenton sludge as an iron source in the Fenton process and as a synthetic heterogeneous catalyst/adsorbent, as well as the application of the Fenton sludge reuse system as a heterogeneous catalyst for resource utilization. This is the first review article to comprehensively summarize the utilization of Fenton sludge. In addition, this review suggests future research ideas to enhance the cost-effectiveness, environmental sustainability, and large-scale feasibility of Fenton sludge applications.
Dye wastewater; iron-containing sludge electrolytically generates Fe2+ via the Fenton process
1. Enhanced COD and color removal; 2. Significantly higher conductivity; 3. Organic material accumulation can be observed; 4. Negative zeta potential
Li et al., 2007
Synthetic olive wastewater, Fenton process with iron source from baked Fenton sludge
1. High calcination temperature shows better organic depletion, higher levels of iron leaching; 2. Biological oxygen demand in five days was increased;
Rossi et al., 2013
Three different wastewaters; ferric sludge acts as an iron source during the Fenton-based process
1. Behaved similar to the CFOP during four reuse cycles; 2. High iron-containing sludge produced during Fenton-based treatment; 3. Lowered hazardous ferric waste production and overall treatment cost
Bolobajev et al., 2014
Palm Oil Mill Secondary Effluent; solar Fenton oxidation resulted in reusable iron sludge
1. Enhanced COD and color removal after five cycles due to excess iron. 2. Lowered COD and color removal observed between recycles 1 and 5;
Shahrifun et al., 2015
Phenolic contained wastewater, Fenton-based treatment with iron source from ferric sludge
1. Enhanced formation of highly reactive species; 2. A substantial organic contaminant degradation increase
Bolobajev et al., 2016a
Chlorophenols-contained water, ferric sludge with tannic acid served as iron source in the Fenton-based process
1. Tannic acid reduced ferric acid to Fe2+; 2. Higher reactivity and lowered Fe2+ addition costs, which resulted in decreased sludge production.
Bolobajev et al., 2016b
Palm oil mill secondary effluent, which underwent solar Fenton oxidation with wet and dried Fenton sludge iron source
1. Recycled wet Fenton sludge treatment demonstrated higher removal of contaminant compared to the recycled dried Fenton sludge treatment; 2. Repeated use of recycle sludge resulted in higher SS and turbidity; 3. high-temperature calcination in the sludge reuse system may result in iron leaching
1. Lowered applied Fe2+ dosage and solid residue; 2. Optimized addition of Fe2+ activator can improve the overall efficacy of reuse cycles;
Kattel et al., 2016
Landfill leachate, a pilot study continuous ferric sludge reuse in Fenton-like process
1. Ferric sludge as a catalyst in Fenton-like oxidation resulted in a lower COD removal efficiency of 32% as compared to CFOP; 2. Consistent Fenton-like process efficiencies were observed throughout the 12 sludge reuse cycles.
Klein et al., 2016
Bisphenol A, CaO2 oxidation catalyzed by reuse of ferric sludge in the presence of chelating agents
1. Presence of oxalic acid resulted in BPA removal of 95.1%; 2. Lowered ferric sludge production and sludge disposal cost.
1. Complete usage of generated sludge resulted in TOC reduction in sludge systems; 2. Ferrous ions and H2O2 enhanced the efficiency of the reused sludge system.
Gamaralalage et al., 2017
Agro-food industrial wastewater; ferrous ions reused as catalysts in Fenton-like reactions
Sludge reuse system exhibited lowered residual sludge production and metal content in the final effluent.
M Ahmad, A U Rajapaksha, J E Lim, M Zhang, N Bolan, D Mohan, M Vithanage, S S Lee, Y S Ok (2014). Biochar as a sorbent for contaminant management in soil and water: A review. Chemosphere, 99: 19–33 https://doi.org/10.1016/j.chemosphere.2013.10.071
pmid: 24289982
2
M I Badawy, M E Ali (2006). Fenton’s peroxidation and coagulation processes for the treatment of combined industrial and domestic wastewater. Journal of Hazardous Materials, 136(3): 961–966 https://doi.org/10.1016/j.jhazmat.2006.01.042
pmid: 16540240
3
W G Barb, J H Baxendale, P George, K R Hargrave (1949). Reactions of ferrous and ferric ions with hydrogen peroxide. Nature, 163(4148): 692–694 https://doi.org/10.1038/163692a0
4
P Bautista, A F Mohedano, J A Casas, J A Zazo, J J Rodriguez (2008). An overview of the application of Fenton oxidation to industrial wastewaters treatment. Journal of Chemical Technology and Biotechnology (Oxford, Oxfordshire), 83(10): 1323–1338 https://doi.org/10.1002/jctb.1988
5
Y Z Belete, E Ziemann, A Gross, R Bernstein (2021). Facile activation of sludge-based hydrochar by Fenton oxidation for ammonium adsorption in aqueous media. Chemosphere, 273: 128526 https://doi.org/10.1016/j.chemosphere.2020.128526
pmid: 33070979
6
M M Bello, A A Abdul Raman, A Asghar (2019). A review on approaches for addressing the limitations of Fenton oxidation for recalcitrant wastewater treatment. Process Safety and Environmental Protection, 126: 119–140 https://doi.org/10.1016/j.psep.2019.03.028
7
C T Benatti, A C Costa, C R Tavares (2009). Characterization of solids originating from the Fenton’s process. Journal of Hazardous Materials, 163(2–3): 1246–1253 https://doi.org/10.1016/j.jhazmat.2008.07.094
pmid: 18809248
8
C T Benatti, C R Tavares, T A Guedes (2006). Optimization of Fenton’s oxidation of chemical laboratory wastewaters using the response surface methodology. Journal of Environmental Management, 80(1): 66–74 https://doi.org/10.1016/j.jenvman.2005.08.014
pmid: 16377070
9
J Bolobajev, E Kattel, M Viisimaa, A Goi, M Trapido, T Tenno, N Dulova (2014). Reuse of ferric sludge as an iron source for the Fenton-based process in wastewater treatment. Chemical Engineering Journal, 255: 8–13 https://doi.org/10.1016/j.cej.2014.06.018
10
J Bolobajev, M Trapido, A Goi (2016a). Role of organic wastewater constituents in iron redox cycling for ferric sludge reuse in the fenton-based treatment. International Journal of Environmental and Ecological Engineering, 10: 39944
11
J Bolobajev, M Trapido, A Goi (2016b). Interaction of tannic acid with ferric iron to assist 2,4,6-trichlorophenol catalytic decomposition and reuse of ferric sludge as a source of iron catalyst in Fenton-based treatment. Applied Catalysis B: Environmental, 187: 75–82 https://doi.org/10.1016/j.apcatb.2016.01.015
12
G M Cao, M Sheng, W F Niu, Y L Fei, D Li (2009). Regeneration and reuse of iron catalyst for Fenton-like reactions. Journal of Hazardous Materials, 172(2–3): 1446–1449 https://doi.org/10.1016/j.jhazmat.2009.08.010
pmid: 19733973
13
L Chen, J Ma, X Li, J Zhang, J Fang, Y Guan, P Xie (2011). Strong enhancement on fenton oxidation by addition of hydroxylamine to accelerate the ferric and ferrous iron cycles. Environmental Science & Technology, 45(9): 3925–3930 https://doi.org/10.1021/es2002748
pmid: 21469678
14
M Cheng, W Ma, J Li, Y Huang, J Zhao, Y Wen, Y Xu (2004). Visible-light-assisted degradation of dye pollutants over Fe(III)-loaded resin in the presence of H2O2 at neutral pH values. Environmental Science & Technology, 38(5): 1569–1575 https://doi.org/10.1021/es034442x
pmid: 15046361
15
J H Chu, J K Kang, S Park, C Lee (2020). Application of magnetic biochar derived from food waste in heterogeneous sono-Fenton-like process for removal of organic dyes from aqueous solution. Journal of Water Process Engineering. 37: 101455
16
E R B Dantas, E J Silva, W S Lopes, M R do Nascimento, V D Leite, J T de Sousa (2020). Fenton treatment of sanitary landfill leachate: Optimization of operational parameters, characterization of sludge and toxicology. Environmental Technology, 41(20): 2637–2647 https://doi.org/10.1080/09593330.2019.1576773
pmid: 30696358
17
J De Laat, H É Gallard (1999). Catalytic decomposition of hydrogen peroxide by Fe(III) in homogeneous aqueous solution: mechanism and kinetic modeling. Environmental Science & Technology, 33(16): 2726–2732 https://doi.org/10.1021/es981171v
18
L Demarchis, M Minella, R Nisticò, V Maurino, C Minero, D Vione (2015). Photo-Fenton reaction in the presence of morphologically controlled hematite as iron source. Journal of Photochemistry and Photobiology A Chemistry, 307–308: 99–107 https://doi.org/10.1016/j.jphotochem.2015.04.009
C Di Iaconi, G Del Moro, M De Sanctis, S Rossetti (2010). A chemically enhanced biological process for lowering operative costs and solid residues of industrial recalcitrant wastewater treatment. Water Research, 44(12): 3635–3644 https://doi.org/10.1016/j.watres.2010.04.017
pmid: 20494396
21
B H Diya’uddeen, S Rahim Pouran, A R Abdul Aziz, W M Daud (2015). Fenton oxidative treatment of petroleum refinery wastewater: process optimization and sludge characterization. RSC Advances, 5(83): 68159–68168 https://doi.org/10.1039/C5RA08079G
22
X Duan, H Sun, Z Shao, S Wang (2018). Nonradical reactions in environmental remediation processes: Uncertainty and challenges. Applied Catalysis B: Environmental, 224: 973–982 https://doi.org/10.1016/j.apcatb.2017.11.051
23
B Ensing, F Buda, E J Baerends (2003). Fenton-like chemistry in water: Oxidation catalysis by Fe(III) and H2O2. Journal of Physical Chemistry A, 107(30): 5722–5731 https://doi.org/10.1021/jp0267149
24
F Fan (2016). The preparation of efficient magnetic polymeric ferric sulfate with recycled fenton iron sludge. Dissertation for the Master Degree. Guilin: Guangxi University (in Chinese)
25
S Fan, J Tang, Y Wang, H Li, H Zhang, J Tang, Z Wang, X Li (2016). Biochar prepared from co-pyrolysis of municipal sewage sludge and tea waste for the adsorption of methylene blue from aqueous solutions: Kinetics, isotherm, thermodynamic and mechanism. Journal of Molecular Liquids, 220: 432–441 https://doi.org/10.1016/j.molliq.2016.04.107
26
G Fang, J Gao, C Liu, D D Dionysiou, Y Wang, D Zhou (2014). Key role of persistent free radicals in hydrogen peroxide activation by biochar: Implications to organic contaminant degradation. Environmental Science & Technology, 48(3): 1902–1910 https://doi.org/10.1021/es4048126
pmid: 24422431
27
J Fernandez, J Bandara, J Kiwi, A Lopez, P Albers (1998). Efficient photo-assisted Fenton catalysis mediated by Fe ions on Nafion membranes active in the abatement of non-biodegradable azo-dye. Chemical Communications, 14(14): 1493–1494 https://doi.org/10.1039/a802539h
28
D Gamaralalage, O Sawai, T Nunoura (2017). Sludge reuse in Fenton oxidation of crepe rubber wastewater and palm oil mill effluent. In: The 28th Annual Conference of JSMCWM, 2017. Tokyo: JSMCWM, 5–6
29
A C Garade, M Bharadwaj, S V Bhagwat, A A Athawale, C V Rode (2009). An efficient γ-Fe2O3 catalyst for liquid phase air oxidation of p-hydroxybenzyl alcohol under mild conditions. Catalysis Communications, 10(5): 485–489 https://doi.org/10.1016/j.catcom.2008.10.044
30
J Ge, B Guha, L Lippincott, S Cach, J Wei, T L Su, X Meng (2020). Challenges of arsenic removal from municipal wastewater by coagulation with ferric chloride and alum. Science of the Total Environment, 725: 138351 https://doi.org/10.1016/j.scitotenv.2020.138351
pmid: 32304965
31
D Ghernaout, N Elboughdiri, S Ghareba (2020). Fenton technology for wastewater treatment: dares and trends. Open Access Library Journal, 7(01): 1–26 https://doi.org/10.4236/oalib.1106045
32
A M Guedes, L M Madeira, R A Boaventura, C A Costa (2003). Fenton oxidation of cork cooking wastewater--overall kinetic analysis. Water Research, 37(13): 3061–3069 https://doi.org/10.1016/S0043-1354(03)00178-7
pmid: 14521136
33
S Guo, N Yuan, G Zhang, J C Yu (2017). Graphene modified iron sludge derived from homogeneous Fenton process as an efficient heterogeneous Fenton catalyst for degradation of organic pollutants. Microporous and Mesoporous Materials, 238: 62–68 https://doi.org/10.1016/j.micromeso.2016.02.033
34
S Y Guvenc, G Varank (2021). Degradation of refractory organics in concentrated leachate by the Fenton process: Central composite design for process optimization. Frontiers of Environmental Science & Engineering, 15(1): 2
35
X Hou, X Huang, F Jia, Z Ai, J Zhao, L Zhang (2017). Hydroxylamine promoted goethite surface fenton degradation of organic pollutants. Environmental Science & Technology, 51(9): 5118–5126 https://doi.org/10.1021/acs.est.6b05906
pmid: 28358480
36
W Hua (2017). Fenton wastewater treatment sludge disposal and recovery of iron salits using technology. Dissertation for the Master Degree. Guangzhou: South China University of Technology (in Chinese)
37
J O Ighalo, A G Adeniyi (2020). Adsorption of pollutants by plant bark derived adsorbents: An empirical review. Journal of Water Process Engineering, 35: 101228 https://doi.org/10.1016/j.jwpe.2020.101228
38
N H Ince, I G Apikyan (2000). Combination of activated carbon adsorption with light-enhanced chemical oxidation via hydrogen peroxide. Water Research, 34(17): 4169–4176 https://doi.org/10.1016/S0043-1354(00)00194-9
39
B Jain, A K Singh, H Kim, E Lichtfouse, V K Sharma (2018). Treatment of organic pollutants by homogeneous and heterogeneous Fenton reaction processes. Environmental Chemistry Letters, 16(3): 947–967 https://doi.org/10.1007/s10311-018-0738-3
40
E Kattel, M Trapido, N Dulova (2016). Treatment of landfill leachate by continuously reused ferric oxyhydroxide sludge-activated hydrogen peroxide. Chemical Engineering Journal, 304: 646–654 https://doi.org/10.1016/j.cej.2016.06.135
N Kishimoto, T Kitamura, M Kato, H Otsu (2013). Reusability of iron sludge as an iron source for the electrochemical Fenton-type process using Fe2+/HOCl system. Water Research, 47(5): 1919–1927 https://doi.org/10.1016/j.watres.2013.01.021
pmid: 23391331
43
K Klein, A Kivi, N Dulova, I Zekker, E Molder, T Tenno, M Trapido, T Tenno (2016). A pilot study of three-stage biological-chemical treatment of landfill leachate applying continuous ferric sludge reuse in Fenton-like process. Clean Technologies and Environmental Policy, 19(2): 541–551 https://doi.org/10.1007/s10098-016-1245-5
44
V Leifeld, T P M Dos Santos, D W Zelinski, L Igarashi-Mafra (2018). Ferrous ions reused as catalysts in Fenton-like reactions for remediation of agro-food industrial wastewater. Journal of Environmental Management, 222: 284–292 https://doi.org/10.1016/j.jenvman.2018.05.087
pmid: 29860122
45
L Leng, X Yuan, H Huang, J Shao, H Wang, X Chen, G Zeng (2015). Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption. Applied Surface Science, 346: 223–231 https://doi.org/10.1016/j.apsusc.2015.04.014
46
C W Li, Y M Chen, Y C Chiou, C K Liu (2007). Dye wastewater treated by Fenton process with ferrous ions electrolytically generated from iron-containing sludge. Journal of Hazardous Materials, 144(1–2): 570–576 https://doi.org/10.1016/j.jhazmat.2006.10.076
pmid: 17137712
47
Q Liao, J Sun, L Gao (2009). Degradation of phenol by heterogeneous Fenton reaction using multi-walled carbon nanotube supported Fe2O3 catalysts. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 345(1–3): 95–100 https://doi.org/10.1016/j.colsurfa.2009.04.037
48
S S Lin, M D Gurol (1998). Catalytic decomposition of hydrogen peroxide on iron oxide: Kinetics, mechanism, and implications. Environmental Science & Technology, 32(10): 1417–1423 https://doi.org/10.1021/es970648k
49
A Mahiroglu, E Tarlan-Yel, M F Sevimli (2009). Treatment of combined acid mine drainage (AMD—flotation circuit effluents from copper mine via Fenton’s process. Journal of Hazardous Materials, 166(2–3): 782–787 https://doi.org/10.1016/j.jhazmat.2008.11.119
pmid: 19147282
50
M S Mahtab, I H Farooqi, A Khursheed (2021a). Zero Fenton sludge discharge: A review on reuse approach during wastewater treatment by the advanced oxidation process. International Journal of Environmental Science and Technology, 10: 1–14 https://doi.org/10.1007/s13762-020-03121-0
51
M S Mahtab, D T Islam, I H Farooqi (2021b). Optimization of the process variables for landfill leachate treatment using Fenton based advanced oxidation technique. Engineering Science and Technology, an International Journal, 24(2): 428–435 https://doi.org/10.1016/j.jestch.2020.08.013
52
H Meng, C Nie, W Li, X Duan, B Lai, Z Ao, S Wang, T An (2020). Insight into the effect of lignocellulosic biomass source on the performance of biochar as persulfate activator for aqueous organic pollutants remediation: Epicarp and mesocarp of citrus peels as examples. Journal of Hazardous Materials, 399: 123043 https://doi.org/10.1016/j.jhazmat.2020.123043
pmid: 32526439
53
E Neyens, J Baeyens (2003). A review of classic Fenton’s peroxidation as an advanced oxidation technique. Journal of Hazardous Materials, 98(1–3): 33–50 https://doi.org/10.1016/S0304-3894(02)00282-0
pmid: 12628776
54
M A Oturan, J J Aaron (2014). Advanced oxidation processes in water/wastewater treatment: Principles and applications: A review. Critical Reviews in Environmental Science and Technology, 44(23): 2577–2641 https://doi.org/10.1080/10643389.2013.829765
55
M D Paciolla, G Davies, S A Jansen (1999). Generation of hydroxyl radicals from metal-loaded humic acids. Environmental Science & Technology, 33(11): 1814–1818 https://doi.org/10.1021/es980921y
56
X Pan, Z Gu, W Chen, Q Li (2021). Preparation of biochar and biochar composites and their application in a Fenton-like process for wastewater decontamination: A review. Science of the Total Environment, 754: 142104 https://doi.org/10.1016/j.scitotenv.2020.142104
pmid: 33254921
57
J Páramo-Vargas, S G Granados, M I Maldonado-Rubio, J M Peralta-Hernández (2016). Up to 95% reduction of chemical oxygen demand of slaughterhouse effluents using Fenton and photo-Fenton oxidation. Environmental Chemistry Letters, 14(1): 149–154 https://doi.org/10.1007/s10311-015-0534-2
58
A F Rossi, R C Martins, R M Quinta-ferreira (2013). Reuse of homogeneous Fenton’s sludge from detergent industry as Fenton’s catalyst. Journal of Advanced Oxidation Technologies, 16(2): 298–305 https://doi.org/10.1515/jaots-2013-0212
N A Shahrifun, N N Ab’lah, H Hussain, A Aris, Q Omar, N Ahmad (2015). Reusability of Fenton sludge to reduce COD and color on palm oil mill secondary effluent (POMSE). Advanced Materials Research, 1113: 486–491 https://doi.org/10.4028/www.scientific.net/AMR.1113.486
61
S A Shahrifun, H Hussain, Q Omar (2016). Optimization of solar Fenton Oxidation and comparison of recycle wet and dried Fenton sludge in treating palm oil mill secondary effluent. Jurnal Teknologi, 78(6–7): 61–67 https://doi.org/10.11113/jt.v78.9085
62
M Shen, Z Huang, X Luo, Y Ma, C Chen, X Chen, L Cui (2020a). Activation of persulfate for tetracycline degradation using the catalyst regenerated from Fenton sludge containing heavy metal: Synergistic effect of Cu for catalysis. Chemical Engineering Journal, 396: 125238 https://doi.org/10.1016/j.cej.2020.125238
63
M Shen, Z Huang, L Qiu, Z Chen, X Xiao, X Mo, L Cui (2020b). Recycling of Fenton sludge containing Ni as an efficient catalyst for tetracycline degradation through peroxymonosulfate activation. Journal of Cleaner Production, 268: 122174 https://doi.org/10.1016/j.jclepro.2020.122174
64
P Shukla, S Wang, H Sun, H Ang, M Tadé (2010). Adsorption and heterogeneous advanced oxidation of phenolic contaminants using Fe loaded mesoporous SBA-15 and H2O2. Chemical Engineering Journal, 164(1): 255–260 https://doi.org/10.1016/j.cej.2010.08.061
65
M Sillanpää, M C Ncibi, A Matilainen (2018). Advanced oxidation processes for the removal of natural organic matter from drinking water sources: A comprehensive review. Journal of Environmental Management, 208: 56–76 https://doi.org/10.1016/j.jenvman.2017.12.009
pmid: 29248788
66
X Tan, Y Liu, Y Gu, Y Xu, G Zeng, X Hu, S Liu, X Wang, S Liu, J Li (2016). Biochar-based nano-composites for the decontamination of wastewater: A review. Bioresource Technology, 212: 318–333 https://doi.org/10.1016/j.biortech.2016.04.093
67
Y Tang, H Ren, P Yang, H Li, J Zhang, C Qu, G Chen (2019). Treatment of fracturing fluid waste by Fenton reaction using transition metal complexes catalyzes oxidation of hydroxypropyl guar gum at high pH. Environmental Chemistry Letters, 17(1): 559–564 https://doi.org/10.1007/s10311-018-0805-9
68
X Tao, W Ma, J Li, Y Huang, J Zhao, J C Yu (2003). Efficient degradation of organic pollutants mediated by immobilized iron tetrasulfophthalocyanine under visible light irradiation. Chemical Communications, 1(1): 80–81 https://doi.org/10.1039/b209083j
pmid: 12610975
69
S Tong, J Shen, X Jiang, J Li, X Sun, Z Xu, D Chen (2021). Recycle of Fenton sludge through one-step synthesis of aminated magnetic hydrochar for Pb2+ removal from wastewater. Journal of Hazardous Materials, 406: 124581 https://doi.org/10.1016/j.jhazmat.2020.124581
pmid: 33302190
70
M Umar, H A Aziz, M S Yusoff (2010). Trends in the use of Fenton, electro-Fenton and photo-Fenton for the treatment of landfill leachate. Waste Management, 30(11): 2113–2121 https://doi.org/10.1016/j.wasman.2010.07.003
pmid: 20675113
71
B M Voelker, B Sulzberger (1996). Effects of Fulvic acid on Fe (II) oxidation by hydrogen peroxide. Environmental Science & Technology, 30(4): 1106–1114 https://doi.org/10.1021/es9502132
H Wang, K Xiao, J Yang, Z Yu, W Yu, Q Xu, Q Wu, S Liang, J Hu, H Hou, B Liu (2020). Phosphorus recovery from the liquid phase of anaerobic digestate using biochar derived from iron-rich sludge: A potential phosphorus fertilizer. Water Research, 174: 115629 https://doi.org/10.1016/j.watres.2020.115629
pmid: 32113013
74
J Wang, S Wang (2018). Activation of persulfate (PS) and peroxymonosulfate (PMS) and application for the degradation of emerging contaminants. Chemical Engineering Journal, 334: 1502–1517 https://doi.org/10.1016/j.cej.2017.11.059
75
M Wang, Z Zhao, Y Zhang (2018). Sustainable strategy for enhancing anaerobic digestion of waste activated sludge: driving dissimilatory iron reduction with Fenton sludge. ACS Sustainable Chemistry & Engineering, 6(2): 2220–2230 https://doi.org/10.1021/acssuschemeng.7b03637
76
M Wang, Z Zhao, Y Zhang (2019). Disposal of Fenton sludge with anaerobic digestion and the roles of humic acids involved in Fenton sludge. Water Research, 163: 114900 https://doi.org/10.1016/j.watres.2019.114900
pmid: 31362207
77
N Wang, T Zheng, G Zhang, P Wang (2016). A review on Fenton-like processes for organic wastewater treatment. Journal of Environmental Chemical Engineering, 4(1): 762–787 https://doi.org/10.1016/j.jece.2015.12.016
78
S Xiao, M Cheng, H Zhong, Z Liu, Y Liu, X Yang, Q Liang (2020). Iron-mediated activation of persulfate and peroxymonosulfate in both homogeneous and heterogeneous ways: A review. Chemical Engineering Journal, 384: 123265 https://doi.org/10.1016/j.cej.2019.123265
79
Z X Xu, H Song, X Q Deng, Y Y Zhang, M Xue-Qin, S Q Tong, Z X He, Q Wang, Y W Shao, X Hu (2019). Dewatering of sewage sludge via thermal hydrolysis with ammonia-treated Fenton iron sludge as skeleton material. Journal of Hazardous Materials, 379: 120810 https://doi.org/10.1016/j.jhazmat.2019.120810
pmid: 31255849
80
Y Yi, Z Huang, B Lu, J Xian, E P Tsang, W Cheng, J Fang, Z Fang (2020). Magnetic biochar for environmental remediation: A review. Bioresource Technology, 298: 122468 https://doi.org/10.1016/j.biortech.2019.122468
pmid: 31839494
81
H Yoo, S Cho, S Ko (2001). Modification of coagulation and Fenton oxidation processes for cost-effective leachate treatment. Journal of Environmental Science and Health. Part A, Toxic/Hazardous Substances & Environmental Engineering, 36(1): 39–48 https://doi.org/10.1081/ESE-100000470
pmid: 11381784
82
K Yoon, D W Cho, D C W Tsang, N Bolan, J Rinklebe, H Song (2017). Fabrication of engineered biochar from paper mill sludge and its application into removal of arsenic and cadmium in acidic water. Bioresource Technology, 246: 69–75 https://doi.org/10.1016/j.biortech.2017.07.020
pmid: 28712779
83
H Zhang, J Liu, C Ou, Faheem, J Shen, H Yu, Z Jiao, W Han, X Sun, J Li, L Wang (2017). Reuse of Fenton sludge as an iron source for NiFe2O4 synthesis and its application in the Fenton-based process. Journal of Environmental Sciences-China, 53: 1–8 https://doi.org/10.1016/j.jes.2016.05.010
pmid: 28372733
84
H Zhang, G Xue, H Chen, X Li (2018). Magnetic biochar catalyst derived from biological sludge and ferric sludge using hydrothermal carbonization: Preparation, characterization and its circulation in Fenton process for dyeing wastewater treatment. Chemosphere, 191: 64–71 https://doi.org/10.1016/j.chemosphere.2017.10.026
pmid: 29031054
85
H Zhang, G Xue, H Chen, X Li (2019a). Hydrothermal synthesizing sludge-based magnetite catalyst from ferric sludge and biosolids: Formation mechanism and catalytic performance. Science of the Total Environment, 697: 133986 https://doi.org/10.1016/j.scitotenv.2019.133986
pmid: 31487596
86
J Zhang (2013). Fenton iron mud preparation of ferrous sulfate and polymeric ferric sulfate and its application. Dissertation for the Master Degree. Nanning: Guangxi University (in Chinese)
87
Y Zhang, S Guo, J Zhou, C Li, G Wang (2010). Flue gas desulfurization by FeSO4 solutions and coagulation performance of the polymeric ferric sulfate by-product. Chemical Engineering and Processing, 49(8): 859–865 https://doi.org/10.1016/j.cep.2010.06.002
88
M Zhang, H Dong, L Zhao, D Wang, D Meng (2019b). A review on Fenton process for organic wastewater treatment based on optimization perspective. Science of the Total Environment, 670: 110–121 https://doi.org/10.1016/j.scitotenv.2019.03.180
89
R Zhou, W Zhang (2017). Reuse of ferric sludge by ferrous sulfide in the fenton process for nonylphenol ethoxylates wastewater treatment. Computational Water, Energy, and Environmental Engineering, 6(01): 89–96 https://doi.org/10.4236/cweee.2017.61007
90
Y Zhou, X Fang, T Wang, Y Hu, J Lu (2017). Chelating agents enhanced CaO2 oxidation of bisphenol A catalyzed by Fe3+ and reuse of ferric sludge as a source of catalyst. Chemical Engineering Journal, 313: 638–645 https://doi.org/10.1016/j.cej.2016.09.111
91
L Zhu, D Shen, K H Luo (2020). A critical review on VOCs adsorption by different porous materials: Species, mechanisms and modification methods. Journal of Hazardous Materials, 389: 122102 https://doi.org/10.1016/j.jhazmat.2020.122102
pmid: 32058893
92
S Zhu, X Huang, F Ma, L Wang, X Duan, S Wang (2018). Catalytic removal of aqueous contaminants on N-doped graphitic biochars: Inherent roles of adsorption and nonradical mechanisms. Environmental Science & Technology, 52(15): 8649–8658 https://doi.org/10.1021/acs.est.8b01817
pmid: 30027739