TREATMENT OF DYEING WASTEWATER

Abstract

Corn cob was obtained from local vendors and it was activated by chemical activation method to examine the removal of COD and colour from dyeing wastewater by ACC. The adsorbent prepared was characterized by BET, FTIR, XRD, SEM/XRD and TGA/DTA analysis. The surface area of the adsorbent was 165.349 m2/g and a pore volume of 0.1056m2/g. The FTIR spectra showed that it contained carboxylic groups, aliphatic compounds and alcohols while no sharp distinct were observed in XRD pattern suggesting that it was amorphous in structure. The wastewater was obtained from a textile mill and characterized after procurement. Two stage batch adsorptions were carried out. First the effect of various parameters such as pH, temperature, adsorbent dosage and time were examined. The optimum conditions were found out to be, pH=3, adsorbent dosage=0.6g/100ml of wastewater, time=3.5 hours and temperature=15°C. Four different isotherms models were used and it was found that Redlich-Peterson isotherm was the best fitting model for both colour and COD. The removal in first stage was 76.9 % and 81.3 % for COD and colour respectively. After the second stage the removal was found out to be 93.76 % and 96.19 % for COD and colour respectively. Since the prepared adsorbent was cheaper than commercially available adsorbents and it brought down the COD and colour level in the wastewater within the norms set by CPCB, it was concluded to be a good alternative.