Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia.
Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia.
Chemosphere. 2021 Jan;262:127829. doi: 10.1016/j.chemosphere.2020.127829. Epub 2020 Aug 1.
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, 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 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.
从废水回收增值产品的最新趋势要求更有效的预处理技术。传统的垃圾渗滤液处理往往很复杂，因此会对环境产生负面影响并带来经济负担。为了便于下游处理渗滤液废水以生产能源或增值产品，通过使用简单有效的技术最大限度地提高渗滤液处理性能是很重要的，该技术可以去除污染物，而无需向废水中添加可能会影响下游处理的化学物质。因此，优化混凝-絮凝渗滤液处理采用多元方法是至关重要的。中心复合设计用于优化操作参数，即明矾剂量、pH 值和混合速度。二次模型表明，在低明矾剂量、pH 值和混合速度分别为 750 mg/L、8.5 和 100 rpm 的条件下，COD 去除率最佳可达 54%。优化结果表明，成熟垃圾填埋场渗滤液样品的自然 pH 值最适合明矾混凝过程。因此，通过采用优化参数，可以降低工业应用中 pH 值调整的成本。污染物去除的内在机制通过 3853 cm 处的 FTIR 峰得到了阐明，这表明氢键在通过形成良好聚集的絮体去除渗滤液中起着主要作用。这与 SEM 图像一致，絮体具有多孔连接和无定形表面结构，并且聚集良好。通过在优化条件下最小化明矾的使用量，实现了渗滤液处理的优化。
