Removal of colour from textile effluent by adsorption using banana stem and coffee husk: A Review

摘要

Background: The effluent from the textile industry is an important source of dye pollution. Many dyes and their break down products may be toxic for living organism. Therefore, decolourisation of dyes is an important aspect of wastewater treatment before discharge. The various colour removal methods being adopted commonly are coagulation, ultrafiltration, electrochemical adsorption and photo oxidation. Among these methods, adsorption is a widely used for removal of dyes from wastewater. A number of non-conventional low cost adsorbents used for dye removal, include fruit waste of Prosopisn juliflora, wood, waste orange peel, banana stem, maze cobs, barley husk, coffee husk, bagasse pith etc. This study explores the feasibility of banana stem and coffee husk as a natural adsorbent with respect to various parameters such as colour adsorbent capacity of material with initial concentration at different doses and contact time, and to optimize these parameters affecting the adsorption process. Materials and Methods: In this study, banana stem and coffee husk is used. Waste banana stem and coffee husk were collected and their powder is prepared. The batch adsorption experiments are conducted to study optimum removal of colour from textile wastewater. The different doses (0.1 g, 0.2 g, 0.3 g, 0.4 g, 0.5 g) of adsorbents coffee husk and banana stem are taken for analysis. The contact time between the adsorbent and the effluent solution is taken as 20 min, 40 min, 60 min, 80 min, 100 min. The colour concentration is determined using UV-spectrophotometer. Results: Banana stem and coffee husk are indeed viable, affordable adsorbent for the adsorptive removal of Brown R dye from textile wastewater with 80-85% dye removal the optimum dosage was obtained as 0.1 gram in both the cases. The optimum time duration required for colour removal is 80 minutes forbanana stem and 60 minutes for coffee husk. Conclusion:Banana stem and coffee husk are suitable and efficient adsorbent for removing Brown R from textile dye wastewater. These adsorbents could be employed as eco-friendly adsorbents as an alternative to overcome problems related to an excessive of colour in textile waste water.