| Background:Water resource is essential for human survival and development.In recent years,a large number of pollutants discharge has caused serious water resource pollution.At present,more and more attention has been paid to the technology of wastewater treatment by biological methods such as algae and bacteria.Objective:In this paper,I studied the static culture condition and removal effect of nutrients in water by culturing a kind of filamentous chlorophyta in laboratory.Furthermore,the actual treatment effect of Rhodophyta on river sewage near a chemical plant in henan province was studied.In view of the poor COD removal effect of Rhodophyta on sewage,a strain capable of digestion and transformation of chemical dye intermediate naphthamine was screened,and its transformation ability and new products were further studied.It lays a theoretical foundation for the treatment and application of algal engineering wastewater and biological treatment with naphthylamine.Methods:(1)Select a kind of Rhizoclonium from long-term culture in the laboratory,static culture of different water bodies in and out of the room through orthogonal experiment,determine the growth conditions of Rhizoclonium and monitor the use of nitrogen,phosphorus,COD and other nutrients in water bodies,to explore the removal effect of Rhizoclonium on water nutrients.(2)Dynamic plate troughs of Rhizoclonium and circulating Rhizoclonium alga bed devices were designed to treat actual river sewage under static and dynamic conditions.Through monitoring water quality changes before and after treatment,the ability of Rhodophyta to treat sewage was further explored.(3)A strain capable of digestion and transformation of chemical intermediate naphthamine to produce red compounds was screened,and the transformation conditions and structure of the red compounds were explored,which provided a theoretical basis for the biological treatment of naphthamine wastewater and the recovery and utilization of naphthamine wastewater in the future.Results:(1)Under static indoor culture,the optimal conditions for the growth of Rhizoclonium were:COD was 40mg/L,NH4~+was 1mg/L,inorganic P was 0.2mg/L,and soil leachate was 15%.The highest removal rate of nitrate nitrogen was 70%,the highest removal rate of nitrogenous nitrogen was 95%,the highest removal rate of ammonia nitrogen was 84.1%,the highest removal rate of inorganic P was 85.3%,and the highest removal rate of COD was 52.4%.(2)The optimal conditions for the growth of Rhizoclonium under static outdoor culture were as follows:COD was 40mg/L,NH4~+was 1mg/L,inorganic P was 0.2mg/L,and soil leachate was 15%,which was consistent with the results of static indoor culture.For the removal of nutrients in water,it can remove nitrate nitrogen in the early stage,but the nitrate nitrogen content increases in the later stage of culture,nitrite nitrogen can be completely removed,the highest removal rate of ammonia nitrogen can reach83%,the highest removal rate of inorganic P can reach 92%,the removal effect of COD is general,the highest removal rate is 58.7%.(3)Under static culture of the treatment of river sewage by Rhodophyta the highest removal rate of ammonia nitrogen was 89.1%,the highest removal rate of inorganic P was 64.5%,the highest removal rate of nitrate nitrogen was 75%,the highest removal rate of nitrogenous nitrogen was 44%,and the highest removal rate of COD was 56.3%.(4)The removal efficiency of nitrogen and phosphorus in the river water was better and relatively stable in the dynamic plates and troughs of Rhodophyta,with the highest removal rate of ammonia nitrogen reaching 97.1%,the highest removal rate of nitrate nitrogen reaching 83.7%,and the highest removal rate of nitrogenous nitrogen reaching85%.For inorganic P in river water,the effect of dynamic plate and trough treatment of Rhodophyta was better,and the maximum removal rate could reach 100%.The removal efficiency of COD in the river water was poor.the highest removal rate was only 29.4%.(5)When the river water was treated by the algal bed,the removal efficiency of ammonia nitrogen and inorganic P in the water was better.The removal efficiency of the water quality indexes at the water outlet and the water inlet was basically similar,with the highest removal rate of ammonia nitrogen reaching 90%,the highest removal rate of inorganic P reaching complete removal,the highest removal rate of nitrate nitrogen being 72%,and the highest removal rate of nitrogenous nitrogen being78%.For the unstable COD removal rate in the river water,compared with the increase in the dynamic plate trough,the maximum COD removal rate was 58.6%.(6)After screening a large number of strains,a strain capable of transforming naphthylamine to produce red compounds was found.The genome and 16S rDNA of the target strain were extracted.The electrophoresis results showed that the size of 16S rDNA of the strain was about 1500bp.(7)Single factor experimental conditions were optimized.When the optimal pH value was 6,the yield of the product red compound was the highest at 0.03%naphthylamine,0.015%sodium nitrite,0.25%glucose and 10%inoculum dose.Orthogonal experiments on the transformed substrates showed that the major substrates affecting product A and product B both were naphthylamine>glucose>sodium nitrite,and the optimal medium combination was glucose 0.3%,sodium nitrite 0.02%and naphthylamine 0.03%.(8)The optimal medium combination was used to prepare A large number of transformation products.The product A and product B were separated by extraction,concentration and silica gel column chromatography.The structure of product A and product B was detected by NMR hydrogen spectrum,NMR carbon spectrum and mass spectrum.Finally,the molecular weight and structure of product A were roughly obtained.Product B failed to be detected due to its low concentration and many impurities.Conclusion:In this paper,the treatment of river water by rhizocladal algae and microbial transformation naphthene technology are effective and feasible,Rhizocladal algae has obvious removal effect on nitrogen and phosphorus in river water,and Rhizoclonium algae equipment is simple in structure,easy to maintain,low cost,and has broad prospects in sewage treatment.The transformation of-naphthamine by microorganisms has great potential application value for naphthamine wastewater treatment and recycling,and the corresponding application of red products in dyeing and synthesis also has great prospect. |
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