Studies On Screening Microorganisms Degrading Detergent Wastewater And Its Degrading Characteristics

With the development of modern biotechnology,more and more microorganism is being used in environment disposal.In this paper,the biodegradation research of linear alkylbenzene sulphonate(LAS) which is the most popular used anionic surfactants in synthetic detergent industry by screening of degrading bacteria is conducted.After cultivation of the microorganisms from wastewater treatment plant in Chengdu Baojie Company,a LAS degrading bacteria CS3 with high efficiency is founded.According to the bacterial strain,biochemical characteristics of physiology, CSs is identified as Alcaligenes sp..To attain the goal that CS3 can degrade detergent wastewater in which concertration of LAS is from 150 to 200mg/l,LAS is used as inducing chemical to acclimate the bacteria .The results showed that the LAS degrading abilities are greatly promoted from 20mg/l to 200mg/l after 6 ages' acclimation.Bacterium CS3 can keep high growth rate and LAS degradation under the environmental terms of pH6~9,in 25~37℃ of temperature.The best environmental conditions for the growth and LAS degradation of bacterium CS3 are 30℃, pH7,cultivation of needed time 24h.Main elements in culture medium such as carbon sources,nitrogen sources are important factors for the growth and LAS degradation of bacteria CS3. Mental ions Fe3+, Ca2+,Al3+can impress the the growth and LAS degradation of bacteria CS3 with certain degree.However,heavy metal ions Zn2+, Cu2+, Hg2+ can greatly restrain the growth and LAS degradation of bacteria CSs.Meanwhile.increasing inoculation amount can speed up reaction rate and cut down delaying phrase.The suitable inoculation amount is 4%.Through studying on its degrading rate,we can find that the growth and LAS degradation of bacterium CS3 are nearly synchronic.In addition,the performance of degrading LAS of mixture bacterial strain have much advantage over that of pure bacterial strains that is isolated in the experiment.