The Space-time Distribution Characteristics, Causes And Degradation Technology Research Of Microcystin In Taoranting Lake

The shallow hypertrophic lake is an important part of urban water ecologicalsystem, it can regulate regional climate and also have other ecological functions.Recently, eutrophic and harmful algae blooms have attracted more concern in Chinadue to their adverse effectson the environment.The TaoRanTing lake is cities in southBeijing leisure and as the most important tourism lake, it is famous for theTaoRanTing which is one of the most four famous pavilios, the anniversary of thelake water body in a severe state of eutrophication, fall cyanobacterial blooms occurfrequently.In view of the important ecosystem services value,the TaoRanTing lakehas been selected as "national science and technology major projects of waterpollution control (special) water" in the Beijing area.Therefore,this paper represents topropose an effective extraction procedure for traditional toxin determinationtechniques in this lake. Along with the increasingly serious eutrophicationphenomenon, its a series of environmental problems also gradually to the attention ofthe people.Especially intensified eutrophication caused by cyanobacteria blooms ofmicrocystin algae toxins (MCs) pollution, a serious threat to human health. In order togovernance city lake eutrophication and cyanobacterial bloom pollution to providecertain theoretical basis.This research mainly the results of the study are as follows:the main results were as follows:(1) The TaoRanTing lake cyanobacteria toxin detection and the establishment ofthe extraction and purification methods.For smoothly conducting the related theoretical research about cyanobacteriatoxin of the shallow hypertrophic lake, by optimizing the experimental conditions,eventually establish a set of liquid chromatography detection,and also extrace thecyanobacterial toxins in the largest amount.The research results show that using highperformance liquid chromatography (HPLC) method to detect cyanobacteria toxindetection conditions for mobile phase: methanol: water=60:40, column temperature:40℃, the wavelength:238nm, the flow rate:1.0mL/min, sample quantity:10μL.Under the condition of the above test, two kinds of toxins MC-RR and MC-LRcan get a good separation in a relatively short period of time, and the peak shape isgood, no obvious trailing phenomenon.Two types of toxins recovery rate can be90.56%and86.37%, respectively, the correlation coefficient of0.999above;Extraction and purification conditions for two different types of toxins:1Lcyanobacterial blooms in water samples by40%methanol and3%glacial acetic acid,300hz continuous ultrasonic15min, pH adjustment for3after the determination ofthe SPE extraction and purification, can obtain the largest amount of MC-RR,content of632ng/ml;Same water samples by40%methanol and5%glacial aceticacid,300hz continuous ultrasonic20min, after pH adjustment is3, the determinationof the SPE extraction and purification for algal toxins MC-LR, the maximum contentof257ng/ml. (2) The space-time distribution characteristics research of MCs in cyanobacteriabloom periodUsing high performance liquid chromatography (HPLC) method, optimize theMCs testing conditions.Mobile phase flow and the best matching ratio, MC-RR andMC-LR best temperature and the amount of sample testing.Comprehensive twosubstances of retention time, the time of separation, and the stand or fall of each peakshape, finally the optimum testing conditions for: methanol: water=60:40, columntemperature of40℃, the wavelength of238nm, the flow rate of1.0mL/min, samplequantity10mu L experiments respectively, and the chromatographic conditions foundin the temperature of40℃when both can not only a good separation, and the timeneeded for the shortest.(3) The MCs degradation technology research of TaoRanTing lakeIsolate several bacterias from sedimen and water of TaoRanTing lake in algaebloom period which can degradate microcystin MC-RR and MC-LR.Isolationbacterias through LC/MS to research the degradation of ability, and according to theseparation of bacteria colony morphology, physiological and biochemicalcharacteristics and its16s rDNA sequence analysis to identify the degradationbacteria.The results show that20strains of MCs were isolated from the sediment andwater samples of TaoRanTing lake, T11have a very obvious degradation effect toMC-RR and MC-LR.Within5days, can be the initial concentration of335ng/mL,respectively the MC-RR and1050ng/mL MC-LR fully biodegradable.Thephysiological and biochemical and molecular biology identification, T11strainsection rod bacteria genera.