| The emissions of Textile printing and dyeing industry are one of most important China's industrial pollution sources. Desizing wastewater in dyeing wastewater are the main reasons of environmental pollution, Desizing wastewater includes many pollutants from the Sizing process which used the slurry--PVA. PVA is a resources which has recycling value. This article focuses on the treatment of the textile desizing wastewater.To recycle desizing wastewater which contains PVA used flocculation sedimentation.Specific research is divided into three parts bellow:1. Study on determination about making sure the content of PVA in desizing wastewater.PVA is a water-soluble polymers, which soluble in water is colorless and transparent.Because of iodine with polyols to form a typical non-ferrous complex, different quantity and distribution density of hydroxyl of the complex has different color. According to this principle to determine the concent of PVA by spectrophotometry.When the boric acid exist,it makes polyvinyl alcohol and iodine form blue-green complex. Chromogenic solution at U-3010 Spectrophotometer absorbance was read out , absorbance A stands the content of PVA, to make standard curve, and then converted to the concentration of PVA. At the same time, to determine the most feasible method need analysis the impact of various factors to the content of PVA2.Study on process conditions of PVA recovery use Flocculation.Used flocculation to recovery of PVA from printing and dyeing wastewater.Dis -cussed the flocculation temperature, pH and pharmaceutical dosage. The article should be pointed out that the use of concentrated sulfuric acid and sodium hydroxide to form sodium sulfate as the salting-out agent which had a good effect on both system of boric acid and sodium polyphosphate. In order to reduce the dosage of salts in the original system by adding two flocculation flocculant and the use of orthogonal experiment analysis of the effect of various factors affect the recovery.Ultimately get the best conditions for the recovery process.3. Study on recovery of the structure and properties of PVAUsed infrared spectroscopy to analysis the structure of recovery PVA.Used the Ukrainian-style viscometer measured the degree of polymerization. |
