Experimental determination of Cd^2+ adsorption mechanism on low-cost biological waste
Experimental determination of Cd^2+ adsorption mechanism on low-cost biological waste作者机构:Environmental Forensics Research Centre Faculty of Environmental Studies Universiti Putra Malaysia UPM Serdang 43400 Malaysia
出 版 物:《Frontiers of Environmental Science & Engineering》 (环境科学与工程前沿(英文))
年 卷 期:2013年第7卷第3期
页 面:356-364页
核心收录:
学科分类:083002[工学-环境工程] 0830[工学-环境科学与工程(可授工学、理学、农学学位)] 08[工学]
主 题:carbonate shell cadmium heavy metal,adsorption mechanism saturation state
摘 要:Carbonate shells have an astonishing ability in the removal of Cd^2+ in a short time period with emphasis on being a low cost adsorbent. In the present study, the sorption capacity of carbonate shells was studied for Cd^2+ in batch experiments. The influence of different carbonate shell sizes and physico-chemical factors were evaluated and the results were analyzed for its correlation matrices by using Predictive Analytics Software (PASW). The miner- alogy state of aqueous solution regarding the saturation index was simulated using PHREEQC to identify the Cd^2+ uptake mechanism. The Cd uptake rates were calculated as well as Ca^2+, HCO3- concentration, pH, ambient humidity and temperature were measured. Cd2+ removal of 91.52% was achieved after 5 h adsorption. The adsorption efficiencies were significantly influenced by pH as they increased with the increase of pH from acidic solution (5.50±0.02) to slightly alkaline (7.60±0.05). In addition, the mineralogy state of aqueous solution calculated from PHREEQC confirmed that the increment of Ca^2+ and HCO3- concentrations in solution was attributed to the dissolution of carbonate shells. Moreover, the ion exchange adsorption mechanism of Cd^2+ toward Ca^2+ was identified as the process involved in Cd^2+ uptake.