Evaluasi Pengolahan Limbah Cair Tekstil Dalam Suspended dan Attached Growth Dengan Variasi Intermittent Aeration

Alzena Mille Dhita Dewanti, Lisendra Marbelia, S.T., M.Sc., Ph.D ; Dr. Joko Wintoko, S.T., M.Sc.

2025 | Tesis | S2 Teknik Kimia

Industri tekstil merupakan salah satu sektor utama penyumbang pencemaran lingkungan secara global. Proses pewarnaan tekstil menghasilkan limbah cair yang mengandung zat warna sintetis seperti azo dyes, logam berat, serta senyawa organik berbahaya yang sulit terdegradasi. Zat warna ini menurunkan kualitas perairan, bersifat toksik, bahkan dapat menghasilkan senyawa karsinogenik selama proses degradasi mikroba. Oleh karena itu, pengolahan limbah cair tekstil menjadi isu penting dalam menjaga keseimbangan ekosistem akuatik.

Pendekatan biologis semakin diminati dalam pengolahan limbah tekstil karena lebih ramah lingkungan dan ekonomis. Dua sistem utama yang digunakan adalah activated sludge process (ASP) dan integrated fixed-film activated sludge (IFAS). ASP berbasis suspended growth namun terbatas dalam degradasi bahan organik. Sebaliknya, IFAS menggabungkan pertumbuhan mikroba secara suspended dan attached, memberikan keunggulan dalam stabilitas dan efisiensi degradasi organik. Untuk meningkatkan efisiensi dan menekan konsumsi energi, diterapkan strategi intermittent aeration, yaitu pengaturan siklus aerasi hidup-mati.

Penelitian ini dilakukan secara batch dengan tiga tujuan yaitu mengetahui pengaruh sistem ASP dan IFAS, pengaruh variasi aerasi, dan pengaruh perpanjangan durasi siklus terhadap pertumbuhan mikroba, penurunan COD dan kadar warna pada limbah tekstil. Jenis reaktor berpengaruh terhadap pertumbuhan mikroba dan penurunan kadar COD. Pada IFAS, nilai µmax dan Ks yang lebih baik yaitu 0,068 1/h dan 1400 mg/L. COD removal dan sCOD removal tertinggi terdapat pada IFAS yaitu sebesar 76?n 90%.  Yield substrat per oksigen tertinggi terdapat pada IFAS sebesar 1,6 mg COD/mg O?. Variasi aerasi secara signifikan mempengaruhi efisiensi penurunan kadar warna dan COD karena laju aerasi yang optimal dapat meningkatkan aktivitas mikroorganisme dan efektivitas proses degradasi. COD removal dan sCOD removal tertinggi terdapat pada aerasi on 45/off 45 yaitu sebesar 94?n 90%. Yield substrat per oksigen tertinggi terdapat pada aerasi on 45/off 45 yaitu 2,2 mg COD/mg O?. Degradasi warna yang terbaik terdapat pada reaktor anaerobik yaitu sebesar 84%. Sehingga variabel yang paling optimum adalah aerasi on 45/off 45. Perpanjangan waktu siklus intermittent aeration dalam pengolahan batch limbah tekstil secara signifikan meningkatkan sefisiensi penurunan warna dan sCOD, karena waktu reaksi yang lebih lama dapat meningkatkan degradasi senyawa organik yang lebih lengkap. Penghilangan sCOD tertinggi terdapat pada aerasi 1 jam off/3 jam on yaitu sebesar 96?lam 144 jam. Penghilangan warna tercepat terdapat pada aerasi 3 jam off/1 jam on yaitu sebesar 97?lam 72 jam. Yield Substrat/oksigen paling besar terdapat pada aerasi 2 jam off/ 2 jam on yaitu sebesar 4,11 mg COD/mg O?. Namun intermittent aeration yang dilakukan baik pada siklus pendek maupun siklus panjang masih belum bisa menggambarkan kondisi anaerobik (stabil di +100 s.d +200mV). Sehingga siklus panjang terbukti memberikan hasil yang lebih baik dalam degradasi warna dan sCOD. Dengan variabel yang optimum adalah aerasi 3 jam off/1 jam on.

The textile industry is a major contributor to global environmental pollution. The textile dyeing process produces liquid waste containing synthetic dyes such as azo dyes, heavy metals, and hazardous organic compounds that are difficult to degrade. These dyes degrade water quality, are toxic, and can even produce carcinogenic compounds during microbial degradation. Therefore, textile wastewater treatment is a crucial issue in maintaining the balance of aquatic ecosystems.

Biological approaches are gaining popularity in textile wastewater treatment due to their environmentally friendly and economical advantages. Two main systems used are the activated sludge process (ASP) and the integrated fixed-film activated sludge (IFAS). ASP is based on suspended growth but is limited in its ability to degrade organic matter. In contrast, IFAS combines suspended and attached microbial growth, offering advantages in stability and efficiency of organic degradation. To increase efficiency and reduce energy consumption, an intermittent aeration strategy was implemented, which involves regulating the aeration cycle on and off.

This batch study was conducted with three objectives: to determine the effect of the ASP and IFAS systems, the effect of varying aeration, and the effect of extending the cycle duration on microbial growth, COD reduction, and color content in textile wastewater. The type of reactor affects microbial growth and COD reduction. In IFAS, the best µmax and Ks values are 0.068 l/h and 1400 mg/L. The highest COD and sCOD removal rates are found in IFAS at 76% and 90%, respectively. The highest substrate yield per oxygen is found in IFAS at 1.6 mg COD/mg O?.. Aeration variations significantly affect the efficiency of color and COD reduction because optimal aeration rates can increase microbial activity and the effectiveness of the degradation process. The highest COD and sCOD removal rates are found in on 45°C/off 45°C aeration at 94% and 90%, respectively. The highest substrate yield per oxygen is found in on 45°C/off 45°C aeration at 2.2 mg COD/mg O?. The best color degradation is found in the anaerobic reactor at 84%. So the most optimum variable is aeration on 45/off 45. The extension of the intermittent aeration cycle time in the processing of textile waste batch significantly increases the efficiency of color reduction and sCOD, because longer reaction times can increase the degradation of organic compounds more completely. The highest sCOD removal is found in aeration 1 hour off / 3 hours on, which is 96% in 144 hours. The fastest color removal is found in aeration 3 hours off / 1 hour on, which is 97% in 72 hours. The highest substrate/oxygen yield is found in aeration 2 hours off / 2 hours on, which is 4.11 mg COD / mg O?. However, intermittent aeration carried out in both short and long cycles still cannot describe anaerobic conditions (stable at +100 to +200 mV). So the long cycle is proven to provide better results in color degradation and sCOD. With the optimum variable being aeration 3 hours off / 1 hour on.

Kata Kunci : Aerasi; Pewarna Azo; Bioreaktor; sCOD; Limbah Tekstil