The Reuse Of Special Acrylate Wastewater

Special acrylates have been developing rapidly in recent decades. Many kinds of them are widely applied to UV coatings, inks, flocculants, papermaking, optical products and so on. Nevertheless, they also put a tremendous pressure on the environmental protection because of the large quantities of high concentration organic wastewater. The wastewater always contains acrylic acid, sodium acrylate, polyol acrylate, hydroxyl acrylate, aromatic compounds and suspended solids. The chemical oxygen demand(COD) of wastewater is very high. In addition, there are three key features of this wastewater. The first one is large amount. Taking UV curing agent as an example, the domestic production has reached about 150 thousand tons / year at present. Then, it comprises more available resources as a result of special synthetic process, such as acrylic acid and sodium acrylate. At last, the water quality has a greater fluctuation. The wastewater is ordinarily divided into acidic wastewater(p H value is about 2~3) and basic wastewater(p H value is about 9~10).There are three kinds of wastewater reusing methods, for example direct incineration, catalytic wet air oxidation and biological method. But most of them are mainly treated on direct combustion method. The wastewater can not burn directly, as a consequence the heavy oil has to be added, which leads to a higher running cost. If treated inappropriately or under a high temperature, the wastewater will severely polymerize, which produces large amounts of solid waste. Ultimately, the burden of enterprises will be further exacerbated and meanwhile many valuable resources have been wasted.In this study, the samples of special acrylate wastewater(hereinafter referred to ―wastewater‖)), which have been pretreated, are provided by a chemical plant in Jiangsu province. Based on the full understanding of wastewater’s key features, this paper mainly focus on how to make acrylic acid and sodium acrylate in wastewater into cotton anti-staining agent through chemical method. To be specific, this study contains three parts: the first part is to check physical and chemical properties of wastewater with some appropriate and suitable techniques. Then, on account of the theory of free radical polymerization, this paper synthesizes maleic anhydride-acrylic acid copolymers(AA-MA) in wastewater system; the third part is to test anti-staining abiliy of the copolymer and the universality of the polymerization process.At first, acrylic acid content, polymerization inhibitor(MEHQ) residual amount and the content of sodium, calcium, magnesium and iron ions were tested by ion chromatography, spectrophotometry and flame atomic absorption spectrometry respectively.In the second part, the monomer ratio, polymerization initiator dosage, temperature and time are discussed. The ability of chelating value, dispersion value and anti-stain were compared by ―Variable-controlling approach‖.At last, a enoumous number of anti-staining tests are carried out to evaluate the anti-staining ability of DB and the reliability of the polymerization. The K/S value of fabrics treated by anti-staining agent DB dropped considerably as compared with the untreated samples, Furthermore, DB also can be used to wash out unfixed dyes and enhance the color fastness of dyed fabrics.