Exploration of the Local Clay in Removing the Blue Textile Dye from the Blue Stream Commonly Known as ‘Mabolou Running through Thetsane Industrial Area, Maseru

Abstract

As a search for affordable and efficient adsorbents for purification of textile wastewater continues, different natural materials are being investigated. Herein we report the investigation of clay obtained from Lesotho as a low cost and ecofriendly adsorbent for removal of blue textile dye from the stream running through the textile industry populated area in Ha Thetsane about 3 km South West of Maseru – the capital city of Lesotho. Batch adsorption studies were carried out for the effect of mass of adsorbent and particle size, pH, temperature and contact time on the adsorption capacity of the blue dye on the clay. The results show that the smaller the particle size of the adsorbent the higher the efficiency, although the smaller particles could also clog the pores of the filter paper; the adsorption increases under the basic media (pH ≥ 10) and at a low temperature (10-15°C) achieving an extraction efficiency of 88% for a 4 g clay and a 15 mL solution after 15 minutes extraction relative to the original solution. Despite the identity of the dye not being known, the clay adsorbent was found to be quite effective for the removal of this dye. The focus of the future experiments will be to obtain the information from the factories through the relevant government departments about the identity of the dye so that definitive quantitative analysis could be carried out.