Polyvinyl Alcohol Recovery From Desizing Wastewater

At present the drainage of many kinds of wastes from textile industry has greatly threatened the environment in China. However many of those wastes can be recycled or reused and become valuable. My study has focused on the pollution control and waste recycle in textile industry. In allusion to the desizing wastewater in textile industry, I explored the production techniques of ZrO₂ porcelain dynamic membrane, researched the methods of reclaiming the Polyvinyl alcohol from desizing wastewater in textile industry by using ZrO₂ porcelain dynamic membrane. The study may bring new hope for solving the environmentalproblems caused by textile industry and empolder a brand-new approach for environmental engineering to reclaim wastes.After being treated by ZrO₂ porcelain dynamic membrane, the desizing wastewater could be drained to the environment, and the PVA in it was concentrated, which could be reused as architectural materials and chemical pastes. The detailed contents are as follows :At first, I established a way to determine the concentration of the PVA solution by spectrophotometry, constituted a curve which related the concentration of the PVA solution to the absorbance;also researched theconnection between the COD and the concentration of the PVA solution, constituted a curve which showed the relationship between the concentration of the PVA solution and the CODCr. So I could know the relation between CODCr and absorbance in the simulated wastewater. It is easy to determine the absorbance under certain conditions. By using the two curves, I could find the CODCr accurately and quickly.Consulting many literatures, I determined to produce the ZrO2 porcelain dynamic membrane by using 0.8g/L coating suspension at 150KPa pressure and 0.1 m/s cross flow velocity. Under these conditions, I got theZrC>2 porcelain dynamic membrane, and used it to treat the simulated wastewater. The effect of operation conditions including diameter of ZrC>2, trans-membrane pressure, cross-flow velocity and temperature on permeate flux was investigated, and the optimum parameters were determined :lu.m ZrO2, at lOKPa pressure, at O.lOm/s cross-flow velocity and at 40 "CoTreating the actual wastewater under the optimum parameters, I could receive these results: the filtrated wastewater could be drained to the environment as the stipatation of national standard, and the PVA-size in the system was concentrated approximately to seven times as many as before the treatment.During the study of the rebirth of ZrC?2 porcelain dynamicmembrane, ZrO2 was used to simulate the membrane pollution and hot water was used to wash the membrane reversely.In one word, the production and application of ZrC>2 porcelain dynamic membrane have not been studied on a large scale in China. And the report of ZrC>2 porcelain dynamic membrane is very limited. I hope that my study of the production techniques of ZrO2 porcelain dynamic membrane and its application in the treatment of desizing wastewater can make ZrO2 porcelain dynamic membrane receive more and more attention. At the same time, ZrO2 porcelain dynamic membrane techniques may help membrane techniques as a whole to get more broad application in wastewater disposal field.Zhang Yi (Application of chemistry)Supervised by GU Run-nan...