This paper describes the effect of the in situ hydrolysis of 2-cyanopyridine and its derivatives on the synthesis of dimethyl carbonate（DMC） from CO2 and methanol over CeO2.2-Cyanopyridine.with the highest electroni...This paper describes the effect of the in situ hydrolysis of 2-cyanopyridine and its derivatives on the synthesis of dimethyl carbonate（DMC） from CO2 and methanol over CeO2.2-Cyanopyridine.with the highest electronic charge number of the carbon in the cyanogroup,is the most effective agent to accelerate the desired reaction by a decrease of water.CeO2（110） planes are active for the hydrolysis of 2-cyanopyridine,further enhancing the DMC formation by in situ removal of water effectively.The DMC yield is improved drastically up to 378.5 mmol g cat^-1 from 12.8 mmol g cat^-1 with the in situ hydrolysis of 2-cyanopyridine over rod-CeO2（1 1 0） catalyst.展开更多
Carbon source is a critical constraint on nutrient removal in domestic wastewater treatment.However,the functions of particulate organic matter（POM） and some organics with high molecular weight（HMW） are overlooked...Carbon source is a critical constraint on nutrient removal in domestic wastewater treatment.However,the functions of particulate organic matter（POM） and some organics with high molecular weight（HMW） are overlooked in the conventional process,as they cannot be directly assimilated into cells during microbial metabolism.This further aggravates the problem of carbon source shortage and thus affects the effluent quality.Therefore,to better characterize organic matter（OM） based MW distribution,microfiltration/ultrafiltration/nanofiltration（MF/UF/NF） membranes were used in parallel to fractionate OM,which obtained seven fractions.Hydrolysis acidification（HA） was adopted to manipulate the MW distribution of dissolved organic matter（DOM） and further explore the correlation between molecular size and biodegradability.Results showed that HA pretreatment of wastewater not only promoted transformation from POM to DOM,but also boosted biodegradability.After 8 hr of HA,the concentration of dissolved organic carbon（DOC） increased by 65%,from the initial value of20.25 to 33.48 mg/L,and the biodegradability index（BOD5（biochemical oxygen demand）/SCOD（soluble chemical oxygen demand）） increased from 0.52 to 0.74.Using MW distribution analysis and composition optimization,a new understanding on the characteristics of organics in wastewater was obtained,which is of importance to solving low C/N wastewater treatment in engineering practice.展开更多
基金Financial support by Natural Science Foundation of China (NSFC,Nos.21176179,U1462122)the Program for New Century Excellent Talents in University(No.NCET-13-0411) is gratefully acknowledged
文摘This paper describes the effect of the in situ hydrolysis of 2-cyanopyridine and its derivatives on the synthesis of dimethyl carbonate（DMC） from CO2 and methanol over CeO2.2-Cyanopyridine.with the highest electronic charge number of the carbon in the cyanogroup,is the most effective agent to accelerate the desired reaction by a decrease of water.CeO2（110） planes are active for the hydrolysis of 2-cyanopyridine,further enhancing the DMC formation by in situ removal of water effectively.The DMC yield is improved drastically up to 378.5 mmol g cat^-1 from 12.8 mmol g cat^-1 with the in situ hydrolysis of 2-cyanopyridine over rod-CeO2（1 1 0） catalyst.
基金supported by the Jiangsu Water Resources Protection Project(No.2015005)the National High-Tech Research Program(863)of China(No.2012AA063302)the Fundamental Research Funds for Central Universities(No.2013/B14020391)
文摘Carbon source is a critical constraint on nutrient removal in domestic wastewater treatment.However,the functions of particulate organic matter（POM） and some organics with high molecular weight（HMW） are overlooked in the conventional process,as they cannot be directly assimilated into cells during microbial metabolism.This further aggravates the problem of carbon source shortage and thus affects the effluent quality.Therefore,to better characterize organic matter（OM） based MW distribution,microfiltration/ultrafiltration/nanofiltration（MF/UF/NF） membranes were used in parallel to fractionate OM,which obtained seven fractions.Hydrolysis acidification（HA） was adopted to manipulate the MW distribution of dissolved organic matter（DOM） and further explore the correlation between molecular size and biodegradability.Results showed that HA pretreatment of wastewater not only promoted transformation from POM to DOM,but also boosted biodegradability.After 8 hr of HA,the concentration of dissolved organic carbon（DOC） increased by 65%,from the initial value of20.25 to 33.48 mg/L,and the biodegradability index（BOD5（biochemical oxygen demand）/SCOD（soluble chemical oxygen demand）） increased from 0.52 to 0.74.Using MW distribution analysis and composition optimization,a new understanding on the characteristics of organics in wastewater was obtained,which is of importance to solving low C/N wastewater treatment in engineering practice.
