Landfill leachate wastewater treatment to facilitate resource recovery by a coagulation-flocculation process via hydrogen bond
Document Type
Article
Publication Date
1-1-2021
Abstract
Recent trend to recover value-added products from wastewater calls for more effective pre-treatment technology. Conventional landfill leachate treatment is often complex and thus causes negative environmental impacts and financial burden. In order to facilitate downstream processing of leachate wastewater for production of energy or value-added products, it is pertinent to maximize leachate treatment performance by using simple yet effective technology that removes pollutants with minimum chemical added into the wastewater that could potentially affect downstream processing. Hence, the optimization of coagulation-flocculation leachate treatment using multivariate approach is crucial. Central composite design was applied to optimize operating parameters viz. Alum dosage, pH and mixing speed. Quadratic model indicated that the optimum COD removal of 54% is achieved with low alum dosage, pH and mixing speed of 750 mgL(-1), 8.5 and 100 rpm, respectively. Optimization result showed that natural pH of the mature landfill leachate sample is optimum for alum coagulation process. Hence, the cost of pH adjustment could be reduced for industrial application by adopting optimized parameters. The inherent mechanism of pollutant removal was elucidated by FTIR peaks at 3853 cm(-1) which indicated that hydrogen bonds play a major role in leachate removal by forming well aggregated flocs. This is concordance with SEM image that the floc was well aggregated with the porous linkages and amorphous surface structure. The optimization of leachate treatment has been achieved by minimizing the usage of alum under optimized condition. (C) 2020 Elsevier Ltd. All rights reserved.
Keywords
Alum, Central composite design (CCD), Coagulation-flocculation, Leachate, Mature landfill, Multivariate, Pretreatment
Divisions
sch_civ,InstituteofBiologicalSciences,nanotechnology
Funders
University of Malaya under SATU Joint Research Scheme (ST022-2019),University of Malaya under SATU Joint Research Scheme (ST014-2018),Impact Oriented Interdisciplinary Research Grant (IIRG004A-19IISS),Impact Oriented Interdisciplinary Research Grant (RP025B-SUS18),Ministry of Education, Malaysia (FRGS/1/2019/STG05/UNIM/02/2),Ministry of Education, Malaysia (MyPAIR/1/2020/STG05/UNIM/1)
Publication Title
Chemosphere
Volume
262
Publisher
Pergamon-Elsevier Science Ltd
Publisher Location
THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND