颗粒活性炭对尾渣污染地下水中氰化物的吸附去除效能

Study on adsorption and removal efficiency of granular activated carbon for cyanide in groundwater contaminated by tailings

对4种材质的颗粒活性炭去除污染地下水中氰化物的效能进行了评估,筛选出具有高效去除氰化物能力的松木质颗粒活性炭(SW-AC),揭示了SW-AC的结构特征,开展了SW-AC在不同吸附时间、反应温度、活性炭投加量和共存阴离子条件下的吸附试验,并进行了吸附动力学规律探讨和吸附等温线拟合.结果表明,SW-AC投加量为4.0 g时,0—1 h为快速反应阶段,反应3 h后达到吸附平衡,若增加其投加量,达到吸附平衡所需反应时间越短.反应温度(10—30℃)越高,SW-AC投加量越大,SW-AC对氰化物的吸附率越大.而地下水中的共存阴离子CO^(2-)_(3)、SO^(2-)_(3)、Cl-对吸附氰化物起抑制作用,且离子浓度越高,抑制作用越大.SW-AC对水中氰化物的吸附过程较好符合Elovich模型(R^(2)>0.99)和Freundlich模型(R^(2)>0.94).

The effectiveness of four types of granular activated carbon to remove cyanide in groundwater was evaluated,and pine wood granular activated carbon(SW-AC)with high cyanide removal ability was selected,revealing the SW-AC structural features.The adsorption experiments of SW-AC under different adsorption time,reaction temperature,activated carbon dosage and coexisting anions were carried out,and the adsorption kinetics law and adsorption isotherm fitting were carried out.The results showed that when the dosage was 4.0 g,0—1 h was the rapid reaction stage,and the adsorption equilibrium was reached after 3 hours of reaction.If the SW-AC dosage was increased,the shorter the reaction time required to reach the adsorption equilibrium.The higher the reaction temperature(10—30℃),the greater the dosage of SW-AC,the greater the adsorption rate of SW-AC to cyanide.The coexisting anions CO^(2-)_(3),SO^(2-)_(3),and Cl-in groundwater inhibited the adsorption of cyanide,and the higher the ion concentration,the greater the inhibition.The adsorption process of cyanide in water by SW-AC fit well with the Elovich model(R^(2)>0.99)and Freundlich model(R^(2)>0.94).