| The high inorganic components and low carbon and nitrogen ratio in the influent of wastewater have become one of the most difficult problems in the field of sewage treatment.It is the only way which must be passed for the future development of sewage plant,to strengthen the primary treatment and use the biodegradable organic matter in sewage converting to high quality carbon source is necessary.However,the current relevant research is relatively scarce,requiring in-depth research on the basis of combining theory with practice.Therefore,in this study,the advanced primary treatment technology of sewage based on membrane grid and the internal carbon source recycling technology of residues which can be transformed to the carbon source by anaerobic fermentation was investigated.This study investigated the interception efficiency and relevant characteristics of the membrane grids residues under different pore size,exploring the most suitable ratio and p H of membrane grids residues and waste activated sluge fermentation,strengthening the fermentation efficiency of the mixed sludge by adding different additives.Firstly,the interception efficiency of SS of 0.5、0.75 and 1.0mm and the removal rate of COD、nitrogen and phosphorus were analyzed.The results showed that the 0.5mm membrane grille had the best interception efficiency on SS,and ensures the better retention of SCOD and other nutrients in sewage on the basis of maintaining the high removal rate of granular COD and TN and TP.The analysis of the characteristics of membrane grid residues were similar to that of the primary sedimentation tank,but it had rich carbon sources due to its shorter residence time,which can produce soluble COD and volatile fatty acids(VFAs)by hydrolysis and fermentation technology,which can be used as the high-quality denitrification carbon source in the sewage nitrogen removal process.Secondly,the hydrolysis and acid production under different ratios and different alkaline conditions were explored.The results show that the efficiency of hydrolysis and acid production reached the highest in the ratio of 2:1.Besides,the addition of waste activated sludge makes up for the defects of single raw material and lacking of hydrolysis and acid bacteria,so that the efficiency of membrane grid residues was greatly improved,.Also,the sludge reduction also achieved a better effect.In addition,under alkaline conditions,the efficiency of dissolved organic matter in sludge was higher,producing more substrates used for acid production bacteria.In the meantime,the efficiency of acid production is also greatly improved.Under this condition,the sludge reduction effect is better,but the high p H had a toxic effect on hydrolysis and acid production bacteria,which reduced the efficiency of hydrolysis and acid production.Finally,the anaerobic fermentation process of β-cyclodextrin and magnetite was studied.The results showed that both β-CD and magnetite can effectively promote the sludge hydrolysis and acid production process.Under the additive amount of 0.3g / g VSS,β-CD has the highest efficiency of sludge hydrolysis,while magnetite has the best hydrolysis of 0.15 g /g VSS.In addition,the microbial community structure analysis showed that the addition of β-CD reduced the number of species in the fermentation system but enriched the bacteria related to hydrolysis;the addition of magnetite not only increased the number of species in the fermentation system but also increased the abundance of key bacteria in hydrolysis.In conclusion,it is feasible to use membrane grid interception technology as a reinforced sewage treatment technology,and its interception couples residual sludge to produce SCOD and VFAs through hydrolysis and fermentation technology.The first stage treatment technology based on membrane grid and the internal carbon source reuse technology of interception fermentation can provide effective help for the development of internal carbon source in sewage plant and achieve carbon neutrality for sewage treatment. |
PDF Full Text Request