The Effect of pH on the Production and Composition of Short- and Medium-Chain Fatty Acids from Food Waste in a Leachate Bed Reactor at Room Temperature

This study evaluated the hydrolysis and acidogenesis of food waste at different operating pHs (uncontrolled, 5.5, 6.5, 7.5, 8.5) in a leachate bed reactor (LBR) room temperature. LBR operation pH 6.5–8.5 resulted yield 718–729 g SCOD/kg VSadded, which was statistically (p ≤ 0.05) higher than that obtained 5.5 (577 VSadded) uncontrolled (462 VSadded). The rate 6.5 highest amongst all values. Stabilization also high fatty acid (FA) 643 CODFA/kg VSadded. Butyrate main FA 5.5–6.5, while acetate 7.5–8.5. At pH, lactate production highest, indicating shift microbial community from fatty-acid-producing bacteria to lactate-producing bacteria. compositions medium-chain acids, such as caproate, were 5.5.