Production of hydrogen peroxide in an intra-meander hyporheic zone at East River, Colorado

The traditionally held assumption that photo-dependent processes are the predominant source of H2O2 in natural waters has been recently questioned by an increrasing body of evidence showing the ubiquitiousness of H2O2 in dark water bodies and in groundwater. In this study, we conducted field measurement of H2O2 in an intra-meander hyporheic zone and in surface water at East River, CO. On-site detection using a sensitive chemiluminescence method suggests H2O2 concentrations in groundwater ranging from 6 nM (at the most reduced region) to ~ 80 nM (in a locally oxygen-rich area) along the intra-meander transect with a maxima of 186 nM detected in the surface water in an early afternoon, lagging the maximum solar irradiance by ∼ 1.5 h. Our results suggest that the dark profile of H2O2 in the hyporheic zone is closely correlated to local redox gradients, indicating that interactions between various redox sensitive elements could play an essential role. Due to its transient nature, the widespread presence of H2O2 in the hyporheic zone indicates the existence of a sustained balance between H2O2 production and consumption, which potentially involves a relatively rapid succession of various biogeochemically important processes (such as organic matter turnover, metal cycling and contaminant mobilization). More importantly, this study confirmed the occurrence of reactive oxygen species at a subsurface redox transition zone and further support our understanding of redox boundaries on reactive oxygen species generation and as key locations of biogeochemical activity.

Experimental Study of Steel Shot and Lead Shot Transformation Under the Environmental Factors

This paper presents the results of an experimental study of the patterns of steel and lead shot transformation under the impact of environmental factors (two types of shot exposed alone and in combination with each other). The analyzed environmental factors include atmospheric precipitation of various acidity and soil solutions with a higher content of organic acids. This research demonstrated that steel shot is characterized by a high transformation rate that is an order of magnitude higher on average than the transformation rate of lead under the same conditions. The prevalence of the suspended iron form (excluding the interaction with organic acids) presents risks for such environmental components as soils and sediments and may be hazardous to the ambient air and natural waters in case of wind erosion and surface runoff from the catchment area. Furthermore, the joint presence of steel and lead shot mutually accelerates the corrosion of both metals, thus increasing the environmental risks.

Technogenesis and Ecological State of Natural Waters in Eastern Transbaikalia

The research on the state of water ecosystems is significant in terms of future biological impacts of natural and anthropogenic effects. The key branches of natural resources management in Eastern Transbaikalia (agriculture, hydraulic power industry) are based on using water resources. The findings show that technogenesis affects surface waters of the region. Alluvial gold mining represents a significant part of mining industry. Gold mining in river channels results in run-of-stream diversion and interferes with the ecosystem of watercourses. A newly formed structure of a water ecosystem is not favourable for self-purification capacity of rivers. This leads to pollutants accumulation in water objects and deteriorates ecological state of watercourses. Natural components in the technoecosystem of hydropower objects in Eastern Transbaikalia are Lake Kenon and the Kharanor Reservoir. Although the catchment area is polluted by TPP-1, the ecosystem of the lake is still capable of self-purification due to biodiversity of hydrobionts. Under the dry climate in recent years, the Kharanor Reservoir ecosystem turned as rather unstable due to constant refilling from the Onon River. However, generally, pigment indices show physiological activity of primary producers of organic matter.

Features of the metal distribution in the technogenic and natural waters of the Novoshirokinsky deposit (Eastern Transbaikalia)

To identify the degree of impact of technogenic activity on the main water bodies located in the immediate vicinity of mining production, an analysis of the composition and pH of the water, the chemical components of which are normalized by the Order of the Ministry of Agriculture of the Russian Federation (dated 13.12.2016, No. 552 with amendments), was carried out starting on 10.03.2020.

Geochemical peculiarities of underground and surface waters in the area of influence of the ash dump of the Chita CHPP-1

As a result of filtration leaks from the ash dump, an envelope with a length of over 3 km up to the lake Kenon has been formed along the flow of groundwater bicarbonate-sulphate waters with a mineralization of more than 1.0 g / l, substandard in terms of drinking waters relative to the total mineralization, the magnitude of stiffness and the content of magnesium and silicon. Pollution of natural waters in the areas of disposal of ash dumps is a common problem of coal power plants and thermal power plants [1, 2]. In this regard, the Chita CHPP-1 is no exception. The purpose of this message is to show the change in the chemical characteristics of groundwater and surface water in the zone of influence of its hydraulic ash dump, based on the results of the work performed by the authors. The study was based on the results of hydrogeochemical studies of natural and man-made objects for 2002, 2008 and 2015. Samples were taken in the autumn-summer period (open water period), which, given the fairly stable hydrogeochemical regime within the annual cycle, is fairly representative.

Thermodynamics of the evolution of the biosphere

The thermodynamic foundations of the evolution of the biosphere are considered: the variability of natural systems with different dispersion of their components, the alternative ways of development of such systems, the alternative of intermediate stable states of ecosystems depending on fluctuations of external factors, primarily climate. The necessity of developing a system of mutually agreed complex indicators of this process is postulated. The necessity of including the water content of ecosystems in the number of parameters of nonequilibrium thermodynamics is justified. A new section of land hydrology is formulated -the study of thermodynamic aspects of the dynamics of natural waters.