生物质电厂底渣对水溶液中Cu2＋的吸附特性

Adsorption of Cu^(2+) in water by biomass ash

本实验选用安徽某生物质发电厂燃烧炉底渣,通过研究吸附等温线、吸附时间以及电厂灰投加量和溶液初始p H对生物质灰吸附Cu2+的影响,以确定其对水溶液中Cu2+的吸附特性.结果表明,Cu2+初始浓度在50—100 mg·L^(-1)范围内,Langmuir模型能很好地描述生物质电厂底渣对Cu2+的等温吸附规律,其理论饱和吸附量为20 mg·g^(-1),非常接近实际饱和吸附量19.45 mg·g^(-1).溶液初始p H值在2—6范围时,Cu2+的去除率随p H值的升高而增加,当p H在6附近时去除率最佳,接近100%.溶液Cu2+初始浓度为100 mg·L^(-1),体积为50 m L时,随生物质电厂底渣投加量增加,其对Cu2+的去除率上升,但去除效率下降,0.2 g左右可能是达到最佳去除效率和去除率的用量.溶液中Cu2+的去除率随吸附时间的增加而升高,用量越大达到吸附平衡的时间越短,但90 min左右时各个用量的去除率均趋于稳定.

In the experiment, biomass ash was selected as an adsorbent to investigate me ettects oi time, dosage and initial pH on the adsorption for Cu. Results showed that the Langinuir model could well fit the isothermal adsorption of Cu by biomass ash, and its calculated adsorption capacity （20 mg.g-1） was close to the experimental value （19.45mg. g-1）. The removal rate of Cu2＋ increased with the increase of initial pH value （2-8）, and the removal rate （ - 100%） of Cu was the highest at pH -6. The removal rate of Cu2＋increased with the increase of the dosage, and the best removal efficiency for Cu was obtained with 0.2 g biomass ash. The removal rate of Cu2＋ increased over time and adsorption reached equilibrium after 90 mins. Our results indicated biomass ash has strong adsorption capacity for Cu and could be used to remediating wastewater treatment.