Desain Teknik Proses Co-composting Sludge, Abu Ketel dan Dregs PT Tanjungenim Lestari Pulp and Paper dengan Metode Windrow Composting

Abstract

PT Tanjungenim Lestari Pulp and Paper menghasilkan limbah padat dalam jumlah besar diantaranya sludge 30 ton/hari, abu ketel 33,7 ton/hari dan dregs 3 ton/hari. Limbah ditangani dengan ditimbun langsung di sanitary landfill, diperlukan pemanfaatan lain agar bisa meminimalisir dampak limbah terhadap lingkungan dan menciptakan produk bernilai tambah. Limbah mengandung bahan organik yang dapat digunakan sebagai bahan baku co-composting. Co-composting merupakan metode pamanfaatan limbah dengan mencampurkan dua bahan atau lebih dengan bantuan mikroorganisme untuk mendekomposisi bahan. Penelitian dilakukan untuk mengetahui karakteristik limbah padat, merancang desain proses co-composting sludge, abu ketel dan dregs serta menganalisis mutu produk kompos sesuai dengan SNI-7847-2012. Co-composting dilakukan dengan menggunakan komposter berdimensi (100×80×70) cm untuk panjang, lebar dan tingginya. Berdasarkan nilai rasio C/N bahan didapatkan formulasi komposisi bahan untuk pengomposan adalah 2:1:1 dengan nilai rasio C/N awal yang ditetapkan 30. Co-composting dilakukan selama 32 hari dengan pemberian aerasi setiap 3 hari sekali. Produk kompos yang dihasilkan memiliki nilai rasio C/N sebesar 19,58. Nilai pH yang dihasilkan pada produk kompos adalah sebesar 5,75 dengan kadar air akhir 41,88%. Rendemen yang dihasilkan sebesar 75,1% dengan penyusutan 24,9%. Kompos yang dihasilkan memiliki warna kehitaman khas dregs dengan bau khas dregs pula. Kompos tidak mengandung bakteri pathogen Coliform fecal dan Salmonella sp.

PT Tanjungenim Lestari Pulp and Paper produces a large amount of solid waste including sludge 30 tons/day, boiler ash 33.7 tons/day and dregs 3 tons/day. Waste is handled by being dumped directly in sanitary landfills, other utilization is needed in order to minimize the impact of waste on the environment and create value-added products. Waste contains organic matter that can be used as raw material for co-composting. Co-composting is a method of utilizing waste by mixing two or more materials using the help of microorganisms to decompose the material. The research was conducted to determine the characteristics of solid waste produced, design the process of co-composting sludge, boiler ash and dregs and analyze the quality of compost products in accordance with SNI-7847-2012. Co-composting was carried out using a composter with dimensions of 100 cm for length, 80 cm for width and 70 cm for height. Based on the C/N ratio value of the material, the material composition formulation for composting was 2:1:1 with the initial C/N ratio value set at 30. Co-composting was carried out for 32 days with aeration every 3 days. The resulting compost product has a C/N ratio value of 19.58. The pH value produced in the compost product was 5.75 with a final moisture content of 41.88%. The resulting yield was 75.1% with 24.9% shrinkage. The compost produced has a blackish color typical of dregs with a distinctive smell of dregs as well. The compost does not contain pathogenic bacteria Coliform fecal and Salmonella sp.