| With the continuous improvement of economy and urbanization,the output of kitchen waste is increasing year by year.If it can not be effectively treated,it will cause waste of resources and secondary pollution of the environment.Anaerobic fermentation technology can not only treat waste,but also generate clean energy to realize resource utilization,which has become the main way of kitchen waste treatment.However,the food waste has the characteristics of high salt and high organic matter,which can easily affect the gas production performance of fermentation system.Existing studies have shown that excessive salt can produce inhibition to eat hutch waste anaerobic fermentation,high organic load will cause the accumulation of organic acids also can produce inhibition of fermentation process,when both exist at the same time,the inhibition of anaerobic fermentation process whether there is a synergy or antagonist role is unclear,in addition,how to effectively alleviate the effect also seldom reported.Based on this,this article through to produce gas system performance and system stability analysis explores the salts and organic load combination of eat hutch garbage anaerobic fermentation to produce the influence of the gas,and put forward the use of eat hutch garbage and sludge fermentation method to relieve the salts and organic load combination effect on methane production,based on this,Spline interpolation prediction model was used to predict methane production and methane production curve.（1）In the anaerobic fermentation experiment of food waste,the inhibition of methane production increased gradually with the increase of salt and organic load,and the cumulative methane production was the lowest at the high organic load and salt concentration(OLR=10g VS·L-1,Na+=15 g·L-1),and the gas production stagnated for 8-9 days.There was a very high risk of acidification collapse(p H=5.78,VFA=7355.5 mg·L-1).Anova showed that salt and organic load had a combined effect,and the increase of organic load could significantly enhance the inhibition of salt（p<0.05）.The optimal organic load was determined to be 3g VS·L-1 when the salt concentration was 2 and 10 g·L-1.The optimal organic load ranges from3 to g VS·L-1 at salt concentrations of 5 and 15 g·L-1.（2）In the experiment of co-fermentation of food waste and excess sludge,the methane production can be promoted by appropriate salt content.The cumulative methane production reaches the highest at(OLR=3 g VS·L-1,Na+=5 g·L-1),and the methane production is inhibited with the further increase of salt concentration and organic load.The final p H value at high organic loading and salt concentration(OLR=10 g VS·L-1,Na+=15 g·L-1)was.57,without the risk of fermentation system collapse.The variance analysis of the experimental data showed that salt and organic load also had a joint effect on the co-fermentation results,and the increase of organic load significantly enhanced the inhibition of salt（p<0.05）.The optimal organic load was determined to be 3 g VS·L-1 when the salt concentration was 2～10 g·L-1.When the salt concentration is 15 g·L-1,the optimal organic load range is from 3 to 8 g VS·L-1.Compared with anaerobic fermentation of food waste,co-fermentation of food waste and residual sludge can not only improve methane production,but also improve the buffering capacity of fermentation system.（3）The Spline interpolation model was used to predict the co-fermentation gas production.The results show that the model can not only predict the methane production,but also predict the dynamic process of methane production effectively.In the case of missing data,the model can still perform better prediction and obtain more comprehensive gas production information.The cumulative methane production is the highest at(OLR=3 g VS·L-1,Na+=3g·L-1),which is 597.0 m L·g-1VS.The model can accurately predict the cumulative methane production for 21 days,and the prediction error range is basically between 0.01 and 5.08%,which is much lower than the quadratic regression model（5.85 to 13.33%）.Meanwhile,the model can accurately predict the dynamic methane production change（R2>0.9805）except for the region with large gas production fluctuation.The results showed that salt inhibited the activity of enzymes during methanation,resulting in accumulation of organic acids and decrease of p H.However,the organic load increased the yield of organic acids,and the further decrease of p H,the organic load significantly enhanced the inhibition of salt.Compared with anaerobic fermentation of food waste,co-fermentation of food waste and residual sludge can not only increase methane production,but also avoid the risk of system acidification collapse.Spline interpolation model can accurately predict the methane production rate and dynamic change process of the co-fermentation of food waste and excess sludge.The results of this study can provide theoretical reference for the engineering application of food waste and excess sludge treatment. |
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