Anaerobic Co-Digestion Of Kitchen Waste And Pig Manure Matrix

With the improvement of living standards and the expansion of the aquaculture industry, kitchen waste and animal manure pollution on the environment problem is becoming more and more serious. Meanwhile, with the development of biomass energy and the technology promotion, it has become a consensus that the waste of organic matter’s minimization, harmlessness and resources is an effective way to solve such problems. Using anaerobic fermentation processing kitchen waste and animal manure, which can convert such organic pollutants to harmless, can also obtain biogas biomass energy.In this experiment, the kitchen waste and pig manure were used as raw materials. Comparison test was divided into two groups R1and R2.The R1feed into a single kitchen waste, the R2feed for the kitchen waste and pig manure combination by VS1:1. Through monitoring and analysis of anaerobic digestion system in gas production, methane rate, VS, VFA ammonia, alkalinity and other parameters under different organic loading conditions, the feasibility of the process were demonstrated. And the optimization of process parameters was got. Conclusions of the study were as follows:1. Both reactors’gas production steadily increased with the organic load increase. The higher organic load, the greater difference on gas production between R1and R2. When R1in the low load range, the daily gas production increased marginally. When the load increased to2.0gVS/(L· d), the daily gas production increased significantly. The joint matrix R2gradually increase the organic loading, the increase in gas production is stable.2. In the same organic loading, kitchen waste matrix R1was higher than the mixed matrix R2on methane emissions. R1was greater than R2on methane production capacity. Pig manure methane-producing potential was lower, but R2was more stable than R1on methane content. The appropriate amount of pig manure, which added to the kitchen waste matrix, can make anaerobic digestion methane output more stable.3. The average VFA of the joint matrix R2was32mg/L. while the average VFA of kitchen waste matrix R1was157.8mg/L. VFA value of R2was nearly two times than R1. Analysis of variance shows that VFA concentration of the R1was more stable than R2. This means that the VFA concentration would become relatively more volatile when the kitchen waste matrix was digested with pig manure.4. The alkalinity of R2was significantly more stable. And it would be smaller changes in amplitude, which is conducive to the stable operation of anaerobic digestion. The alkalinity of R1system was the lowest when it was startup, after that the alkalinity rapid increase and maintained at14000mg/L-15000mg/L.5. R1ammonia level was relatively stable, there was no increase or decrease trend, while linear fitting of the R2ammonia data show that the fitting was good. The ammonia level of R2was gradually increased. Especially in the range of high organic load. R2’s ammonia concentrations were significantly higher than R1’s ammonia concentration. So, if the proportion of pig manure was too high, especially at high organic loading and long-running conditions, it would be easy to ammonia accumulation.