The Study On Microbial Flocculation Treatment And Resource Utilization Of Sweet Potato Starch Wastewater

Based on the agricultural surface source pollution control of the middle and lower reaches of Shayinghe,the integrated technology and comprehensive demonstration project of water quality improvement(subject number 015ZX07204-007),regarded the sweet potato starch wastewater as object,compared with the current research situations,the study of traditional chemical flocculants and microbial flocculants was carried out by the single factor test.Local indigenous strains to develop microbial flocculants were screened,and the feasibility of microbial flocculation to treat the resource utilization of sweet potato starch wastewater was explored from two aspects,which are the extraction of protein used in the production of cultured feed and wastewater recovery.(1)PAC and PAM were selected for flocculation experiment of the sweet potato starch wastewater.At the same time,the flocculation of the sweet potato starch wastewater was experimented by using the biological flocculant-chitosan,which is used as a transverse contrast.According to the analysis of the experimental results,the traditional polymer flocculant PAC has a good effect on the deposition of SS and total phosphorus.While the biological flocculant chitosan maintains a good effect on the deposition of SS and total phosphorus,the effect on the deposition of total nitrogen and COD is also obvious.(2)Six kinds of microorganisms,namely candida tropicalis,myxobacteria,bacillus globose,radioactive rhizobium,saccharomyces cerevisiae and saccharomyces cerevisiae of local yeast from Yingshang county,were selected for the flocculation experiment of sweet potato starch wastewater,so the deposition of COD from the sweet potato starch wastewater can be preliminarily inspected by these kinds of microorganisms.The structural properties of the saccharomyces cerevisiae were analyzed,including the shape of bacterial flora,the composition of bacteria diversity,the identification of OTU division and classification,the comparation of bacteria and the selection of key species.In the end,two strains with good flocculation effect were screened from the saccharomyces cerevisiae,which are Saccharomycopsis fibuligera and Onion Burke GL13.(3)By the orthogonal test method,the flocculation rate,TP and COD were used as the indexes to obtain the match of the better level and combination of microbial flocculant.The pH value is 8,the shake flask culture time is 36 h,and the centrifugal condition is 10000r/min,10 min.The order of three factors is: shake flask culture time >pH> centrifugal condition.The results showed that the removal rate of COD from wastewater was 58.7%,the TP rate was 85.5%,and the flocculation rate was 86.5%,which was better than that under the condition of single factor experiment.The experiment results showed that the flocculation rate of microbial flocculants on wastewater was 85.5%.The flocculation sediment was treated by dehydration and drying,and then the protein content in sediment was 24.1%,which can be prepared into protein feed or protein feed additive,and the flocculation effluent was irrigated into the field as liquid fertilizer.Relying on the beautiful village construction project of Yingshang County,the technology of Microbial Compound Flocculant and Air Flotation,the research of protein and other useful components of the resource utilization from the starch wastewater,the combination process of Hydrolyzed acidizing pool,Anaerobic intensive treatment,and Oxidation pond ecological purification to treat the starch wastewater biologically,the study has been used in the practical projects.