Hawari Alaa H, Mulligan Catherine N
Department of Building, Civil and Environmental Engineering, Concordia University, 1455 de Maisonneuve Blvd., W. Montreal, QC, Canada H3G 1M8.
Bioresour Technol. 2006 Mar;97(4):692-700. doi: 10.1016/j.biortech.2005.03.033. Epub 2005 Jun 2.
Biosorption is potentially an attractive technology for treatment of wastewater for retaining heavy metals from dilute solutions. This study investigated the feasibility of anaerobic granules as a novel type of biosorbent, for lead, copper, cadmium, and nickel removal from aqueous solutions. Anaerobic sludge supplied from a wastewater treatment plant in the province of Quebec was used. Anaerobic granules are microbial aggregates with a strong, compact and porous structure and excellent settling ability. After treatment of the biomass with Ca ions, the cation exchange capacity of the biomass was approximately 111 meq/100 g of biomass dry weight which is comparable to the metal binding capacities of commercial ion exchange resins. This work investigated the equilibrium, batch dynamics for the biosorption process. Binding capacity experiments using viable biomass revealed a higher value than those for nonviable biomass. Binding capacity experiments using non-viable biomass treated with Ca revealed a high value of metals uptake. The solution initial pH value affected metal sorption. Over the pH range of 4.0-5.5, pH-related effects were not significant. Meanwhile, at lower pH values the uptake capacity decreased. Time dependency experiments for the metal ions uptake showed that adsorption equilibrium was reached almost 30 min after metal addition. It was found that the q(max) for Pb2+, Cd2+, Cu2+, and Ni2+ ions, were 255, 60, 55, and 26 mg/g respectively (1.23, 0.53, 0.87, and 0.44 mmol/g respectively). The data pertaining to the sorption dependence upon metal ion concentration could be fitted to a Langmiur isotherm model. Based on the results, the anaerobic granules treated with Ca appear to be a promising biosorbent for removal of heavy metals from wastewater due to its optimal uptake of heavy metals, its particulate shape, compact porous structure, excellent settling ability, and its high mechanical strength.
生物吸附可能是一种从稀溶液中去除重金属的有吸引力的废水处理技术。本研究调查了厌氧颗粒作为一种新型生物吸附剂从水溶液中去除铅、铜、镉和镍的可行性。使用了从魁北克省一家废水处理厂提供的厌氧污泥。厌氧颗粒是具有坚固、致密且多孔结构以及优异沉降能力的微生物聚集体。用钙离子处理生物质后，生物质的阳离子交换容量约为111 meq/100 g生物质干重，这与商业离子交换树脂的金属结合能力相当。这项工作研究了生物吸附过程的平衡和间歇动力学。使用活生物质的结合容量实验显示的值高于非活生物质。使用经钙处理的非活生物质的结合容量实验显示出较高的金属吸收值。溶液初始pH值影响金属吸附。在4.0 - 5.5的pH范围内，pH相关影响不显著。同时，在较低pH值下吸收容量降低。金属离子吸收的时间依赖性实验表明，添加金属后几乎30分钟达到吸附平衡。发现Pb2 +、Cd2 +、Cu2 +和Ni2 +离子的q(max)分别为255、60、55和26 mg/g（分别为1.23、0.53、0.87和0.44 mmol/g）。与吸附对金属离子浓度的依赖性相关的数据可以拟合到Langmiur等温线模型。基于这些结果，经钙处理的厌氧颗粒似乎是一种有前途的用于从废水中去除重金属的生物吸附剂，因为它对重金属的最佳吸收、其颗粒形状、致密多孔结构、优异的沉降能力以及高机械强度。
