Accumulation And Gas Production Effect Of Salinity And Ammonia On Dry Anaerobic Digestion Of Food Waste

Managing food waste by dry mesophilic anaerobic digestion technology, has the advantage of high utilization of the reactor volume and low output of digestive. However due to food waste with high protein, salinity, organic matter, relative to the wet anaerobic digestion, in a dry anaerobic digestion system are more prone to the accumulation of ammonia nitrogen and salt, and influence on the performance of the system of gas, in turn, influence on the performance of the system of gas, in order to study the ammonia and salt accumulation in dry anaerobic digestion system of process and after the cumulative effect on the properties of gas,This research through laboratory scale reactor, on meals kitchen garbage for the dry mesophilic anaerobic digestion, to half continuous type of into material way makes whole test process in the organic load has been stable in 3 kgVS·m-3·d-1, through monitoring system of Nissan gas, and methane produced rate, and pH, and VFA, and TA, and ammonia nitrogen, and salt, and volume produced gas rate and VS removal rate, analysis of salt and ammonia nitrogen in anaerobic digestion system of accumulation process and its effect on the properties of gas analysis, in order to dry mesophilic anaerobic digestion of food wastes operation and optimization of the underlying data.① Salinity on 0-80 days rapid accumulation from 1.36 g·L-1 to 6.04 g·L-1, on 80-150 days accumulated slowly to the maximum of 6.56 g·L-1, the salt accumulation model for material balance is Y=CV1/V2-((CV1/V2)-C0)×e(V2/Vt) is also accumulated in the early reaction speed, slow build-up in the late.② Ammonia nitrogen (TAN) until to 60 days increased rapidly from 1737 mg·L-1 to 3209 mg·L-1; on 60-130 days TAN slowly accumulating to the maximum 3516 mg·L-1. The ammonia nitrogen accumulation model for material balance is Y=CV1/V2-((CV1/V2)-C0)×(V2/V1)t,presents the early accumulation rate, cumulative rate is slow and late to accumulate gradually saturated.③ On the whole test process, the removal rate of organic from 88.32% to 86.02%, declined not obviously; the methane produced rate from 0.54 LCH4·gVS-1 of system stable to 0.16 LCH4·gVS-1 of the off-test, declined 70%; on 163 day,VFA exceeded the 3000 mg·L-1,on 181 day VFA/TA is greater than the warning value of 0.35, the methane yield decreased 44% at this time. In 184-206 days production rate of gas production and methane in 55.04 L·d-1 and 0.25 LCH4·gVS-1 level fluctuations, the system in the stage of steady-state inhibition; on 206 day, biogas and methane yields are declining. Experiment is analyzed,99,221,38 days of 24 hours of gas production, the early stage of the gas rate are getting slower and slower, and gas production is more and more close to an hour.Is obtained by analysis, the accumulation of salt and ammonia nitrogen gas performance has the inhibition effect on the system.