The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflo...The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflow anaerobic biofilter(UAF)treating municipal wastewater was established.The performances of stable operation and recovery operation of UAF after long-term starvation(234 days)and the changes of microbial community structure were researched.By gradually reducing HRT from 10 h to 4 h,the UAF achieved the treatment performance of pre-starvation after only 50 days recovery operation,in which total COD and soluble COD removal efficiencies reached 66%and 69%,respectively,and the CH_(4) production rate was 0.21 L CH_(4)/g CODremoval.The recovery performance of UAF after long term starvation showed that the recovery sequence of three main anaerobic processes was hydrolytic acidification,hydrogen-acetate production and methanogenesis.High-throughput sequencing results indicated that dominant bacteria associated with hydrolytic acidification process changed from Moduliflexaceae and Trichococcus in stable operation stage to Trichococcus and Romboutsia in recovery stage.Besides,the dominant archaea changed from Methanosaeta(hydrotrophic methanogens)to Methanobacterium(acetotrophic methanogens),showing Methanobacterium was more resistant to starvation environment.Therefore,by using UAF for biological treatment of organic matter,even after a long period of starvation,the system would not be completely destroyed.Once it resumed operation,the treatment performance could be restored in a short period of time.展开更多
Anammox was successfully transited from heterotrophic denitrification and autotrophic denitrification in two upflow biofilm reactors, respectively. The results showed that the volumetric loading rate and nitrogen remo...Anammox was successfully transited from heterotrophic denitrification and autotrophic denitrification in two upflow biofilm reactors, respectively. The results showed that the volumetric loading rate and nitrogen removal efficiency in the reactor transited from heterotrophic denitrification were higher than that in its counterpart. When the hydraulic retention time was 12 h or so, the total nitrogen loading rate was about 0.609 kg N/(m3·d), and the effluent ammonia and nitrite concentrations were less than 8.5 mg/L and 2.5 mg/L, respectively. The upflow anammox biofilm reactor was capable of keeping and accumulating the slow-growing bacteria efficiently. During operation of the reactor, the biomass color was gradually turned from brownish to red, and the ratio of ammonia consumption, nitrite consumption and nitrate production approached the theoretical one. These changes could be used as an indicator for working state of the reactor.展开更多
Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demon...Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time（HRT） of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand（TCOD）of 89%, removal of soluble chemical oxygen demand（SCOD） of 92%, and conversion of chemical oxygen demand（COD） to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids（VFAs） in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.展开更多
The hydrodynamic and mass transfer characteristics of a downflow liquid jet loop reactor (D-JLR) were studied experimentally with water/air and CMC (carboxymethyl cellulose) solution/air systems. The effects of the ge...The hydrodynamic and mass transfer characteristics of a downflow liquid jet loop reactor (D-JLR) were studied experimentally with water/air and CMC (carboxymethyl cellulose) solution/air systems. The effects of the geometry, the operating parameters and the physical properties of the liquid phase on gas hold-up and mass transfer coefficient were measuered. Compared with other types of gas-liquid reactor, D-JLR shows higher mass transfer coefficient and lower energy dissipation rate, the optimum diameter ratio was found to be about 0.42-0.6. A model for gas hold-up in D-JLR with Newtonian and non-Newtonian fluids has been developed on the basis of the equation of motion and the concept of average mixing length. The prediction of gas hold-up with the model agreed with the experimental results of this work.展开更多
Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) w...Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.展开更多
In order to extend the operating cycle of the upflow reactor for resid hydrotreating,the Re-search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has develope...In order to extend the operating cycle of the upflow reactor for resid hydrotreating,the Re-search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has developed the high-performance RUF series of catalysts suitable for operation in the upflow reactor.The results of commercial application of catalysts revealed that this RUF series of catalysts loaded after optimized grading could effectively remove metals,sulfur and carbon residue from the re-siduum to provide improved oil for the following fixed-bed reactor.In the meantime,the RUF series of catalysts have excellent stability to reach an operating cycle of 1.5 years,resulting in minimization of losses caused by refinery downtime.展开更多
【目的】冷轧含油废水中油、化学需氧量(COD)含量高,可生化性差,传统物理化学法处理冷轧含油废水存在产生大量含油污泥的问题,运行成本高并产生二次污染,而基于污水处理过程中的污泥生物减量化已成为国内外的研究热点和发展趋势。上流...【目的】冷轧含油废水中油、化学需氧量(COD)含量高,可生化性差,传统物理化学法处理冷轧含油废水存在产生大量含油污泥的问题,运行成本高并产生二次污染,而基于污水处理过程中的污泥生物减量化已成为国内外的研究热点和发展趋势。上流式厌氧污泥床(UASB)对较高的有机负荷具有良好的耐受性,且能提高废水的可生化性,有利于解决上述问题。【方法】采用UASB对冷轧含油废水进行了预处理的可行性试验,通过逐渐提高进水有机负荷和油含量来考察UASB对油和COD的去除效果及试验过程中冷轧含油废水可生化性的变化,并探究有机负荷对产气率和颗粒污泥的影响。【结果】当有机负荷为4~12 kg COD/(m^(3)·d),油质量浓度小于500 mg/L时,COD和油平均去除率分别为77.27%和64.13%,产气率可达0.35 m^(3)/(kg COD),可生化性显著提高,且颗粒污泥粒径、污泥沉降性、胞外聚合物(EPS)随有机负荷的增加而提高;当有机负荷增加至13 kg COD/(m^(3)·d)以上,油质量浓度高于500 mg/L时,UASB处理效果急剧下降,颗粒污泥沉降性变差甚至上浮流失。【结论】UASB对有机负荷的波动和油有较好的耐受性,研究结果为UASB代替破乳、气浮等产生大量含油污泥的物理方法进行冷轧含油废水预处理提供了数据支撑。展开更多
基金supported by the National Natural Science Foundation of China(No.52270018).
文摘The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflow anaerobic biofilter(UAF)treating municipal wastewater was established.The performances of stable operation and recovery operation of UAF after long-term starvation(234 days)and the changes of microbial community structure were researched.By gradually reducing HRT from 10 h to 4 h,the UAF achieved the treatment performance of pre-starvation after only 50 days recovery operation,in which total COD and soluble COD removal efficiencies reached 66%and 69%,respectively,and the CH_(4) production rate was 0.21 L CH_(4)/g CODremoval.The recovery performance of UAF after long term starvation showed that the recovery sequence of three main anaerobic processes was hydrolytic acidification,hydrogen-acetate production and methanogenesis.High-throughput sequencing results indicated that dominant bacteria associated with hydrolytic acidification process changed from Moduliflexaceae and Trichococcus in stable operation stage to Trichococcus and Romboutsia in recovery stage.Besides,the dominant archaea changed from Methanosaeta(hydrotrophic methanogens)to Methanobacterium(acetotrophic methanogens),showing Methanobacterium was more resistant to starvation environment.Therefore,by using UAF for biological treatment of organic matter,even after a long period of starvation,the system would not be completely destroyed.Once it resumed operation,the treatment performance could be restored in a short period of time.
基金TheNationalNaturalScienceFoundationofChina (No . 30 0 70 0 1 7) theScienceandTechnologyFoundationforKeyProjectofZhejiang
文摘Anammox was successfully transited from heterotrophic denitrification and autotrophic denitrification in two upflow biofilm reactors, respectively. The results showed that the volumetric loading rate and nitrogen removal efficiency in the reactor transited from heterotrophic denitrification were higher than that in its counterpart. When the hydraulic retention time was 12 h or so, the total nitrogen loading rate was about 0.609 kg N/(m3·d), and the effluent ammonia and nitrite concentrations were less than 8.5 mg/L and 2.5 mg/L, respectively. The upflow anammox biofilm reactor was capable of keeping and accumulating the slow-growing bacteria efficiently. During operation of the reactor, the biomass color was gradually turned from brownish to red, and the ratio of ammonia consumption, nitrite consumption and nitrate production approached the theoretical one. These changes could be used as an indicator for working state of the reactor.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China (No. 2011ZX07301-003)the National Key Research and Development Plan (No. 2016YFC0400806)
文摘Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time（HRT） of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand（TCOD）of 89%, removal of soluble chemical oxygen demand（SCOD） of 92%, and conversion of chemical oxygen demand（COD） to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids（VFAs） in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.
文摘The hydrodynamic and mass transfer characteristics of a downflow liquid jet loop reactor (D-JLR) were studied experimentally with water/air and CMC (carboxymethyl cellulose) solution/air systems. The effects of the geometry, the operating parameters and the physical properties of the liquid phase on gas hold-up and mass transfer coefficient were measuered. Compared with other types of gas-liquid reactor, D-JLR shows higher mass transfer coefficient and lower energy dissipation rate, the optimum diameter ratio was found to be about 0.42-0.6. A model for gas hold-up in D-JLR with Newtonian and non-Newtonian fluids has been developed on the basis of the equation of motion and the concept of average mixing length. The prediction of gas hold-up with the model agreed with the experimental results of this work.
基金Supported by the National Natural Science Foundation of China (No.: 29676042)
文摘Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.
文摘In order to extend the operating cycle of the upflow reactor for resid hydrotreating,the Re-search Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has developed the high-performance RUF series of catalysts suitable for operation in the upflow reactor.The results of commercial application of catalysts revealed that this RUF series of catalysts loaded after optimized grading could effectively remove metals,sulfur and carbon residue from the re-siduum to provide improved oil for the following fixed-bed reactor.In the meantime,the RUF series of catalysts have excellent stability to reach an operating cycle of 1.5 years,resulting in minimization of losses caused by refinery downtime.
文摘【目的】冷轧含油废水中油、化学需氧量(COD)含量高,可生化性差,传统物理化学法处理冷轧含油废水存在产生大量含油污泥的问题,运行成本高并产生二次污染,而基于污水处理过程中的污泥生物减量化已成为国内外的研究热点和发展趋势。上流式厌氧污泥床(UASB)对较高的有机负荷具有良好的耐受性,且能提高废水的可生化性,有利于解决上述问题。【方法】采用UASB对冷轧含油废水进行了预处理的可行性试验,通过逐渐提高进水有机负荷和油含量来考察UASB对油和COD的去除效果及试验过程中冷轧含油废水可生化性的变化,并探究有机负荷对产气率和颗粒污泥的影响。【结果】当有机负荷为4~12 kg COD/(m^(3)·d),油质量浓度小于500 mg/L时,COD和油平均去除率分别为77.27%和64.13%,产气率可达0.35 m^(3)/(kg COD),可生化性显著提高,且颗粒污泥粒径、污泥沉降性、胞外聚合物(EPS)随有机负荷的增加而提高;当有机负荷增加至13 kg COD/(m^(3)·d)以上,油质量浓度高于500 mg/L时,UASB处理效果急剧下降,颗粒污泥沉降性变差甚至上浮流失。【结论】UASB对有机负荷的波动和油有较好的耐受性,研究结果为UASB代替破乳、气浮等产生大量含油污泥的物理方法进行冷轧含油废水预处理提供了数据支撑。
