Department of Chemical Engineering, University of Calcutta, 92, A.P.C. Road, Kolkata 700009, India.
Environ Sci Pollut Res Int. 2012 Jul;19(6):2212-26. doi: 10.1007/s11356-011-0725-8.
The purpose of the research is to investigate the applicability of the low-cost natural biosorbents for the removal of Pb(II) ions from aqueous solution and effluent from battery industry.
Six different biosorbents namely rice straw, rice bran, rice husk, coconut shell, neem leaves, and hyacinth roots have been used for the removal of Pb(II) ions from aqueous solution in batch process. All the biosorbents were collected from local area near Kolkata, West Bengal, India. The removal efficiency was determined in batch experiments for each biosorbent.
The biosorbents were characterized by SEM, FTIR, surface area, and point of zero charge. The sorption kinetic data was best described by pseudo-second-order model for all the biosorbents except rice husk which followed intraparticle diffusion model. Pb(II) ions adsorption process for rice straw, rice bran, and hyacinth roots were governed predominately by film diffusion, but in the case of rice husk, it was intraparticle diffusion. Film diffusion and intraparticle diffusion were equally responsible for the biosorption process onto coconut shell and neem leaves. The values of mass transfer coefficient indicated that the velocity of the adsorbate transport from the bulk to the solid phase was quite fast for all cases. Maximum monolayer sorption capacities onto the six natural sorbents studied were estimated from the Langmuir sorption model and compared with other natural sorbents used by other researchers. The Elovich model, the calculated values of effective diffusivity, and the sorption energy calculated by using the Dubinin–Radushkevich isotherm were indicated that the sorption process was chemical in nature. The thermodynamic studies indicated that the adsorption processes were endothermic. FTIR studies were carried out to understand the type of functional groups responsible for Pb(II) ions binding process. Regeneration of biosorbents were carried out by desorption studies using HNO3. Battery industry effluents were used for the application study to investigate applicability of the biosorbents.
The biosorbents can be utilized as low-cost sorbents for the removal of Pb(II) ions from wastewater.
本研究旨在探讨低成本天然生物吸附剂在去除水溶液和电池工业废水中 Pb(II)离子方面的适用性。
采用稻草、米糠、稻壳、椰子壳、印楝叶和水葫芦根等 6 种不同的生物吸附剂，在批处理过程中从水溶液中去除 Pb(II)离子。所有生物吸附剂均取自印度西孟加拉邦加尔各答附近的当地地区。在批实验中确定了每种生物吸附剂的去除效率。
通过 SEM、FTIR、表面积和零电荷点对生物吸附剂进行了表征。除稻壳外，所有生物吸附剂的吸附动力学数据均符合准二级模型，而稻壳则符合内扩散模型。对于稻草、米糠和水葫芦根，Pb(II)离子吸附过程主要受膜扩散控制，但对于稻壳，它是内扩散。膜扩散和内扩散对等地负责生物吸附过程到椰子壳和印楝叶。质量转移系数的值表明，对于所有情况，吸附剂从主体到固相的传输速度都相当快。从 Langmuir 吸附模型估计了研究的六种天然吸附剂的最大单层吸附容量，并与其他研究人员使用的其他天然吸附剂进行了比较。Elovich 模型、计算的有效扩散系数值以及使用 Dubinin–Radushkevich 等温线计算的吸附能表明吸附过程是化学性质的。热力学研究表明吸附过程是吸热的。进行 FTIR 研究以了解负责 Pb(II)离子结合过程的官能团类型。通过使用 HNO3 进行解吸研究对生物吸附剂进行了再生。使用电池工业废水进行应用研究，以考察生物吸附剂的适用性。
生物吸附剂可作为从废水中去除 Pb(II)离子的低成本吸附剂。
