Studies On Electrolysis And Micro-electrolysis Treatment Of Dyeing Wastewater

Lacking of water resources and serious pollution are the severe situation that our country faces at present. The dyeing and finishing wastewater is a kind of difficult to treat organic wastewater with the character of difficult to degrade, lots of toxic substances and large quantity. It is one of the difficult problems in the traditional wastewater treatment. In recent years, micro-electrolysis technology has played an active role in the area of printing and dyeing wastewater treatment. However, iron and carbon powder in the reactor bottom is easy to harden during the use of traditional micro-electrolysis, and the passivation film reduce the occurrence of the primary battery efficiency, which will influences the application and promotion of micro-electrolysis technology. In this paper, a new micro-electrolytic material was prepared by calcination and activation hole making technology and applied in the simulated wastewater treatment, respectively, combining with traditional electrolysis method. We obtained the following findings:(1)Two new micro-electrolytic materials were generated by calcination and activation hole making technology, and the surface morphology was observed by scanning electron microscope. The iron-carbon, aluminum-carbon micro-electrolysis material have a rough surface and internal porous structure, thus it have a large specific surface area and a stable structure.(2)The treatment of simulated wastewater was studied by using electrolysis、 iron-carbon and aluminum-carbon micro-electrolysis, respectively.1) For the electrolysis method, the optimum conditions according to the orthogonal test showed that the electrolytic voltage is 15 v, electrolyte solution concentration 0.1g/L, wastewater concentration 200 mg/L, electrolytic time 1.5 h, electrolytic temperature 35 oC, pH 8.2) For the iron-carbon micro-electrolysis method, the best treatment effect of acid fuchsin wastewater treated by iron-carbon micro-electrolysis was that the mass ratio of iron to carbon is 1:1, the calcination temperature 1000 oC, calcination time 2 h, pH 3-4, the reaction time 2 h. In this case, the removal efficiency of COD was 36.0%, color removal rate reached above 85%.3) For the aluminum-carbon micro-electrolysis method, the best treatment effect of acid fuchsin wastewater treated by aluminum-carbon micro-electrolysis was that the mass ratio of aluminum to carbon is 1: 1, the firing temperature 1000 ℃, the calcination time 2.5 h, pH 10-11. In this case, the removal efficiency of COD was 68.2%, color removal rate reached above 90%.(3)This paper also makes an elementary discussion on the treatment of high concentration dyeing wastewater by coupling of micro-electrolysis and electrolysis. Studies shows that the removal rate of COD and color can be greatly increased by the micro-electrolysis pretreatment and subsequent electrolysis treatment. Specifically, the removal efficiency of COD and color increased from 30% to 62.3%, from 85% to 90%, respectively. The treatment effect was significantly improved.