In this study two types of biological contact oxidation processes(BCOP),a step-feed(SBCOP)unit and an inter-recycle(IBCOP)unit,were designed to investigate the treatment of heavily polluted river water.The Daqing Rive...In this study two types of biological contact oxidation processes(BCOP),a step-feed(SBCOP)unit and an inter-recycle(IBCOP)unit,were designed to investigate the treatment of heavily polluted river water.The Daqing River,which is the largest pollutant contributor to the Dianchi Lake,one of the most eutrophic freshwater lakes in China,was taken for the case study.It was found that the SBCOP had higher adaptability and better performance in the reduction of COD,TN,and TP,which made it applicable for the treatment of polluted river water entering the Dianchi Lake.Nitrification rate was observed to be greatly affected by the influent temperature.During each season,the nitrification in the SBCOP was higher than that in the IBCOP.TN removal efficiency in the SBCOP was higher than that in the IBCOP during the winter and spring but poorer during the summer,possibly due to the inhibition of denitrification by higher dissolved oxygen level in the summer.Moreover,symbiotic algaebacteria growth may be conducive to the removal of pollutants.展开更多
Nowadays,a stack of heavily doped polysilicon(poly-Si)and tunnel oxide(SiO_(x))is widely employed to improve the passivation performance in n-type tunnel oxide passivated contact(TOPCon)silicon solar cells.In this cas...Nowadays,a stack of heavily doped polysilicon(poly-Si)and tunnel oxide(SiO_(x))is widely employed to improve the passivation performance in n-type tunnel oxide passivated contact(TOPCon)silicon solar cells.In this case,it is critical to develop an in-line advanced fabrication process capable of producing high-quality tunnel SiO_(x).Herein,an in-line ozone-gas oxidation(OGO)process to prepare the tunnel SiO_(x) is proposed to be applied in n-type TOPCon solar cell fabrication,which has obtained better performance compared with previously reported in-line plasma-assisted N2O oxidation(PANO)process.In order to explore the underlying mechanism,the electrical properties of the OGO and PANO tunnel SiO_(x) are analyzed by deep-level transient spectroscopy technology.Notably,continuous interface states in the band gap are detected for OGO tunnel SiO_(x),with the interface state densities(D_(it))of 1.2×10^(12)–3.6×10^(12) cm^(-2) eV^(-1) distributed in Ev+(0.15–0.40)eV,which is significantly lower than PANO tunnel SiO_(x).Furthermore,X-ray photoelectron spectroscopy analysis indicate that the percentage of SiO_(2)(Si^(4+))in OGO tunnel SiO_(x) is higher than which in PANO tunnel SiO_(x).Therefore,we ascribe the lower D_(it) to the good inhibitory effects on the formation of low-valent silicon oxides during the OGO process.In a nutshell,OGO tunnel SiO_(x) has a great potential to be applied in n-type TOPCon silicon solar cell,which may be available for global photovoltaics industry.展开更多
A novel hybrid anaerobic-contact oxidation biofilm baffled reactor （HAOBR） was developed to simultaneously remove nitrogenous and carbonaceous organic pollutants from decentralized molasses wastewater in the study. ...A novel hybrid anaerobic-contact oxidation biofilm baffled reactor （HAOBR） was developed to simultaneously remove nitrogenous and carbonaceous organic pollutants from decentralized molasses wastewater in the study. The study was based on the inoculation of anaerobic granule sludge in anaerobic compartments and the installation of combination filler in aerobic compartments. The performance of reactor system was studied regarding the hydraulic retention time （HRT）, microbial characteristics and the gas water ratio （GWR）. When the HRT was 24h and the GWR was 20：1, total ammonia and chemical oxygen demand （COD） of the effluent were reduced by 99% and 91.8%, respectively. The reactor performed stably for treating decentralized molasses wastewater. The good performance of the reactor can be attributed to the high resistance of COD and hydraulic shock loads. In addition, the high solid retention time of contact oxidation biofilm contributed to stable performance of the reactor.展开更多
The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater. Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5. The CODcr r...The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater. Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5. The CODcr removal efficiency by biochemical process can be more than 80%. During a half year抯 operation, the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge stan-dards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.展开更多
The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidatio...The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs （phosphorus accumulating organisms） in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio （C/N）. Furthermore the SRT （sludge retention time） of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%, 75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR （bypass sludge flow rate） should be controlled at 0.35 around.展开更多
The purpose of this study was to identify microbial strains that have a strong ability to biodegrade lubricating oil. No. 20 lubricating oil was used as the sole carbon source in an isolation medium to screen bacteria...The purpose of this study was to identify microbial strains that have a strong ability to biodegrade lubricating oil. No. 20 lubricating oil was used as the sole carbon source in an isolation medium to screen bacteria from sludge that had been contaminated with crude oil. Through both morphological and biochemical methods, the bacterial strain that had the highest biodegrading capacity was identified as Zoogloea sp. On the basis of these preliminary results, a biological contact oxidation method was employed to further assess the ability of the Zoogloea sp. strain to treat wastewater contaminated by No. 20 lubricating oil using three oxidation cabins and two hydraulic retaining times （HRT）. Results showed that the concentration of No. 20 lubricating oil with a 12 h hydraulic retaining time and 16.5 L h^-1 inflow rate was reduced by 99.3% in 15 d, and with a 6 h hydraulic retaining time and 33 L h%^-1 inflow rate it decreased by 98.6070 in 12 d. The results from this study indicated that Zoogloea sp. had a strong potential to be utilized in biodegradation of lubricating oil.展开更多
The advent of the passivating contact concept and its accelerated development have propelled crystalline silicon(c-Si)solar cells into a new era,establishing them as a driving force behind the latest breakthroughs in ...The advent of the passivating contact concept and its accelerated development have propelled crystalline silicon(c-Si)solar cells into a new era,establishing them as a driving force behind the latest breakthroughs in photovoltaic(PV)conversion efficiency.The continual refinement of passivation performance is pivotal to the fabrication of high-efficiency devices.Here,we report a novel deuteration/hydrogenation hybrid strategy involving the deliberate incorporation of deuterium(D,2H)via atmosphere annealing to neutralize defects and enhance the passivation performance of tunnel oxide passivating contact(TOPCon)solar cells.Our findings reveal that hydrogen and deuterium can coexist within the TOPCon structure,where they exhibit a synergistic effect.Notably,when combined at an optimal ratio of 1%deuterium oxide(D2O),this mixture significantly enhances passivation performance compared to the individual addition of hydrogen or deuterium.Specifically,it results in an approximate 15 mV increase in the implied open-circuit voltage(iVOC)for doublesided passivated samples,achieving an average iVOC value of 734 mV.The mechanisms underlying the enhancement in passivation can be inferred,suggesting that deuterium forms stronger bonds with silicon than hydrogen,effectively passivating interfaces and neutralizing defects within polycrystalline silicon(poly-Si).In the presence of dangling bonds on the poly-Si surface,the presence of H2O molecules expands the range of silicon atoms in the vicinity of the contact site where electrons are exchanged or reacted with D2O both horizontally and vertically,demonstrating enhanced adsorption capacity.Proof-of-concept TOPCon solar cells using this novel deuteration/hydrogenation hybrid strategy achieve a promising efficiency of 23.19%,accompanied by substantial improvements in electrical performance,thereby highlighting the exceptional potential of deuterium passivation for high-efficiency TOPCon solar cells.展开更多
In order to control water pollution in the rapidly urbanizing South China area,biological contact oxidation(BCO)process and biological aerated filter(BAF)process were applied in a pilot-scale experiment for decentrali...In order to control water pollution in the rapidly urbanizing South China area,biological contact oxidation(BCO)process and biological aerated filter(BAF)process were applied in a pilot-scale experiment for decentralized wastewater treatment.An investigation to find the optimal parameters of the two biofilm systems was conducted on hydraulic loading,organic loading,and aeration rate.The results indicated that the water reuse criteria required a maximum hydraulic and organic loading of 30.0 m^(3)/(m^(2)·d)and 4.0 kg COD/(m^(3)·d),respectively,as well as a minimum effluent DO of 4.0 mg/L.The utilization of a new media allowed BAF to perform better than BCO.The kinetic description of the COD removal process for BAF and BCO are Se=S0e^(-0.639t)/(1+1.035t),and S_(e)=S_(0)/[(1+0.947t)(1+1.242t)],respectively.The correlativity analysis showed that the two models could predict the effluent water quality based on the hydraulic retention time.Thus,the appropriate hydraulic loading for certain effluent water quality demands could be determined.The two models could be applied to wastewater treatment practice.展开更多
基金This study was supported by the National High Technology Research and Development Program of China(863 Program)(Grant No.2005AA601010-03)the National Natural Science Foundation of China(Grant No.50778001).
文摘In this study two types of biological contact oxidation processes(BCOP),a step-feed(SBCOP)unit and an inter-recycle(IBCOP)unit,were designed to investigate the treatment of heavily polluted river water.The Daqing River,which is the largest pollutant contributor to the Dianchi Lake,one of the most eutrophic freshwater lakes in China,was taken for the case study.It was found that the SBCOP had higher adaptability and better performance in the reduction of COD,TN,and TP,which made it applicable for the treatment of polluted river water entering the Dianchi Lake.Nitrification rate was observed to be greatly affected by the influent temperature.During each season,the nitrification in the SBCOP was higher than that in the IBCOP.TN removal efficiency in the SBCOP was higher than that in the IBCOP during the winter and spring but poorer during the summer,possibly due to the inhibition of denitrification by higher dissolved oxygen level in the summer.Moreover,symbiotic algaebacteria growth may be conducive to the removal of pollutants.
基金supported by the National Natural Science Foundation of China(Nos.62025403 and U23A20354)the Natural Science Foundation of Zhejiang Province(LD22E020001)+1 种基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2022C01215,2024C01055)the Fundamental Research Funds for the Central Universities(226-2022-00200).
文摘Nowadays,a stack of heavily doped polysilicon(poly-Si)and tunnel oxide(SiO_(x))is widely employed to improve the passivation performance in n-type tunnel oxide passivated contact(TOPCon)silicon solar cells.In this case,it is critical to develop an in-line advanced fabrication process capable of producing high-quality tunnel SiO_(x).Herein,an in-line ozone-gas oxidation(OGO)process to prepare the tunnel SiO_(x) is proposed to be applied in n-type TOPCon solar cell fabrication,which has obtained better performance compared with previously reported in-line plasma-assisted N2O oxidation(PANO)process.In order to explore the underlying mechanism,the electrical properties of the OGO and PANO tunnel SiO_(x) are analyzed by deep-level transient spectroscopy technology.Notably,continuous interface states in the band gap are detected for OGO tunnel SiO_(x),with the interface state densities(D_(it))of 1.2×10^(12)–3.6×10^(12) cm^(-2) eV^(-1) distributed in Ev+(0.15–0.40)eV,which is significantly lower than PANO tunnel SiO_(x).Furthermore,X-ray photoelectron spectroscopy analysis indicate that the percentage of SiO_(2)(Si^(4+))in OGO tunnel SiO_(x) is higher than which in PANO tunnel SiO_(x).Therefore,we ascribe the lower D_(it) to the good inhibitory effects on the formation of low-valent silicon oxides during the OGO process.In a nutshell,OGO tunnel SiO_(x) has a great potential to be applied in n-type TOPCon silicon solar cell,which may be available for global photovoltaics industry.
基金This research was supported by the National High Technology Research and Development Program of China （Grant No. 2012BAJ21B04） and the National Natural Science Foundation of China （Grant No. 51108436）.
文摘A novel hybrid anaerobic-contact oxidation biofilm baffled reactor （HAOBR） was developed to simultaneously remove nitrogenous and carbonaceous organic pollutants from decentralized molasses wastewater in the study. The study was based on the inoculation of anaerobic granule sludge in anaerobic compartments and the installation of combination filler in aerobic compartments. The performance of reactor system was studied regarding the hydraulic retention time （HRT）, microbial characteristics and the gas water ratio （GWR）. When the HRT was 24h and the GWR was 20：1, total ammonia and chemical oxygen demand （COD） of the effluent were reduced by 99% and 91.8%, respectively. The reactor performed stably for treating decentralized molasses wastewater. The good performance of the reactor can be attributed to the high resistance of COD and hydraulic shock loads. In addition, the high solid retention time of contact oxidation biofilm contributed to stable performance of the reactor.
文摘The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater. Results showed that Fe-C micro-electrolysis can remove about 30% CODcr, raise pH from 0.7 to 5.5. The CODcr removal efficiency by biochemical process can be more than 80%. During a half year抯 operation, the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge stan-dards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.
文摘The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs （phosphorus accumulating organisms） in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio （C/N）. Furthermore the SRT （sludge retention time） of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%, 75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR （bypass sludge flow rate） should be controlled at 0.35 around.
基金Project supported by the Natural Science and Technology Program of Lanzhou University (Nos. 582402 and 582403).
文摘The purpose of this study was to identify microbial strains that have a strong ability to biodegrade lubricating oil. No. 20 lubricating oil was used as the sole carbon source in an isolation medium to screen bacteria from sludge that had been contaminated with crude oil. Through both morphological and biochemical methods, the bacterial strain that had the highest biodegrading capacity was identified as Zoogloea sp. On the basis of these preliminary results, a biological contact oxidation method was employed to further assess the ability of the Zoogloea sp. strain to treat wastewater contaminated by No. 20 lubricating oil using three oxidation cabins and two hydraulic retaining times （HRT）. Results showed that the concentration of No. 20 lubricating oil with a 12 h hydraulic retaining time and 16.5 L h^-1 inflow rate was reduced by 99.3% in 15 d, and with a 6 h hydraulic retaining time and 33 L h%^-1 inflow rate it decreased by 98.6070 in 12 d. The results from this study indicated that Zoogloea sp. had a strong potential to be utilized in biodegradation of lubricating oil.
基金the National Key Research and Development Program of China(No.2022YFB4200201)Natural Science Foundation of Tianjin(Nos.23JCYBJC01620,22JCYBJC01300)+3 种基金the National Natural Science Foundation of China(Nos.62074084,62274098)the project of highefficiency heterojunction solar cell technology and equipment industrialization(TC220A04A-159)111 Project(B16027)the Fundamental Research Funds for the Central Universities,Nankai University(Nos.63241573,63241568).
文摘The advent of the passivating contact concept and its accelerated development have propelled crystalline silicon(c-Si)solar cells into a new era,establishing them as a driving force behind the latest breakthroughs in photovoltaic(PV)conversion efficiency.The continual refinement of passivation performance is pivotal to the fabrication of high-efficiency devices.Here,we report a novel deuteration/hydrogenation hybrid strategy involving the deliberate incorporation of deuterium(D,2H)via atmosphere annealing to neutralize defects and enhance the passivation performance of tunnel oxide passivating contact(TOPCon)solar cells.Our findings reveal that hydrogen and deuterium can coexist within the TOPCon structure,where they exhibit a synergistic effect.Notably,when combined at an optimal ratio of 1%deuterium oxide(D2O),this mixture significantly enhances passivation performance compared to the individual addition of hydrogen or deuterium.Specifically,it results in an approximate 15 mV increase in the implied open-circuit voltage(iVOC)for doublesided passivated samples,achieving an average iVOC value of 734 mV.The mechanisms underlying the enhancement in passivation can be inferred,suggesting that deuterium forms stronger bonds with silicon than hydrogen,effectively passivating interfaces and neutralizing defects within polycrystalline silicon(poly-Si).In the presence of dangling bonds on the poly-Si surface,the presence of H2O molecules expands the range of silicon atoms in the vicinity of the contact site where electrons are exchanged or reacted with D2O both horizontally and vertically,demonstrating enhanced adsorption capacity.Proof-of-concept TOPCon solar cells using this novel deuteration/hydrogenation hybrid strategy achieve a promising efficiency of 23.19%,accompanied by substantial improvements in electrical performance,thereby highlighting the exceptional potential of deuterium passivation for high-efficiency TOPCon solar cells.
基金the National High Technology Research and Development Program(863 Program)of China(No.2003AA601040)the Program for the High-Level Returned Overseas Chinese Scholars(No.2005-118).
文摘In order to control water pollution in the rapidly urbanizing South China area,biological contact oxidation(BCO)process and biological aerated filter(BAF)process were applied in a pilot-scale experiment for decentralized wastewater treatment.An investigation to find the optimal parameters of the two biofilm systems was conducted on hydraulic loading,organic loading,and aeration rate.The results indicated that the water reuse criteria required a maximum hydraulic and organic loading of 30.0 m^(3)/(m^(2)·d)and 4.0 kg COD/(m^(3)·d),respectively,as well as a minimum effluent DO of 4.0 mg/L.The utilization of a new media allowed BAF to perform better than BCO.The kinetic description of the COD removal process for BAF and BCO are Se=S0e^(-0.639t)/(1+1.035t),and S_(e)=S_(0)/[(1+0.947t)(1+1.242t)],respectively.The correlativity analysis showed that the two models could predict the effluent water quality based on the hydraulic retention time.Thus,the appropriate hydraulic loading for certain effluent water quality demands could be determined.The two models could be applied to wastewater treatment practice.
