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The influences of different fixed ways of polyurethane on the purification performance of wastewater treatment in biological contact oxidation were discussed, the polyurethane was put into biological contact oxidation by up-floating, sinking and general up-floating general sinking respectively, the relationship between microbial community structure and purification performance was analyzed. The results showed that polyurethane fixed by general up-floating general sinking could most efficiently remove pollutants, the purification rate of COD and NH4+ -N were 90% and 94% ; the attached microbial populations were with the largest number, the highest diversity, the strongest activity and the most reasonable function in this way. Therefore, the purification performance was affected by the fixed way of polyurethane in biological contact oxidation and the general up-floating general sinking was the most effective fixed way. [ABSTRACT FROM AUTHOR]

Microbial culture-independent technology, such as DNA fingerprinting technology, pyrosequencing, molecular hybridization technology, metagenomics, metatranscriptomics, metaproteomics, metabolomics and so on, has developed rapidly and been applied extensively in many fields, which could assist in the identification of microbial species from natural or anthropogenic environment rapidly and accurately. The microbial culture-independent technology has provided crucial in-sights for revealing microbial community structures, functions and remediation mechanism during bioremediation process and improving the detection efficiency of bioremediation. This review is mainly focused on the advanced applications of molecular biology and microbial culture-independent technology of "-- omics" in gauging microbial community structures, functions and dynamics at contaminated areas. [ABSTRACT FROM AUTHOR]

Extraction of metagenomic DNA from environmental sample was the main restrictive factor for the metagenomic sequencing. Three different extraction methods were used and compared in this study. The results indicated that the metagenomic DNA obtained from the activated sludge by Liquid Nitrogen Grinding + DNA Extraction Kit was the best sample due to the largest information and best quality, and D (260/280 nm) was between 1. 69 -1. 72. During the sample preparation for the next generation sequencing, D (260/280 nm) of the metagenomic DNA reached to 1. 83 after purification, which met the requirement of library construction. After the sequencing by Solexa Genome Analyzer System, the results showed that the forward sequencing of these two samples was successful, and the high quality data was about 90. 8%, which could be used for assemble. [ABSTRACT FROM AUTHOR]

To improve demulsifying property, the original biodemulsifier-producing bacterium, Bacillus mojavensis XH1, was mutated and bred by the combined treatment method using UV irradiation and niitrosoguanidine (NTG). A high efficient biodemulsifier-producing mutant XN5 with the better stability was obtained after continuous passages. The optimal cultural conditions were as follows: the mixture of 10 g/L glucose and 4 % liquid paraffin is the carbon source, the mixture of 4.0 g/L NH4Cl and 1.0 g/L yeast extract is nitrogen source, pH =6. 5 , the rotating rate is 140 r/min and the incubated time is 24 h. The 12 h and 24 h demulsification ratios of the mutant XN5 were 94. 17% and 98. 67% , which were 64. 81% and 15. 12% higher than that of the original strain XH1, respectively. [ABSTRACT FROM AUTHOR]

In the process of destabilization and aggregation of aquatic colloidal particles, different mechanisms of agglomerants, coagulants and flocculants were analyzed. Classification and representatives of coagulants and flocculants in water treatment were introduced from such aspects as chemical composition, molecular weight, production source and nature of functional groups. Different technical characteristics between combination effect of flocculants and compound flocculants were put forward. The properties and development of microbial compound flocculants and the combination effect between bioflocclant and other flocculants were investigated. [ABSTRACT FROM AUTHOR]

To improve the growth and efficiency of aerobic denitrifying bacteria, by adding different dose of magnetic powder (within 0.5 - 3.0 g/L, 0. 5 g/L for a gradient) and after 24 h, the growth absorbency, nitrate removal rate and dehydrogenase activity were determinated. Results show that the growth increases, and the nitrogen removal efficiency and dehydrogenase activity of T13 first increase and then decrease with increasing of magnetic powder dosage. The magnetic powder promotes the aerobic denitrifying bacteria growth and efficiency, and 2.0 g/L of magnetic powder is the optimal dosing quantity, under which the dehydrogenase activity and denitration nitrogen removal of T13 go to the maximum 73.9 µ/( mL⋅ h) and 100% respectively. [ABSTRACT FROM AUTHOR]

In order to strengthen the activity of biofilm on the carrier surface, the tourmpaline on polyurethane (TPU) carrier was prepared using waterborne polyurethane as medium. The physical properties of TPU carrier were characterized by scanning electron microscope(SEM) and water absorbency, and its effect on biofilm biomass and nitrifying ability was studied. The results showed that the tourmaline loading amount of TPU carrier can be affected by waterborne polyurethane. Tourmaline can optimize the number of polar groups of the TPU carrier and the pH of the nitrification condition. The amount of nitrobacteria and nitrate bacteria irreversibly adsorbed on the TPU carrier was increased by 74.82% and 71.89% , respectively. Correspondingly, the removing rate of NH+4 -N and NO-2 -N has risen by 8.12% and 9.08%, respectively, compared to the control without carrier. The TPU carrier was indicated to promote the nitrification.

The performance and feasibility of immobilization biological activated carbon (IBAC) were investigated to treat micro-pollutant water containing nitrobenzene. IBAC has been developed on the granular activated carbon by immobilization of selected and acclimated species of engineering bacteria to treat the micro-pollutant water containing nitrobenzene. The IBAC removal efficiencies for nitrobenzene, permanganate index, turbidity, UV, ammonia and nitrite were compared with granular activated carbon (GAC) process. Biological toxicity of influent and effluent of filter were determined. Amount of bacteria in carbon was measured when carbon filter was inoculated and circulated stably. The results showed that compared with GAC, it took short time for IABC to startup and recover to normal after impact burden. In addition, IBAC was more effective to treat micro-pollutants. In order to ensure security of drinking water, the influent nitrobenzene should be controlled below 26 microg/L. Effluent biological toxicity treated with IBAC was less than that with GAC. The performance of IBAC was much better than that of GAC. Amount of bacteria in both activated carbon filter increased first and then declined from inlet to outlet.