• Energy Research
• 2021-2025close
• 6. Clean water close
• BG close

The object of the study is the water supply and sanitation system of an industrial enterprise. Currently, many enterprises do not use the treated industrial waste water in the water supply cycle. Therefore, the use of treated wastewater is of practical importance. The scheme of thermal treatment of waste water for obtaining pure condensate by evaporation is proposed. The main results of the study are the technical solution for the development of the enterprise's wastewater treatment complex. Pure condensate is obtained in an instant boiling evaporator. The research method is based on the calculation of energy costs in wastewater treatment for different types of waste water. The results of the study allow us to determine the optimal set of energy equipment for obtaining pure condensate and its further use. The specific practical significance lies in the development of a technical solution that helps the treatment of wastewater and the reduction of emissions into the water basin.

Agro-wastes, such as crop residues, leaf litter, and sawdust, are major contributors to global greenhouse gas emissions, and consequently a major concern for climate change. Nowadays, mushroom cultivation has appeared as an emerging agribusiness that helps in the sustainable management of agro-wastes. However, partial utilization of agro-wastes by mushrooms results in the generation of a significant quantity of spent mushroom substrates (SMS) that have continued to become an environmental problem. In particular, Shiitake (Lentinula edodes Berk.) mushrooms can be grown on different types of agro-wastes and also generate a considerable amount of SMS. Therefore, this study investigates the biotransformation of SMS obtained after Shiitake mushroom cultivation into biogas and attendant utilization of slurry digestate (SD) in tomato (Solanum lycopersicum L.) crop fertilization. Biogas production experiments were conducted anaerobically using four treatments of SMS, i.e., 0% (control), 25, 50, and 75% inoculated with a proportional amount of cow dung (CD) as inoculum. The results on biogas production revealed that SMS 50% treatment yielded the highest biogas volume (8834 mL or 11.93 mL/g of organic carbon) and methane contents (61%) along with maximum reduction of physicochemical and proximate parameters of slurry. Furthermore, the biogas digestate from 50% treatment further helped to increase the seed germination (93.25%), seedling length (9.2 cm), seedling root length (4.19 cm), plant height (53.10 cm), chlorophyll content (3.38 mg/g), total yield (1.86 kg/plant), flavonoids (5.06 mg/g), phenolics (2.78 mg/g), and tannin (3.40 mg/g) contents of tomato significantly (p < 0.05) in the 10% loading rate. The findings of this study suggest sustainable upcycling of SMS inspired by a circular economy approach through synergistic production of bioenergy and secondary fruit crops, which could potentially contribute to minimize the carbon footprints of the mushroom production sector.

In the context of limited water resources and the deterioration of natural water bodies’ state, and with the increase in the regulatory requirements for the quality of effluents, assessing the impact of the industrial and energy complex on water bodies is a task of increasingly greater significance to the whole energy sector. “zero discharge” is considered the most effective strategy for creating environmentally friendly thermal power plants. Hybrid reverse osmosis electrodialysis systems make it possible to obtain solutions with a higher concentration of components compared to single electrodialysis treatment, i.e., more efficient separation of brine and pure water. This article proposes experimental and pilot-industrial studies of a hybrid membrane system operation using industrial wastewater for the disposal of liquid waste from an ion-exchange chemical-desalting water treatment plant of a thermal power plant, followed by a calculation of economic efficiency and an analysis of the environmental feasibility of its use. The developed technological scheme offers separate processing of acidic and alkaline waste regeneration solutions using calcium carbonate reagent and desalination on baromembrane and electromembrane units to obtain clean water and dry residue. The hybrid system includes a booster filter press and an evaporator. The hybrid system makes it possible to provide a thermal power plant with a “zero discharge” with a minimum consumption of reagents and electricity, as well as return all wastewater back to the power plant cycle.

Rice is the staple food for 2.5 billion people worldwide and most farmers depend solely on rice for their livelihood. This study estimates how paddy ecosystem elasticity and external human activity affect paddy ecosystem sustainable food supply. In particular, we analyzed how sustainable food supply is affected by three key domains of external factors—ecological factors, including the proportion of paddy Area (Are), per capita cultivated land area (Lan), and annual wastewater discharge per capita (Was); economic factors, including the agricultural economy level (Inv) and urbanization rate (Urb); and social factors, including the education of farmers (Edu) and rural medical level (Med). We use ANEV, or net paddy ecosystem services value per unit area, to assess the sustainable food supply, which not only represents the food supply quantity and quality, but also the sustainability of the food supply. Results from our panel and threshold regressions suggest that Lan and Urb have a threshold effect on paddy ANEV; Are, Was, Inv, and Edu have a linear negative correlation with ANEV; and Med has a positive linear correlation with ANEV. Based on our findings, we lay out a series of recommendations that may guide future formulation of policies on paddy ecosystem protection and sustainable food supply.

Food waste has become a challenging global issue due to its inefficient management, particularly in low and middle-income countries. Among food waste items, fruit peel waste (FPW) is generated in enormous quantities, especially from juice vendors, resulting in arduous tasks for waste management personnel and authorities. However, considering the nutrient and digestible content of organic wastes, in this study four types of FPW (pineapple: PA; sweet lemon: SL; kinnow: KN; and pomegranate: PG) were investigated for their potential use within biogas production, using conventional and electro-assisted anaerobic reactors (CAR and EAR). In addition, the FPW digestate obtained after the biogas production experiments was considered as a soil bio-fertilizer under radish (Raphanussativus L. cv. Pusa Himani) cultivation. In the results, all four types of FPW had digestible organic fractions, as revealed from physicochemical and proximate analysis. However, PA-based FPW yielded the maximum biogas (1422.76 ± 3.10 mL/62.21 ± 0.13% CH4) using the EAR system, compared to all other FPW. Overall, the decreasing order of biogas yield obtained from FPW was observed as PA > PG > SL > KN. The kinetic analysis of the biogas production process showed that the modified Gompertz model best fitted in terms of coefficient of determination (R2 > 0.99) to predict cumulative biogas production (y), lag phase (λ), and specific biogas production rate (µm). Moreover, fertilizer application of spent FPW digestate obtained after biogas production significantly improved the arable soil properties (p < 0.05). Further, KN-based FPW digestate mixing showed maximum improvement in radish plant height (36.50 ± 0.82 cm), plant spread (70.80 ± 3.79 cm2), number of leaves (16.12 ± 0.05), fresh weight of leaves (158.08 ± 2.85 g/plant), fruit yield (140.10 ± 2.13 g/plant), and fruit length (25.05 ± 0.15 cm). Thus, this study suggests an efficient method of FPW management through biogas and crop production.

This paper develops a dual sectors dynamic equilibrium model and introduces electricity consumption and water consumption in a growth model that tested by using a time series data set from 1950 to 2014 in Guangzhou, China. It presents a theoretical prediction on the interactions between electricity consumption, water consumption, and the metropolitan economic growth. Consistent with this prediction, electricity consumption and water consumption by themselves appear to have significant effects on metropolitan economic performance. The cointegration techniques show that electricity consumption, water consumption, and the metropolitan economic performance have long-run equilibrium relationship. The results of kernel-based regularized least squares reveal that metropolitan economic growth is positively correlated with electricity consumption. Also consistent with the theory, water consumption is positively associated with metropolitan economic performance. These results are generally stable and hold with alternative measures of unit roots, with alternative estimation strategies, and with or without controlling for trends, intercepts, and break points.

An experiment was carried out to investigate the effects of different mineral fertilizers on mineral contents in turmeric rhizomes and soil enzyme activities and soil properties under field conditions in Uzbekistan. The present study is the first report on the impact of mineral fertilizers in turmeric rhizomes and soil enzymes and soil properties in Uzbekistan. The experiment was carried out with four treatments: T1—Control, T2—N75P50K50 kg/ha, T3—N125P100K100 kg/ha, and T4—N100P75K75 + B3Zn6Fe6 kg/ha. Turmeric rhizomes and soil samples were collected from field experiments at the Surkhandarya scientific experimental station of the vegetable, melon crops and potato research institute, Surkhandarya, Uzbekistan. The data showed that T3—the NPK (125:100:100 kg/ha) and T4—the NPK + BZnFe (100:75:75:3:6:6 kg/ha) treatments significantly enhanced K content by 27–21%, Ca content by 43–38%, and P content by 54–17% in turmeric rhizomes as compared to control without fertilizer. A maximum of turmeric rhizome microelements content was recorded with T4, which also resulted in improved Fe, Zn, Cu, Cr, and Mo contents in turmeric rhizomes and mineral contents of soil compared to other treatments. This treatment significantly enhanced active P content by 34%, active K content by 25%, total P content by 62%, total K content by 14%, and the activities of soil urease, invertase, catalase, and phosphatase over those in the control. The present study results suggest that the application of NPK + BZnFe (100:75:75:3:6:6 kg/ha) improves macro and micronutrient contents in turmeric rhizomes and activities of soil enzymes and physicochemical properties of soil.

The assessment of ecosystem service (ES) supply and demand is crucial for the sustainable development of dryland drainage basins. The natural ecosystems in the Kaidu-Kongque River Basin have experienced severe ecological degradation in recent years, and the ES supply and demand were contradicted due to water scarcity and excessive water utilization. In this paper, the supply–demand of five key ecosystem services were evaluated, and their spatial matching was also analyzed to provide total insights. The services assessed were food supply, water yield, carbon sequestration, habitat quality, and windbreak and sand fixation. We utilized various models, including InVEST, RWEQ, and GeoDa, to quantify and analyze the spatial and temporal patterns of ecosystem service supply and demand between 1990 and 2020. Our findings indicate that the supply and demand for all ecosystem services in the basin have increased over the last 30 years. However, the spatial distribution of supply and demand for each ecosystem service is not completely consistent. Except for windbreak and sand fixation, where supply exceeds demand, there is a spatial mismatch between supply and demand for each service. Furthermore, we observed a positive and synergistic correlation between the supply and demand of each ecosystem service, with water yield services being the dominant and limiting factor. The spatial correlation between the supply and demand of ecosystem services was dominated by “low supply—low demand”, “high supply—high demand” spatial matching, and “low supply—high demand” mismatch, which could explain the variation in water yield from upstream to downstream. Based on our findings, we recommend policies and recommendations for ecological conservation and sustainable development in the Kaidu-Kongque River Basin. The ES supply and demand will become more reliable by increasing water supplies in the middle and lower reaches of the basin. Our results provide illumination for the maintenance and sustainability of ecosystem services in arid regions.