•The public as another decision body participates in LSGDM problem.•The concept of public dynamic reliability is defined.•A novel information entropy measure on IFN is to determine the criteria ...weight.•An optimization model is built to determine weight of different decision bodies.•Information fusion from different decision bodies is based on knowledge-unit model.
With the rapid development of social media, reliable information released by the public on social media can provide important decision-making support. Therefore, the consideration of the public as another decision-making body participating in large-scale group decision-making (LSGDM) problems has become an extensively researched topic. However, the participation of the public as a decision-making body with decision-making experts faces several issues, such as the acquisition of public opinion, the reliability of public opinion, the integration of public and expert opinions, etc. Given this, this paper proposes a public and large-scale expert information fusion method that considers public dynamic reliability via sentiment analysis and intuitionistic fuzzy number (IFN) expressions. First, sentiment analysis technology is used to process public social media data and obtain IFNs as the opinions of the public decision-making body. Second, the concept of public dynamic reliability is defined to measure the degree of integration of public opinion. Third, a novel information entropy measure of IFNs is proposed, and a new method is introduced to determine the criteria weights under the two different decision-making bodies. Finally, an optimization model that considers the consensus levels of expert subgroups is proposed to determine the weights of different decision-making bodies. The public and expert opinions are then aggregated to obtain collective decision-making information. A case study is proposed to illustrate the application of the proposed method, and the comparative analysis reveals the features and advantages of this model.
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•The promotion of CH4 yield from biochar was stronger at higher FM ratio.•Biochar promoted anabolism as well as catabolism of anaerobes.•The dominant methanogenic pathway shifted due ...to increasing biochar dosage.•Biochar enriched Acinetobacter which enhanced the VFA degradation.•Excessive biochar triggered excess biomass growth and thus decreased CH4 yield.
Biochar (BC) promotes the performance of anaerobic digestion (AD) through different routes, such as enriching microbes, buffering pH and promoting electron transfer. However, the mechanisms and processes of AD that enhanced by BC under various food to microorganism (F/M) ratios are still unclear. The organic transformations, bioelectrochemical characteristics and microbial consortia under the different BC dosages and F/M ratios were studied to reveal the role of BC in an AD process. The electron transfer system (ETS) was proportional to BC dosage and considered to be a key for AD promotion. At the F/M ratios of 0.5 and 1.0, BC accelerated methane production mainly by promoting ETS. The most enhanced specific methanation activities (SMAs) were obtained with 10.0 g/L BC, and the promotion efficiency under the F/M ratio of 1.0 was significantly higher (P < 0.05) than that under the F/M ratio of 0.5. Under the higher F/M ratio of 2.0, BC shortened the entire AD duration for 5.0 ∼ 13.0 days and guaranteed the resilience of AD by expanding the thermodynamic window of syntrophic methanogenesis via direct interspecies electron transfer (DIET). The COD balance analysis and the ecological functional profiles of microbes demonstrated that BC promoted both the anabolism and catabolism of anaerobes, and enhanced the DIET by converting hydrotrophic methanogenesis into acetolastic methanogenesis pathway. Besides, excessive BC enhanced SMA and simultaneously triggered superfluous biomass growth and thus decreased CH4 yield. This study provided an important reference for further application of BC under various F/M ratios and dosages in AD.
Nitrate-dependent anaerobic methane oxidation (N-DAMO) links the oxidation of greenhouse gases with the removal of nitrogen oxide, and such a linkage constitutes distinctive carbon-nitrogen coupling. ...This study utilizes a laboratory slurry incubation, carbon isotope tracing, and metagenomic techniques to explore the N-DAMO process in mangrove soils and measure its reaction rate. In addition, review on the N-DAMO processes in fifty-two different ecosystems around the world is conducted to further reveal the environmental and ecological impact of the N-DAMO process in mangrove soils. The results indicated that the N-DAMO rate in mangrove soil was 63.62 ± 0.39 nmol CO
2
-C g
− 1
d
− 1
, and the N-DAMO process converted over 60% of the CH
4
generated by mangrove soils to CO
2
. Without the N-DAMO process, the CH
4
emissions of mangrove soils will definitely increase. Moreover, the nitrogen removal rate of this process was 169.66 ± 1.04 nmol N g
− 1
d
− 1
, which demonstrated an obvious purification effect. Hence, the N-DAMO process is critical to balance C/N values in mangrove soils. Existing studies have shown that high-levels of N-DAMO exist in rivers/lakes, peatlands, and wetland ecosystems. Among the wetland ecosystems, the rate of the N-DAMO process in mangrove soils is higher. Overall, these results illustrated the occurrence and significance of N-DAMO processes in mangrove ecosystems. This study deepens the understanding of coupling biogeochemical cycle of carbon and nitrogen and provides a scientific basis for an accurate assessment of blue carbon sink functionality in mangrove soils.
This article investigates the current status of the livestock industry (cattle, pigs, sheep, and poultry) in China and assesses the potential for biogas production from anaerobically digested ...livestock manure. According to calculation results based on the latest data of livestock released by the National Bureau of Statistics of China in 2018, China produced 2 × 1012 kg of manure pollution in 2017, with pig waste representing the largest single manure source. Biogas that can be converted from high organic containing manure is a kind of clean bioenergy with low carbon footprint. In 2017, the energy potential from manure-produced biogas was about 5.74 × 1012–6.73 × 1012 MJ, which corresponds to 4–5% of China's total energy demand. Correlation analysis between biogas production and the livestock industry showed that crop production had significant effects on manure-generated biogas production. However, it is necessary to address the challenges when applying AD technology. Bioenergy potential from manure will be lost during material collection and transportation. Although large-scale livestock farming remains controversial, this type of farming can improve the energy recovery rate of livestock manure. How to gain benefits and maintain sustainable development is also a bottleneck for AD promotion. Reducing energy input in AD projects as well as enhancing the efficiency of methanogenesis of livestock manure are key factors for achieving a high net output of biogas projects. More inclusive strategies and a broader vision should be adopted to allow stakeholders to benefit from manure-generated biogas projects.
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•The energy recovery potential from livestock manure in China was estimated.•Worldwide anaerobic digestion applications for livestock waste were summarized.•The bottlenecks of biogas project promotion in the whole chain were assessed.•Large-scale farming is the key for reducing biogas energy potential loss.
The geographical setting of the Jiulong River estuary determines that the estuary receives wastes from both riverine input and adjacent urban sewage. However, the dominant nitrogen (N) source remains ...unclear. A nutrient mass-balance model and a preliminary LOICZ (Land–Ocean Interactions in the Coastal Zone) biogeochemical model were linked to evaluate agricultural N contributions from the Jiulong River catchment to the estuary and coastal water. Results showed that agricultural N surplus was the largest N source in the catchment, contributing 60.87% of the total Nitrogen (N) and 68.63% of the dissolved inorganic nitrogen (DIN). Household wastes and other sources followed. Riverine DIN fluxes were about 20.3% of exportable DIN and 14.4% of exportable total N, but approximately 9.7% of DIN inputs, and 7.3% of total N inputs to the Jiulong River catchment. The model system clearly showed that agricultural and anthropogenic activities in the catchment were the major N sources of the estuary and coastal water, and riverine N fluxes from these sources substantially impacted the estuary and coastal water quality and biogeochemical processes.
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•BC expanded the membrane flow capacity for wastewater from 720.3 to 1855.4 m3/m2.•BC scoured 60% of foulants from the fouling membrane.•BC expanded 90% of the membrane capacity for ...organic foulants.•Inorganic foulants were prevented from precipitation on the membrane surface by BC.•BC-enhanced scouring and biodegradation promoted the membrane fouling resilience.
Membrane fouling is a daunting challenge in applying anaerobic membrane reactors (AnMBRs). The effects and mechanisms of biochar (BC) in enhancing the fouling resilience of an AnMBR for treating municipal wastewater (MWW) were revealed in this study. During the half-year operation, the twice addition of BC effectively alleviated membrane fouling through multiple approaches. BC expanded the membrane capacity of AnMBR for wastewater from 720.3 to 1855.4 m3/m2. BC prevented inorganic foulants from precipitating on the membrane surface and enhanced the capacity for organic foulants. The functional groups and protein structures suggested that foulants with lower binding forces were stripped from the membrane surface by BC, while foulants with stronger binding forces were trapped on the membrane, forming a more homogeneous and compact fouling structure. The BC-scrub-effect test indicated that BC detached 71.3% of the cake and 41.6% of the gel foulants. The descent of the transmembrane pressure was divided into fast (0.34 kPa/h) and slow (0.07 kPa/h) foulant release rates, which was attributed to the varied characteristics of composition, spatial distribution and binding forces between foulants from the cake and gel layers. BC significantly enriched functional microbes like Longilinea, Acinetobacter and Methanobacterium and stimulated metabolic functions such as Fermentation and Hydrocarbon degradation, thus improving membrane resilience for organics, and resulting in a lower content of soluble organic foulants on the membrane. This study provides a better understanding of the multiple approaches by BC to enhance the fouling resilience of an AnMBR treating MWW.
Phytoplankton is sensitive to changes in river ecosystems. Increasing dams disrupt the continuity of river ecosystems. However, the spatial impacts of dams on phytoplankton have not been well ...documented. In this study, using multiple statistical analyses, the relationships between environmental drivers and phytoplankton community structures in natural background reaches, reservoirs, and corresponding post-dam reaches were explored in the Jiulong River with multiple cascaded dams, which encountered eutrophication and algal blooms in the past 15 years. Results illustrated that damming exacerbated longitudinal discontinuities of phytoplankton communities. The relative abundance of phytoplankton varied in three types of river sections. The average phytoplankton abundance in the reservoirs (1.62 × 105 cell·L−1) was higher than those in the natural background reaches (5.15 × 104 cell·L−1) and the corresponding downstream reaches (4.55 × 104 cell·L−1). The total β diversity ranged from 0.38 to 0.89 with an average of 0.64 and dominated by species replacement and least by species richness. The water environmental factors and hydraulic parameters rather than nutrients were more attributable to phytoplankton community variability in three river sections. These findings facilitate the management of rivers with multiple cascade dams by releasing environmental flows, jointly operating cascade hydropower stations, and developing nutrient reduction schemes to mitigate the negative impacts of damming in the river.
•The phytoplankton in reservoirs had higher abundance than that in river reaches.•β diversity was high and species replacement was mainly attributable.•Water environmental factors were dominant drivers of phytoplankton community.•The phytoplankton in reservoirs was significantly affected by water retention time.
Text mining is the process of deriving high-quality information from text so that it can focus on extracting useful information from text or web documents. IoT devices generate massive structured or ...unstructured data including text data. The opportunity coming behind big data and unstructured data is a great impulse for governments or companies to choose solutions based on text mining approaches to improve strategic business activities and boost decision making. Expert information is an important reference information for decision making. How to collect the expert information from text or web documents is a problem. In this paper, a text mining approach is introduced to crawl and extract expert information from Internet. We build a basic framework and main modules including information extraction, data cleaning and deduplication, expert recommendation model to cope with text data from Web content. We also define several metrics, data structures and propose some algorithms to help text mining. Finally, the experiment is implemented with datasets and the results show that our text mining approach can extract expert attributes accurately.
•In this paper, a text mining approach is introduced to crawl and extract expert information from Internet.•A basic framework is built, which is including information extraction, data cleaning and deduplication, expert recommendation model to cope with text data from Web content.•Several metrics, data structures, some algorithms are proposed to help text mining.
An increase in riverine nutrient fluxes significantly influences the estuarine ecosystem. This study collected nutrient data in most of China's rivers from 1963 to 2015 to estimate the nutrient ...fluxes from major rivers and analyze interannual variability of nutrient fluxes and estuarine environmental effects. The results showed that the nutrient fluxes from the Yangtze River increased annually from 1963 to 2012. The trend of nutrient fluxes from the Yellow River was consistent with that from the Jiulong River, i.e., nutrient fluxes increased from 1998 to 2007 and then decreased. The areal nutrient fluxes from China's major rivers were higher than those from major world rivers, while the areal nutrient yield rates per capita were lower than those from major world rivers. We also found that China's estuaries were predominantly phosphorus-limited and slowly moving toward lower dissolved silica over dissolved inorganic nitrogen (DSi:DIN) ratios with time. Meanwhile, the nutrient limitation of phytoplankton growth in most of China's estuary systems was moving toward a higher incidence of phosphorus and silicon limitations as a result of increased DIN fluxes, and this would likely alter phytoplankton communities. Furthermore, the decreases in the DSi:DIN ratio and dissolved silica over dissolved inorganic phosphate (DSi:DIP) ratio, and the increases in both DIN and DIP fluxes, caused increased red tide blooms.
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•The areal nutrient yield rates from China's rivers are high among major world rivers.•Nutrient limitation is moving toward a higher incidence of P and Si limitations.•Ratios of DIN, DIP and DSi had significant influences on near shore eutrophication.•The decreases in the DSi:DIN ratios might cause increased red tide blooms.
