• Energy Research

Livestock farming and its products provide a diverse range of benefits for our day-to-day life. However, the ever-increasing demand for farmed animals has raised concerns about waste management and its impact on the environment. Worldwide, cattle produce enormous amounts of manure, which is detrimental to soil properties if poorly managed. Waste management with insect larvae is considered one of the most efficient techniques for resource recovery from manure. In recent years, the use of black soldier fly larvae (BSFL) for resource recovery has emerged as an effective method. Using BSFL has several advantages over traditional methods, as the larvae produce a safe compost and extract trace elements like Cu and Zn. This paper is a comprehensive review of the potential of BSFL for recycling organic wastes from livestock farming, manure bioconversion, parameters affecting the BSFL application on organic farming, and process performance of biomolecule degradation. The last part discusses the economic feasibility, lifecycle assessment, and circular bioeconomy of the BSFL in manure recycling. Moreover, it discusses the future perspectives associated with the application of BSFL. Specifically, this review discusses BSFL cultivation and its impact on the larvae's physiology, gut biochemical physiology, gut microbes and metabolic pathways, nutrient conservation and global warming potential, microbial decomposition of organic nutrients, total and pathogenic microbial dynamics, and recycling of rearing residues as fertilizer.

Brownfields or objects of accumulated environmental damage are a complex object characterized by both the absorption and release of uncontrolled energy (for example, biogas or hydrothermal energy). The brownfield redevelopment process provides unique opportunities to ensure efficient energy transfer and maintain environmental stability. However, the implementation of these solutions depends on the quality of the assessment of the cumulative impact of unspent deposits, namely, the assessment of the damage caused to the environment, which, in turn, gives an understanding of how to ensure the elimination of damage to energy efficiency and environmental safety from uncontrolled carbon dioxide emissions. In this article, we consider the problems of assessing the cumulative effect of waste management activities, as a result of which abandoned deposits or objects of accumulated environmental damage appear. A cycle of measures to achieve socio-economic efficiency through the re-development of brownfields and their integration within energy-efficient systems and environmentally balanced systems is proposed, and a new concept of identifying the negative occurrence of brownfields under the influence of climate change is substantiated. Particularly, we assess the possibilities of integrating brownfields or objects of accumulated environmental damage into energy-efficient and environmentally balanced systems for goals of sustainable development.

Disposal of production and consumption waste is a worldwide problem. Despite the experience of foreign countries, waste disposal practice in the Russian Federation remains at the level of the 1970s. The method of waste burial at landfill sites prevails, leading to a loss of secondary resources and the appearance of sites of accumulated environmental damage, which is connected with the lack of a clear legal framework for waste management activities. Analysis of waste accumulation standards for apartment buildings in 20 regions of the Russian Federation showed that the difference in accumulation standards can vary by 2.32 times (from 0.125 m3 in the Kursk region to 0.279 m3 in the Voronezh region). At the same time, the difference in the cost of solid waste removal services can be varied by 2.74 times from 51.55 rubles in the Altai Territory (on average in the region) to 141.45 rubles in the Tyumen region. At the same time, the share of the population with incomes below the subsistence minimum in different regions reaches 7 - 36%. This is largely due to the critically low recovery of secondary materials (about 7%). The capacity of landfills in the regions of the European part of Russia (where more than 2/3 of the population lives) is almost exhausted. Many landfills of solid waste are objects of accumulated environmental damage. The decision to introduce the «institute» of “regional environmental operators”, which was adopted at the level of the Russian Federation to implement the waste management reform, has not, yet had any positive effect. Given the constant deficit of the consolidated budgets of most regions, the high level of poverty and the lack of state support, the prospects for waste management reform indicate the need for additional efforts on the part of the state, business and society. 

Introduction. Heavy metals discharged with wastewater can lead to a toxic effect on the microbiocenosis of activated sludge and significantly decrease the degree of wastewater treatment, which dictates the need for a more detailed study and search for ways to detoxify activated sludge at the recycling stage and, at the same time, solve the problems of the neutralization of sewage sludge for safe soil disposal. To ensure the adequacy of the approach to the choice of the methodology for the neutralization of sludge, including sewage sludge, it is necessary to perform compositional analysis of their organic fractions and heavy metal compositions. Methods. To determine the quantitative content of organic components in activated sludge, a sample of sludge was dried to an air-dry state and then subjected to separation into fractions using a method based on the different solubility of compounds with the use of different solvents. Then, extractants were added step by step to the weighted samples of sewage sludge weighing about 2 g each (in a volume 20 times greater than the weight of the weighted sample (40 ml)). Results. The results of the study show that polysaccharides are the dominant form of the organic fraction (polymers) in sewage sludge. Most heavy metals were identified in acidic polysaccharides, humic-like acids and lipids. Significant concentrations of phosphates were observed for the same components of polymer substances in the biomass of activated sludges. Conclusion. The products of extraction of polymer substances of the activated sludge biomass and the content of heavy metals in them may indicate the biosorption of heavy metals by zoogleal accumulations (having a polysaccharide structure) of activated sludges in aeration tanks during biological treatment. Therefore, extracellular biopolymers can be a “target” in the development of targeted technologies for the neutralization of activated sludges.

The purpose of this study was to assess the groundwater contamination from a sewage sludge landfill. The analysis was carried out in 2017 in accordance with the requirements of the national legislation for monitoring landfills and priority pollutants. The samples of groundwater from the landfill were taken from 25 observation wells, from depths of 45-60 m. The status and dynamics of changes in the landfill groundwater quality were estimated according to the data from the groundwater observation wells of the city observation network with regard to the chemical composition of groundwater and national standards of groundwater quality. The forecast estimates of a low level of pollutants entering groundwater through the soils characterized by low filtration properties were not justified. The concentration of heavy metals in groundwater was within the following range: Fe > Mn > Zn > Al > Cu > Ni > Pb > Cd > Hg. The excess concentration of the nitrogen-containing pollutants was observed within the range from 1.5 to 76 (on average 10 times) above the background value. The organic contamination of landfill groundwater (COD) is 2-9 times and BOD5 – 1.5-3 times higher than the average background value of groundwater observation wells in the city network. The probable cause for the pollutants entry into groundwater is associated with lithogenous and exogenous fracturing of the rocks and insufficient efficiency of the existing anti-filtration system of the landfill.