Alkaline pretreatment of straw materials prior to enzyme hydrolysis is a key step for bioconversion of lignocellulose to bioethanol and chemicals.Wastewater from the alkaline pretreatment process must be treated befor...Alkaline pretreatment of straw materials prior to enzyme hydrolysis is a key step for bioconversion of lignocellulose to bioethanol and chemicals.Wastewater from the alkaline pretreatment process must be treated before discharge to minimize its environmental impact.In this study,biotreatment of the wastewater from soda-pretreatment process of corn stover was investigated using fungus Z-6,and some indexes such as color,chemical oxygen demand(COD),and lignin content of wastewater before and after biotreatment were determined to assess the effect of the biotreatment.Results showed that fungus treatment could remove color up to approximately 72%after 2 d,and decrease COD and lignin content by about 63%and 60%,respectively after 3 d.The wastewater was fractionated using dynamic ultrafiltration method,and the changes in lignin contents of the effluent fractions with different molecular weights before and after biotreatment were analyzed.Some compounds produced by the fungus during treatment were identified using gas chromatography-mass(GC-MS)spectrometer,which revealed that depolymerization of lignin occurred during the biotreatment process.展开更多
Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,...Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.展开更多
The global demand for water for agricultural use is continuously increasing worldwide as a result of population growth and food supply, approximately 1% per year since the 1980s. Irrigated agriculture represents 20% o...The global demand for water for agricultural use is continuously increasing worldwide as a result of population growth and food supply, approximately 1% per year since the 1980s. Irrigated agriculture represents 20% of the total cultivated area and contributes 40% of the total food production worldwide. Competition for water resources is particularly much needed in arid and semi-arid regions, where irrigation is essential for successful agriculture. This leads to the need to treat larger amounts of wastewater, in order to compensate for the lack of rainwater to irrigate crops and thus favor the environment and the economic development of farmers. In Mexico there are two highly consumed food products, they are: corn and beans, a fundamental part of the Mexican people diet. It can be said that corn is basic in the diet of Mexicans, it is consumed mainly as “tortilla” and in “tamales”, also in some stews;there is a variety called fodder corn to feed cattle. Beans are also an essential part of the Mexican diet for its nutritional value and pleasant flavor. To solve the challenges of the future in the supply of water for agriculture, it is necessary to reconsider that not all farmers can afford irrigation systems and depend on rainwater, so the use of treated wastewater in treatment plants can be useful.展开更多
A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater （ethanol fuel production） treatment has been designed.The characteristics of nitrifying bacteria entrapped in a w...A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater （ethanol fuel production） treatment has been designed.The characteristics of nitrifying bacteria entrapped in a waterborne polyurethane （WPU） gel carrier were evaluated after acclimation.In the acclimation period,nitrification rates of WPU-immobilized nitrobacteria were monitored and polymerase chain reaction （PCR） was also carried out to investigate the change in ammonium-oxidizing bacteria.The results showed that the pellet nitrification rates increased from 21 to 228 mg-N/（L-pellet·hr） and the quantity of the ammonia oxidation bacteria increased substantially during the acclimation.A continuous ammonia removal experiment with the anaerobic pond effluent of a distillery wastewater system was conducted with immobilized nitrifying bacteria for 30 days using an 80 L airlift reactor with pellets at a fill ratio of 15% （V/V）.Under the conditions of 75 mg/L influent ammonia,hydraulic retention time （HRT） of 3.7-5.6 hr,and dissolved oxygen （DO） of 4 mg/L,the effluent ammonia concentration was lower than 10 mg/L and the ammonia removal efficiency was 90%.While the highest ammonia removal rate,162 mg-N/（L-pellet·hr）,was observed when the HRT was 1.3 hr.展开更多
基金This study was financially supported by the Key research and development project of Shandong province,China(2019GSF107009,2019JZZY020223 and 2019JZZY020807).
文摘Alkaline pretreatment of straw materials prior to enzyme hydrolysis is a key step for bioconversion of lignocellulose to bioethanol and chemicals.Wastewater from the alkaline pretreatment process must be treated before discharge to minimize its environmental impact.In this study,biotreatment of the wastewater from soda-pretreatment process of corn stover was investigated using fungus Z-6,and some indexes such as color,chemical oxygen demand(COD),and lignin content of wastewater before and after biotreatment were determined to assess the effect of the biotreatment.Results showed that fungus treatment could remove color up to approximately 72%after 2 d,and decrease COD and lignin content by about 63%and 60%,respectively after 3 d.The wastewater was fractionated using dynamic ultrafiltration method,and the changes in lignin contents of the effluent fractions with different molecular weights before and after biotreatment were analyzed.Some compounds produced by the fungus during treatment were identified using gas chromatography-mass(GC-MS)spectrometer,which revealed that depolymerization of lignin occurred during the biotreatment process.
基金Supported by the Technological Project of Heilongjiang Province"the Open Competition Mechanism to Select the Best Candidates"(2022ZXJ05C01-03)。
文摘Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.
文摘The global demand for water for agricultural use is continuously increasing worldwide as a result of population growth and food supply, approximately 1% per year since the 1980s. Irrigated agriculture represents 20% of the total cultivated area and contributes 40% of the total food production worldwide. Competition for water resources is particularly much needed in arid and semi-arid regions, where irrigation is essential for successful agriculture. This leads to the need to treat larger amounts of wastewater, in order to compensate for the lack of rainwater to irrigate crops and thus favor the environment and the economic development of farmers. In Mexico there are two highly consumed food products, they are: corn and beans, a fundamental part of the Mexican people diet. It can be said that corn is basic in the diet of Mexicans, it is consumed mainly as “tortilla” and in “tamales”, also in some stews;there is a variety called fodder corn to feed cattle. Beans are also an essential part of the Mexican diet for its nutritional value and pleasant flavor. To solve the challenges of the future in the supply of water for agriculture, it is necessary to reconsider that not all farmers can afford irrigation systems and depend on rainwater, so the use of treated wastewater in treatment plants can be useful.
基金supported by the National Water Pollution Control and Management Technology Major Projects(No. 2008ZX07101-010-03)the National Natural Science Foundation of China (No. 50708058)+2 种基金the National High Technology Research and Development Program (863)of China (No. 2012AA062703)the Shanghai Municipal Science and Technology Commission Major Project (No.04DZ12030-2)the Shanghai Committee of Science and Technology (No.10231201800)
文摘A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater （ethanol fuel production） treatment has been designed.The characteristics of nitrifying bacteria entrapped in a waterborne polyurethane （WPU） gel carrier were evaluated after acclimation.In the acclimation period,nitrification rates of WPU-immobilized nitrobacteria were monitored and polymerase chain reaction （PCR） was also carried out to investigate the change in ammonium-oxidizing bacteria.The results showed that the pellet nitrification rates increased from 21 to 228 mg-N/（L-pellet·hr） and the quantity of the ammonia oxidation bacteria increased substantially during the acclimation.A continuous ammonia removal experiment with the anaerobic pond effluent of a distillery wastewater system was conducted with immobilized nitrifying bacteria for 30 days using an 80 L airlift reactor with pellets at a fill ratio of 15% （V/V）.Under the conditions of 75 mg/L influent ammonia,hydraulic retention time （HRT） of 3.7-5.6 hr,and dissolved oxygen （DO） of 4 mg/L,the effluent ammonia concentration was lower than 10 mg/L and the ammonia removal efficiency was 90%.While the highest ammonia removal rate,162 mg-N/（L-pellet·hr）,was observed when the HRT was 1.3 hr.
