As the effluent quality standards for industrial wastewater are becoming more stringent, it is important for the industry to improve their wastewater treatment efficiency. The research about potential of cellulase application in the activated sludge process has been done. Theoritically, the addition of cellulase was required to support the activity of microorganism on the activated sludge. Since cellulose is the major organic pollutant component in the wastewater, it was expected that cellulase addition could improve the performance of activated sludge process. The experiments were conducted in a continuous process and consisted of two treatments which were with and without activated sludge at about 2400 mg MLVSS/L. The variations in each treatment were the enzyme dosages of 0; 0.2; 0.5; and 0.7 unit/g COD, and the residence time of 4, 8, 12, and 24 hours. The experiment result showed that the addition of cellulase can increase COD and BOD reduction compared to the treatment without enzymes. The highest COD reduction increment was 7.9% at the enzyme dosage of 0.2 unit/g COD and the residence time of 4 hours, while the highest BOD reduction increment was 14.6% at the same enzyme dosage and residence time. In conclusion, celullase application can be combined with the activated sludge process which will be effective in the high load organic wastewater. ABSTRAKDengan semakin ketatnya baku mutu air limbah, peningkatan efisiensi dalam pengolahan limbah menjadi sangat penting bagi industri. Penelitian ini dilakukan untuk mengetahui potensi selulase dan pengaruh laju pembebanan pada efektifitas pengolahan air limbah kertas sistem lumpur aktif. Secara teori, penambahan selulase diperlukan untuk membantu aktivitas mikroorganisme lumpur aktif. Dengan adanya kandungan selulosa sebagai komponen utama pencemar organik dalam air limbah, penambahan selulase diharapkan dapat meningkatkan kinerja proses lumpur aktif. Percobaan dilakukan dengan proses kontinyu yang terdiri dari dua perlakuan, yaitu tanpa dan dengan lumpur aktif pada MLVSS sekitar 2400 mg/L. Variasi pada setiap perlakuan berupa variasi dosis selulase (0; 0,2; 0,5; dan 0,7 unit/g COD) dan variasi laju pembebanan dengan mengatur waktu tinggal 4, 8, 12, dan 24 jam. Hasil percobaan menunjukkan bahwa perlakuan lumpur aktif dengan penambahan selulase dapat menghasilkan peningkatan reduksi COD dan BOD bila dibandingkan perlakuan tanpa menggunakan selulase. Peningkatan reduksi COD tertinggi mencapai 7,9% dengan perlakuan selulase dosis 0,2 unit/g COD dan waktu tinggal 4 jam, sedangkan peningkatan reduksi BOD tertinggi mencapai 14,6%. Perlakuan selulase dapat dikombinasikan dengan proses lumpur aktif yang berjalan efektif pada waktu tinggal yang lebih singkat atau pada beban tinggi.Kata kunci: selulase, lumpur aktif, chemical oxygen demand, biological oxygen demand
Adding Growth-Promoting Ingredients in Activated Sludge Process as a Troubleshooting Strategy for Pulp and Paper Mill Wastewater Treatment
