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为研究生物炭对溶液中重金属Cd的吸附去除效果,进一步提升生物炭对Cd的吸附性能,以玉米芯、玉米秸秆、木屑为原料,分别在400℃、500℃、600℃和700℃密闭缺氧条件下热解制备生物炭,通过微波改性、Na OH改性方法对生物炭进行改性处理,研究初始浓度、溶液p H、吸附时间等因素对生物炭吸附Cd效果的影响,筛选出适合用于处理镉污染水体的生物炭品种。结果表明:当Cd浓度为100 mg/L时,玉米秸秆-600℃-Na生物炭(B-6-Na)对Cd的吸附可用Langmuir方程拟合,吸附量可达78.7 mg/g,去除率为78.7%,基本达到吸附平衡的时间为60~120 min;当溶液p H达到7时,三种生物炭对Cd吸附率均超过80%以上;600℃条件下经Na OH溶液改性制备的玉米秸秆生物炭能够更好地吸附溶液中的Cd。该研究结果为制备对污染物具有高效、深度净化功能的生物炭方法提供参考,在深入研究生物炭在重金属Cd污染修复的可行性方面提供理论支撑。
In order to study the biochar adsorption and removal of heavy metal Cd in solution and to further improve the biochar adsorption properties to Cd, using corn cob, corn stalks and sawdust as raw materials, respectively, at 400 ℃, 500 ℃, 600 ℃ and 700 ℃ The biochar was prepared by pyrolysis under aerobic conditions. The modified biochar was modified by microwave and NaOH, and the effect of initial concentration, solution pH and adsorption time on Cd adsorption on biochar was screened Biochar suitable for use in cadmium contaminated water. The results showed that when the Cd concentration was 100 mg / L, the adsorption of Cd on corn straw-600 ℃ -N-biochar (B-6-Na) was fitted by Langmuir equation, the adsorption capacity reached 78.7 mg / g, Was 78.7%, and the adsorption equilibrium time was basically 60 to 120 min. When the pH of the solution reached 7, the adsorption rates of Cd to the three biochar exceeded 80%, and the adsorption of Cd by NaOH solution at 600 ℃ Corn stalk biochar can better adsorb Cd in solution. The results of this study provide a reference for the preparation of biochar method with high efficiency and deep purification of pollutants, and provide theoretical support for the further study on the feasibility of biochar in the remediation of Cd pollution by heavy metals.