Heterotrophic nitrification-aerobic denitrification(HNAD)is essential in diverse nitrogen-transforming processes.How HNAD is modulated by quorum sensing(QS)systems is still ambiguous.The QS system in Pseudomonas aerug...Heterotrophic nitrification-aerobic denitrification(HNAD)is essential in diverse nitrogen-transforming processes.How HNAD is modulated by quorum sensing(QS)systems is still ambiguous.The QS system in Pseudomonas aeruginosa manipulates colony behavior.Here,we described the influence of the Pseudomonas quinolone signal(PQS)and N-acyl-L-homoserine lactone(AHL)on HNAD.The HNAD of P.aeruginosa was inhibited by the oversecretion of PQS.AHL-or PQS-deficient P.aeruginosa mutants had a higher ability for nitrogen removal.QS inhibited heterotrophic nitrification mainly via controlling the activity of nitrite oxidoreductase(NXR)and the depressed aerobic denitrification by regulating the catalytic abilities of nitric oxide reductase(NOR),nitrite reductase(NIR),and nitrate reductase(NAR).The addition of citrate as the sole carbon source increased the nitrogen removal efficiency compared with other carbon sources.Nitrite,as the sole nitrogen source,could be used entirely with only the moderate concentration of PQS contained.AHL and PQS controlled both nitrification and denitrification,suggesting that QS plays an important role in nitrogen cycle under aerobic conditions.展开更多
Ships generate large amounts of wastewater including oily bilge water, blackwater and greywater. Traditionally they are treated separately with high energy consumption. In this study we demonstrate the feasibility tha...Ships generate large amounts of wastewater including oily bilge water, blackwater and greywater. Traditionally they are treated separately with high energy consumption. In this study we demonstrate the feasibility that these waste streams can be treated using an integrated electrocoagulation cell (ECC) and microbial fuel cell (MFC) process, which not only synergized the contaminants removal but also accomplished energy neutrality by directly powering EC with MFC electricity. Results showed that MFC stack powered ECC removed 93% of oily organics, which is comparable to the performance of an external DC voltage powered ECC. In the meantime, more than 80% of COD was removed from MFCs when fed with either acetate or municipal wastewater. Moreover, the ECC electrode area and distance showed notable effects on current generation and contaminants removal, and further studies should focus on operation optimization to enhance treatment efficiency.展开更多
基金supported by the National Key Research and Development Program of China(No.2018YFD1100503).
文摘Heterotrophic nitrification-aerobic denitrification(HNAD)is essential in diverse nitrogen-transforming processes.How HNAD is modulated by quorum sensing(QS)systems is still ambiguous.The QS system in Pseudomonas aeruginosa manipulates colony behavior.Here,we described the influence of the Pseudomonas quinolone signal(PQS)and N-acyl-L-homoserine lactone(AHL)on HNAD.The HNAD of P.aeruginosa was inhibited by the oversecretion of PQS.AHL-or PQS-deficient P.aeruginosa mutants had a higher ability for nitrogen removal.QS inhibited heterotrophic nitrification mainly via controlling the activity of nitrite oxidoreductase(NXR)and the depressed aerobic denitrification by regulating the catalytic abilities of nitric oxide reductase(NOR),nitrite reductase(NIR),and nitrate reductase(NAR).The addition of citrate as the sole carbon source increased the nitrogen removal efficiency compared with other carbon sources.Nitrite,as the sole nitrogen source,could be used entirely with only the moderate concentration of PQS contained.AHL and PQS controlled both nitrification and denitrification,suggesting that QS plays an important role in nitrogen cycle under aerobic conditions.
文摘Ships generate large amounts of wastewater including oily bilge water, blackwater and greywater. Traditionally they are treated separately with high energy consumption. In this study we demonstrate the feasibility that these waste streams can be treated using an integrated electrocoagulation cell (ECC) and microbial fuel cell (MFC) process, which not only synergized the contaminants removal but also accomplished energy neutrality by directly powering EC with MFC electricity. Results showed that MFC stack powered ECC removed 93% of oily organics, which is comparable to the performance of an external DC voltage powered ECC. In the meantime, more than 80% of COD was removed from MFCs when fed with either acetate or municipal wastewater. Moreover, the ECC electrode area and distance showed notable effects on current generation and contaminants removal, and further studies should focus on operation optimization to enhance treatment efficiency.
