Applicability of a new pre-hydrated industrial grade polyaluminium salt for the decolourisation of textile wastewater

This study was conducted to assess the decolourisation and chemical oxygen demand (COD) reduction efficiency of a novel pre-hydrated aluminium salt as aluminium chlorohydrate (ACH) for the treatment of textile wastewater using coagulation/flocculation technology. Though, ACH belongs to the same group of polyaluminium salts, it is significantly different from polyaluminium chloride (PACl) in terms of the degree of hydration and alumina content and was used for the first time as a coagulant for the decolourisation of synthetic as well as real textile wastewater. The experimental results revealed that ACH is highly effective for the treatment of synthetic textile wastewater producing more than 99% of colour removal and 45% of COD reduction efficiency at a very low dosage of 200 mg L-1. The decolourisation of real textile wastewater was found to be very much in line with the results obtained for the treatment of synthetic textile wastewater. Superior decolourisation efficiency at a very low dosage as compared to that of the pre-established studies for real textile wastewater and least volume of easily dewatered sludge production makes ACH a novel and very promising coagulant for the treatment of industrial textile wastewater.