بررسي كارايي حذف رنگ صنايع نساجي با استفاده از مخلوط كلريد منيزيم و آلوم

Survey of dye Removal by Mixed Magnesium Chloride and Alum in Textile Industry wastewater

Textile wastewater is still a problem to handle and solved tactfully. The development of textile industry, on the other hand, brings upon the generation of a huge amount of colored wastewater. In this study, mixtures of alum and MgCI2 have been used as coagulant to remove colored matter. The optimal pH and optimal dosage for those coagulants were detrminated. A six-beaker jar test appartus was used in this study. Each beaker contained 150 ml of dye solution. NaOII was then added to adjust the pH, Then coagulants were added to the beakers. The samples were mixed at 60-65 rpm for 3 minutes. The solution was then allowed to settle and supernatant was taken for analysis. The pH of the solution was measured using Lasco pH meter. The dye concentrations of the supernatant were measured at a wavelength corresponding to maximum absorbance using a Spectrophotometer.Coagulation of 1 g/l reactive dye with a mixture of MgC12 and alum gives two distinct effective color removal zones. At pH 4.5 and 9.5, for each combination treatment, a curve of two maximum zones was obtained, one maximum zone occure at acidic pH rang, another at alkaline pH range. Color removal of more than 97% has been achieved for mixture of MgCI2 and alum with concentration of 4000 ppm (Alum 2g/l and MgCl2 2g/l). The resultes showed that mixtures MgC12 and alum have a higher efficiency in ellimination of dyes as compare to alum and magnesim chlorid alone. Addition of alum to MgC12 Changed the optimal cogulation pH range of MgCI2 from 10.5-11 to 9.5. The presence of 2000 ppm of alum in the mixtures increases the color removal from %25 to %55.