Acidification, coagulation-flocculation, and adsorption: a study on Tegeran (Cudrania sp.) natural dye batik water footprint reduction
摘要
Batik production by Small and Medium Entreprises causes environmental problems in the form of pollution from its wastewater. Although many novel batik wastewater treatment technologies exist, they are unsuitable for batik industries because they are costly and technically complicated for batik craftsmen. Therefore, appropriate technology that is easy to operate and has adequate investment and maintenance costs is needed. This study was conducted to (1) examine the effectiveness of combined acidification, coagulation-flocculation, and adsorption to treat natural dye batik wastewater resulting from the batik-making process; and (2) analyze the natural dye batik water footprint. The research was conducted through a batik-making experiment using Tegeran natural dye, one of the most important natural dyes historically used in batik production. The resulting wastewater was treated sequentially using acidification, coagulation-flocculation, and adsorption. This study found that the combination of methods using glacial acetic acid, lime, and commercial activated carbon could reduce pollutants in batik wastewater colored by Tegeran, mordanted with lime, alum, and copperas, with soda ash used for the wax removal process. Total effectiveness for Total Suspended Solids, Biological Oxygen Demand, and Chemical Oxygen Demand reduction was 98.22%, 94.42%, and 94.87%, respectively. This study also found that the wastewater treatment contributes to a low Grey Water Footprint and results in a total Water Footprint of 37.46 L/pc for a batik fabric of 1,050 mm × 2,500 mm. This study reveals that combined acidification, coagulation-flocculation, and adsorption could serve as an alternative for simple and low-cost wastewater treatment for batik industries.