Development And Study On Properties Of Two Ternary Micro-electrolytisis Packings

In recent years, micro-electrolysis technology is widely used to treat wastewater as pretreatment technology. Under the effect of micro-battery formed by iron and carbon, pollutants in wastewater were degraded by oxidation-reduction. Traditional micro-electrolysis packing was consists of iron and carbon. Micro-electrolysis technology is low cost and high efficiency. But in practice, it is easy to passivation and harden during the using. So it will lead to replace micro-electrolysis packing frequently. This problem was solved by the new micro-electrolysis packing.Using iron powder, zinc powder, aluminum powder, activated carbon powder and clay as raw material, two ternary micro-electrolytisis packings were made by the method of calcination. The influences of mass ratio of metals, mass ratio of metals and activated carbon, clay proportion, additives proportion and calcination temperature on the removal rate of Reactive Black KNB in the simulated wastewater were investigated and the optimum conditions of preparation were obtained. Besides, the influence factors to the microelectrolysis process of Reactive Black KNB were studied, such as the pH of the original wastewater, packing content and reaction time. The main experimental conclusions are as follows:(1) The optimum conditions of preparation of the iron-zinc-carbon packing: iron-zinc ratio is 15:1, metals-carbon ratio is 1:1, the calcination temperature is 900℃, the percentage of clay is 40% and the percentage of additives is 3%. The optimum conditions of preparation of the iron-aluminum-carbon packing: iron-aluminum ratio is 1:1, metals-carbon ratio is 1:1, the calcination temperature is 900℃, the percentage of clay is 40% and the percentage of additives is 3%.(2) The optimum conditions of treatment of simulated wastewater using the iron-zinccarbon packing: initial pH is 3, packing content is 0.3kg/L, the reaction time is 2h. Under the optimum conditions of treatment, removal rate of Reactive Black KNB was above 81.8%. The optimum conditions of treatment of simulated wastewater using the iron-aluminum-carbon packing: initial pH is 3 or 11, packing content is 0.3kg/L, the reaction time is 2h. Under the optimum conditions of treatment, removal rate of Reactive Black KNB was above 89%.(3) Two ternary micro-electrolytisis packings were recycled three times, which still can reduce the removal rate of Reactive Black KNB in the simulated wastewater and the effect of treatment was better than effect of treatment using iron-carbon micro-electrolysis packing at the same condition. After useing, packing coagulability still was good, and it can be used for a long time.(4) The main reation process of azo dye wastewater treated by ternary micro-electrolytisis packings are galvanic interaction, oxidation-reduction and flocculation of iron ions.