Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Nugegoda, Sri Lanka; Science and Engineering Faculty, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, 4001, Queensland, Australia; Department of Civil Engineering, University of Peradeniya, Sri Lanka.
Zedz Consultants Pty Ltd, Hillcrest, QLD, 4118, Australia.
Chemosphere. 2019 Nov;234:488-495. doi: 10.1016/j.chemosphere.2019.06.074. Epub 2019 Jun 14.
Heavy metals present in industrial wastewater contribute to human and ecosystem health risk when discharged without proper treatment. Low-cost biosorbents with high metal-binding capacity are increasingly being utilized for the removal of heavy metals. Inherent physico-chemical properties of biosorbents significantly influence their adsorption capacity. Studies quantifying the influence exerted by these properties on adsorption capacity are scarce. This study quantifies the influence and relative importance of selected physico-chemical properties on the adsorption capacity of three divalent heavy metals; Cu, Cd and Pb using multivariate analysis. Twenty one biosorbent mixtures were created, systematically varying their physico-chemical properties using tea factory waste and coconut shell biochar. Their adsorption capacities were measured using batch sorption studies. The influence of physico-chemical properties on the adsorption capacity is comparable for all three metal cations. Regression models were developed to quantify the influence of physico-chemical parameters on the adsorption capacity based on regression coefficients. All models were found to have high reliability with R values above 0.98. Acidic surface functional groups were found to act as the key property that governs the adsorption capacity of Pb, Cu and Cd. Carboxylic groups played a major role in the adsorption of Cu and Pb, while lactonic groups were more important in providing binding sites to Cd. SSA failed to demonstrate a significant impact on the adsorption capacity of these three metals on its own when the biosorbent had a low surface functional group density.
工业废水中存在的重金属，如果未经适当处理就排放，会对人类和生态系统的健康造成风险。具有高金属结合能力的低成本生物吸附剂越来越多地被用于去除重金属。生物吸附剂的固有物理化学性质会显著影响其吸附能力。然而，量化这些性质对吸附能力的影响的研究却很少。本研究使用多元分析量化了三种二价重金属（Cu、Cd 和 Pb）的吸附能力受所选物理化学性质影响的程度和相对重要性。使用茶厂废料和椰子壳生物炭系统地改变 21 种生物吸附剂混合物的物理化学性质，通过批量吸附研究测量它们的吸附能力。结果表明，对于所有三种金属阳离子，物理化学性质对吸附能力的影响是可比的。基于回归系数，开发了回归模型来量化物理化学参数对吸附能力的影响。所有模型的可靠性都很高，R 值均高于 0.98。酸性表面官能团被发现是控制 Pb、Cu 和 Cd 吸附能力的关键性质。羧基在 Cu 和 Pb 的吸附中起主要作用，而内酯基在为 Cd 提供结合位点方面更为重要。当生物吸附剂的表面官能团密度较低时，SSA 本身并不能显著影响这三种金属的吸附能力。
