Removal of Hexavalent Chromium with Scrap Iron Filling.

Abstract

Chromium is a transition element commonly found in the environment as trivalent and hexavalent forms. Apparently, the hexavalent form is much more toxic than the trivalent form. Textile wastewater treatment is required in order to prevent hexavalent chromium to contaminate the environment. The methods of this research consisted of effect of pH determination, effect of agitating rate determination, effect of agitating time determination, and effect of iron level determination; and its application in textile wastewater sample. The methods used in textile wastewater application are: determination of textile wastewater hexavalent chromium concentration, determination of textile wastewater hexavalent chromium concentration with standard addition method, and removal of hexavalent chromium in textile wastewater with scrap iron filling. Concentration of hexavalent chromium was determined using visible light spectrophotometry method. Optimum conditions of pH, agitating rate, iron amount, and agitating time obtained were pH 3, 450 rpm, 5 grams, and 10 minutes giving concentrations of hexavalent chromium 16.98 ppm, 15.96 ppm, 0.24 ppm, and 0.14 ppm, respectively. Iron filling could effectively remove hexavalent chromium ions from textile wastewater in a relatively short time. Absorbance of hexavalent chromium in textile coloring process wastewater after the addition of iron filling was 0.002, whereas in textile final wastewater was 0.000.