A large flow of effluent is generated from brewery plants and needs treatment before discharging into the environment. A laboratory-scale investigation was conducted to examine the effectiveness of the anaerobic upflow blanket filter (UBF) process for the biomethanation of a brewery effluent. The results show that the process, when operated at ambient temperatures of 20–29°C and influent chemical oxygen demand (COD) of 2440 mg/l, could remove the majority of the organic matter at a low hydraulic retention time. The process produced a potentially usable energy. These results compare favorably with the results obtained from investigations into the biomethanation of brewery effluent using other anaerobic processes. 相似文献
Microbial enzymes are crucial for material biotransformation during the composting process. In this study, we investigated the effects of adding bamboo charcoal (BC) (i.e., at 5%, 10%, and 20% corresponding to BC5, BC10, and BC20, respectively) on the enzyme activity levels during chicken manure composting. The results showed that BC10 could increase the cellulose and urease activities by 56% and 96%, respectively. The bacterial community structure in BC10 differed from those in the other treatments, and Luteivirga, Lactobacillus, Paenalcaligenes, Ulvibacter, Bacillus, Facklamia, Pelagibacterium, Sporosarcina, Cellvibrio, and Corynebacterium had the most important roles in composting. Compared with other treatments, BC10 significantly enhanced the average rates of degradation of carbohydrates (D-xylose (40%) and α-D-lactose (44%)) and amino acids (L-arginine (16%), L-asparagine (14%), and L-threonine (52%)). We also explored the associations among the bacterial community and their metabolic functions with the changes in the activities of enzymes. Network analysis demonstrated that BC10 altered the co-occurrence patterns of the bacterial communities, where Ulvibacter and class Bacilli were the keystone bacterial taxa with high capacities for degrading carbon source, and they were related to increases in the activities of cellulase and urease, respectively. The results obtained in this study may help to further enhance the efficiency of composting. 相似文献
Carbon dioxide (CO2) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO2 emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO2 partial pressures (pCO2) and degassing in a monsoonal river (Yue River) within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO2 with a mean ± standard deviation of 1474 ± 1614 µatm, leading to emissions of 557 - 971 mmol/m2/day from river water to the atmosphere. Annual CO2 emissions were 1.6 - 2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO2 was positively correlated to anthropogenic land use (urban and farmland), and negatively correlated to forest cover. pCO2 also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict pCO2. Farmland and urban land released nutrients and organic matter to the river system, driving riverine pCO2 enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO2, which should be considered in future large-scale estimates of CO2 emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers. 相似文献
Environmental Fluid Mechanics - Laboratory experiments were performed to investigate how flow patterns and bed morphology are affected around a submerged vegetation patch in the condition without... 相似文献
ABSTRACTOutsourcing maintenance is an economical way for wind farm owners to address sophisticated and expensive maintenance operations of wind turbines. This paper proposes three options for the post-warranty maintenance contract of wind turbines from the perspective of service providers. Option 1 involves corrective maintenance only. In option 2, the first preventive maintenance is performed at a certain time point and after that periodic maintenance is carried out. Option 3 initiates with a preventive replacement and performs periodic maintenance subsequently. An availability target is set over the contract period and failing to satisfy the target incurs a penalty from the service provider. The objective is to determine the optimal preventive maintenance programs of option 2 and option 3 that minimize the contract servicing cost. Numerical examples are provided to illustrate the proposed policies. The results show that option 2 and option 3 are more effective than option 1 and their effectiveness grows when warranty and contract coverages increase. 相似文献
Freshwater lakes are important reservoirs for antibiotic resistance genes (ARGs). In this study, we determined the ARG profiles in water samples from Ying Lake, China, using high-throughput quantitative PCR. The high prevalence of ARGs suggested significant pollution with ARGs in the study area, where the ARG diversity and abundance were greater in an area with box-type fish farming than an area with fenced fish farming. Network analysis indicated the widespread co-occurrence of ARGs and mobile genetic elements. cphA-01, blalMP02, and blaCMY202 were identified as adequate indicator genes for estimating the total ARG abundances. Redundancy analysis indicated that changes in the microbial communities caused by variations in the physicochemical parameters with different fish culture methods mainly determined the ARGs in the lake system. Thus, analyzing the factors that affect ARGs provided novel insights into the mechanisms responsible for the maintenance and propagation of ARGs in a lake.