Coagulation and Filtration Methods on Tofu Wastewater Treatment

Abstract

The tofu industry is a small industry (home industry) that produces wastewater between 100-200 times the allowable limit and is usually discharged directly into water bodies, thus polluting the environment. This study aims to combine the coagulation method (stage 1) using Polyalumunium Chloride (PAC) with filtration (stage 2) on several variations of materials (quartz, activated carbon, and zeolite). The study was conducted with six replications. The comparison of waste quality (BOD, COD) was observed at each stage of the study. The SAS 9.4 was used for data analysis, including the application of the T-test and ANOVA. The study found that coagulation with PAC 690 mg/L reduced BOD by 51.7% and a dose of 765 mg/L by 61.1%. In the COD parameter, the reductions were 65.84% and 67.55%. In the second stage (filtration), the reduction in BOD was higher in activated carbon (79.33%) compared to zeolite (78.67%) and quartz (75.46%).\xa0 Activated carbon also had the most COD reduction effect (73.22%) . Although the statistical results showed significant differences in all doses and media, the use of 765 mg / L PAC and activated carbon filtration had the most effect on reducing BOD and COD of tofu industrial wastewater. This research can be used as an alternative in the physical processing of tofu industrial wastewater. Abstrak: Industri tahu dan tempe merupakan industri kecil (home industry) yang menghasilkan limbah \xa0antara 100-200 kali batas yang diijinkan dan biasanya langsung dibuang ke badan air, sehingga mencemari lingkungan. Penelitian bertujuan menggunakan metode koagulasi (tahap 1) dengan Polyalumunium Chloride (PAC), dan metode filtrasi (tahap 2) dengan tiga variasi bahan (kuarsa, karbon aktif, dan zeolit). Penelitian dilakukan dengan enam replikasi. Perbandingan kualitas limbah (BOD, COD) diamati pada setiap tahap penelitian. Perangkat SAS 9.4 digunakan untuk analisis data, termasuk penerapan uji T dan ANOVA. Penelitian mendapatkan, bahwa nilai BOD dan COD limbah segar industri tahu sebesar 1.813 mg/L dan 2.570 mg/L. Pada tahap pertama perlakuan (koagulasi dengan PAC 690 mg/L dan 765 mg/L) terjadi penurunan BOD sebesar 51,7%, dan 61,1%. Pada parameter COD, penurunan sebesar 65,84% dan 67,55%. Pada tahap kedua (filtrasi), penurunan BOD lebih tinggi pada carbon aktif (79,33%) dibandingkan dengan zeolit (78,67%) dan kuarsa (75,46%). Penurunan COD terbesar juga pada karbon aktif (73,22%). Walaupun hasil statistik menunjukkan perbedaan yang nyata pada semua variasi dosis dan media, namun penggunaan PAC dosis 765 mg/L dan filtrasi karbon aktif memberikan efek terbesar terhadap penurunan BOD dan COD limbah cair industri tahu. Hasil penelitian dapat digunakan sebagai alternatif dalam pengolahan fisika limbah cair industri tahu.