Pilot-Scale Anaerobic Co-Digestion of Wastewater Sludge with Lignocellulosic Waste: A Study of Performance and Limits

The effects of co-digesting sewage sludge (SS) and horse waste (HW), the composition HW, ratio HW:SS were studied using two semi-continuous digesters 9.5 L working volume. These operated in parallel with mono-digestion SS digester 1 (D1) co-digestion HW 2 (D2). In 2, there phases digestion (durations 40 43 weeks, respectively). first phase was 85% wheat straw (WS), 14% wood chips (WC), 1% manure (HM), 99% (WS) (HM) second phase. Variable ratios digesters. (HW) produced more biogas than alone, a maximum 15.8 L·d−1, compared to 9 L·d−1 at end experiment. When comparing results obtained both phases, production methane 18 NmL·gVS−1 higher 1. This slight increase yield could be linked absence which is considered have diluting effect on production. Therefore, this study shows that an organic loading rate (OLR) 4.8 kgVS·m−3·d−1, 3, (99% WS, HM) should respected actual experimental conditions for well-functioning anaerobic digestion.