Produksi Biogas dari Lindi melalui Penambahan EM4 dan Ulva lactuca dalam Sistem Degradasi Anaerobik

Abstract

Pengembangan energi terbarukan diperlukan untuk mengurangi ketergantungan pada bahan bakar fosil sekaligus mendukung pengelolaan limbah organik secara berkelanjutan. Lindi memiliki potensi sebagai substrat biogas karena kandungan bahan organik biodegradable yang tinggi. Penelitian ini bertujuan untuk mengoptimalkan produksi biogas melalui proses degradasi anaerobik lindi dengan penambahan EM4 dan Ulva lactuca serta mengevaluasi pengaruh variasi komposisi substrat terhadap konsentrasi metana dan karakteristik proses. Penelitian dilakukan menggunakan tiga perlakuan, yaitu lindi, EM4, dan Ulva lactuca (100:0:0, 90:10:0, 80:10:10) dengan dua ulangan pada kondisi mesofilik selama 30 hari. Parameter yang diamati meliputi volume biogas, konsentrasi metana, pH, total dissolved solids (TDS), dan electrical conductivity (EC). Hasil menunjukkan bahwa perlakuan optimum diperoleh pada rasio 80:10:10 dengan volume biogas tertinggi 7655 mL dan volume metana 3909 mL. Substrat tunggal lindi menghasilkan kinerja terendah dengan volume biogas 4185 mL dan volume metana 965 mL akibat adanya inhibisi senyawa kompleks seperti amonia dan volatile fatty acids. Penambahan EM4 meningkatkan kinerja proses degradasi, namun sinergi dengan Ulva lactuca lebih efektif dalam meningkatkan produksi metana. Perubahan pH, TDS, dan EC merefleksikan dinamika degradasi anaerobik dan dapat digunakan sebagai indikator proses.

The development of renewable energy is essential for reducing dependence on fossil fuels while supporting sustainable organic waste management. Leachate has a strong potential as a biogas substrate because of its high biodegradable organic content. This study aimed to optimize biogas production through anaerobic co-digestion of leachate with EM4 and Ulva lactuca and evaluate the effect of substrate composition on methane concentration and process characteristics. The experiment was conducted using three treatments, namely leachate, EM4, and Ulva lactuca (100:0:0, 90:10:0, and 80:10:10) with two replicates under mesophilic conditions for 30 d. The parameters observed included biogas volume, methane volume, pH, total dissolved solids (TDS), and electrical conductivity (EC). The results showed that the optimum condition was achieved at a ratio of 80:10:10, producing the highest biogas volume (7655 mL) and methane volume (3909 mL). The single substrate leachate exhibited the lowest performance, with 4185 mL of biogas and 965 mL of methane, likely due to the inhibitory effects of complex compounds such as ammonia and volatile fatty acids. The addition of EM4 improved the digestion performance. However, its synergy with Ulva lactuca was more effective in enhancing methane production. Changes in pH, TDS, and EC reflect anaerobic degradation dynamics and can serve as indirect indicators of the process.