Original Article: Evaluation of chemical oxygen demand and color removal from leachate using coagulation/flocculation combined with advanced oxidation process


1 Student Research Committee, Shahrekord University of Medical Sciences

2 Department of Environmental Health Engineering, School of Health, Shahrekord University of Medical Sciences

3 Social Determinants of Health Research Center, Shahrekord University of Medical Sciences, Shahrekord

4 Department of Biostatistics, Shahrekord University of Medical Sciences

5 Department of Environmental Health Engineering, School of Health, Iran University of Medical Sciences, Tehran, Iran


Background: One of the basic practices in the field of waste management is the collection and treatment of leachate. Leachate from municipal waste due to high chemical oxygen demand (COD) and dark color is a potential pollutant of the environment, which causes a lot of problems in the absence of treatment and direct discharge to the environment. This study aimed to determine the efficiency of ultrasonic process in combination with coagulation and flocculation process using sodium ferrate in COD and color reduction. Materials and Methods: In this experimental study, all experiments were performed in batch conditions and with changing process variables such as pH and sonication time, and the effect of three parameters, including ultrasonic reaction time (15, 30, and 45 min), pH (2, 4, 5/5, and 7), and coagulant dosage (from 1 to 150 g/l) on the COD reduction and color removal, was evaluated. Coagulant concentration and then the removal efficiency of COD and color were analyzed by ANOVA using SPSS 18. Results: The COD reduction and color removal were 87.05% and 88.6% in optimal condition (using 120 g/L of sodium ferrate at pH 5.5), with coagulation/flocculation, after ultrasound (15 min). Ultrasound (15 min) + sodium ferrate (without coagulation/flocculation) achieved 46.25% of COD reduction and 90.35% of color elimination, whereas the ultrasonic process alone allowed removing the COD and color in the leachate by less than 50%. Conclusion: The results indicate that C–F followed by ultrasonic can be used to efficiently reduce the organic matter and color from municipal waste leachate, and it would be an ideal option for leachate treatment.


Afsharnia M, Torabian A, Moussavi G, Abdoli M. Municipal landfill leachate treatment by advanced oxidation process (Ultrasound/H2O2). Horizon Med Sci 2012;17:5-10.  Back to cited text no. 1
Tejera J, Miranda R, Hermosilla D, Urra I, Negro C, Blanco Á. Treatment of a mature landfill leachate: Comparison between homogeneous and heterogeneous PHoto-fenton with different pretreatments. Water 2019;11:1849.  Back to cited text no. 2
Sun D, Hong X, Cui Z, Du Y, Hui KS, Zhu E, et al. Treatment of landfill leachate using magnetically attracted zero-valent iron powder electrode in an electric field. J Hazard Mater 2020;388:121768.  Back to cited text no. 3
Tawakkoly B, Alizadehdakhel A, Dorosti F. Evaluation of COD and turbidity removal from compost leachate wastewater using Salvia hispanica as a natural coagulant. Ind Crops Prod 2019;137:323-31.  Back to cited text no. 4
Rasool MA, Tavakoli B, Chaibakhsh N, Pendashteh AR, Mirroshandel AS. Use of a plant-based coagulant in coagulation-ozonation combined treatment of leachate from a waste dumping site. Ecol Eng 2016;90:431-7.  Back to cited text no. 5
Ghanbari F, Wu J, Khatebasreh M, Ding D, Lin KY. Efficient treatment for landfill leachate through sequential electrocoagulation, electrooxidation and PMS/UV/CuFe2O4 process. Sep Purif Technol 2020;242:116828.  Back to cited text no. 6
Pisharody L, Gopinath A, Malhotra M, Nidheesh PV, Kumar MS. Occurrence of organic micropollutants in municipal landfill leachate and its effective treatment by advanced oxidation processes. Chemosphere 2021;287:132216.  Back to cited text no. 7
Wijekoon P, Koliyabandara PA, Cooray AT, Lam SS, Athapattu BC, Vithanage M. Progress and prospects in mitigation of landfill leachate pollution: Risk, pollution potential, treatment and challenges. J Hazard Mater 2022;421:126627.  Back to cited text no. 8
Raghab SM, El Meguid AM, Hegazi HA. Treatment of leachate from municipal solid waste landfill. HBRC J 2013;9:.187-92  Back to cited text no. 9
Donneys-Victoria D, Marriaga-Cabrales N, Camargo-Amado RJ, Machuca-Martínez F, Peralta-Hernández JM, Martínez-Huitle CA. Treatment of landfill leachate by a combined process: Iron electrodissolution, iron oxidation by H2O2 and chemical flocculation. Sustain Environ Res 2018;28:12-9.  Back to cited text no. 10
Hu Y, Gu Z, He J, Li Q. Novel strategy for controlling colloidal instability during the flocculation pretreatment of landfill leachate. Chemosphere 2022;287:132051.  Back to cited text no. 11
Azizan M, Shaylinda M, Mohd-Salleh S, et al., editors. Treatment of leachate by coagulation-flocculation process using polyaluminum chloride (PAC) and tapioca starch (TS). IOP Conference Series: Materials Science and Engineering; 2020: IOP Publishing.  Back to cited text no. 12
Abu Amr SS, Aziz HA, Adlan MN. Optimization of stabilized leachate treatment using ozone/persulfate in the advanced oxidation process. Waste Manag 2013;33:1434-41.  Back to cited text no. 13
Talaiekhozani A, Eskandari Z, Bagheri M, Talaie MR. Removal of H2S and COD using UV, ferrate and UV/ferrate from municipal wastewater. J Hum Environ Health Promot 2016;2:1-8.  Back to cited text no. 14
Akunna JC. Anaerobic waste-wastewater treatment and biogas plants: A practical handbook: CRC Press; 2018.  Back to cited text no. 15
Im JH, Woo HJ, Choi MW, Han KB, Kim CW. Simultaneous organic and nitrogen removal from municipal landfill leachate using an anaerobic-aerobic system. Water Res 2001;35:2403-10.  Back to cited text no. 16
Wang F, Gu Z, Hu Y, Li Q. Split dosing of H2O2 for enhancing recalcitrant organics removal from landfill leachate in the Fe0/H2O2 process: Degradation efficiency and mechanism. Sep Purif Technol 2021;278:119564.  Back to cited text no. 17
Dia O, Drogui P, Buelna G, Dubé R. Hybrid process, electrocoagulation-biofiltration for landfill leachate treatment. Waste Manag 2018;75:391-9.  Back to cited text no. 18
Bandala ER, Liu A, Wijesiri B, Zeidman AB, Goonetilleke A. Emerging materials and technologies for landfill leachate treatment: A critical review. Environ Pollut 2021;291:118133.  Back to cited text no. 19
Poveda M. Evaluation of physico-chemical pretreatment methods for landfill leachate prior to sewer discharge. A Thesis of the university of Manitoba; 2015.  Back to cited text no. 20
Lan S, Liu X, Chen R, Wan Y, Wu X, Zhang H. Study on pretreatment of landfill leachate by potassium ferrate. Desalin Water Treat 2014;52:2757-64.  Back to cited text no. 21
Joshi SM, Gogate PR. Treatment of landfill leachate using different configurations of ultrasonic reactors combined with advanced oxidation processes. Sep Purif Technol 2019;211:10-8.  Back to cited text no. 22
Deng Y, Chen N, Hu W, Wang H, Kuang P, Chen F, et al. Treatment of old landfill leachate by persulfate enhanced electro-coagulation system: Improving organic matters removal and precipitates settling performance. Chem Eng J 2021;424:130262.  Back to cited text no. 23
Grosser A, Neczaj E, Madela M, Celary P. Ultrasound-assisted treatment of landfill leachate in a sequencing batch reactor. Water 2019;11:516.  Back to cited text no. 24
Tałałaj IA, Bartkowska I, Biedka P. Treatment of young and stabilized landfill leachate by integrated sequencing batch reactor (SBR) and reverse osmosis (RO) process. Environ Nanotechnol Monit Manag 2021;16:100502.  Back to cited text no. 25
Korniluk M, Ozonek J, editors. Application of Hydrodynamic Cavitation for Leachate of Municipal Landfill Site. Environmental Engineering Proceedings of the International Conference on Environmental Engineering ICEE; 2011: Vilnius Gediminas Technical University, Department of Construction Economic; 2011.  Back to cited text no. 26
Alfaiaa R, Nascimentoa M, Bilab D, Camposa J. Coagulation/flocculation as a pretreatment of landfill leachate for minimizing fouling in membrane processes. Desalin Water Treat 2019;159:53-9.  Back to cited text no. 27
Osu CI, Chukwu Uche J. Potassium ferrate (K2FeO4) oxidation of landfill leachate and sewage: Removal of COD and BOD. J Am Sci 2016;12:10.  Back to cited text no. 28
Li X, Song J, Guo J, Wang Z, Feng Q. Landfill leachate treatment using electrocoagulation. Procedia Environ Sci 2011;10:1159-64.  Back to cited text no. 29
Samadi M, Saghi M, Rahmani A, Hasanvand J, Rahimi S, Syboney MS. Hamadan landfill leachate treatment by coagulation-flocculation process. J Environ Health Sci Eng 2010;7:253-8.  Back to cited text no. 30
Bohdziewicz J, Kwarciak A, Neczaj E. Influence of ultrasound field on landfill leachate treatment by means of anaerobic process. Environ Protection Eng 2005;31:61.  Back to cited text no. 31
Yang C, Fu T, Wang H, Chen R, Wang B, He T, et al. Removal of organic pollutants by effluent recirculation constructed wetlands system treating landfill leachate. Environ Technol Innov 2021;24:101843.  Back to cited text no. 32
Laksono FB, Kim I. Removal of 2-BromopHenol by advanced oxidation process with in-situ liquid ferrate (VI). Int Proc Chem Biol Environ Eng 2016;94:128-35.  Back to cited text no. 33
Sales Junior SF, Amaral IC, Mannarino CF, Hauser-Davis RA, Correia FV, Saggioro EM. Long-term landfill leachate exposure modulates antioxidant responses and causes cyto-genotoxic effects in Eisenia andrei earthworms. Environ Pollut 2021;287:117351.  Back to cited text no. 34
Neczaj E, Kacprzak M. Ultrasound as a pre-oxidation for biological landfill leachate treatment. Water Sci Technol 2007;55:175-9.  Back to cited text no. 35
Amirhossein M, Aliakbar R, Ramin NN, Simin N, Mohammadhadii D, Mahmood A. Improvement of landfill leachate biodegradability with ultrasonic process. J Chem 2012;9:766-71.  Back to cited text no. 36
Batarseh ES, Reinhart DR, Daly L. Liquid sodium ferrate and Fenton's reagent for treatment of mature landfill leachate. J Environ Eng 2007;133:1042-50.  Back to cited text no. 37
Sia MC. Effect of Sonication Combined with Hydrogen Peroxide for Sanitary Landfill Leachate Treatment: UTAR; 2015.  Back to cited text no. 38
Amuda O. Removal of COD and colour from sanitary landfill leachate by using coagulation – Fenton's process. J Appl Sci Environ Manag 2006;10:49-53.  Back to cited text no. 39
de Almeida R, Moraes Costa A, de Almeida Oroski F, Carbonelli Campos J. Evaluation of coagulation-flocculation and nanofiltration processes in landfill leachate treatment. J Environ Sci Health A Tox Hazard Subst Environ Eng 2019;54:1091-8.  Back to cited text no. 40
Liu Y, Wang J. Treatment of fresh leachate from a municipal solid waste incineration plant by combined radiation with coagulation process. Radiat Phys Chem 2020;166:108501.  Back to cited text no. 41
Bis M, Montusiewicz A, Ozonek J, Pasieczna-Patkowska S. Application of hydrodynamic cavitation to improve the biodegradability of mature landfill leachate. Ultrason Sonochem 2015;26:378-87.  Back to cited text no. 42
Rajoriya S, Bargole S, George S, Saharan VK. Treatment of textile dyeing industry effluent using hydrodynamic cavitation in combination with advanced oxidation reagents. J Hazard Mater 2018;344:1109-15.  Back to cited text no. 43
Tizaoui C, Bouselmi L, Mansouri L, Ghrabi A. Landfill leachate treatment with ozone and ozone/hydrogen peroxide systems. J Hazard Mater 2007;140:316-24.  Back to cited text no. 44
Chaouki Z, Hadri M, Nawdali M, Benzina M, Zaitan H. Treatment of a landfill leachate from Casablanca city by a coagulation-flocculation and adsorption process using a palm bark powder (PBP). Sci Afr 2021;12:e00721.  Back to cited text no. 45
Hurairah SN, Halim AA, Aziz NA, editors. Stabilized Leachate Treatment By Using Combination of Struvite Precipitation and Coagulation-Flocculation Methods: RSM Optimization. IOP Conference Series: Earth and Environmental Science; 2021: IOP Publishing; 2021.  Back to cited text no. 46
Azizan M, Shaylinda M, Mohd-Salleh S, Amdan N, Yashni G, Fitryaliah M, et al., editors. Treatment of Leachate by Coagulation-Flocculation Process Using Polyaluminum Chloride (PAC) and Tapioca Starch (TS). IOP Conference Series: Materials Science and Engineering; 2020: IOP Publishing; 2021.