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Study On Isolation And Identification Of The Denitrifying Phosphorous Accumulating Bacteria And The Preparation Of Immobilized Microorganism Pellets

Posted on:2016-11-02Degree:MasterType:Thesis
Country:ChinaCandidate:H T YuFull Text:PDF
GTID:2191330473459897Subject:Biochemistry and Molecular Biology
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The excessive nitrogen and phosphorus content is the primary cause of eutrophication. The microbe remediation technology, which mainly applied the microorganism, is an important technology to the control of eutrophication. The technology has some advantages such as low price, convenience to operate, has the obvious effect and not easy to cause the secondary pollution, etc. Finding out the microbes that have the efficient nitrogen phosphorus ability is the key to the effective governance of eutrophication.This study has extracted a strain of denitrifying phosphorus accumulating bacteria and a strain of efficient phosphorus accumulating bacteria from the sludge and garbage that were placed at the outlet of the factory in Gao Qi Industrial Park, Minhou County, Fuzhou City. Then, the two kinds of bacteria were respectively identified as Pseudomonas pseudoalcaligenes and Acinetobacter junii through the physiological and biochemical analysis and the gene sequencing. Their registration number is NR037000 and AB745654 in Genebank,respectively. What’s more, they were named as P. pseudoalcaligenes L7 (Referred to as L7)and A. junii LH4(Referred to as LH4). Then, the growth characteristics of the strains and how do the physical and chemical factors to effect the nitrogen phosphorus ability of the strains were further researched. The botanical Sapindus mukorossi actived carbon was produced and prepared for the study, then, it was used to produce the immobilized microorganism pellets with Polyving akohol (Referred to as PVA), Sodium alga acid (Referred to as SA), Strain L7, Stain LH4 and Strain A-13. At the same time, the effectiveness of the immobilized microorganism pellets removed the nitrogen and phosphorus in the medium was observed to discovery the theoretical basis for the practical application of its.The main results of the research are as follows:1.The denitrifying phosphate-accumulating organisms L7 has the quite strong ability of denitrifying phosphorus accumulating. Its removal rate to the initial concentration of 620 mg/L of NO3- can reach to 81.65% and without the accumulation of nitrite. In the meantime, the removal rate is 43.21% to the initial concentration of 24.5 mg/L PO43 With the analysis of the enzyme genes encoding NirS and NirK, which were reduced by type copper nitrite with the denitrifying phosphorus accumulating bacteria and Cytochrome model cdl nitrite, repectively, it proves the Strain L7 contains the genes NirS and NirK. Through observing how do the physical and chemical factors, such as the temperature, pH, the carbon source, the nitrogen source, the table speed and the initial NO3-, PO43-, effect the growth of the strain L7 and the ability of nitrogen and phosphorus of itself. The result shows that when the table speed is 100 r/min, the removal rate of NO3- is highest, which is at 88.43%, the removal rate of PO43- is 56.1%. when the pH is 7, the removal rate of NO3- is 79.64%, the removal rate of PO43- is 64.14%. If PH value below 6 will inhibit the growth of the strains, the optimal temperature for the bacterial strain is 30 degrees Celsius, the optimal carbon source is Succinic acid sodium, respectively.2.By exploring the phosphorus removal behavior of the strain LH4 on the different nutritional conditions. The researches of the physical and chemical factors, showed that not only the bacteria grow well, but the phosphorus removal rate can stabilize at around 90%, as well, when the carbon source is sodium formate, the nitrogen source is (NH4)2SO4, and C/N is above 5:1. The PH ranges from 6 to 9 is suitable for the growth of the strains. When the temperature is 30-35℃, the growth state of the strains is fairly good and the phosphorus removal effect is pretty good. When the table speed is 100 r/min the strains grow best, has the strongest capacity of the phosphorus removing, the phosphorus removal rate reaches to 99.26%. In addition, a high phosphorus concentrations on the growth of the strain does not produce inhibition, the strains that can tolerate high levels of phosphorus. When the phosphorus concentration is more than 70 mg/L, the phosphorus removal efficiency of the bacteria decreases, but the phosphorus removal rate is still about 50%. It shows the strain LH4 has the high phosphorus ability, which can be applied for the restoration of eutrophication.3.How to produce the activated carbon of the plant source, which is made of S. mukorossi? The carbon content of S.mukorossi is high and the ash content is low, So S.mukorossi is good material for the production of the activated carbon. Utilizing the leaf, branch, nutshell of S.mukorossi to produce the activated carbon by the phosphoric acid activation method, the specific surface area is more than 500m2/g, the Vtotal of the produced activated carbon rangs from 0.2 to 0.5 cm3/g, the average pore diameter size is in close to 2nm. The Maximum specific surface area of the activated carbon which was produced with the leaf of S.mukorossi is 840.21 m2/g, the one made of the shell of S.mukorossi is 544.35 m2/g.4.Taking PVA and SA as the immobilized carrier, taking Pseudomonas pseudoalcaligenes, Acinetobacter junii and Pseudomonas stutzeri YHA-13 as the immobilized microorganisms, then the activated carbon powder made from the nutshell of S.mukorossi will be taken into them to produce the immobilized microorganism pellets. Then, the effect of removing the nitrogen and phosphorus the immobilized microorganism pellets will be inspected. By the detection, the microorganism still have the strong nitrogen phosphorus ability after immobilization, the removal effect of nitrogen and phosphorus in water is absolutely obvious. The immobilized materials, PVA^ SA and the activated carbon, have the abilities to dislodge nitrogen and phosphorus. What is more, the activated carbon which is made from the nutshell of S.mukorossi has the dramaticlly strong ability to adsorb nitrogen and phosphorus. Further investigated how do the time of immobilization and the volume of addition affect the ability of the immobilized microorganism pellets to nitrogen and phosphorus, we get the following conclusions:(1)With the increasing amount of PVA, the ability to remove the phosphorous of the immobilized pellets decreases. More than 90% effect of removing the phosphorous is not affected. (2)If without SA, the produced immobilized particles easily cohere. When the concentration of SA is over 3%, it is not easy to form, unable to form a small ball. (3)When the content of PVA is 4% and the adding amount of SA is 1%, the effect of the produced immobilized pellets to remove nitrogen and phosphorus is best. The phosphorus removal efficiency is 62.54%, the nitrogen removal efficiency is 94.27%. (4)The time of immobilization will affected the effect of the produced immobilized pellets to remove nitrogen and phosphorus. With the increasing time of immobilization, the efficiency of the immobilized pellets to remove denitrification and phosphorus improve. The produced pellets’effect of removing nitrogen and phosphorus is quite good, when their time of immobilization is more than half an hour.
Keywords/Search Tags:Eutrophication, Denitrifying phosphoms accumulating bacteria, Phosphoms accumulating bacteria, Sapindus mukurossi, The activated carbon, The immobilized pellets
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