Biokoagulan Cangkang Keong (Pila ampullacea) Sebagai Upaya untuk Peningkatan Kualitas Pengolahan Air Limbah Pabrik Tahu

Abstract

Pabrik tahu menghasilkan limbah cair dengan kandungan organik tinggi berupa protein, lemak, dan serat yang dapat mencemari lingkungan bila tidak diolah. Salah satu metode pengolahan adalah koagulasi-flokulasi, namun koagulan kimia berisiko menimbulkan dampak negatif. Penelitian ini bertujuan memanfaatkan cangkang keong sawah (Pila ampullacea) sebagai koagulan alami serta menguji kinerja alat prototipe kombinasi koagulasi-filtrasi. Prosedur meliputi pembuatan serbuk dan larutan koagulan, uji jar test dengan variasi dosis 20–60 ml dan kecepatan 100–150 rpm, serta penerapan pada prototipe sederhana. Hasil menunjukkan dosis 20 ml pada 150 rpm menurunkan TSS 67,53%, kekeruhan 58,44%, serta menaikkan pH ke kisaran 6–9. Penurunan COD hanya 14,52% sehingga belum memenuhi baku mutu. Sistem koagulasi-filtrasi lebih efektif dibandingkan koagulasi tunggal. Oleh karena itu, cangkang keong sawah berpotensi menjadi alternatif koagulan ramah lingkungan untuk pengolahan limbah cair tahu skala kecil

Tofu factories generate wastewater with high organic content, such as proteins, fats, and fibers, which can pollute the environment if discharged without treatment. One commonly applied method is coagulation-flocculation; however, chemical coagulants may pose negative impacts. This study aims to utilize rice field snail shells (Pila ampullacea) as a natural coagulant and to evaluate the performance of a coagulation–filtration prototype. The procedure included preparing shell powder and coagulant solution, conducting jar tests with 20–60 ml dosage variations and mixing speeds of 100–150 rpm, and applying them to a simple prototype. The results showed that a dosage of 20 ml at 150 rpm reduced TSS by 67.53%, turbidity by 58.44%, and increased pH to the standard range of 6– 9. COD removal reached only 14.52%, which did not meet the quality standard. The coagulation–filtration system was more effective than coagulation alone. Therefore, rice field snail shells have the potential to be eco-friendly coagulants and can be applied to small-scale tofu wastewater treatment.