电渗析法处理氧化铝厂外排废水

ON WASTEWATER TREATMENT FROM ALUMINA PRODUCTION BY ED PROCESSING

氧化铝厂每日排放大量生产废水 ,这些废水对环境造成了严重污染 ,同时也严重浪费了水资源。针对这一问题 ,本文用电渗析法处理及回收利用氧化铝厂外排废水。试验采用循环式脱盐 ,试验过程中控制淡水体积是浓水体积的 4倍 ,即废水回收率为 80 % ,分别进行恒压、恒电流操作以及恒压条件下淡水进水线速度对脱盐效果的影响等试验 ,确定本体系的最佳操作条件。采用 1 0 0 V端电压 ,控制淡水、浓水进水线速度为 5cm/ s的条件下 ,进行 3次平行脱盐试验 ,结果表明试验重复性好 ,制得的淡水含盐总量低于 50 0 mg/ L,水质符合氧化铝厂工业用水要求。单位产水量能耗较低 ,小于 1 .75k W· h/ m3淡水 ,具有良好的经济效益。

The present paper is concerned about the treatment of wastewater discharged from the alumina manufacturing process by using Electrolysis. As is known, alumina processing brings about large quantities of wastewater every day, resulting in serious pollution to the environment and deteriorating freshwater resources. To solve this problem, the present study has been trying to treat and recycle the water resources discharged from the alumina processing. The optimum operating voltage is determined by the actual experiments, in which the circulation of the liquid desalination can be enhanced so as for the fresh-water flow rate to be controlled four times as high as the thick-water rate, thus enabling to increase the wastewater recovery rate to 80%. In addition, we have done various experiments to search for the optimum operating voltages, such as the desalination of constant voltage to control the current density under the limited current density; desalination of the constant current intensity and the effect of linear freshwater current speed under the constant voltage. And, last of all, we experimented three times respectively on the condition of 100 V operation voltage and the 5 cm/s linear velocity of liquid. The results indicate that the repeatability is good, with all of the salt weights of acquired fresh-water being less than 500 mg/L, which conforms to the demand for alumina production in water use standard. The actual energy consumption is actual rather low, less than 1.75 kW·h/m^3, which is beneficial for economic development.