摘要
An effective and economic process for removing arsenic in waste water which is acuminating in the process of etching, cutting and washing in semiconductor industry has been developed in this paper. The proposed technique of arsenic removal is as follows: first pretreatment step is to oxidize arsenite to arsenate by potas-sium permanganate, second key step is precipitation based on arsenic compound solubility with ferric sulfate and slaked lime under pH adjustment, and the last complementary step is followed by the adsorption of the bentonite with enhanced by activated carbon and organic adsorbent. Experimental results show that under the optimal condition the removal efficiency of arsenic in the waste water is better than 99.99%, or the concen-tration of arsenic is from its original 100mg/l reduced to less than 10µg/l accordingly.
An effective and economic process for removing arsenic in waste water which is acuminating in the process of etching, cutting and washing in semiconductor industry has been developed in this paper. The proposed technique of arsenic removal is as follows: first pretreatment step is to oxidize arsenite to arsenate by potas-sium permanganate, second key step is precipitation based on arsenic compound solubility with ferric sulfate and slaked lime under pH adjustment, and the last complementary step is followed by the adsorption of the bentonite with enhanced by activated carbon and organic adsorbent. Experimental results show that under the optimal condition the removal efficiency of arsenic in the waste water is better than 99.99%, or the concen-tration of arsenic is from its original 100mg/l reduced to less than 10µg/l accordingly.
