| Phosphorus is the main water pollutant.Phosphorus removal methods with high efficiency,energy saving and resource recycling are one of the current research priorities.The use of agricultural waste into biochar and its application in the treatment of phosphorus-containing wastewater is worth studying.good way.In this paper,banana straw biochar was applied to the adsorption treatment and adsorption-biological coupling gasification phosphorus removal of phosphorus-containing wastewater,and the adsorption performance of magnesium-loaded banana straw biochar on phosphorus in wastewater and the adsorption-biological coupling gasification phosphorus removal mechanism were studied.The specific research contents and conclusions are as follows:1.Preparation,screening and performance research of adsorbents: Banana straw biochar（BC）,magnesium-loaded banana straw biochar（MBC）,iron-loaded coke,and magnesium-loaded coke were prepared,and the prepared adsorbents and coke were shaken.In the adsorption and beaker hanging film experiments,the carrier was screened by comparing the biodegradation of phosphorus.The results showed that:（1）The biochar of magnesium-loaded banana straw had the highest biodegradation of phosphorus,which was 16.51 mg/g,and the other adsorbents were ranked in order.are banana straw biochar,iron-loaded coke,magnesium-loaded coke,and coke;（2）The adsorption of phosphorus by magnesium-loaded biochar is an exothermic process,which conforms to the Lagergren pseudo-second-order kinetic model,and the adsorption isotherm can be described by the Langmuir equation.2.Study on the treatment of phosphorus-containing wastewater by banana straw biochar adsorption column: The influence of influent concentration and rate on the adsorption process of the adsorption column was investigated.The results showed that:（1）Under the same conditions,the breakthrough time of MBC adsorption column was higher than that of BC adsorption column.（2）The greater the TP concentration in the wastewater,the shorter the breakthrough time,but when the influent TP concentration is less than 5 mg/L,the breakthrough time does not change much;The higher the rate,the shorter the breakthrough time.For 5 mg/L phosphorus-containing wastewater,when the empty bed velocity was 17.7,28.3,and 35.4 cm/min,the volumes of MBC treated wastewater were 2600,2600,and 2400 m L/g,respectively.3.Study on the mechanism of adsorption-biocoupled gasification phosphorus removal（1）Study on the influence mechanism: The influence of adsorption amount,light environment and oxygen environment on the gasification phosphorus removal process was investigated,and the results showed that when the influent concentration was 50 mg/L（The corresponding adsorption amount was 15 mg/g）,the adsorption removal amount was the largest,and the single-day biodegradation amount was 10.66 mg/（d·g）.Aeration and shading can increase the biodegradation of phosphorus by the adsorption reaction column,which is more conducive to gasification and phosphorus removal.（2）Analysis of the change of phosphorus species in the process of adsorption-biocoupled gasification and phosphorus removal: SEM scanning and XPS analysis of MBC before and after adsorption and adsorption biodegradation were conducted to explore the conversion pathway of phosphorus during the adsorption process.The ammonium and magnesium forms are adsorbed on the surface of MBC.Compared with the pure adsorption process,the concentration of phosphorus on the MBC is lower than that in the pure adsorption process,and the content of-OP in the MBC is reduced,indicating that the phosphorus is converted into gaseous phosphorus by the microorganisms on the MBC and removed..（3）Microbial community analysis of adsorption-biocoupled gasification for phosphorus removal:High-throughput sequencing of MBC under different light and oxygen environments was performed to explore the colonies and dominant populations that play a major role in adsorption-biological coupling.The results show that: the dark and anaerobic environment is more suitable for the growth of Firmicutes bacteria,which is positively correlated with the amount of phosphorus adsorption;aerobic environment is beneficial to Proteobacteria,and Candidatus＿Saccharibacteria bacteria are more suitable for growth and reproduction in the light environment;never shading aeration The relative abundance of Bacteroidetes increased gradually from shading without aeration to shading aeration;the dominant phyla in shading and aeration environments were Firmicutes,Proteobacteria,Bacteroidetes,Candidatus＿Saccharibacteria,Actinomycetes The phylum Actinobacteria,in which the relative abundance of Actinobacteria was negatively correlated with the amount of phosphorus adsorption;the genera with relatively large relative abundance at the genus level and related to phosphorus removal included Clostridium＿sensu＿stricto,Raoultella,Acinetobacter,Saccharibacteria＿genera＿incertae＿sedis,Klebsiella,Lactococcus,unclassified＿Bacteroidetes,etc. |
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