Environmental Impact Factors Research Articles

Effect of coconut shell nanopowder reinforcement in the development of palm fiber composites

Lightweight materials are being employed in aeronautical and automobile industries for high strength, lower weight, and energy consumption. Attention is needed to control pollution through the usage of harmful synthetic composites globally. In this work, coconut shell nanofillers are reinforced in the development of various palm fiber (leaf stalk, leaf sheath, leaf-spine, and fruit) composites using the hand layup technique. Mechanical and morphological effects of the addition of nano-coconut-shell-powder to the composites are addressed. The palm fibers are sandwiched within the glass fiber to improve the strength of composites. The addition of coconut shell nanoparticles in the composites improves the tensile, flexural, impact, hardness, and water absorption characteristics. SEM image observations on the composite indicate the buildup of nanomodified matrix residues around the fiber bundle. The adhesive property of the composite is confirmed by Fourier transform infrared spectroscopy examination, which reveals the presence of one additional alcohol/phenol OH stretch, one less alkyl CH stretch, and aromatic CH bending functional groups. The inclusion of palm fibers during the fabrication of composites facilitated the pushing of curves to higher temperatures with considerable degradation temperatures, thereby increasing thermal stability and making them suitable for thermal applications. Development of the eco-composite changes environmental impact factors aiming sustainability.

Spatio-temporal Distribution Characteristics and Environmental Impact Factors of Lung Cancer Mortality: A Case Study of Yuhui District in Bengbu City, China

Spatio-temporal Distribution Characteristics and Environmental Impact Factors of Lung Cancer Mortality: A Case Study of Yuhui District in Bengbu City, China

In-situ preparation of coal gangue-based catalytic material for efficient peroxymonosulfate activation and phenol degradation

Based on the urgency of comprehensive utilization of large amount of coal gangue and the demand for the treatment of organic pollution in coal chemical sites and water bodies, novel coal gangue-based persulfate catalytic material (GCM) which can effectively activate peroxymonosulfate (PMS) were prepared by using coal gangue as raw material and adding activator under inert atmosphere. Under the optimized conditions, the degradation rate of GCM-ZnCl2 material can reach 82.6% in 25min. Among different environmental impact factors, anions have little effect on the degradation rate of phenol, while the initial pH value has a greater impact. When the pH value is 9.0, it belongs to the synergistic effect of alkali activation, and the degradation effect of phenol is relatively better. The GCM-ZnCl2 material can realize the efficient adsorption of phenol through its large specific surface area and pore volume, and provide more catalytic active sites. The oxygen-containing groups CO (carboxyl, ester, ketone, etc.) on its surface can react with PMS to produce free radical SO4•− or induce the production of non-free radical 1O2, so as to realize the efficient degradation of phenol.

Investigation of exergy-energy and environ-economic performance parameters of active indirect solar dryer for pineapple drying without and with energy storage unit

The quality, quantity and availability of energy, the environmental impact, and the economic importance (4E) of a forced convection indirect solar dryer without (setup-1) and with thermal energy storage (TES) system (setup-2) were analyzed during the drying pineapple. Once the tests were finished in setup-1, setup-2 was adopted by integrating with a system having paraffin as a TES unit. The temperature, velocity, and mass data were recorded to evaluate the 4E parameters. The collector and drying efficiency for setup-1 and setup-2 were 67.04, 66.97 % and 7.23, 10.84 %, respectively. Setup-2 was better in activation energy and specific energy consumption. The average exergy efficiency of collector and dryer for setup-1 and setup-2 were 2.33 and 2.12 % and 34.66 and 57.07 %, respectively. Other exergy parameters like inflow, outflow, and loss for collector and dryer and sustainability indicators like waste energy ratio, improvement potential, the environmental impact factor, and sustainability index were enhanced in setup-2. CO2 emission, mitigation, and credit were improved in setup-2. The energy payback period for setup-1 and setup-2 was 1.503 and 1.831 years, while the corresponding economic payback period was 1.41 and 0.93 years in 35 years, respectively. Setup-2 performed better than setup-1 based on the estimated parameters.

The Impacts of Urban Form on Carbon Emissions: A Comprehensive Review

As a result of global climate change and urban development, the interaction between urban form and carbon emissions has become a frontier issue and a key area of carbon emission research. This paper presents a scientometric analysis of 2439 academic publications between 2002 and 2021 on urban form and carbon emissions to explore the current state of global research and future development potential. Citespace and VOSviewer were the primary analysis tools. The results showed the following: (1) The number of articles published on urban form and carbon emission research shows an increasing trend, especially after 2012. (2) Scientific research institutions and authors in developed countries paid attention sooner to the urban ecological environment. With the deepening of economic globalization, developing countries began to pay more attention to the urban environment. (3) Through an analysis of keyword clusters, timelines, and stacked area charts, the development of the urban form and carbon emissions can be divided into the following three stages. The first is the budding stage, which is characterized by preliminary research on the atmospheric environmental impact factors. The second stage is the development stage, with urban areas becoming the leading research object of carbon theory. The third stage is the mature stage, which is characterized by an emphasis on the optimization of carbon emissions. (4) Finally, the influence of urban form on carbon emissions includes four main aspects: land use, built environment, transportation networks, and development patterns.

Granger Causality Analysis of Foreign Trade in Cement Products and Ecological Impact in China

This paper presents an in-depth study and analysis of the impact of foreign trade on cement products and the ecological environment in China through Granger causality analysis. Based on the theoretical basis of foreign trade, ecological environment, and the relationship between them, a general equilibrium model is used to empirically analyze the “three effects” of foreign trade in Chinese cement products on the ecological environment, and the effects of import and export trade on ecological environment and the net effects are calculated, respectively. Then, based on the data of domestic and foreign cement product production and trade, the purpose, scope, and environmental impact factors of the ecological impact of foreign trade of Chinese cement products were determined by the life cycle assessment method, and the inventory analysis was carried out in phases based on the six aspects of nonrenewable resource depletion, global warming, photochemical ozone generation, acidification, eutrophication, and human health damage. The results were characterized and standardized, and the hierarchical analysis method was used to weight the evaluation of each environmental impact type, and finally, the resource consumption coefficient and environmental impact load index values and corresponding ratios were determined based on the green product evaluation method. This paper establishes an index system for the ecological and environmental impacts of foreign trade of cement products, which is a guide for the ecological and environmental impacts of foreign trade of other products in China. The results of the study on the ecological and environmental impacts of foreign trade of Chinese cement products also have important practical significance for the formulation of regulations and standards related to the cement industry, the adjustment of the import and export structure of cement products, and the improvement of production equipment and processes.

Heat Transfer and Exergy Analysis of a Shell and Tube Heat Exchanger using PGW based ZnO Nanofluids

In this experimental work, ZnO nanoparticles were synthesized using the chemical precipitation method, and the nanoparticle structure and morphology were characterized through XRD and SEM. Heat transfer and exergetic characteristics were then studied in a shell and tube heat exchanger using PGW-based ZnO nanofluids varying nanoparticle volume concentration and nanofluid (shell side) flow rate at 6, 8, 10 and 12 litres/min. The hot water flow rate was fixed at 12 litres/min. The experimental results show that the heat transfer rate was improved by increasing the nanoparticle concentration and nanofluid flow rate. When the nanoparticle volume concentration was 0.3 per cent, the maximum enhancement of heat transfer rate and average heat transfer coefficient using ZnO nanofluids were 35.9 per cent and 40.2 per cent, respectively, in comparison to the base fluid. Exergy loss and dimensionless exergy loss both increased with nanofluid flow rate and dropped substantially with increased nanoparticle volume concentrations. The average increment of exergetic effectiveness at three different nanoparticle volume concentration (0.1%, 0.2%, and 0.3%) are 10.68%, 23.64%, and 31.23% respectively. The highest exergetic sustainability index (0.41) and lowest environmental impact factor (2.42) were observed when the nanoparticle concentration was 0.3% with the nanofluid flow rate of 6 litres/min.

Community Structure of Phytoplankton and Environmental Impact Factors in Lake Hongze from 2015 to 2020

Lake Hongze is an essential storage lake for the "Eastern Route of the South-North Water Diversion Project" and plays an important role in climate adjustment and flood prevention and control. To study the structural evolution of phytoplankton communities in Lake Hongze and their relationship with environmental factors and to understand the status of the ecosystem of Lake Hongze before the "ten-year fishing ban," monthly monitoring was carried out from 2015 to 2020. During the study period, total nitrogen showed a significant downward trend starting in 2017, the total phosphorus and chemical oxygen demand declined slightly, the water temperature had no obvious change trend, and the water depth and transparency increased from 2015 to 2018 and then declined significantly. A total of 102 genera of phytoplankton in eight phyla were identified, with a total of 310 species. The dominant phytoplankton phyla mainly included Chlorophyta and Bacillariophyta, followed by Cyanophyta and Pyrrophyta. The dominant genera were Scenedesmus, Aulacoseira, Cryptomonas, Cyclotella, Tetraedron, Microcystis, and Dolichospermum. The results of non-metric multidimensional scaling (NMDS) showed that the structural composition of the phytoplankton community differed significantly among years, seasons, and sampling areas, mainly due to the redistribution among dominant genera. NMDS analysis also indicated that variation in the phytoplankton community in Lake Hongze was mainly related to water temperature, total nitrogen, total phosphorus, water depth, and transparency. Total nitrogen, water depth, and phytoplankton community structure were significantly correlated with interannual succession, whereas water temperature, total nitrogen, and phytoplankton seasonal succession were also significantly correlated. Combined with the measures taken by the management department in recent years, the changes in the structure of the phytoplankton community may be related to the removal of the fence and other management and restoration measures in Lake Hongze.

Environmental risk assessment of inter-well partitioning tracer compounds shortlisted for the offshore oil and gas industry

Quantifying residual oil saturation (SOR) in the inter-well region of oil and gas reservoirs is key for successfully implementing EOR solutions. Partitioning inter-well tracer tests (PITTs) has become a common method for quantifying SOR. A new group of seven chemicals – pyridine, 2,3-dimethyl pyrazine, 2,6-dimethyl pyrazine, 4-methoxybenzyl alcohol, 3,4-dimethoxybenzyl alcohol, 4-chlorobenzyl alcohol, and 2,6-dichlorobenzyl alcohol – have been proposed as potential partitioning tracers for quantifying SOR. Using these tracers can lead to their environmental release in the marine environment through produced water discharges, with currently limited knowledge on impacts in the marine ecosystem. The primary objective of the present study is to assess the environmental risk of discharging the tracer compounds in the marine environment. We investigated the fate and effect of these tracers in the marine environment. Biodegradability in seawater was measured to understand the fate of tracers in the marine environment. The acute toxicity of tracers was measured in terms of the percent cell viability of a rainbow trout gill cell line (RTgill-W1) and growth inhibition of the algae Skeletonema costatum. The ecotoxicological information obtained from these experiments was used in the dynamic risk and effects assessment model (DREAM) to calculate the tracers’ contribution to the environmental impact factor (EIF). The results from the DREAM simulations suggest no contribution towards EIF values from any of the tracers at the expected back-produced concentrations. Results from simulations at higher concentrations suggest that both pyrazines have the lowest environmental risk, followed by 3,4-dimethoxybenzyl alcohol, 4-methoxybenzyl alcohol, and pyridine; while both chlorobenzyl alcohols show the highest environmental risk.

Energy-exergy and environ-economic (4E) analysis while drying ivy gourd in a passive indirect solar dryer without and with energy storage system and results comparison

The energy-exergy and environ-economic (4E) analysis was conducted while drying ivy gourd in a natural convection indirect solar dryer (ISD) without and with a thermal energy storage system (TESS). The initial setup was modified with TESS by integrating a rectangular glass box holding polycarbonate tubes filled with paraffin wax. The paraffin wax was selected based on its easy availability in the market, and also the existing studies suggested that it works successfully by shortening the drying time, homogenizing the process and maintaining temperature. Mass loss, air velocity, and temperature data were recorded during experiments in both setups. The average collector and drying efficiencies of ISD were 62.56 and 61.87 (without and with TESS) and 6.62% and 13.13% (without and with TESS), respectively. The specific energy consumptions were 1.549 and 0.253 kWh/kg for without and with TESS, respectively. The exergy parameters for collector and drying cabinet such as average exergy efficiency, loss, outflow, and inflow without and with TESS were estimated. Other exergy parameters such as the ratio of waste exergy, improvement potential, sustainability index and environmental impact factor were estimated and compared for both setups. CO2 mitigation and credit were better with the TESS setup. The energy payback period of the dryer was 1.04 and 1.51 years for without and with TESS setups for a lifespan of 25 years. Comparatively, with TESS setup performed well in all the evaluated parameters.

Distribution and Environmental Impact Factors of Picophytoplankton in the Eastern Indian Ocean

Picophytoplankton (pico) in the eastern Indian Ocean (EIO) were investigated during the inter-monsoon periods. They were found to typically comprise Prochlorococcus (Pro), Synechococcus (Syn), and Picoeukaryotes (PEuks). In the survey area, the pico showed two different vertical distribution patterns in different regions, whereby the Syn abundance decreased with depth, whereas those of Pro and PEuks increased and then decreased with depth, with the maximum depths ranging from 50 to 100 m. The cell abundance and community structure of the pico were similar at the equator (EQ) and the eastern boundary of the Indian Ocean near Sumatra (EB), but the pico cell abundance was significantly lower in the Bay of Bengal (BOB). Pro dominated most regions of the entire EIO and were approximately one-to-two orders of magnitude more abundant than Syn and PEuks. The distributions of Syn and PEuks showed little difference across various regions. Influenced by the physicochemistry of circulation and water masses, there were many different environmental factors in the different regions. The abundance of pico domination by Pro showed a strong positive correlation with the nutrients and salinity in the survey area, indicating increasing nutrient availability, particularly in the oligotrophic EIO. Generalized additive models (GAMs) analysis showed the differences in their responses to environmental variability. Pro and PEuks both increased strongly with warming up to below 26 °C, and Pro and PEuks were more responsive to chemical (nutrient) variability. Syn showed a broader tolerance of low-salinity conditions. In a certain range, an increase in nitrite and nitric acid can improve the cell abundance of Pro. As a significant contributor to primary productivity in oligotrophic waters, this study provides essential information for studying pico communities in the EIO and its adjacent marine ecosystems.

Distribution and Environmental Impact Factors of Phytoplankton in the Bay of Bengal during Autumn

In order to better understand the effects of environmental factors and water mixing on the phytoplankton community structure in the Bay of Bengal, a field investigation was conducted from October to December 2016. A total of 276 species from 68 genera were identified, including Bacillariophyta (81 species), Miozoa (188 species), Cyanobacteria (four species), and Ochrophyta (three species). The abundance and distribution of dominant cyanobacteria gradually decreased along the latitude. This is evidenced in the vertical direction, which shows that cyanobacteria were affected by changes in environmental factors caused by the vertical mixing of seawater. The relationship between stratified N:P and phytoplankton also revealed that the changes in the vertical direction of the water deeply affected the phytoplankton community structure in the Bay of Bengal. The regions with strong vertical stratification were more favorable for the growth of cyanobacteria, while the regions with weak vertical stratification were more favorable for the growth of diatoms and dinoflagellates. According to the canonical correspondence analysis, nitrogen, silicates, phosphates, vertical stratification, and temperature were key control factors for phytoplankton communities. However, changes in these chemical parameters in the study area were also caused by the seawater cycle process.

Evaluation of net anthropogenic nitrogen inputs in the Three Gorges Reservoir Area

Excessive nitrogen input caused by human activities is an important factor threatening regional water security and economic development. In this study, net anthropogenic nitrogen input has offered an advantage in evaluating nitrogen input’s temporal and spatial variation in the Three Gorges Reservoir Area in 2006–2019. Component characteristics like sensitivity and proportional contribution of net anthropogenic nitrogen input in the time trend were assessed using a mathematical differential equation multivariate function principle for the first time. Then, redundancy analysis quantitatively analysed the distribution and interpretation of districts’ socio-economic and environmental impact factors on net anthropogenic nitrogen input. The results showed high net anthropogenic nitrogen input levels in the Three Gorges Reservoir Area in 2006–2019 with significant temporal and spatial variations (one-way ANOVA, p < 0.01), the mean value of net anthropogenic nitrogen input in the Three Gorges Reservoir Area was 12399.35 kg·km−2·a−1. Net anthropogenic nitrogen input in Xingshan (4907.45 kg·km−2·a−1) was the smallest, and that in Fuling (24005.10 kg·km−2·a−1) was the largest. The spatial distribution characteristics were high at two ends, they were low in the middle of the Three Gorges Reservoir Area. Even though the proportion of nitrogen fertiliser with the largest input source of net anthropogenic nitrogen input, accounted for 48%–53%, the main methods to reduce net anthropogenic nitrogen input also reduced the nitrogen fertilisers’ input in the Three Gorges Reservoir Area. Subsequently, since the atmospheric nitrogen deposition proportion was generally increasing, we focused on controlling the emission of the atmospheric nitrogen in the future. Districts had different net anthropogenic nitrogen input compositions, revealing the analysis of districts was necessary. Additionally, the sensitive coefficients of the nitrogen fixation and nitrogen of crop production were the largest, accounting for 1.09 and 0.98, which indicated that biological nitrogen fixation is the most sensitive factor in adjusting the agricultural structure that can quickly affect net anthropogenic nitrogen input in the Three Gorges Reservoir Area. Similarly, results showed that the sensitive coefficient and proportional contributions changed with districts and presented different characteristics. Therefore, the transformation from the reservoir to the region can serve as a more accurate management strategy. Moreover, the distribution of net anthropogenic nitrogen input in the districts was highly and significantly correlated with sowing area (p < 0.01), making it significantly and negatively correlated with the forest coverage rate. This result indicated that while the agricultural structure was the most sensitive factor affecting net anthropogenic nitrogen input, accurate nitrogen input management could be realised on a district scale. Therefore, we consider analyses of district component characteristics and impact factors important in providing decision support for the accurate and effective regional control of nitrogen input management.

IMPORTANT FACTORS OF OPEN DEFECATION CONTROLLING EFFORTS IN GREATER BANDUNG URBAN SLUM AREA

Sanitation is one of development aspects which human basic necessity. One of sanitation development policies in Indonesia is refers to community needs (demand driven) rather than achieving technical target (supply driven). Communities in urban slum area, as a target focus management, should play a major role in the development process and become an active participant in facility planning, construction, utilization and maintenance. This research is intended to identify the condition of sanitation management implementation in slum areas and explore important factors for community in sanitation management. This research is using Fishbein method and then followed by Importance Performance Analysis (IPA) with Cartesius diagram, with focus in exploring community ideas/perception for sanitation management in slum area. There are two responded components : fact (stating performance) and expectation (stating importance level) related to the operated policy/program in important factors. This research is conducted in Greater Bandung Area which is a metropolitan area comprising of 4 (four) cities/regencies that structure West Java Province capital area. The result is among ten requested important factors, the financial factor becomes major important factor that had to be improved (2,24;4,25), however community participation (2,86;4,05), environmental (2,79;4,07) and social impact factors (2,86;4,01) are satisfied important factors. Resilience to the climate change is also considered in this research since the effects of climate change on sanitation may be direct while water is an essential part of the technology process (e.g. sewerage) is indirect where the capability of the environment to absorb or reduce the adverse effect of wastes is changed. The result concludes that community has experience their self sanitation management to overcome environmental and social problems. On the other hand financial factor is still required to improve the better sanitation management.

72 Life Cycle Assessment of Environmental Impacts of Swine Growing-Finishing Feeding Programs Using Different Amounts of Soybean Meal, Distillers Dried Grains with Solubles, and Crystalline Amino Acids

Abstract The objective of this study was to quantify and compare the environmental impact, using life-cycle assessment (LCA) analysis, of 4 different, 4-phase growing-finishing feeding programs consisting of diets containing corn and soybean meal (CSBM), low protein CSBM supplemented with crystalline amino acids (LP), CSBM with 30% distillers dried grains with solubles (DDGS), and DDGS supplemented with crystalline Ile, Val, and Trp (DDGS+IVT). The LCA analysis was performed using an online software application (Opteinics, BASF, Lampertheim, Germany) with calculations based on environmental impact factors from the Global Feed LCA Institute feed ingredient database. The specific model included impacts of feed production, animal farming, manure management, and meat processing. Environmental impacts were calculated at the farm gate and the functional unit was 1,000 kg of carcass weight. Diet composition, growth performance, and carcass data obtained from a feeding trial were used as inputs in the LCA calculations. Using CSBM as the reference feeding program (Table 1), the LP feeding program resulted in an overall decrease in impacts associated with acidification (10.9%), water use (7.6%), and land use (9.8%), but increased impacts associated with climate change (3.3%) and fossil resource use (3.7%). Both DDGS and DDGS+IVT feeding programs increased impact on climate change (18.4-18.7%), fossil resource use (42.7-47.3%), and water use (47.2-50.0%), but decreased impacts associated with acidification (3.0-3.4%) and land use (27.2-27.3%) compared with the CSBM feeding program. Overall, the LP feeding program resulted in the lowest total environmental footprint (1.0776 person years), followed by the CSBM (1.1081 person years), DDGS+IVT (1.1845 person years), and DDGS (1.1884 person years) feeding programs. These results indicate that feeding CSBM diets without and with crystalline amino acids have less impact on climate change, water use, fossil resource use, and total environmental footprint than DDGS feeding programs per 1,000 kg of pork carcass weight.

Life cycle assessment of hydrogen peroxide produced from mainstream hydrogen sources in China

Hydrogen peroxide (H2O2) is a mild chemical synthetic oxidant, which has gained wide importance in industrial and research fields. However, systematic assessment of its environmental performance during H2O2 production is limited worldwide. In this regard, a life cycle assessment was conducted to quantify the environmental impacts of H2O2 produced by four mainstream hydrogen production technologies in the upstream, identify the optimization potential, and provide a basis for chemical product research. Results illustrated that compared with the hydrogen from coal, petroleum, and natural gas, the utilization of chlor-alkali by-product hydrogen to produce H2O2 could prevent 27%, 11%, and 25% environmental contamination throughout the national life cycle, respectively. Fossil depletion, global warming, water depletion, and non-carcinogens categories are the main areas of concern for H2O2 production. The potential environmental impacts of H2O2 production are primarily ascribed to energy (i.e., electricity and steam) consumption and direct water consumption. Therefore, several suggestions are provided for the critical environmental impact factors of H2O2 production toward the achievement of sustainable development requirements. The recommendations are to develop renewable energy sources, change the fuel composition, optimize the steam heat recovery systems, and apply air–water coupled cooling technology in the H2O2 production process to achieve cleaner production and improve environmental performance. From the perspective of industrial layout, China's western region should consider the promotion of H2O2 production from the chlor-alkali industry given the abundant renewable energy and raw material resources to enhance inter-regional coordination and sustainability.

메가이벤트 개최지역민의 지역사회 애착이 영향인식, 참여의도에 미치는 영향 : 정보 노출도에 따른 차이를 중심으로

The purpose of this study is to find out how community attachment of Busan residents, the venue of the 2030 Busan World Expo, affects Mega Event Impact Perception and Participation Intention, and to see if there is a difference according to information exposure. As a result of the analysis, first, it was found that identity and dependence had a significant effect on the economic and social and cultural effects of the perception of mega-events. However, it was found that social intimacy had a negative effect on all impact perceptions, and all three factors had a negative effect on environmental impact factors. Second, it was found that the perception of the influence of mega events had a positive effect on the intention to participate. Fourth, it was found that there was a difference in impact recognition and participation intention according to the exposure of information related to the 2030 Busan World Expo. These results are meaningful in providing basic data that can be used to effectively predict and elicit the active participation and support of local residents for a successful hosting.

Energy Distribution Characteristics and Environmental Impact Factors in Different Regions of the Summer Monsoon Transition Zone

The summer monsoon transitional zone is a typical transitional ecosystem that is, also ecologically fragile. It is critical to explore the land surface energy balance and the water and heat transfer processes in this region for water resource management. However, the processes of surface water and heat transfer throughout the transition zone and the effects of environmental factors on energy distribution are understudied. Therefore, we analyzed the surface energy distribution and the environmental factors influencing it in the eastern and western transition zone from July to September, and compared the differing effects of meteorological factors and vegetation on the energy distribution between the two regions. The results show that the main consumption item of the available energy in the west of the transition zone is the latent heat flux. The same is true in the eastern region from July to August, but it changes to sensible heat flux in September. The factors influencing the Bowen ratio in the two regions were ground temperature difference, vapor pressure deficit, shallow soil water content, and drought stress index. Nevertheless, the Bowen ratio in the western region was more sensitive to water factors, whereas that in the eastern region was more sensitive to energy factors. The relationship between the Bowen ratio and the normalized difference vegetation index in the eastern region was more regular. This study provides a scientific basis for reasonably guiding agricultural production in the transition area.

Assessment of environmental safety indicators of rural areas

The article shows the features of quantitative assessment of the use of natural resources in agricultural sector, environmental impact factors in order to develop adaptation scenarios and mitigate their consequences are identified. This is an alternative option for environmentally sustainable development in agriculture, which allows rational use of land resources. The purpose of the study is to determine the criteria for assessing the impact of agriculture on the environment components, in particular on the atmosphere, hydrosphere and land resources. Methods of economic analysis, comparison, synthesis, decomposition are used for a comprehensive assessment of the functioning of an enterprise in production of agricultural products. In the process of working on this topic, the following results were obtained: an assessment of the impact of functioning of agro-industrial complex on the environment was done. According to the current methods for determining the degree of impact on land resources, the soil quality scores were calculated before and after it. Anthropogenic pressure on the atmosphere and water resources was assessed in accordance with equivalent indicators. On the basis of the results, the authors present recommendations and conclusions on the determination of data characterizing the impact of the stages of agricultural production on the environment. The results of the calculations make it possible to make forecasts and assess the level of environmental safety in agricultural production.

Characterization of nitrous oxide and nitrite accumulation during iron (Fe(0))- and ferrous iron (Fe(II))-driven autotrophic denitrification: mechanisms, environmental impact factors and molecular microbial characterization

The iron (Fe(0))-/ferrous iron (Fe(II))-driven autotrophic denitrification processes have been alternative methods for nitrogen removal from low organic carbon (OC) wastewater, but the accumulation of nitrous oxide (N2O) and nitrite (NO2−) along with these processes remains unclear. This research aimed to systematically characterize the N2O/NO2− accumulation in Fe(0)-/Fe(II)-ADN processes through investigating the mechanisms, impact factors, and molecular biological characteristics. Results showed that Fe(II)-ADN was effective in NO3− reduction but was less efficient in N2O reduction (k = 0.50 h−1) than Fe(0)-ADN (k = 1.82 h−1). NO2−/N2O accumulation in Fe(II)-ADN (28.6%/30.7%) was much higher than that in Fe(0)-ADN (12.6%/1.5%). Introducing hydrogenotrophic denitrification (H-ADN) into Fe(II)-ADN system significantly (p < 0.05) reduced NO2−/N2O accumulation. Fe(0)-ADN was proved a coupled process of Fe(II)- and H-ADN by in-situ generating Fe(II)/H2, and Fe(II)-ADN and H-ADN mainly contributed to NO3− and NO2−/N2O reduction, respectively. Optimum pH (7.5) and temperature (30–35 °C) were confirmed with controlled NO2–/N2O accumulation and effective denitrification. Dosing inorganic carbon (IC) and OC enhanced denitrification and reduced NO2–/N2O accumulation, where OC was more efficient with an optimum dosage of 0.25 mmol C/mmol N. 16S rRNA high-throughput sequencing and Pearson Correlation Coefficients verified that Thiobacillus was the main contributor to NO3− reduction, whereas Thauera and Acidovorax possessed high NO2−/N2O reduction capability. Real-time quantitative polymerase chain reaction and enzyme activity assay demonstrated that the nitrite reductase encoded by gene nirK and the nitrous oxide reductase encoded by gene nosZ were efficient in catalyzing the further reduction of NO2− and N2O, respectively. This study could provide an in-depth understanding of NO2−/N2O accumulation in Fe(II)-/Fe(0)-ADN processes and contribute to their application, optimization and secondary pollutants control.