Removal of organic matter from stabilized landfill leachate using Coagulation-Flocculation-Fenton coupled with activated charcoal adsorption

Abstract

The treatment of stabilized landfill leachate (SLL) by conventional biological treatment is often inefficient due to the presence of bio-recalcitrant substances. In this study, the feasibility of coagulation-flocculation coupled with the Fenton reaction in the treatment of SLL was evaluated. The efficiency of the selected treatment methods was evaluated through total organic carbon (TOC) removal from SLL. With ferric chloride as the coagulant, coagulation-flocculation was found to achieve the highest TOC removal of 71% at pH 6. Then, the pretreated SLL was subjected to the Fenton reaction. Nearly 50% of TOC removal was achieved when the reaction was carried out at pH 3, HO:Fe ratio of 20:1, HO dosage of 240 mM and 1 h of reaction time. By coupling the coagulation-flocculation with the Fenton reaction, the removal of TOC, COD (chemical oxygen demand) and turbidity of SLL were 85%, 84% and 100%, respectively. The ecotoxicity study performed using zebrafish revealed that 96 h LC for raw SLL was 1.40% (v/v). After coagulation-flocculation, the LC of the pretreated SLL was increased to 25.44%. However, after the Fenton reaction, the LC of the treated SLL was found to decrease to 10.96% due to the presence of HO residue. In this study, HO residue was removed using powdered activated charcoal. This method increased the LC of treated effluent to 34.48% and the removal of TOC and COD was further increased to 90%. This finding demonstrated that the combination of the selected treatment methods can be an efficient treatment method for SLL.

Organic matter and nutrients removal from landfill leachate by airlift aerobic three‐phase fluidized bed reactor

“…applied, in a stabilized leachate, coagulation and flocculation processes with ferric chloride and pH 6, subsequently coupled to Fenton reaction with pH 3, reaching an efficiency of 84% of COD removal for respective coagulation, flocculation, sedimentation, and adsorption times of 2, 30, and 60 min. [ 46 ]…”

Assessment of Pretreatments for Highly Concentrated Leachate Waters to Enhance the Performance of Catalytic Wet Peroxide Oxidation with Sustainable Low-Cost Catalysts

“…Furthermore, several ions, such as chlorides, carbonates or sulfates, can also be found, affecting its treatment performance [6,7]. Thus, the need to develop technologies suitable to handle such complex matrices emerges [8,9].…”

“…To enhance the performance of the chemical treatment of complex matrixes, such as for the leachate, an interesting strategy is to couple a pretreatment process with CWPO [8,15,19,20]. Coagulation-flocculation is a low-cost technology that can be operated with simple equipment and that has been used as a pretreatment step to remove part of non-biodegradable organic matter and colloidal particles from leachate waters.…”

Simultaneous Desalination and Removal of Recalcitrant Organics from Reverse Osmosis Leachate Concentrate by Electrochemical Oxidation

“…The AOPs are characterized as producing strong oxidation species such as • OH/ • O 2 – / • HO 2 – / during the treatment process, exhibiting superiority in recalcitrant organic removal and biodegradability improvement . The AOPs commonly used in ROLC include electrochemical oxidation, , Fenton-active persulfate-coupling oxidation, , coagulation–flocculation Fenton method, , coagulation–ozonation method, , electro-Fenton oxidation, − and photoelectro-Fenton oxidation . However, many kinds of research studies on AOPs are still at the laboratory stage because of the high treatment cost, complicated operation, large generation of sludge, and secondary pollution.…”