Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 6

The pulp and paper industry is developed in the northern regions. Ecosystems of northern rivers are less capable of biological self-rinsing and more sensitive to anthropogenic pollution. Assessing the pollution of water bodies is important for controlling the conservation of their bioresources. This article provides a literature review which illustrates the main impacts of wastewater of the pulp and paper industry on aquatic ecosystems. It will be useful for monitoring practitioners. This paper discusses examples of the impact of wastewater of the pulp and paper industry on aquatic organisms at different levels of organization - from the molecular to the ecosystem. The review describes the responses of aquatic zoocenoses (zooplankton and zoobenthos) to pollution and the effects of specific substances that enter water bodies from the effluents of the pulp and paper industry. The paper analyses information about transformation of bottom sediments of rivers and lakes in the wastewater zone. An overview of data is given, which evaluates the impact of thermal pollution. This type of pollution often characterizes industrial wastewater. One of the large rivers in the European part of Russia is the Vychegda River. The rivers in its basin are important in the Komi Republic. Therefore, monitoring the condition of communities of aquatic organisms that inhabit it is an urgent task. This paper presents the results of hydrobiological observations carried out in the Vychegda in the 1980s. At that time, changes in communities of aquatic organisms in the area of pulp and paper industry were shown.

The results of three-year measurements (2018-2020) of hydrophysical and hydrochemical indicators of the Vychegda River in places where treated wastewater is discharged from the Mondi Syktyvkar JSC pulp and paper mill are presented. At conventionally background stations and exposed to wastewater in concentrations significantly lower than the MPC: mineralization, the content of ions of Ca²⁺, Mg²⁺, Cl^-, SO4^2-, NO3^-, heavy metals, oil products, anionic surfactants, benz[a]pyrene were noted, an excess of MPC was noted for Suspended substances, COD, РО4^3-, Fe, Mn. Studies have shown that in connection with the modernization of the treatment facilities of Mondi Syktyvkar JSC, there is a noticeable improvement in the quality of wastewater and a decrease in the environmental load on the ecosystem of the Vychegda River in places of their discharge. With a high water level in the Vychegda River (2018-2019) for all investigated hydrochemical indicators in the places of wastewater discharge, no significant excess over conditionally background values - was revealed. It was possible to register the impact of pollutants only in the low-water period (2020), with a decrease in the degree of dilution by river waters of effluent from treatment facilities. During this period, at the observation points in the places of wastewater discharge, a significant increase was noted relative to the conditionally background indicators of the concentration of ions Cl^-, SO4^2-, РО4^3-, NH₄⁺, S_tot, K, Na, Fhenol, as well as COD, Permanganate Value, turbidity, electrical conductivity. In terms of environmental, sanitary and toxicological indicators, the waters of all surveyed observation points were assigned to the 3rd class of water quality (satisfactory purity).

Like most of the northern rivers, the Vychegda river, the second largest water system of the Komi Republic and the main tributary of the Northern Dvina river, is experienced intense anthropogenic load. Agricultural, domestic and industrial, at a greater extent, waste waters are currently the main polluting sources of river waters. The largest pulp and paper enterprise in Russia, Mondi Syktyvkar JSC, is located on the Vychegda riverbanks among the numerous enterprises operating here. The composition and structure of the zooplankton communities were investigated in the Vychegda river area, where effect of waste waters from the pulp and paper enterprise is observed. The research aim is to find out there is a negative impact of the conditionally treated waste waters on the aquatic biota. As a result, a rich species composition and quantitative development of zooplankton communities were established for the investigated river area. Rotifera was the dominant group on species abundance, number and biomass. This is characteristic feature of zooplankton communities in the watercourse as a whole. The indicator species of waters with a high level of pollution were registered both at points located in the area of waste waters influence and at the background plots of the river. The species which are not peculiar to the natural waters of the river were found in points of waste water discharge. The dominant complexes are represented by 9-15 species лучше. Their composition differs at background, waste waters and downstream points. According to the state of zooplankton communities, the river waters in the studied area are conditionally clean, except the points located downstream of waste waters discharge, where they are qualified as eutrophic.

We characterized the composition and diversity of benthic communities, as well as the current ecological state of Vychegda River in the zone of influence of wastewater from a pulp and paper production. A high diversity of benthic fauna and quantitative indicators of its development which are not typical for benthic biocenoses in the middle reaches of Vychegda River were registered. In the composition of the zoobenthos, 23 taxonomic groups of benthic invertebrates were identified. For 7 model groups, we identified 125 species and forms, as well as a persistent complex of species dominating in the studied section of the river. The model groups were dominated by indicator species of о-β- and β-saprobic conditions. In general, the water quality assessment indices based on the composition and structure of benthic invertebrate communities characterize the state of the river at the monitoring site as “satisfactory”. An exception was the wastewater discharge points, where the role of indicator species of α- and polysaprobic conditions was higher and the values of most of the indices were significantly lower.

In 2018-2020. we identified in Vychegda and Sysola Rivers new for the Komi Republic and the entire Northern Europe species of copepods: Elaphoidella bidens, Phyllognatopus viguieri, Paracyclops imminutus. All of these species were found exclusively in the areas of wastewater discharge of a timber processing company or urban wastewater of the city of Syktyvkar. The analysis of the identified specimens showed their morphological similarity with the type descriptions, only in P. viguieri from Sysola River we found certain features in the structure of the furca which distinguished it from the type form. As a result of molecular genetic studies, we determined that the crustacean Attheyella crassa native to the Vychegda basin is identical in the structure of mtDNA-COI to specimens of this species from the Moscow Oblast, while E. bidens from the zone of influence of wastewaters of a pulp and paper production company in the Vychegda basin differed from representatives of the species from the Moscow Oblast by 14 % and was similar to E. bidens from New Zealand. This characteristic feature of the Vychegda population of E. bidens indirectly confirms that the mechanism of invasion of the species into a new habitat is associated with wastewater. The identified species of copepod crayfish which are new for the Komi Republic represent a facultative synanthropic fauna in the study region that is capable of development only in urbanized areas.

The results of a study of summer phytoplankton (July 2018-2020) in the middle reaches of the Vychegda River in the places where treated wastewater is discharged from the Mondi Syktyvkar JSC pulp and paper mill are presented. In the phytoplankton of the investigated section of the River, 263 species with varieties of algae of seven divisions were identified: Cyanoptokaryota - 8, Ochrophyta - 4, Rhodophyta - 1, Euglenophyta - 1, Bacillariophyta - 232, Chlorophyta- 15, Charophyta - 2. Mostly widespread in terms of diversity, eurytopic species. For three years of research, the stability of the complex of dominant species and structural diversity has been noted for phytoplankton communities. The basis of the dominant complexes is formed by species from the genera Aulacoseira , Dolichospermum , Pandorina , Eudorina , Closterium , etc. The composition of dominants is similar for conditionally background points and the zone of discharge of fine waters. Below the wastewater discharge site, a massive development of the thermophilic species of diatom Diadesmis confervacea , an indicator of thermal pollution, was noted. The total number of phytoplankton in the Vychegda River at the studied stations was recorded in the range from 1150 to 18000 thousand cells / dm³, biomass - from 0.01 to 0.29 mg / dm³. The ratio of the total abundance and biomass of phytoplankton algae and indicator species forming a complex of dominants reflect an increase in the trophic status of the waters of the surveyed areas and a high degree of anthropogenic load on the ecosystem of the Vychegda River. On the basis of algoindication, the waters of the conditionally background and receiving wastewaters of observation points were assigned to the III quality class (with the quality category 3b - slightly polluted).

The paper is presented the results of a study of the species diversity and developmental stability of individuals of common fish species from the Vychegda River in the area of treated wastewater discharge of one of the largest pulp and paper mill in the European northeast of Russia. It was shown that for the period from 2018 to 2020, perch, roach, and bleak predominate in the catches of a set of nets with a mesh size of 10 to 60 mm in the littoral zone of the monitoring sites. These species are widespread representatives of the ichthyofauna in the basin of the studied river. The catches included non-native species such as white-eye bream, asp and pike-perch. They recent appearance of which became possible due to the construction of canals connecting the Northern Dvina River basin with other river systems. Indices of species diversity (the number of species, their relative abundance and the Shannon index) in monitoring sites from the region of the studed of pulp and paper production is similar. The integral index of individual development assessing, based on the fluctuating asymmetry indicator, indicates the absence of a negative effect on the formation of bilateral morphological structures in early ontogenesis in fish that lived as in the impact as in the conditionally background sits. It was recommended to conduct an additional study to identify physiological disorders in the body of fish or the accumulation of heavy metals or other pollutants in their tissues and organs to clarify the obtained results.

The results of long-term studies of the collembolan population in the gradient of pollution of pine and spruce forests (middle taiga) in the zone of influence of pulp and paper industry (JSC Mondi SLPK, Komi Republic), the main pollutants of which are oxides of carbon, nitrogen, sulfur, hydrogen sulfide, mineral dust are given. The study was carried out in the period when the total amount of emissions was 20-30 thousand tons (2003, 2007-2009 years) and 10-15 years after their reduction by 2-3 times to 10 thousand tons (2018-2019 years). It was shown that after a decrease of emissions, the species richness of springtails significantly increases in the zones of strong and medium coniferous forests, but their number decreases in all zones, which may be associated with weather conditions. It was found that in pine forests, especially in the background plots, euedaphic species predominate, and the proportion of hemiedaphic and epiedaphic species increases in the zone of sting impact. At the same time, the spectrum of life forms, biotopic groups, the structure of the springtail population does not undergo significant changes over the course of 10 years. In spruce forests, on the contrary, differences were revealed in these parameters between years of research, which are expressed in a change in the dominance of species, their relative life forms and biotopic groups. The observed changes in the communities of springtails in spruce forests are apparently determined by changes in the ground cover. In general, there has been a significant improvement in the state of the collembola community of spruce forests in the zones of strong and medium imact from 2003 to 2019.

The analysis of the state of soil macrofauna during the period of reduction of emissions of pulp and paper production revealed changes in the structural parameters of invertebrate communities in the pine and spruce forests of the impact, buffer and background areas. The macrofauna of pine and spruce forests is characterized by a high degree of similarity and low diversity at the level of large taxa. It is a typical feature of coniferous forests in the middle taiga subzone. The species richness of invertebrate communities is estimated for the period from 2003 to 2019 years. It is comparable for the impact and buffer areas, and it is almost twice lower than for the background area. The total number of macrofauna, as well as taxonomic groups, varies by periods and areas of load. In 2007 and 2010, a change of dominant species was observed in the pine forests of the impact area. Lithobius curtipes C. L. Koch, 1847, Pella humeralis (Gravenhorst, 1802) predominated in the buffer and background area, and Philonthus rotundicollis (Menetries, 1832), Philonthus politus (Linnaeus, 1758) predominated in the impact area. In 2018, no changes of dominants were detected in pine forests, as in spruce forests (in 2006, 2010, 2019). Dendrobaena octaedra (Savigny, 1826) and L. curtipes were dominants in the impact, buffer and background area. The predominance of zoophages is typical for all the studied plots. The number of some taxa (Lumbricidae, Diplopoda, Elateridae) indicated an increase in the relative abundance of saprophages in the soils of coniferous forests at the impact area. The soils of background area, with high natural acidity, are unsuitable for activity of invertebrates. Due to the effect of neutralizing the acidity of the soil near the pulp and paper enterprise favorable conditions are created for them.