Effect And Evaluation Of Biochemical And Biological Collaborative Remediation To Polluted Sediment

In recent years,the in situ remediation technology has gradually become hot research topic in the sediment remediation field,with the advantages of less investing and smaller destruction to environment.But single remediation technology has its limitations,collaborative remediation can fully together and play out the advantages of various technique,thus collaborative remediation is important way of sediment management.In this research,we isolated efficient heterotrophic nitrification and aerobic denitrification bacteria,and research the in situ chemical-biological and ecological remediation of sediment.The research mainly aimed at the isolation and performance of the heterotrophic nitrification and aerobic denitrification bacteria.And through applying the bacteria to sediment remediation with bio-energizer,chemicals and plants,discussed the effect and evaluation of in situ chemical-biological and ecological remediation of sediment.In this study,4 strains of effective heterotrophic nitrification and aerobic denitrification bacteria was isolated.And 1 strain of bacteria was chosen to study its colony morphology,gram's test,utilization of carbon source and nitrogen source,and its nitrification and denitrification function.It turned out that the bacteria had greater demand of carbon source,in the case of at 30?,C/N=10,the concentration of initial ammonia was 50 mg/L,the nitrification performance of the bacteria was the best,the removal rate of TN was 70.67%;in the case of at 30?,C/N=10,the concentration of initial nitrate nitrogen was 100 mg/L,the denitrification performance of the bacteria was the best,the removal rate of TN was 74.52%.The bacteria had better nitrification and denitrification function when the environment was weak alkaline,it had a relatively wide range of pH tolerance range.In the biochemical and biological collaborative remediation,the concentration of microbial agents was 108cfu/mL,and its dosage was 50mL;the dosage of bio-energizer and calcium nitrate were set as 0.06‰,0.08‰,0.10‰ and 50,70,100gNO3--N/m2 respectively;the total number of plants was 5.It turned out that,the system of the collaborative remediation of microbial agents and bio-energizer had the most significant influence on urease activity of sediment,when the dosage of bio-energizer was 0.10‰,urease activity increment was up to 9.33mg/(kg·h),the t removal rate of TOC was best,it was 6.02%,and the system had best remediation effect of sediment.In the collaborative remediation of microbial agents and calcium nitrate,the system had the most significant influence on the removal rate of TOC and TN;the best removal rate of TN was 23.33%,when the dosega of calcium nitrate was 50gNO3--N/m2;when the dosega of calcium nitrate was 100gNO3--N/m2,the removal effect of TOC was best,the removal rate of TOC was up to 25.49%,sediment organic index rose was range from ? degree to ? degree,this system had the best remediation effect of organic pollution in sediment.In the collaborative remediation of microbial agents and scirpus tabernaemontani,the removal rate of TN was up to 22.70%;and the increment of urease activity was up to 4.86mg/(kg·h)in the collaborative remediation of microbial agents and reed.