A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has ...A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has the function of nitrification and removing organic substrate. In this study, we focused on the denitrification performance of LBAF and its possible mechanism under thorough aeration. We identified the existence of simultaneous nitrification and denitrification (SND) by analyzing nitrogenous compounds along the flow path of LBAF and supportive microbial microscopy, and studied the effects of air/water ratio and hydraulic loading on the performance of nitrogen removal and on SND in LBAF to find out the optimal operation condition. It is found that for saving operation cost, aeration can be reduced to some degree that allows desirable removal efficiency of pollutants, and the optimal air/water ratio is 10:1. Hydraulic loading less than 0.43 m h?1 hardly affects the nitrification and denitrification performance; whereas higher hydraulic loading is unfavorable to both nitrification and denitrification, far more unfavorable to denitrification than to nitrification.展开更多
The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elementa...The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elemental sulfur and carbon dioxide, respectively, at high loading rates. This study has determined that the reaction rate of sulfide oxidized into sulfur could be enhanced in the presence of 1,2-naphthoquinone-4-sulphonate(NQS). The presence of NQS mitigated the inhibition effects of sulfide species on denitrification. Furthermore, the reaction rates of nitrate and acetate to nitrogen gas and CO_2, respectively, were also promoted in the presence of NQS, thereby enhancing the performance of DSR granules. The advantages and disadvantages of applying the NQS-DSR process are discussed.展开更多
A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were studied.It can be seen from the fluorescence in situ hybridization results of the bio-membrane ...A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were studied.It can be seen from the fluorescence in situ hybridization results of the bio-membrane sample from the bio-ceramic reactor,the spots of green nitrosobacteria are obviously more than those of orange nitrobacteria.Two heterotrophic nitrobacteria were isolated from the bio-ceramic reactor.By sequencing 16SrDNA and establishing the phylogenic tree,they were identified physiologically and biochemically as Pseudomonas sp..After 12 d,the COD removal efficiency of wgy55 and wgy68 were 45.03% and 50.85%,the NH4-N removal efficiency of them were 80.12% and 85.93%,and the TN removal efficiency of them were 69.71% and 64.7%.The final concentration of NO2-N of wgy55 and wgy68 was 0.753 mg/L and 0.601 mg/L,and that of NO3-N was 3.21 mg/L and 3.38 mg/L.These results show that wgy55 and wgy68 have the capability of nitrification and they are heterotrophic nitrobacteria.展开更多
基金Funded by the National Key Technologies R & D Program of China During the 10th Five-Year Plan Periods of China (No.2001BA604A01-03).
文摘A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has the function of nitrification and removing organic substrate. In this study, we focused on the denitrification performance of LBAF and its possible mechanism under thorough aeration. We identified the existence of simultaneous nitrification and denitrification (SND) by analyzing nitrogenous compounds along the flow path of LBAF and supportive microbial microscopy, and studied the effects of air/water ratio and hydraulic loading on the performance of nitrogen removal and on SND in LBAF to find out the optimal operation condition. It is found that for saving operation cost, aeration can be reduced to some degree that allows desirable removal efficiency of pollutants, and the optimal air/water ratio is 10:1. Hydraulic loading less than 0.43 m h?1 hardly affects the nitrification and denitrification performance; whereas higher hydraulic loading is unfavorable to both nitrification and denitrification, far more unfavorable to denitrification than to nitrification.
基金supported bythe National Natural Science Foundation of China under Grant No. 21307160the Natural Science Foundation of Shandong Province under Grant No. ZR2013EEQ030
文摘The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elemental sulfur and carbon dioxide, respectively, at high loading rates. This study has determined that the reaction rate of sulfide oxidized into sulfur could be enhanced in the presence of 1,2-naphthoquinone-4-sulphonate(NQS). The presence of NQS mitigated the inhibition effects of sulfide species on denitrification. Furthermore, the reaction rates of nitrate and acetate to nitrogen gas and CO_2, respectively, were also promoted in the presence of NQS, thereby enhancing the performance of DSR granules. The advantages and disadvantages of applying the NQS-DSR process are discussed.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50521140075)
文摘A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were studied.It can be seen from the fluorescence in situ hybridization results of the bio-membrane sample from the bio-ceramic reactor,the spots of green nitrosobacteria are obviously more than those of orange nitrobacteria.Two heterotrophic nitrobacteria were isolated from the bio-ceramic reactor.By sequencing 16SrDNA and establishing the phylogenic tree,they were identified physiologically and biochemically as Pseudomonas sp..After 12 d,the COD removal efficiency of wgy55 and wgy68 were 45.03% and 50.85%,the NH4-N removal efficiency of them were 80.12% and 85.93%,and the TN removal efficiency of them were 69.71% and 64.7%.The final concentration of NO2-N of wgy55 and wgy68 was 0.753 mg/L and 0.601 mg/L,and that of NO3-N was 3.21 mg/L and 3.38 mg/L.These results show that wgy55 and wgy68 have the capability of nitrification and they are heterotrophic nitrobacteria.