Treatment of coking wastewater by immobilized Rhodococcus sp.W7 particles with controlled release of nitrogen source
In this study,the immobilized microorganisms coupling with controlled release of nitrogen source was used to improve the biodegradation efficiency of common immobilized microorganisms in nitrogen source deficient environment.Urea was used as the controlled release of nitrogen source.The mixed gel(containing urea)of polyvinyl alcohol and sodium alginate was first crosslinked in 3％CaCl2 saturated boric acid solution and then crosslinked in 0.5 mol L-1 sodium sulfate solution.The prepared immobilized microbial particles with controlled release of urea had an encapsulation efficiency of higher than 98％,swelling rate of 15％～25％and high mechanical strength.In nitrogen free environments,100 mg·L-1 phenol,pyridine or quinoline could be biodegraded by these particles within 4,8 and 12 hours,respectively.In the simulated coking wastewater with high C/N ratio,the mixture of 100 mg·L-1 phenol,10 mg·L-1 pyridine and 10 mg·L-1 quinoline could be degraded within 6 hours.Meanwhile,the nitrogen source provided by the urea in the immobilized microbial particles could meet the needs of the immobilized microorganisms to degrade 100 mg·L-1 phenol every day for 20 days.The above results show that the prepared immobilized microbial particles with controlled release of urea can be used to treat wastewater lack of nitrogen source and have a good application effect.
国家科技期刊平台
NSTL
万方数据
