Current situation of batik wastewater treatment in Pekalongan City, Indonesia

Batik is an Indonesian technique of wax-resist dyeing applied to whole cloth. The designation of the Indonesian batik as a UNESCO Intangible Cultural Heritage has increased demand for batik. Consequently, Indonesia faces severe environmental problems caused by waste/wastewater generated by batik enterprises. However, current circumstances in batik and textile wastewater treatment have not been fully reported. This paper reports the current situations in three wastewater treatment plants (WWTPs) for batik wastewater in Pekalongan City based on field survey and data analysis. Jenggot Village has used a horizontal subsurface flow constructed wetland. Kauman Village has used an activated sludge process. Banyuurip Village has used anaerobic biological treatment followed by constructed wetland. Those WWTPs have conformed to effluent quality standards for temperature, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids, total chrome, total ammonia, and pH, except for BOD and COD concentrations at Jenggot Village WWTP during maintenance period. Influent and effluent quality scores of those WWTPs were evaluated through the effluent quality index (EQI). The respective EQI scores of influent and effluent of the WWTPs were comparable to water resource class III and II scores in Indonesia. The EQI scores suggest that the Banyuurip Village WWTP was the most effective at batik wastewater treatment.