Analysis Of Carbonization Straw Absorption Function For Nh₄⁺-n And PO₄³⁺

For the past few years, with the development of rural economic, the construction of township and the increasing standards of people’s life in China a large number of industrial waste, sanitary waste, livestock waste and Non-point source pollution caused serious damage of ecological environment in rural areas. Among these the water pollution is particularly severe. Many studies have reported the treatment of sewage in rural areas. But most of them focus on the adsorption effect of nitrogen and phosphorus in sewage by a single absorbent or by biological means separately. In order to explore the removal efficiency of nitrogen and phosphorus with carbonization straw and take advantage of the rich straw resources of rural areas as well, this paper uses straw gasification byproduct-carbonized straw as adsorbing material to compare its adsorption properties with that of fly ash and slag, then make the further investigation on the feasibility of preparing bio-carbonized straw. On this basis, this study find to improve the removal efficiency of NH4+-N, PO43-, and COD in sewage and treat the sewage for a long time according to the principle of using nutrient sources by microbial for growth. To sum up the main valuable conclusions as shown as follows:(1)This paper compares the capability and rate to adsorb pollutants (NH+4-N、PO43-) in waste water among carbonized straw, fly ash and slag. Results showed that the adsorption capacity and the rate of carbonized straw were obviously lower than the fly ash, but higher than the slag. The adsorption capacity of the three materials decreased as the dosage increase. The adsorption rate of fly ash and carbonized straw increased as the dosage increased while that of slag reduced. The trend of the adsorption rate of carbonized straw and slag increased irregularly as the pH rose. The adsorption capacity of the three materials was not changed greatly as the pH increased, however. Comparing the adsorption capacity for NH+4-N among the three materials under different PH, the fly ash was the greatest among the three materials as the pH=6while carbonized straw was the lowest among the three as the pH=4.(2) Study the effect of different combinations of adsorption material to remove nitrogen and phosphorus in water. The results showed that:the absorption effect is better as the proportion of fly ash dosage increased.(3) By inoculating with different initial concentrations of phosphate accumulating bacteria in carbonized straw. The number of bacteria is up to10in48hours. This shows that:the carbonized straw can be to provide rapid growth and reproduction of nutrition carrier for phosphate accumulating bacteria. Study the growth instance of EM fungi accumulating bacteria in carbonized straw. The results showed that:the total microbial biomass in carbonized straw increased from189.2mg.kg-1to382.3mg.kg-1. This proved that the bacteria can make use of carbonized straw as nutrient source to survive.(4)This paper analyzes that the modification of carbonization could accumulate nitrogen and phosphorus in the sewage to high concentrations which required as nutritional source for microbial growth. This can contribute to deal with NH4--N、 PO43-and COD in sewage for a long time. The results showed that:The absorption function for NH4+-N、PO43-and COD of carbonization straw with EM is better than that without EM. And the removal rates of nitrogen, phosphorus and COD can also raise by11.2%、9.6%and30.9%respectively.(5)Analysis of the effect of treating actual water with bio-modified straw and unmodified carbonization straw showed that:the bio-Modification carbonized straw is more stable in removal function. The rate of removal ammonia-nitrogen、 phosphorus and COD by biological modification is increased by14.9%、12.4%、11.9%than unmodified carbonized straw in72h respectively.