Purification Of Rural Water Through Coupling The Microorganisms With Eco-bags

Currently,the situation of rural water environment in our country is not optimistic and the river revetment is mostly in rigid and hardened bank structure,which causes serious harm to the shore water ecological environment.This article was based on the view of restoration for rural polluted water,inherited advantages of eco-bags' revetment technology and learned from microbial water remediation technology.New revetment style which endowed multi-functional of coupling water purification and slope protection was researched,and regarded as optimal revetment suitable for rural water environment.In the laboratory,different auxiliary matrices and the optimum ratio of matrix in the eco-bags were examined,and the static water purification effects of these eco-bags were investigated simultaneously.The denitrifier was used in immobilization technology of the microbial active pellet,diverse cultivation times of bacteria were applied to water purification,the result of different experimental groups was compared.Three different eco-bags systems,that are plant system,bacteria carrier system and symbiosis of bacteria carrier and plant system,were constructed and compared at the same hydraulic condition.Community structure distribution and biodiversity of microbes in eco-bags sample was analyzed through high-throughput sequencing technique.In the construction of demonstration project,the advantages and disadvantages of new eco-bags revetment technology were obtained.(1)The results of static water purification experiment indicated that both the zeolite matrix and the biofiller matrix achieved good removal efficiencies.The water quality indexes of the two groups were better than those of the control group.The zeolite matrix group achieved the highest degration rate of ammonia nitrogen with the removal efficiency of 12.6%higher than that of control group.The biofiller group showed better performance in total phosphorus removal,and the removal rate of total phosphorus was 7.3%higher than that of control group.(2)The results indicated that higher purity of denitrifying bacteria was beneficial for the removal of ammonia nitrogen and total nitrogen with the removal rates increased by 10.5?25.5%and 13.1-20.5%,respectively.The growth of plant was also found helpful for the multiplication of denitrifier in eco-bags.(3)Comparing different systems of eco-bags,the removal rate of ammonia nitrogen in symbiosis of bacteria carrier and plant system was 9.6%higher than that of corresponding bacteria carrier system in the stable operation period of the system,it was supposed that plants could absorb ammonia nitrogen and nitrate nitrogen in water,and assimilate them into own composition.The removal of total phosphorus achieved a good effect with the efficiency of 75.3%,it indicated that eco-bag had a better effect on the degradation of total phosphorus.(4)The microbial community structure of four eco-bags samples(2#denitrifier-zeolite-plant group,5#denitrifier-straw group,6#denitrifier-straw-plant group,10#the control group)was analysed by high-throughput sequencing technology,and the results showed that the abundance of chloroflexi bacteria in four samples reached 6.63%,7.07%,4.96%and 8.71%,respectively.The abundance order of chloroflexi bacteria was 10#>5#>2#>6#,and the concentration order of permanganate index was 10#>5#>6#>2#.Sources suggested that the higher growth abundance of Chloroflexi bacteria means the higher total organic matter content in samples.The abundance order of Pseudomonas bacteria was 6#>2#>5#>10#,and the order of TN in four samples was same to the abundance order of Pseudomonas,the result indicated that the higher abundance of Pseudomonas,the higher removal rate of TN by the coupling microorganism type of eco-bags.(5)The average concentrations of CODMn,NH3-N,TN,TP and SS in demonstration site were 16mg/L,0.27mg/L,1.26mg/L,0.03mg/L and 18mg/L,while these water quality indexes before construction were 42mg/L,0.26mg/L,4.13mg/L,0.34mg/L and 132mg/L.The water quality of demonstration site was effectively improved.Therefore,coupling the microorganisms with eco-bags revetment could be used for demonstration project with a better engineering effect.