Effect of minerals on anaerobic digestion of food waste

s: The effects of three different kinds of inorganic minerals additives (bentonite, clinoptilolite, coal ash fly) on anaerobic digestion of sodium-riched food waste were explored. The results showed that kept at mesophilic temperature (35℃), 10% total solid content, and 1% additives(w/w substrate), the three minerals had good adsorption characters to sodium ion in sodium-riched food waste digestion substrate, and the adsorption efficiency to the sodium were 13.75%, 10.11% and 7.99%, respectively, which namely the bentonite's adsorption to sodium was the highest. The sodium-riched food waste digestion was drastically inhibited by sodium ion at the level of 3000~4000mg·L -1 with no minerals additives. As for the gas production, each sort of the three inorganic minerals significantly enhanced the anaerobic digestion of sodium-riched food waste. Compared with the blank control, the total gas production enhanced 131%, 82% and 45% respectively, and the sequence of improvement efficiency is : bentonite clinoptilolitecoal ash fly.The mechanism about the facilitating the anaerobic digestion with the addition of inorganic minerals was also briefly discussed.