Search Results (213)

The Inner Mongolia Autonomous Region is a crucial area in China with a significant advantage in animal husbandry, particularly in cattle and sheep farming. However, the disposal of the large quantities of manure produced during farming has severely impacted the industry’s healthy development. Proper treatment of the manure can convert it into organic fertilizer beneficial to farmland; otherwise, it will cause substantial environmental pollution. This study focuses on existing composting equipment and addresses the issues of cattle and sheep manure mixture ratios and compost maturity evaluation. Through experiments on the mixture of cattle and sheep manure, the optimal ratio for converting cattle and sheep manure into organic fertilizer was determined. Additionally, a fuzzy mathematical evaluation model was employed, along with experimental data, to establish a comprehensive evaluation system for aerobic compost maturity based on multiple indicators, revealing the variation patterns of maturity levels under different mixture ratios. The test results revealed that the composting equipment effectively controls the composting process, shortens the composting cycle, ensures the complete decomposition of organic matter, and meets national standards for livestock and poultry manure treatment. Regarding temperature and humidity, oxygen concentration, seed germination rate, pH value, electrical conductivity (EC), nitrogen, phosphorus, potassium content, and carbon-to-nitrogen ratio, the mixed compost of cattle and sheep manure in various ratios met the relevant standards for agricultural application. Various ratios of organic fertilizers containing cattle and sheep manure significantly promoted the growth of maize, wheat, and mung bean crops. Specifically, the compost decomposition cycle was shortest when sheep and cattle dung were mixed at a ratio of 2:1, while it was longest for all cattle dung. Finally, a fuzzy mathematical comprehensive evaluation model was established by selecting four indicators: water content, carbon-to-nitrogen ratio, apparent score, and germination index. The study demonstrates that the equipment and method offer significant advantages in efficiently treating cattle and sheep manure and producing organic fertilizer, thereby providing strong support for the sustainable development of animal husbandry. Full article

In present times, with increasing emphasis on circular economies, municipal wastewater treatment plants (WWTPs) are considered resource recovery facilities. The targeted resources are water, biogas, and sludge, organic residuals containing nutrients and elements needed by plants (nitrogen and phosphorus). Sludge is a byproduct that constitutes the largest volume of all other byproducts obtained in wastewater treatment plants. Its processing and disposal are challenging for environmental engineers because of its complexity. Thus, quick development and implementation in industrial practice of sludge valorization and utilization technologies is required, where high nutrient content must be taken into account. Also, the occurrence of a variety of pathogens in sewage sludge is a matter of concern, even in the case of developed countries. The use of untreated sludge or wastewater in agricultural activities poses a serious risk of bacterial and parasitic infection in human beings. To overcome such issues, the application of ionizing radiation processing, especially electron beam (EB), can be considered a promising method. Its effectiveness in pathogen removal has been proven by researchers. Water radiolysis products created during irradiation of water are highly reactive and cause some effects such as DNA damage, ${}_{ }{}^{•}OH$ radical production, etc. Additionally, ionizing radiation technologies in sewage sludge treatment enhance the efficiency of the methane fermentation process. Depending on specific needs, different types of ionizing radiation sources can be discussed. Based on the review information and our research results, the basic engineering parameters of hybrid installation have been presented as the conclusion of the report. In this technical solution, a notably effective additional step would be the use of EB irradiation, combined with conventional wastewater treatment, to achieve efficient removal of pollutants. Full article

The proper disposal of antibiotic mycelial residue (AMR) is a critical concern due to the spread of antibiotics and environmental pollution. Pyrolysis emerges as a promising technology for AMR treatment. In this study, we investigated the effect of pyrolysis temperature on the thermal decomposition behavior and product characteristics of avermectin (AV) mycelial residues. Various characterization techniques were employed to analyze thoroughly the compositions and yields of the obtained gas, liquid, and biochar products. The results indicated that most of the organic matter such as protein, carbohydrate, and aliphatic compounds in AV mycelial residues decomposed intensely at 322 °C and tended to end at 700 °C, with a total weight loss of up to 72.6 wt%. As the pyrolysis temperature increased, the biochar yield decreased from 32.81 wt% to 26.39 wt% because of the enhanced degradation of volatiles and secondary reactions of the formed aromatic rings. Accordingly, more gas components were formed with the gas yield increased from 9.76 wt% to 15.42 wt%. For bio-oil, the contents were maintained in the range of 57.43–60.13 wt%. CO and CO₂ dominated the gas components with a high total content of almost 62.37–97.54 vol%. At the same time, abundant acids, esters (42.99–48.85%), and nitrogen-containing compounds (32.14–38.70%) such as nitriles, amides, and nitrogenous heterocyclic compounds were detected for the obtained bio-oil. As for the obtained biochars, particle accumulation and irregular pores were presented on their bulk surface, which was primarily composed of calcium oxalate (CaC₂O₄) and calcium carbonate (CaCO₃). This work can provide theoretical insights for the harmless disposal and resource recovery for AMR, contributing significantly to the field of solid waste reuse and management. Full article

Nitrogen is one of the significant pollutants emitted from coal combustion, and the study of its distribution and occurrence is very important for the efficient and clean utilization of coal resources. Four kinds of coal with different metamorphic ranks from major coal-producing provinces of China were studied. A gravity float-and-sink experiment was applied to obtain coal samples with different densities from Shanxi Province. The microscope optical method, Kjeldahl method, and X-ray photoelectron spectroscopy (XPS) were used to assess the occurrence, form, and distribution of nitrogen in the coal. The results show that the nitrogen content was about 0.47%–1.85%, and the maximum nitrogen content was positively correlated with the rank of coal, but the difference was not obvious. In the low-rank coal, the nitrogen content was mainly related to vitrinite and inertinite, while in the middle–high-rank coal, the nitrogen content was mainly related to inertinite and minerals. Pyrrolic (N-5) and pyridinic (N-6) were the main forms of nitrogen in the low-rank coal. The contents of N-6 and N-5 decreased with increases in the coal density, but the contents of quaternary N-Q1 and quaternary N-Q2 increased. N-Q2 mainly comes from fixed ammonia nitrogen in minerals, and vitrinite and liptinite contain more N-6 and less N-Q1 than inertinite. This research provides valuable evaluation guidance for the efficient utilization of coal. Full article

In most countries energy needs are satisfied using fossil fuels. Fossil fuel combustion involves environmental pollution and greenhouse gas emissions. The effect of the depletion of natural resources and the growing awareness of the need to protect the environment are the reasons that clean energy and alternative energy sources have been significant research issues. One of the most important technologies enabling efficient generation of low-emission energy is the gasification process of synthesis gas production. Syngas is primarily composed of hydrogen and carbon monoxide, but depending on the feedstock, it can also contain smaller concentrations, e.g., of carbon dioxide, methane and nitrogen. Because synthesis gas contains flammable and toxic substances, it may pose hazards to humans and the environment at every stage of gas production, storage, transport or final utilization if released uncontrollably. This paper presents the results of analyses related to hazards created by an uncontrollable release of synthesis gas during storage. A failure of a syngas system may cause damage to other, subsequent technological systems and facilities located in the neighborhood and containing dangerous substances. The problem gains special significance if syngas is stored in many tanks, where a failure of one may result in damage to subsequent tanks due to the so-called domino effect. The conditions in which the domino effect may occur are analyzed and the effect occurrence probability is determined depending on the mutual location of the tanks. Full article

Urban heat islands (UHI) are a well-known phenomenon adversely affecting human health and urban environments. The worldwide COVID-19 lockdown in 2020 provided a unique opportunity to investigate the effects of decreased emission of air pollution and anthropogenic heat flux (AHF) on UHI. Although studies have suggested that reduced AHF during lockdown decreased atmospheric UHI (AUHI) and surface UHI (SUHI), these results contain inherent uncertainties due to unaccounted weather variability and urban-rural dynamics. Our study comprehensively analyzes the impact of the COVID-19 lockdown on AUHI and SUHI in Prague, Czechia. By selecting days with similar weather conditions, we examined changes in mean SUHI using MODIS satellite images and in AUHI based on air temperature from Prague weather stations for the Lockdown period during March–April 2020 versus a Reference period from March–April 2017–2019. Our results show that, in comparison to the Reference period, the Lockdown period was associated with a 15% (0.1 °C) reduction of SUHI in urbanized areas of Prague and a 0.7 °C decline in AUHI in the city center. Additionally, the observed decreases in satellite-based aerosol optical depth and nitrogen dioxide by 12% and 29%, respectively, support our hypothesis that the weakened UHI effects were linked to reduction in anthropogenic activities during the lockdown. Revealing the largest decrease of mean SUHI magnitude around the periphery of Prague, which has predominantly rural land cover, our study emphasizes the need to consider the effects of urban-rural dynamics when attributing changes in SUHI to AHF. Our findings provide additional insights into the role of reduced anthropogenic activities in UHI dynamics during the COVID-19 lockdown and offer policymakers a comprehensive understanding of how the complex interaction between urban and rural microclimate dynamics influences the SUHI phenomenon. Full article

The implementation of phytoremediation strategies under arid and semiarid climates requires the use of appropriate plant species capable of withstanding multiple abiotic stresses. In this study, we assessed the combined effects of organo-mineral amendments and microbial inoculants on the chemical and biological properties of mine tailings, as well as on the growth of native plant species under drought stress conditions. Plants were cultivated in pots containing 1 kg of a mixture of mine tailings and topsoil (i.e., pre-mined superficial soil) in a 60:40 ratio, 6% marble sludge, and 10% sheep manure. Moreover, a consortium of four drought-resistant plant growth-promoting rhizobacteria (PGPR) was inoculated. Three irrigation levels were applied: well-watered, moderate water deficit, and severe water deficit, corresponding to 80%, 45%, and 30% of field capacity, respectively. The addition of topsoil and organo-mineral amendments to mine tailings significantly improved their chemical and biological properties, which were further enhanced by bacterial inoculation and plants’ establishment. Water stress negatively impacted enzymatic activities in amended tailings, resulting in a significant decrease in acid and alkaline phosphatases, urease, and dehydrogenase activities. Similar results were obtained for bacteria, fungi, and actinomycete abundance. PGPR inoculation positively influenced the availability of phosphorus, total nitrogen, and organic carbon, while it increased alkaline phosphatase, urease (by about 10%), and dehydrogenase activity (by 50%). The rhizosphere of Peganum harmala showed the highest enzymatic activity and number of culturable microorganisms, especially in inoculated treatments. Severe water deficit negatively affected plant growth, leading to a 40% reduction in the shoot biomass of both Atriplex halimus and Pennisetum setaceum compared to well-watered plants. P. harmala showed greater tolerance to water stress, evidenced by lower decreases observed in root and shoot length and dry weight compared to well-watered plants. The use of bioinoculants mitigated the negative effects of drought on P. harmala shoot biomass, resulting in an increase of up to 75% in the aerial biomass in plants exposed to severe water deficit. In conclusion, the results suggest that the combination of organo-mineral amendments, PGPR inoculation, and P. harmala represents a promising approach to enhance the phytoremediation of metal-polluted soils under semiarid conditions. Full article

Carbon nanofibers based on lignin from wood waste have a promising potential for the ability to produce electrodes that can modernize existing energy storage technology. The most important detail is that the low cost, as well as the availability of the initial products for the production of lignin, will reduce the cost of energy storage devices and contribute to improving the environment. In this study, pine sawdust and elm sawdust were used as raw materials for the production of lignin, which accumulate in large quantities in metal workshops in Almaty. Lignin extraction was carried out using an organosolvent method, which is environmentally friendly, low-cost, uses minimal amounts of strong acids and metal catalysts, does not pollute water, and does not emit sulfur dioxide (SO₂). A comprehensive study of the characteristics of the obtained lignins from wood waste was carried out. Infrared spectroscopy (IR) revealed that the obtained lignin contains aromatic, phenolic, hydroxyl, methyl, and methoxyl groups. The results of nuclear magnetic resonance (NMR) spectroscopy showed the presence of a high number of syringyl (S) links compared to guaiacyl (G), which contribute to increased efficiency in the thermal processing of lignin. Also, this study investigated the use of the obtained lignins to produce continuous fibers by electrospinning. The effect of lignin mass on the viscosity of the lignin/polyacrylonitrile (PAN) solution and the effect of the carbonization temperature on the physico-chemical characteristics of the lignin/PAN solution were investigated. The following research methods were used for this purpose: Raman spectroscopy, thermogravimetric analysis (TGA), electron scanning microscopy, energy dispersion analysis, IR, NMR, and optical microscopy. The conditions for the production of lignin-containing carbon fibers at temperatures of 800, 900, and the carbonation heating rate, is an important parameter in the production of carbon fibers as it strongly affects the characteristics of the resulting carbon fibers. The heating rate affects were studied, and it was found that, at a heating rate of 5 °C/min and a carbonation temperature of 800 °C, porous carbon nanofibers with a diameter of 47 nm are formed in a nitrogen medium for 60 min. Full article

Adsorptive, catalytic, and antibacterial properties of clinoptilolite-rich tuffs (ZT) are presented here. ZT transformed into Fe-containing ZT (Fe-ZT) removes various organic and inorganic anions from water. Fe-ZT, which contains selenium, is beneficial for growing Pleurotus ostreatus mushrooms. The fungi convert inorganic Se from Fe-ZT into a more useful organically bonded form. ZT and Fe-ZT as supplements retain nitrogen and potassium in sandy, silty loam and silty clay soils. ZT shows an affinity toward toxic metal cations, which are essential for cleaning contaminated water. The adsorption of atenolol, acetylsalicylic, and salicylic acid onto M-ZT (M–Cu²⁺, Mn²⁺, Ni²⁺, or Zn²⁺) from water solutions suggests that both the natures of M and pharmaceuticals have a significant impact on the adsorption mechanism and determine the adsorption capability of the ZT. ZT is an excellent carrier for ultrafine (2–5 nm) nano oxide particles, which have been shown to have catalytic activity in different chemical processes and photodegradation reactions of organic pollutants. ZT can also be transformed into SO₄-SnO₂-ZT, which is catalytically active as a solid acid. M-ZT is an effective carrier of valuable bacteria. Ag-ZT possesses beneficial bactericidal activity in disinfecting water and soil remediation. Full article

The removal of sulfur- and nitrogen-containing compounds present in fuels is and will be crucial to accomplish actual strict regulations to avoid environmental and humanity health adversities. The conventional hydrodesulfurization and hydrodenitrogenation processes conducted by refineries are limited due to severe operating conditions, and even more importantly, they are inefficient for simultaneously removing nitrogen- and sulfur-containing compounds in fuels. On the other hand, non-hydrogen technologies are beneficial in terms of mild operating conditions, and during the last two decades, some successful works have shown that these can be highly effective at efficiently removing both sulfur- and nitrogen-containing compounds from liquid fuels. For more than four decades, extensive research (thousands of publications since the 1980s) has been dedicated to developing remote desulfurization technologies without taking into consideration the presence of a complex fuel matrix, or even taking into account the presence of other harmful pollutant elements, such as nitrogen. Even more recently, several effective non-hydrogen denitrogenation processes have been reported without considering the presence of sulfur compounds. This review paper is a reflection on the limited work that has been successfully performed to simultaneously remove sulfur- and nitrogen-containing compounds from fuels. An evaluation of different methodologies (adsorption, extraction, oxidative (photo)catalysis, ultrasound-assisted oxidation) is presented here. Furthermore, this review intends to define new future strategies that will allow the design of more suitable and economical technologies, effectively conciliating desulfurization and denitrogenation processes to produce more sustainable fuels. Full article

Plastic debris is a growing threat in freshwater ecosystems and transport models predict that many plastics will sink to the benthos. Among the most common plastics found in the Laurentian Great Lakes sediments are polyethylene terephthalate (especially fibers; PET), polyvinylchloride (particles; PVC), and styrene-butadiene rubber resulting from tire wear (“crumb rubber”; SBR). These materials vary substantially in physical and chemical properties, and their impacts on benthic biogeochemistry and microbial community structure and function are largely unknown. We used a microcosm approach to evaluate the impact of these three plastics on benthic-pelagic coupling, sediment properties, and sediment microbial community structure and function using sediments from Irondequoit Bay, a major embayment of Lake Ontario in Rochester, New York, USA. Benthic metabolism and nitrogen and phosphorous cycling were all uniquely impacted by the different polymers. PET fibers and PVC particles demonstrated the most unique effects, with decreased ecosystem metabolism in sediments containing PET and greater nutrient uptake in sediments with PVC. Microbial diversity was reduced in all treatments containing plastic, but SBR had the most substantial impact on microbial community function, increasing the relative importance of metabolic pathways such as hydrocarbon degradation and sulfur metabolism. Our results suggest that individual polymers have unique impacts on the benthos, with divergent implications for ecosystem function. This provides deeper insight into the myriad ways plastic pollution may impact aquatic ecosystems and will help to inform risk assessment and policy interventions by highlighting which materials pose the greatest risk. Full article

Lead (Pb) pollution, especially from the incineration of municipal solid waste (MSW), poses a significant threat to the environment. Among all the effective methods, activated carbon (AC) injection serves as an effective approach for lead removal from flue gas, while the modification of ACs emerges as a crucial pathway for enhancing Pb adsorption capacities. Density functional theory (DFT) is employed in this study to investigate the mechanisms underlying the enhanced adsorption of Pb species (Pb⁰, PbO, and PbCl₂) on nitrogen-functionalized carbonaceous surfaces. The results show that nitrogen-containing groups substantially enhance lead adsorption capacity, with adsorption energies ranging from −526.18 to −288.31 kJ/mol on nitrogen-decorated carbonaceous surfaces, much higher than those on unmodified surfaces (−310.35 to −260.96 kJ/mol). Additionally, electrostatic potential and density-of-states analyses evidence that pyridinic nitrogen atoms remarkably expand charge distribution and strengthen orbital hybridization, thereby augmenting lead capture. This research elucidates the role of nitrogen-containing functional groups in lead adsorption, offering valuable insights for the development of highly efficient biomass-derived activated carbon sorbents for lead removal. Full article

Due to their potential toxicity and non-degradability, heavy metals pose water and soil quality and safety challenges, impacting crop growth and the ecological environment. The contamination of heavy metals (HMs) and non-point source pollution from agriculture and pastoral presents significant ecological and environmental challenges, necessitating prioritized prevention and mitigation. In this study, 44 water samples and 55 soil samples from Gangba County, a typical agricultural and pastoral area in the Tethys Himalaya tectonic domain, served as research objects. We employed various methods, including the inverse distance weighting, ecological risk assessment model, redundancy analysis, and geographical detector modeling, to investigate the spatial distribution and pollution attributes of arsenic (As), chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), nitrogen (N), phosphorus (P), and potassium (K). Our analysis considered the impact of soil physicochemical properties on heavy metals (HMs), elucidating factors influencing their spatial distribution. Results indicated that 65.46% of soil As in the study area exceeded the screening value, while the concentrations of the eight selected elements in water remained below the standard limit. Simultaneously, the study area exhibited low overall ecological risk and minimal HM pollution. Furthermore, As and Pb were primarily linked to human activities and the environment, while Cd, Cr, and Ni were predominantly associated with natural processes. Additionally, factors, such as per capita net income, mean annual temperature, mean annual precipitation, geomorphic type, organic matter, geology type, and soil texture (sand, silt, and clay) constituted primary controlling factors influencing the spatial distribution of HMs in soil. Therefore, for effective prevention and control of HMs and non-point source pollution in agriculture and pastoral, arsenic should be the primary monitoring target, with careful consideration given to the application rates of fertilizers containing N, P, and K to facilitate sustainable development of the ecological environment. Full article

This study aims to assess the impact of the water ratio and nanoparticle concentration of neat diesel fuel on the performance characteristics of and exhaust gas emissions from diesel engines. The experimental tests were conducted in two stages. In the first stage, the effects of adding water to neat diesel fuel in ratios of 2.5% and 5% on engine performance and emissions characteristics were examined and compared to those of neat diesel at a constant engine speed of 3000 rpm under three different engine loads. A response surface methodology (RSM) based on a central composite design (CCD) was utilized to simulate the design of the experiment. According to the test results, adding water to neat diesel fuel increased the brake-specific fuel consumption and reduced the brake thermal efficiency compared to neat diesel fuel. In the examination of exhaust emissions, hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) in the tested fuel containing 2.5% of water were decreased in comparison to pure diesel fuel by 16.62%, 21.56%, and 60.18%, respectively, on average, through engine loading. In the second stage, due to the trade-off between emissions and performance, the emulsion fuel containing 2.5% of water is chosen as the best emulsion from the previous stage and mixed with aluminum oxide nanoparticles at two dose levels (50 and 100 ppm). With the same engine conditions, the emulsion fuel mixed with 50 ppm of aluminum oxide nanoparticles exhibited the best performance and the lowest emissions compared to the other evaluated fuels. The outcomes of the investigations showed that a low concentration of 50 ppm with a small amount of 11 nm of aluminum oxide nanoparticles combined with a water diesel emulsion is a successful method for improving diesel engine performance while lowering emissions. Additionally, it was found that the mathematical model could accurately predict engine performance parameters and pollution characteristics. Full article

Agricultural non-point source pollution has emerged as a significant driver of declining global water quality in recent years. Ditch systems hold considerable promise for trapping and purifying pollutants. However, the persistent challenge has been the limited availability of carbon sources in drainage water, which significantly hinders nitrogen (N) removal in ditches. This study investigated the dynamic changes in ammonia (NH₄⁺) and nitrate (NO₃⁻) levels caused by three cellulosic carbon additions (rice straw, coir, and sawdust) during both winter and summer seasons. Water column devices were used as containers, and the impacts on environmental factors and water denitrification rates were explored. Results demonstrated that the addition of straw exhibited the most effective N removal in winter and summer, and significantly enhanced water denitrification rates in a short timeframe, with the maximum denitrification rate reaching 1482.42 μmol·L⁻¹·h⁻¹. However, there was an observed accumulation of NH₄-N and chemical oxygen demand (COD) in summer. Also, the addition of sawdust resulted in a notable increase in greenhouse gas emissions during the summer test. In conclusion, during the cooler seasons of winter and spring when temperatures are not as high, the combined use of various cellulosic carbon sources has the potential to enhance water denitrification and mitigate adverse environmental impacts, offering valuable applications for water quality improvement. Full article