Study On Preparation And Performance Of A Composite Filler Micro-embedded With The Pseudomonas Putida

Biodegradation method has the characteristics of low operating cost and no secondary pollution for the purification of volatile organic waste gas.Filler is one of the key components of the biological filtration system,which has great impact on the purification performance.A composite filler embedded with the Pseudomonas putida was prepared by micro-embedding method with polyvinyl alcohol,sodium alginate,decomposed plant fiber and other ingredients.The physicochemical properties and nutrient sustained-release properties of fillers were determined.The performance of the composite filler in treating toluene was evaluated in biological filtration tower.The experimental results are as follows:?1?filler preparation:the proportion of filling materials is Polyvinyl alcohol30-36%,sodium alginate 12-18%,polypropylene fiber 4-8%,decomposed plant material 15-25%,calcium carbonate 15-25%,activated carbon 4-10%,Pseudomonas putida 0.5-1.5%.The results of physical and chemical properties evaluation of the filler showed that,the mechanical strength is 153 N,the bulk density is 271 kg.m^-3,the saturated water content is 55.3%,and the porosity is 13%.The total contents of N,P and K were 0.91%,0.73%and 0.58%respectively.The cumulative release of nitrogen,phosphorus and potassium is less than 5%and pH maintained at 7-8 in 19days.?2?Operation of biofilter:The removal reached 93%at the 8th day after biofilter set-up.The contribution of lower layer was higher than other two layers at a lower inlet load.The removal rate of toluene by Biofilter is higher than 95%when the inlet flow rate is less than 600 L·h^-1 and the intake load is less than 30.85 g·m^-3·h^-1.The maximum elimination capacity was 55.08 g·m^-3·h^-1 for toluene in biofilter Tower.Compared with the Michaelis-Menten model,the maximum degradation rates in the biofilter is better fitted with the Haldane model.The removal rate could restore to over 80%after restarting for 1 h when the system is out of service for 3 d and 7 d,and the removal rate could restore to over 80%after restarting for 1 d when the system is out of service for 15 d.Pressure drop of biofilter increases with the increase of microbial biomass during operation,increasing from initial 56 Pa to 378 Pa.The benzene generates from the degradation of toluence in the biofilter tower.?3?Strain identification:The dominant strain is Firmictes,Actinobacteria and Proteobacteria in the operation of biofilter tower.On the whole,the composite filler with better physicochemical property is highly effective at purifying toluene,which indicates that the filler has a extensive future.