Environmental Chemodynamics Project, National Institute of Fundamental Studies, Kandy, Sri Lanka.
Faculty of Technology, South Eastern University of Sri Lanka, Oluvil, Sri Lanka.
Environ Geochem Health. 2019 Aug;41(4):1739-1753. doi: 10.1007/s10653-017-9973-y. Epub 2017 May 17.
The potential of biochar, produced from fibrous organic fractions of municipal solid waste (MSW), for remediation of benzene, one of the frequently found toxic volatile organic compounds in landfill leachate, was investigated in this study based on various environmental conditions such as varying pH, benzene concentration, temperature and time. At the same time, landfill leachate quality parameters were assessed at two different dump sites in Sri Lanka: Gohagoda and Kurunegala. MSW biochar (MSW-BC) was produced by slow temperature pyrolysis at 450 °C, and the physiochemical characteristics of the MSW-BC were characterized. All the leachate samples from the MSW dump sites exceeded the World Health Organization permissible level for benzene (5 µg/L) in water. Removal of benzene was increased with increasing pH, with the highest removal observed at pH 9. The maximum adsorption capacity of 576 µg/g was reported at room temperature (25 °C). Both Freundlich and Langmuir models fitted best with the equilibrium isotherm data, suggesting the involvement of both physisorption and chemisorption mechanisms. Thermodynamic data indicated the feasibility of benzene adsorption and its high favorability at higher temperatures. The values of [Formula: see text] suggested physical interactions between sorbate and sorbent, whereas kinetic data implied a significant contribution of chemisorption. Results obtained from FTIR provided clear evidence of the involvement of functional groups in biochar for benzene adsorption. This study suggests that MSW biochar could be a possible remedy for benzene removal from landfill leachate and at the same time MSW can be a potential source to produce biochar which acts as a prospective material to remediate its pollutants while reducing the volume of waste.
本研究基于不同的环境条件，如 pH 值、苯浓度、温度和时间的变化，研究了从城市固体废物（MSW）的纤维有机部分生产的生物炭对苯的修复潜力。苯是垃圾渗滤液中常见的有毒挥发性有机化合物之一。同时，评估了斯里兰卡两个不同垃圾填埋场的垃圾渗滤液质量参数：Gohagoda 和 Kurunegala。MSW 生物炭（MSW-BC）是通过 450°C 的慢速热解生产的，并对 MSW-BC 的物理化学特性进行了表征。所有垃圾填埋场的渗滤液样本均超过了世界卫生组织规定的水中苯（5μg/L）的允许水平。随着 pH 值的增加，苯的去除率增加，在约 pH 9 时观察到最高去除率。在室温（约 25°C）下报道的最大吸附容量为 576μg/g。Freundlich 和 Langmuir 模型都与平衡等温线数据拟合得最好，表明涉及物理吸附和化学吸附机制。热力学数据表明苯吸附的可行性及其在较高温度下的高度有利性。[Formula: see text]值表明了吸附质和吸附剂之间的物理相互作用，而动力学数据表明了化学吸附的显著贡献。FTIR 得到的结果为生物炭对苯的吸附涉及官能团提供了明确的证据。本研究表明，MSW 生物炭可能是从垃圾渗滤液中去除苯的一种可行方法，同时 MSW 可以是生产生物炭的潜在来源，生物炭作为一种有前景的材料，可以在减少废物量的同时修复其污染物。
