Wastewater pollution with detergents is one of the environmental problems associated with the rational use of water resources. The existing methods of physicochemical wastewater treatment, despite their efficiency, are open to secondary environmental pollution. Biological coagulation/flocculation...

Pyrophoric iron sulfides formed as a result of oil cracking, when in contact with air oxygen, have the ability to self-ignite, as a result of which they are highly explosive at oil refining enterprises. It is known that oil refineries in Kazakhstan produce from 4 to 10 tons per year of this...

This article discusses the issue of biochemical wastewater treatment by microorganisms. It has been investigated that the rate of iron oxidation by bacteria used in wastewater treatment depends on environmental factors, including temperature. One of the most common and affordable treatment methods is the treatment of industrial wastewater using mineral coagulants (aluminum and iron salts) and flocculants. The main purpose of coagulants and flocculants is to increase the particle size due to their adhesion (aggregation) and, as a result, to increase the efficiency of purification due to filtration, precipitation, and flotation of water. We recommend using the culture liquid of Acidithiobacillus ferrooxidans bacteria as a coagulant for wastewater treatment of enterprises from metal ions and some organic pollutants. A.ferrooxidans uses Fe²⁺ as an energy source, so the concentration of Fe²⁺ in the medium can affect the growth of bacteria. In the process of oxidation of ferrous iron to trivalent iron, bacteria receive the energy necessary for their metabolism. Trivalent iron obtained during the oxidation process can be used as a biocoagulant in wastewater treatment. The article shows the optimal temperature for biochemical oxidation of iron by bacteria.

The purpose of the proposed research work is to determine the number of heavy metals (Pb, Zn, Cd) in soils and agricultural crops located near highways in South Kazakhstan (Turkestan region, Saryagash district) and to evaluate their transfer into plants. Soil samples along the highway and vegetables (tomatoes, cucumbers) and cucurbits (watermelon, melon) grown in this area were selected as the objects of the research. The concentrations of heavy metals were determined by atomic absorption spectroscopy. The transfer factor (TF) was calculated to characterize the rate of element transfer into plants. This study provides new data on heavy metal distribution and transfer in agricultural systems of South Kazakhstan, a region where roadside contamination of crops remains insufficiently studied. According to the research results, the concentrations of Pb, Zn and Cd in the soil along the road were found to be 1.5–3 times higher than the permissible limit values. The spread of heavy metals in the soil was determined in a decreasing order: Pb > Zn > Cd. The transfer factor into plants were within the following limits: Pb — 0.16–0.32; Zn — 1.99–3.0; Cd — 2.9–4.4. The highest migration ability was characteristic of the Cd element, which indicated its high bioavailability. As a result of the correlation analysis, positive relationship (r > 0.90) was revealed between all indicators, especially between Zn and Cd (r = 0.99). The conducted research showed that the migration of heavy metals to agricultural crops poses a significant threat to human health. Therefore, it is recommended to conduct regular monitoring, maintain sanitary distances and apply bioremediation measures aimed at reducing soil contamination to prevent the accumulation of heavy metals in products grown along roads.

This study investigated the potential application of a microorganism-derived biocoagulant based on the bacterial strain Acidithiobacillus ferrooxidans Ach1 to improve the treatment efficiency of wastewater containing organic pollutants. The relevance of the study is associated with the high...

The purpose of this study is to investigate the feasibility and efficiency of using a suspension of Acidithiobacillus ferrooxidans Ach 1 bacterium as a natural bio-coagulant for the treatment of model wastewater containing milk, which simulates effluent from dairy processing plants. Laboratory experiments were conducted using a model solution prepared from cow’s milk and distilled water. The bacterial suspension was introduced into the model solution at various volumetric ratios (1-40%). Lactose concentration, turbidity and elemental composition of the sludge were determined according to GOST standards and instrumental analysis. A comprehensive literature review of dairy wastewater characteristics and treatment methods was performed to contextualize the study. The degree of purification of the model solution was assessed by measuring the lactose content after treatment with the biocoagulant. In the control solution without the biocoagulant, the lactose concentration was found to be 0.46 g/mL. Introduction of the biocoagulant at 6% volume reduced the lactose content by 39.1 ± 3.0%, while at 40% volume it decreased by 92.5 ± 7.1%. The results suggest that A. ferrooxidans Ach 1 suspension can serve as an effective bio-coagulant for the pre-treatment of milk-containing industrial wastewater.