The Direct Oxidation Of Preparation Of Modified Polymeric Ferric Sulfate Decolorizing Agent Technology And Applied Research

Treating the printing and dyeing wastewater, especially decoloring, is an important task with practical value. On the basis of surveying the resource, characteristic and treatment approaches inside and outside of the country of printing and dyeing wastewater, reaction which natrium chlorate oxidates directly with acetic acid to synthesize modified polymerized ferric sulphate decoloring agent is studied systematically in this paper .The synthetic condition is optimized and the application performance of modified polymerized ferric sulphate decoloring agent on printing and dyeing wastewater is also studied. Results show the excellent performance of decolourization and flocculation and operation is simple, convenient and controlled easily. It provides a new-type decoloring agent with high efficiency applying in printing and dyeing wastewater treatment. The main contents of experiment as following:(1) Modified polymerized ferric sulphate decoloring agent is made through oxidation, hydrolyzation, polymerization with ferrous sulphate heptahydrate, sulphate acid, natrium chlorate etc. Experiment shows appropriate acetic acid is feasible to adjust pH value of reactive solution and can improve alkalinity degree of the product.(2) By the measurement of content of alkalinity degree and total iron, the product is indicated to be a kind of liquid with high alkalinity degree. The product shows the characteristic of electrolytical and is adapt to applying in wastewater treatment with fine physical property. It is without deposition in three months and mixed with water by unlimited scale.(3) The curve of work in rapid determination of COD of printing and dyeing is settled through lots of expemiments, referencing normal curve and data involved. It is applied to following experiments in determination of COD of wastewater.(4) It researchs effect and variational rule of the factors including the dosage of sulphate acid, the dosage of acetic acid, the dosage of natrium chlorate, reactive time, etc. Orthogonal experiment is arranged on the basis of selection of the range of experiment condition. The optimum symthetic condition is determined by the evaluation criterion of the removal of CODCr and decolourization. The optimization isto be: the dosage of sulphate acid:0.7mL; the dosage of natrium chlorate: 1.2g; the dosage of acetic acid:0.3mL; reaction time:20 minutes. Experiments show the dosage of sulphate acid is the most important factor on property of the product.(5) The performance of the removal of CODcr and decolourization of modified polymerized ferric sulphate decoloring agent prepared in the optimum condition applying in disperse, acid and reactive dye-containing wastewater treatment are researched, comparing with ordinary polymerized ferric sulphate. Results show it is more excellent than ordinary polymerized ferric sulphate in flocculation and decolourization. The application rule in dyeing and printing wastewater is studied.(6) The feasibility of modified polymerized ferric sulphate decoloring agent applying in practical printing and dyeing wastewater is also studied. The rules influenced by technologic conditions such as dosage, pH value of wastewater and the use of assistant flocculant are studied respectively through experiments. The result of treatment shows: discharging water of content in CODcr under discharge of national standard and decoloured almost. The product is a kind of high effective decoloring agent and applied to printing and dyeing wastewater with the best effect of treatment.