The Study Of Advance Treatment And Fesibility Of Dying Wastewater

This article takes the waste water of a dying and printing plant in Shanghai as an object. Through investigating thoroughly the variety of products, the use of raw material, the origin and the quality of waste water, and so on, in addition to the consulting of the similar technology in domestic and foreign country, and the studying the piratical experience in Jiangsu and Zhejiang provinces, a more reasonable and mature treatment and reuse techniques is proposed. The advance treatment and the reuse of the wastewater are analyzed in the article.In optimization stage of advance treatment by BAC, the treatment effects of different filtering rates and the depth of BAC was be studied. The result indicates the best filtering rate is 0.5 ~ 2.5 L/h, and the best depth of BAC is 300mm ~ 900mm. During the 0.5 ~ 2.5 L/h in filtering rate, COD, color, ammonia nitrogen removing rates basically maintains at 70% ~ 90%, turbidity removing rate basically maintains about 45%. The best depth of BAC is determined because COD, color, SS, turbidity removing rates change slowly above 700mm, but best use of DO and the best ammonia nitrogen removing rate is in 700mm ~ 900mm.In experiment, when the wastewater is used in forepart process, a better result is acquired. So it is feasibility that the wastewater is reuse inforepart process. In the studying of back part process, the color characteristic and dye fastness of the fabric are studied chiefly. The result indicates that the wastewater can be reused in back part process, but it should be according to the different kind of the dyes. The dark and light degrees have a great effect on fabric aberration. In the situation with treatment of different water, the effect of dark fabric is better than light one. In the experiment of dye fastness, the result indicates that in relation to the color characteristic of fabric, the different qualities of water have litter effect on fabric dye fastness.According to the experiment results, when the reuse wastewater is used in flushing the toilet, cleaning equipments, washing roads, circulation cooling and etc, it is need to add disinfection facility, like chlorination. But the agent should be control within the range of standard. It is feasibility that the wastewater is reuse in forepart process. In the backpart process in dying, it is difficult to distinguish the quality of fabric in printing and dying dark fabric. And it should be further studied in printing and dying light one.By process calculating, it can save expend 844200 yuan per year by reuse wastewater. And the direct economic benefit is 331900 yuan per year. In addition, it can save water 670000 m3. The reuse project is invested totally 525500 yuan. The cost can be recovered after putting into products for 19 months. After that, economic benefit can be recovered28000 yuan per month. So the reuse project not only make majority of wastewater be recovery, but also saves water resource.