Stabilized leachate treatment by using combination of struvite precipitation and coagulation-flocculation methods: RSM optimization

Abstract

Leachate is a form of pollution from landfills with pollutants in organic and inorganic forms. Stabilized leachate is characterized by the presence of organic materials with high ammoniacal nitrogen concentrations (>400mg/L), high chemical oxygen demand (COD) concentrations (<4000mg/L) and the ratio of BOD/COD is low (<0.1). In this study, struvite precipitation used to remove high ammonia content and coagulation-flocculation using poly-aluminium chloride (PAC) as coagulant agent and cationic polymer as flocculant agent used for COD and colour removal. Response surface methodology (RSM) is applied to determine the optimum parameters and interaction effects of the four main factors that influence the efficiency of treatment used; coagulant dosage, flocculant dosage, pH and Mg-N-P ratio on COD, NH3-N and colour removal. Optimum parameters obtained from the study were the coagulant dosage of 2250 mg/L, flocculant dosage of 14 mg/L, pH 7, and Mg: N: P ratio 1.1. The combination of struvite precipitation and coagulation-flocculation method results a percentage of removal of COD 48.6%, NH3-N 92.8% and color 98.8%

Research progress of leachate treatment in waste transfer station

“…Their application in leachate pretreatment has also been investigated, offering advantages such as cost-effectiveness, maneuverability, and stable and reliable treatment. Hurairah et al [29] utilized guano precipitation in conjunction with coagulation-flocculation to eliminate high levels of ammonia and COD, as well as to decolorize using polyaluminum chloride as a coagulant and cationic polymer as flocculants. The removal rates for COD, NH4 + -N, and color were 48.6%, 92.8%, and 98.8%, respectively.…”

Changes to Struvite Growth and Morphology as Impacted by Low Molecular Weight Organics

“…16,17 The presence of nondiscrete dissolved organic matter (DOM) in LWE is known to hinder the struvite formation process, which is commonly carried out at optimal pH 9− 10. 18−22 Several approaches are known to mitigate these hindrances to struvite recovery from LWE through DOM removal from the dissolved phase by flocculation, 23,24 osmosis/ filtration, 25,26 and digestion. 27,28 In contrast to hindrance from non-descript DOM such as humic substances to struvite growth, 13,18,29 negatively charged low molecular weight (LMW) organics such as phenols and carboxylic acids promoted nucleation and growth of struvite in simulated LWE.…”

“…The presence of nondiscrete dissolved organic matter (DOM) in LWE is known to hinder the struvite formation process, which is commonly carried out at optimal pH 9–10. − Several approaches are known to mitigate these hindrances to struvite recovery from LWE through DOM removal from the dissolved phase by flocculation, , osmosis/filtration, , and digestion. , In contrast to hindrance from non-descript DOM such as humic substances to struvite growth, ,, negatively charged low molecular weight (LMW) organics such as phenols and carboxylic acids promoted nucleation and growth of struvite in simulated LWE. , Additional research found that adding a negatively charged soluble short peptide labeled shADP5 (short human-derived amelogenin-derived peptide 5, 1736.8 g mol –1 ) to simulated wastewater (SWW) also increased the struvite precipitation rate. This study evaluated the relationship between the ionic charge of the dissolved LMW organics benzylamine, benzoate, and toluene to struvite growth rates and morphology in SWW.…”

A hybrid process for leachate wastewater treatment: Evaporation and reverse osmosis/sequencing batch reactor

“…The aerobic, anaerobic, and/or anoxic biological processes are applied to eliminate ammonium and organic matter (Castrillón et al, 2010; Dahlan, 2019; El‐Gohary & Kamel, 2016; Mccarty, 2018). A large variety of physicochemical processes, for instance, activated carbon adsorption (Ghani et al, 2017; Reshadi et al, 2020), distillation or evaporation (Di Maria & Sisani, 2017), coagulation–flocculation–precipitation (Bouchareb et al, 2020; Hurairah et al, 2021; Kamaruddin et al, 2017; Tripathy & Kumar, 2019), chemical oxidation (Bouchareb et al, 2021; Jung et al, 2017; Mahtab et al, 2021), and membrane separation (Chan et al, 2007; Isik et al, 2021), have been engaged for leachate wastewater treatment.…”