Study On The Multiple Microorganisms And Their Immobilized Technology In Antibiotic Wastewater Treatment.

The effluent emitted from antibiotic production is one kind of high-concentrationorganic waste water with complicated water quality and bad biodegradability, highchroma and suspension substance, even with massive fermentation intermediate andresidua. These characteristics of the effluent of producing antibiotic make it hard totreat and the cost is too high. In this thesis, on the basis of building highly efficientmultiple microorganisms, the multiple microorganisms and immobilizationtechnology were used to deal with the antibiotic wastewater.Eight single strains were screened and cultivated, and six single strains were ineffect in dealing with the antibiotic wastewater. For the six single strains, themaximum and the minimum removing rates of CODcr for the wastewater were69.49％and 54.21％, respectively. In order to build multiple microorganisms, threearbirary strains were mixed and cultivaten, and twenty different multiplemicroorganisms were obtained.All of the obtained multiple microorganisms couddegrade the antibiotic wastewater. Among them, the CODcr removing rate of fivemultiple microorganisms were higher than 70％, and the maximum value was80.38％which was 10 percent higher than the single strain.The research showed that the multiple microorganisms and their immobilizationtechnology had notable removal efficiency to process antibiotics wastewater. TheCODcr concentration was dropped to 153.94 mg/L from 2357.42 mg/L.In theexperiments, immobilization technology was used to encapsulate the multiplemicroorganisms, and the encapsulated multiple microorganisms were used todegrade the antibiotic wastewater. The results showed that the removing rate ofCODcr in the wastewater was 93.47％, which was 13 percent higher than themultiple microorganisms and 23 percent higher than the single strain.The equations of CODcr removing velocity in the wastewater for multiplemicroorganisms and single strain wereμ=1/(1.3135+40.563e^-t) andμ=1/(1.0912+2.5661e^-t), respectively. When the concentration of CODcr decreased to half, 4 days were needed for multiple microorganisms and 1 day for immobilizedmultiple microorganisms.After the single factor and orthogonal experiments as well as the analysis ofdeviation, the optimized conditions for degrading antibiotic wastewater by multiplemicroorganisms were: pH 6.5, temperature 25℃, rotation speed 160 rpm andinoculums 7ml. Similarly, the optimized conditions for encapsulating immobilizedmultiple microorganisms were: PVA concentration 8％, alginate sodiumconcentration 1％, plastic bacteria proportion 1:15and crosslinking time 32h.