Recently,more and more attention has been paid to the strong oxidation ability of newly prepared potassium ferrate(NAPF) in sludge reduction process,but less attention has been paid to the change of phosphorus in this...Recently,more and more attention has been paid to the strong oxidation ability of newly prepared potassium ferrate(NAPF) in sludge reduction process,but less attention has been paid to the change of phosphorus in this process.The feasibility of phosphorus migration and transformation during excess sludge reduction pretre atment using NAPF pre-oxidation combined with anaerobic digestion was investigated.After 70 mg/g suspended solids NAPF pretreatment and 16 days anaerobic digestion,the solid-phase volatile suspended solids decreased by 44.2%,and much organic matter had been released into the liquid-phase and then degraded during digestion by indigenous microorganisms.As the sludge pre-oxidation process was performed,solid-phase organic phosphorus and chemically combined phosphorus also released into the liquid-phase as PO4^3-,peaking at 100 mg/L.During anaerobic digestion,the Fe3+in the liquid-phase was gradually reduced to Fe2+,and then formed Fe^2+-PO4^3- compound crystals and re-migrated to the solid-phase.The concentration of PO4^3- decreased to 17.08± 1.1 mg/L in the liquid-phase after anaerobic digestion.Finally,the phosphorus in the Fe^2+-PO4^3- compound accounts for 80% of the total phosphorus in the solid-phase.A large number of vivianite crystals in sludge were observed.Therefore,this technology not only effectively reduces sludge,but also increases the proportion of PO43-in the sludge in the form of Vivianite.展开更多
In order to study the influence of difference in C<sub>2</sub>H<sub>2</sub> concentration on the production of CO<sub>2</sub>, N<sub>2</sub>O,NH<sub>4</sub>-...In order to study the influence of difference in C<sub>2</sub>H<sub>2</sub> concentration on the production of CO<sub>2</sub>, N<sub>2</sub>O,NH<sub>4</sub>-N and volatile fatty acids （VFA）, soil slurries with a gradient in C<sub>2</sub>H<sub>2</sub> concentration were anaerobicallyincubated at 25°C for 2 weeks. Acetate, butyrate and CO<sub>2</sub> production and NH<sub>4</sub>-N accumulation wereinhibited in the slurries in the presence of C<sub>2</sub>H<sub>2</sub>; and the inhibition effect increased with increasing C<sub>2</sub>H<sub>2</sub>from 0 to 20 kpa in the headspace gas of the incubation bottle. However, N<sub>2</sub>O, isobutyrate and propionateproduction was not obviously different among the slurries amended with C<sub>2</sub>H<sub>2</sub> from 2.5 to 20 kpa. Therefore,the results implied that the C<sub>2</sub>H<sub>2</sub> did not promote the inhibition but only increased the side effect onother microbial processes. The C<sub>2</sub>H<sub>2</sub> of 2.5 kpa was suggested to be the optimum choice for the presentdenitrification study.展开更多
The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digesti...The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digestion reactors were carried out to investigate the effect of ammonia/sulfate concentrations on the methane production.Experimental results manifested that the anaerobic digesters with an ammonia concentration of 3500 mg/L or sulfate of 1600 mg/L showed the best performance of methane production,with an average methane yield of 0.32 and 0.33 L (g VS)^(-1)d^(-1),respectively.Specifically,a higher ammonia (6500 mg/L) or sulfate (1600-3500 mg/L) level hindered the bioconversion of C from liquid to gas phase (2.68%or 1.73%CH_(4)-Gas,respectively),while insignificantly for the hydrolyzation of C and N from solid to liquid phase.Similar to sulfate,high ammonia nitrogen seriously inhibited the methanation process,leading to a significant carbon accumulation in the anaerobic reactor,especially for propionic acid.The predominant archaea Methanosarcina at genus level indicated that aceticlastic methanogenesis was the major methanogenic pathway.Meanwhile,high ammonia level suppressed the activity of Methanosarcina,while modest sulfate improved H_(2)-consuming methanogens activity.A large fraction of unclassified bacteria within the Firmicutes (43.78%-63.17%) and Bacteroidetes (24.20%-33.30%) phylum played an important role in substrates hydrolysis.展开更多
基金supported by the National Natural Science Foundation of China(No.51938010)the Major Science and Technology Projects for Water Pollution Control and Treatment of China(No.2017ZX07205002)+1 种基金National Key Research and Development Programme of China(No.2016YFC0401103)the Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment。
文摘Recently,more and more attention has been paid to the strong oxidation ability of newly prepared potassium ferrate(NAPF) in sludge reduction process,but less attention has been paid to the change of phosphorus in this process.The feasibility of phosphorus migration and transformation during excess sludge reduction pretre atment using NAPF pre-oxidation combined with anaerobic digestion was investigated.After 70 mg/g suspended solids NAPF pretreatment and 16 days anaerobic digestion,the solid-phase volatile suspended solids decreased by 44.2%,and much organic matter had been released into the liquid-phase and then degraded during digestion by indigenous microorganisms.As the sludge pre-oxidation process was performed,solid-phase organic phosphorus and chemically combined phosphorus also released into the liquid-phase as PO4^3-,peaking at 100 mg/L.During anaerobic digestion,the Fe3+in the liquid-phase was gradually reduced to Fe2+,and then formed Fe^2+-PO4^3- compound crystals and re-migrated to the solid-phase.The concentration of PO4^3- decreased to 17.08± 1.1 mg/L in the liquid-phase after anaerobic digestion.Finally,the phosphorus in the Fe^2+-PO4^3- compound accounts for 80% of the total phosphorus in the solid-phase.A large number of vivianite crystals in sludge were observed.Therefore,this technology not only effectively reduces sludge,but also increases the proportion of PO43-in the sludge in the form of Vivianite.
文摘In order to study the influence of difference in C<sub>2</sub>H<sub>2</sub> concentration on the production of CO<sub>2</sub>, N<sub>2</sub>O,NH<sub>4</sub>-N and volatile fatty acids （VFA）, soil slurries with a gradient in C<sub>2</sub>H<sub>2</sub> concentration were anaerobicallyincubated at 25°C for 2 weeks. Acetate, butyrate and CO<sub>2</sub> production and NH<sub>4</sub>-N accumulation wereinhibited in the slurries in the presence of C<sub>2</sub>H<sub>2</sub>; and the inhibition effect increased with increasing C<sub>2</sub>H<sub>2</sub>from 0 to 20 kpa in the headspace gas of the incubation bottle. However, N<sub>2</sub>O, isobutyrate and propionateproduction was not obviously different among the slurries amended with C<sub>2</sub>H<sub>2</sub> from 2.5 to 20 kpa. Therefore,the results implied that the C<sub>2</sub>H<sub>2</sub> did not promote the inhibition but only increased the side effect onother microbial processes. The C<sub>2</sub>H<sub>2</sub> of 2.5 kpa was suggested to be the optimum choice for the presentdenitrification study.
基金financed by the National Key Research and Development Program of China (No. 2018YFC1900902)the State Key Laboratory of Urban Water Resource and Environment (No. 2020TS01)+1 种基金the Heilongjiang Nature Science Foundation (No. YQ2020E022)the National Nature Science Foundation of China (No. 51878213)。
文摘The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digestion reactors were carried out to investigate the effect of ammonia/sulfate concentrations on the methane production.Experimental results manifested that the anaerobic digesters with an ammonia concentration of 3500 mg/L or sulfate of 1600 mg/L showed the best performance of methane production,with an average methane yield of 0.32 and 0.33 L (g VS)^(-1)d^(-1),respectively.Specifically,a higher ammonia (6500 mg/L) or sulfate (1600-3500 mg/L) level hindered the bioconversion of C from liquid to gas phase (2.68%or 1.73%CH_(4)-Gas,respectively),while insignificantly for the hydrolyzation of C and N from solid to liquid phase.Similar to sulfate,high ammonia nitrogen seriously inhibited the methanation process,leading to a significant carbon accumulation in the anaerobic reactor,especially for propionic acid.The predominant archaea Methanosarcina at genus level indicated that aceticlastic methanogenesis was the major methanogenic pathway.Meanwhile,high ammonia level suppressed the activity of Methanosarcina,while modest sulfate improved H_(2)-consuming methanogens activity.A large fraction of unclassified bacteria within the Firmicutes (43.78%-63.17%) and Bacteroidetes (24.20%-33.30%) phylum played an important role in substrates hydrolysis.
