COD removal of batik wastewater using microbial immobilization system for agricultural purposes.

Batik is made through a series of processes that requires large amount of water. One of these processes is dying the fabric using chemical dyes. Many batik producers in Yogyakarta dispose the wastewater straight into the river or on the ground. Since batik is recognized as UNESCO s Intangible Cultural Heritage of Indonesia, batik industries have been grown rapidly. As a result, batik wastewater became a huge contributor to environmental pollution, especially land and water resources. In the present study, application of microorganisms (bioremediation) to remove or degrade pollutant of batik wastewater was investigated. Microorganisms of Bacillus licheniformis were immobilized in bentonite mineral. This microbial immobilized system then applied in aerobic reactor of continuous process. The concentration of Chemical Oxygen Demand (COD) was calculated as daily parameter. Although the final COD concentration still doesn t meet the government standard, this microbial immobilization system shows promising COD removal results. The highest COD removal is 75\%. This experiment is still in the early stages and further phases of the experiment are required to reach safe chemical parameters of batik wastewater for agricultural purposes as regulated by the Indonesian government.