利用非活体生物质去除废水中重金属的研究

Use of non-living biomass materials to remove selected heavy metals from wastewater

为了解非活体牛物质去除废水中重金属的效果，选择了玉米芯、水稻谷壳、花生壳、松树树皮和茶叶等5种非活体生物质，州室内模拟方法比较研究了它们对重金属的吸附能力。结果表明，生物质对重金属的吸附是一个快速反应，可在20-30min内达到平衡。pH值对牛物质吸附阳离子型重金属有很大的影响，吸附量随pH值上升而增加，pH值在4．5以上时可达到较高水平。5种生物质对重金属都有较高吸附能力，它们吸附重金属的能力依次为：花生壳〉松树树皮〉玉米芯〉水稻谷壳〉茶叶。生物质去除废水中重金属的效果一般为：Cu、Pb〉Cd〉Zn。用碱、柠檬酸和磷酸对生物质进行改性处理可显著增强其对重金属的去除能力。生物质是一种廉价、有效的吸附剂，可替代商品吸附剂用于废水中重金属的去除，主要重金属的移除率在85％以上。

Five biomass materials, including corncobs, rice huck, peanut hulls, pine bark and tea leaves, were collected to test their ability to remove heavy metals from aqueous solutions. The biomass materials were modified with either base or citric acid and phosphorus acids to help improve their adsorption capacity. The results indicated that biosorption of heavy metals was a rapid reaction, equilibrium could be achieved within 20 to 30 min. pH had great influence on biosorption of the metals, the adsorption of the metal cations increased with increasing pH. All of the five biomass materials had strong capacity to adsorb heavy metals, the capacity decreased in the order of peanut hulls 〉 pine bark 〉 corncobs 〉 rice huck 〉 tea leaves. Chemical modification of the biolnass treated with base, citric acid or phosphorus acid could increase significantly their adsorption capacity of the heavy metals. Biomass materials could replace commericial cation exchange resins for removal of heavy metals from the aqueous solution, the efficiency of the biomass materials in the removal of the complex matrix containing several heavy metals was more than 85%.