Used Plastic Spoon Application as Anaerobic Biofilter Media in Reducing Bod5, Cod, And Tss Levels in Tofu Industry Liquid Waste

Used plastic spoons and liquid tofu waste are two examples of negative impacts from the food sector. This study aims to utilize used plastic spoons as anaerobic biofilter media to reduce BOD5, COD and TSS levels in liquid tofu industry waste. The research began with the creation of biofilter media from used plastic spoons and the design of an anaerobic biofilter reactor. The seeding process lasted 14 days, followed by a three-day acclimatization process, followed by the treatment process. Wastewater was continuously fed into the anaerobic biofilter reactor using varying residence times of 24, 48, 72, 96, and 120 hours. The results of the tofu liquid waste sampling before processing obtained BOD5 levels of 4485.0 mg/L, COD of 6975.0 mg/L, and TSS of 962 mg/L. The highest efficiency of BOD5 and COD reduction was found at a residence time of 120 hours, for BOD5 of 87.36% with a level of 568.0 mg/L, for COD of 60% with a level of 2750 mg/L; the highest efficiency of TSS reduction was found at a residence time of 24 hours of 86.79% with a level of 127 mg/L. Based on DIY Regional Regulation no. 7 of 2016 concerning wastewater quality standards, tofu liquid waste has a maximum level of 150 mg/L for BOD5, 300 mg/L for COD, and 200 mg/L for TSS. It can be concluded that the results of processing tofu industrial liquid waste with anaerobic biofilters using used plastic spoon media that meet the quality standards are only for the TSS parameter.