Influence of Operating Conditions on the Persulfate Oxidation of Textile Waste Water at Ambient Temperature
At the ambient temperatures, the influence of operating conditions on persulfate (S 2 O 8 ) oxidation of real textile wastewater was investigated for the removal of color, suspended solids (SS) and chemical oxygen demand (COD). The effects of oxidant dosage, initial solution pH and contact time were studied in a series of batch experiments using persulfate (PS) oxidant as sodium persulfate. Oxidant dose was defined by an oxidant/contaminant (PS/COD) molar ratio, varied from 1/1-10/1. Although parameter removals increased with the oxidant dose, especially for color and SS, a PS/COD molar ratio of 4/1 (6720mg/L) was adopted in a bid to use fewer chemicals. The pH was varied from 2-11, with pH of between 2 and 3 being the optimum. At 360minutes contact time, the removals of color, SS and COD were 84%; 71% and 32% respectively. Although relatively effective, especially for color removal, results show that the reactions might have been inhibited at ambient temperatures as shown by the particularly low removal of COD.