Destruction Of Organic Matter Research Articles

PENGARUH PUPUK ORGANIK CAIR DARI BONGGOL PISANG TERHADAP KADAR HARA NITROGEN TOTAL DAN C-ORGANIK PADA BIBIT KELAPA SAWIT (Elaeis guineensis Jacq.)

Suspension media is made of natural ingredients to multiply microorganisms that can accelerate the destruction of organic matter. Banana hump contains water, iron, phosphorus, calcium, carbohydrates, calories and protein, which are potential as organic fertilizers. Application of banana weevil fertilizer is expected to increase the carrying capacity of the soil for the availability of organic matter and nutrients. The purpose of this study was to determine the best concentration or dose of organic liquid fertilizer for banana weevil on the vegetative growth of oil palm (Elaeis guineensis Jacq.) seedlings in the Main Nursery. Based on this statement, this research was compiled with the object of oil palm in the Main Nursery. This research was conducted in the Nursery Practice Garden area at STIP-AP Medan. Soil analysis was carried out at the Soil Laboratory of the Agricultural Technology Research Institute (BPTP) of North Sumatra. The time of the study was carried out for 8 months, from January 2021 - August 2021. This study used a Randomized Block Design (RAK) with 2 factors, namely Factor (1) Liquid Organic Fertilizer Banana Cobs and Factor (2) Compound Fertilizer (NPK) 16:16 :16. The treatment was repeated 3 times, with the number of samples being 2 plants so that the sample population was 54 plants. Parameters observed were seedling height, stem circumference, number of leaves, leaf width, root wet weight, shoot wet weight, shoot dry weight, root dry weight, total nitrogen nutrient content and C-organic nutrient content. The data obtained were analyzed statistically by analysis of variance (ANOVA) with 5% and 1% significant difference tests. The results showed that the treatment of banana weevil liquid organic fertilizer and compound fertilizer had no significant effect on the observed parameters. However, the biomass formed was significantly affected as indicated by the weight parameter. The availability of total nitrogen and C-organic nutrients in Ultisol soil showed a very low classification with total nitrogen values ​​of 0.07 – 0.09% and C-organic values ​​of 0.22 – 0.54%.

ДОСЛІДЖЕННЯ МЕТАНОГЕННОГО ЗБРОДЖУВАННЯ ВІДХОДІВ ХАРЧОВОЇ ПРОМИСЛОВОСТІ

Purpose. To investigate the joint utilization of rice husk, cattle manure and meat processing plant’s waste water by anaerobic fermentation taking to account it is considered as one of the most effective ways of multicomponent sub- strates utilization, and to determine the optimal weight proportions of mixed waste components as a substrate for fer- mentation in an anaerobic bioreactor. Methodology. We have fermented substrates in a bioreactor with an upward flow of liquid through an anaerobic sludge layer UASB of periodic action with a total volume of 50 dm3 to study anaerobic fermentation of substrates with different weight ratio of components in mesophilic conditions. We have monitored the indicators of the amount of released formed biogas and methane, the degree of organic matter biodegradation by the indicator of COD and the medium pH. We have performed a number of experiments of substrates anaerobic fermenta- tion with different weight ratio of cattle manure, waste water and rice husk at mesophilic temperature. Results. We have identified the parameters of the influence of the substrate composition on the efficiency of the organic matter decompo- sition, biogas formation and methane yield as a result of anaerobic reactions. It allows to determine the degree of the organic matter destruction of cattle manure and rice husk and evaluated the negative impact of fatty acids on anaerobic reactions. Originality. For the first time, we have carried out the integrated research of joint fermentation of rice husk and waste from mixed production in an anaerobic bioreactor. We have proved the efficiency of using mixed substrates for methane production and increasing the degree of the waste organic substances biodegradation in comparison with the fermentation rates of monosubstrates. Practical value. We have demonstrated the effectiveness of joint fermenta- tion of rice husk and waste from mixed production in an anaerobic bioreactor, which provides high rates of organic matter destruction in the biological environment with high methane content and stability of similar production reactions.

Microbial analysis of sewage sludge shows closer monitoring needed for landfill waste

A method of high-throughput sequencing of gene libraries was used to identify the microbial communities in samples of sewage sludge at waste treatment facilities in Saint Petersburg, Russia. It was established that the waste had a complicated taxonomic structure and consisted of two main domains: Archaea (8.4% average) and Bacteria (77.6% average). The Archaea domain included three phyla (methanogens): Euryarchaeota, Crenarchaeota and Parvarchaeota. The Bacteria domain was represented by 49 phyla, including Proteobacteria, Firmicutes, Bacteroidetes, Chloroflexi, Cyanobacteria, Planctomycetes, Gemmatimonadetes, Acidobacteria and Verrucomicrobia. Up to 2.8% share of methanogens in sewage sludge deposited in landfills for around 15 years indicated the ongoing destruction of organic matter. In addition, ten pathogenic microorganisms were detected, including Clostridium and Mycobacterium. The results indicated that the national regulatory requirements for waste in Russia need to be reviewed in terms of compiling a list of standardised indicators for environmental monitoring of landfill sites.

Changes Induced by Self-Burning in Technosols from a Coal Mine Waste Pile: A Hydropedological Approach

Coal mining originates environmental impacts on soil and water bodies, including the leaching of Potentially Toxic Elements (PTEs) and Polycyclic Aromatic Hydrocarbons (PAHs) in mine waste piles. This research aims to identify and characterize changes induced by self-burning in Technosols from a coal mine waste pile by means of a comprehensive hydropedological assessment encompassing geochemical, mineralogical, and hydrological data, bearing in mind the potential leaching of PTEs and PAHs. The soil profile from two contiguous areas (an area with normal pedological evolution vs. an area affected by self-burning) was characterized in terms of morphological features. Each soil horizon was sampled and analyzed for geochemical and mineralogical characterization. The unsaturated hydraulic conductivity (Ki) was also measured in all soil horizons. Finally, the leaching potential of PTEs and PAHs in water was evaluated. Several changes induced by self-burning were identified in the studied Technosols: development of specific soil horizons; destruction of humified organic matter; contrasting geochemical composition, especially in the deeper horizons; mineralogical modifications, pointing to clay minerals with higher ion exchange capacity and higher specific surface by sulphates of lower structural order; diverse Ki values in the intermediate and lower part of the soil profile; and specific susceptibility to leaching of PTEs and PAHs. The research demonstrated that self-burning causes severe changes of hydropedological relevance, with influence on the leaching of PTEs and PAHs.

Emprego da Pilarização na Argila Regional do Tipo Montmorilonita na Reação de Isomerizacão do Buteno-1/ Use of Pillarization in Regional Montmorillonite Clay in the Butene-1 Isomerization Reaction

The regional montmorillonite clay from Santo Amaro da Purification, the region of Reconcavo Baiano, was subjected to chemical treatment for the destruction of organic matter, after which the pillarization technique was applied using the hydroxyacetatoferro precursor (III) in order to generate a isomerization of butane 1. The solids were characterized by conventional techniques such as: DRX, TG/DTA, specific surface area measurement, MEV and RTP, in order to evaluate their importance as a clay-resercible that can be restructured chemical composition and crystallographic.. The results indicated that the pillarization resulted in the formation of thermally stable iron oxide. The Bronsted acid sites, detected by absorbed pyridine FTIR, were active in the geometric isomerization of butenes, with 22% selectivity to the cis isomer and 47% to the trans isomer.

Insight into sludge dewatering by advanced oxidation using persulfate as oxidant and Fe2+ as activator: Performance, mechanism and extracellular polymers and heavy metals behaviors

This study established a Fe2+/persulfate oxidation system to dewater sludge in WWTPs. Dewatering performance, persulfate consumption and the variations of sludge pH, TN and TP during dewatering process were monitored. EPS and ζ-potential behaviors for ameliorating sludge dewatering was investigated. Transformation, leaching toxicity and environmental risk of heavy metals in sludge during dewatering were determined. Results demonstrated that after treated by Fe2+/persulfate oxidation system with 0.6 mmol/g–VS of persulfate at Fe2+/persulfate molar ratio 0.6, WC decreased to 53.5% and SCST increased to 4.15, which implied an excellent improvement of sludge dewatering. The fast persulfate consumption, the decrease of sludge pH and the increase of TN illustrated the positive effects of Fe2+ in activating persulfate and the decomposition of EPS by the activation products, SO4•− and •OH. Another product (Fe3+) generated during persulfate activation could decrease the content of phosphorus-containing matter (released from EPS decomposition) through the precipitation reaction with PO43−. The decrease of TOC and UV–254 happened in HPO–A, HPO–N and TPI–A organic substance of EPS (mainly contained in TB–EPS fraction) indicated that the destruction of hydrophobic organic matter of EPS would stimulate the release of bound water, which was beneficial to dewater sludge. The largest protein loss in TB–EPS (from 24.5 to 10.7 mg/L) indicated that the effective decomposition of TB–EPS could significantly ameliorate sludge dewatering. The increase of ζ–potential indicated the degradation of organic matter in EPS with negative charge. To sum up, the destruction of protein–like substances in hydrophobic organic matter of TB–EPS was the main mechanism for improving sludge dewatering by Fe2+/persulfate oxidation system. 3D–EEM fluorescence spectroscopy analysis proved that these protein–like substances were mainly tryptophan protein and humic acid. Moreover, due to the disruption of EPS, the contents of heavy metals in sludge, and their leaching toxicity and environmental risk were reduced. Therefore, Fe2+/persulfate oxidation system has potential and application prospects to improve sludge dewatering and optimize sludge management in WWTPs.

Hydrochemical state of the Uglovoy Bight (Amur Bay) in different seasons

Hydrological and chemical surveys were conducted in the Uglovoy Bight in October, 2019, February, May and June, 2020 (in total 120 stations) and chemical analyses of water from 13 small rivers running into the bight were done on October 21-22, 2020. Extremely high concentration of nutrients was detected in the Peschanka, Saperka and Gryaznukha Rivers that was obviously caused by waste waters discharge. These rivers were the main source of the bight eutrophication. Within the bight, the highest anomalies of chemical parameters, as low oxygen content, low pH, high concentrations of nutrients (N, P, Si), high turbidity, and high CO2 partial pressure were observed close to these rivers mouths, in particular under the ice in winter, when wind mixing was absent. The hypoxia disappeared in the warm period of year because of wind mixing. High concentrations of total nitrogen (10.0-40.0 μmol/L), total phosphorus (1.5-2.0 gmol/L), dissolved organic carbon (3-5 mgC/L), and chlorophyll a (0.5-2.0 μg/L) in all seasons were the results of active production-destruction processes, obviously with prevalence of organic matter destruction, since the water in the bight was undersaturated with oxygen and supersaturated with carbon dioxide — the bight accumulates and mineralizes organic matter from terrestrial and riverine discharge. Underwater photographs did not detect Zostera meadows at the bottom, which were observed in the northwestern Uglovoy bight in the past. Comparison of historical data on episodic studies in the bight with results of the surveys indicates degradation of its ecosystem, with such signs as disappearance of seagrass, hypoxia in winter, and CO2 flux into the atmosphere. Reduce in water exchange between the bight and the Amur Bay caused by construction of the underwater pipeline in 1982 and the bridge in 2012 is suggested as a reason of the degradation.

A Study of Soil Organic Matter Stability Using Derivatography and Long-Term Incubation Methods

Soil organic matter (SOM) includes many classes of labile compounds available for microbial decomposition or, conversely, stable compounds protected from biodegradation by biological, chemical, and physical stabilization. It is believed that the more thermal energy is spent on the destruction of soil organic matter, the more stable and more resistant for biodegradation it is. We compared the thermal and biological stabilities of organic matter in eleven soil types from deciduous forest, forest-steppe, steppe, and semidesert bioclimatic areas of the European Russia. According to the activation energy (Ea), the highest SOM thermal stability was typical of the ordinary chernozem and meadow vertic soil. The lowest SOM thermal stability was found for gray forest soil; other soil types were characterized by an intermediate resistance towards thermal oxidation. The thermally labile pool (<390–400°C) of organic matter in soils was on the average 41% (32–60%) of the total SOM, while the thermally stable pool (>390–400°C) was on the average 59% (40–68%). The SOM biological stability estimated by the ratio of potentially mineralizable organic matter to that resistant to mineralization (biological stability index) decreased in the following order: ordinary chernozem (Haplic Chernozem (Loamic, Pachic)) > meadow vertic soil (Pellic Vertisol (Gleyic, Humic)) > gray forest soil (Luvic Greyzemic Phaeozem (Loamic)) = meadow chestnut soil (Gleyic Kastanozem (Chromic)) > meadow solonetz (Endosalic Gleyic Solonetz (Loamic, Cutanic)) > alluvial meadow soil (Eutric Fluvisol (Humic, Oxyaquic)). The potentially mineralizable SOM pool in the studied soils was 6–27-fold lower as compared with the pool of thermally labile SOM, and the parameters that characterize SOM thermal stability did not correlate with the biological stability index. Thus, SOM thermal lability is not identical to its biodegradability.

Microbial features of newly-formed soils of disposal fields from sugar refineries

Newly-formed soils of wastewater disposal fields from two sugar refineries in forest-steppe zone (Kursk region, European Russia) were studied. Among factors of soil formation on sugar wastewater lagoons the geochemical influence of wastewater mixed with diluted filtration and transport-washing sludge stands out. We have revealed key physico-chemical and microbiological properties of such soils formed under different moisture regimes, substrates, vegetation, and duration of use. Compared to conditionally background soils (Luvic (Anthric) Chernozems), the newly formed soils show shift of pH values to alkaline ones, carbonation, increase of soil organic carbon, growth in mobile forms of phosphorus, potassium and nitrogen. Microflora in studied soils is identical in composition to background soils, but it differs significantly in structure. In soils formed in the decommissioned wastewater lagoons of an active sugar refinery, a higher number of bacteria with low participation of Micromycetes and Actinomycetes was noted, which indicates active destruction of organic matter. In soils of the recultivated and completely abandoned sugar wastewater lagoons indicated as Calcaric Someric Phaeozem, a higher number of Actinomycetes was noted than in the background soils.

CIRCADIAN VARIABILITY OF DISSOLVED OXYGEN CONTENT AS AN INDICATOR OF THE METABOLISM OF AN ICE COVERED LAKE ECOSYSTEM

Circadian variability of dissolved oxygen content is used as an indicator of the ecosystem metabolism in the small ice-covered Lake Vendyurskoe (southern Karelia). In the endof the ice season, before the onset of the spring under-ice convection, the vertical oxygen profile reflected its consumption due to organic matter destruction, which was the most intensive near the bottom. The anoxic zone was 1.5 m thick in the central deep-water part of the lake, and the dissolved oxygen concentration was 9–10.5 mg/L in the surface layer. As under-ice convection in March and April 2020 developed against the background of an increase in under-ice irradiation (up to 100 W/m2 in the daytime), dissolved oxygen oscillations with a circadian period and an amplitude of up to 0.5–0.9 mg/ L (with a minimum at night and a maximum during the daytime) were found within the convective layer. According to the working hypothesis, the decrease in dissolved oxygen concentration was due to respiration of aquatic organisms and destruction of organic matter, while the increase was due to intensification of photosynthesis of algae during the daytime. The concentration of chlorophyll “a” was the highest (up to 2.5 μg/L) in the 0.5 m under-ice water layer, reaching 1 μg/L in the convective layer, and declining to 0.1–0.3 μg/L below this layer. In the time interval from the 20s of March to the end of April, the thickness of the convective layer increased to 7.5 m, and oxygen concentration decreased by ~0.5 mg/L due to the entrainment of oxygen-depleted underlying waters. During the same period, the increase in the oxygen content of the whole water column was about 10 %, presumably due to photosynthesis of algae.

Various Digestion Protocols Within Microplastic Sample Processing—Evaluating the Resistance of Different Synthetic Polymers and the Efficiency of Biogenic Organic Matter Destruction

The digestion of biogenic organic matter is an essential step of sample preparation within microplastic analyses. Organic residues hamper the separation of polymer particles especially within density separation or polymer identification via spectroscopic and staining methods. Therefore, a concise literature survey has been undertaken to identify the most commonly applied digestion protocols with a special focus on water and sediments samples. The selected protocols comprise different solutions, concentrations, and reaction temperatures. Within this study we tested acids (nitric acid and hydrochloric acid), bases (sodium hydroxide and potassium hydroxide), and oxidizing agents [hydrogen peroxide, sodium hypochlorite and Fenton's reagent (hydrogen peroxide 30% in combination with iron(II)sulfate 0.27%)] at different concentrations, temperature levels, and reaction times on their efficiency of biogenic organic matter destruction and the resistance of different synthetic polymers against the applied digestion protocols. Tests were carried out in three parallels on organic material (soft tissue—leaves, hard tissue—branches, and calcareous material—shells) and six polymers (low-density polyethylene, high-density polyethylene, polypropylene, polyamide, polystyrene, and polyethylene terephthalate) in two size categories. Before and after the application of different digestion protocols, the material was weighed in order to determine the degree of digestion efficiency and polymer resistance, respectively. The efficiency of organic matter destruction is highly variable. Calcareous shells showed no to very low reaction to oxidizing agents and bases, but were efficiently dissolved with both tested acids at all concentrations and at all temperatures. Soft and hard tissue were most efficiently destroyed by sodium hypochlorite. However, the other reagents can also have good effects, especially by increasing the temperature to 40–50°C. The additional temperature increase to 60–70°C showed a further but less effective improvement, compared to the initial temperature increase. The resistance of tested polymer types can be rated as good except for polyamide and polyethylene terephthalate. Increasing the concentrations and temperatures, however, results in accelerated degradation of all polymers. This is most evident for polyamide and polyethylene terephthalate, which show losses in weight between 15 and 100% when the digestion temperature is increased. This effect is most pronounced for polyamide in the presence of acids and for polyethylene terephthalate digested with bases. As a concluding recommendation the selection of the appropriate digestion method should be specifically tested within initial pre-tests to account for the specific composition of the sample matrix and the project objectives.

The heavy metal partitioning in the particle flux of the subarctic White Sea (Northwestern Russia)

This research addresses the environmental factors that affect the heavy metal accumulation and partition in the particle fluxes of the White Sea. The particulate material was collected between 2006 and 2014 with sediment traps at 9 stations from depths of 25–220 m to determine its geochemical composition. Contribution of terrigenous and hydrogenous processes was estimated based on the sequential leaching procedure which allowed distinguishing the geochemical fractions: exchangeable, Fe–Mn authigenic oxyhydroxides; organic matter/sulfides; residual (fixed in clastic minerals). Terrigenous processes were dominated in the accumulation of Al, Fe, Cr, Ni, Co, and Mo (60–90% of the total content), while the accumulation of Mn, Cu, Cd, and Pb was primarily associated with hydrogenic processes (authigenic oxyhydroxides' formation, sorption processes, and organic compounds). These two groups of chemical elements demonstrated a different distribution pattern in particle fluxes with water depth. Growth of the total particle fluxes with the water depth took place as a rule against the background of authigenic mineral formation (Fe–Mn oxyhydroxides), a slight increase in the lithogenic components, and the slow destruction of organic matter. In areas, where the vertical particle flux dominates, increased content of elements related to the Fe–Mn oxyhydroxides and bound to organic matter, were detected. The influence of anthropogenic sources based on the criteria of contamination level (EF x and I geo) was found only for Cd in some samples. An insignificant anthropogenic contribution is also possible for Cu and Ni, comparing with the background concentrations.

Hydrothermal pretreatment of sewage sludge for enhanced anaerobic digestion: Resource transformation and energy balance

The objective of this study was to evaluate the effect of hydrothermal pretreatment (HTP) at 90, 125 and 155 °C on the extent of anaerobic digestion (AD) of sewage sludge, energy balance, and the distribution and availability of N and P. AD was evaluated with four bench-scale mesophilic, semi-continuous digesters with 20-d (Phase 1) and 10-d (Phase 2) solids retention time (SRT), fed with raw sludge (R1), 90 °C (R2), 125 °C (R3) and 155 °C (R4) HTP sludge. The two sludge mixtures used in this study had high ultimate biodegradability (58.3 for Phase 1 and 56.9% for Phase 2). With the exception of Phase 2 R4, HTP increased organic matter destruction and methane production. HTP of Phase 2 sludge mixture at 155 °C resulted in the formation of high propionate levels, which led to a lower methane production. HTP significantly changed the digesters’ bacterial communities, but had a minor effect on the archaeal communities. Abundance of well-known propionate degraders in all digesters was very low; however, Proteiniphilum, which is involved in the degradation of intermediates in the propionate degradation pathway, was found in relatively high abundance in Phase 2 R4. The highest net energy gain (ΔE) was obtained with the control (i.e., raw sludge AD without HTP) for both phases. HTP heat recovery greater than 85% is required to attain the same net energy as the control or higher. HTP at 155 °C followed by AD led to increased solids reduction, overall crude protein removal and release of ammonium N. HTP-AD decreased P availability. Thus, P and N recovery is recommended before and after HTP-AD, respectively.

Ecological — microbiological characteristics of new bioderators on the basis of sewage wastewater treatment of Odesa

Results of researches of number of microorganisms — representatives various environmental — trophic groups in new biofertilizers on the basis of precipitation of sewage (further — OSV) Severnaya and Yuzhnaya stations of bioscrubbling (SB) in Odesa for defining their suitability on microbiological indicators for use as fertilizers in agriculture are provided. It is established that in new biofertilizers on the basis of OSV SBO Severnaya and Yuzhnaya of Odesa microorganisms — ammonifiers and bacteria which utilize mineral nitrogen develop actively. At the same time, in new biofertilizers the strengthened development of representatives of other groups of microorganisms, such as streptomitseta and sporous microorganisms which optimize mineral food of plants is noted. Parameters of coefficient of a mineralization of an immobilization (0.0009–0.01) demonstrate prevalence of processes of synthesis over destruction of organic matter in all options of experience. The index of an oligotrofnost (IO) (the indicator of security of new biofertilizers with the easily acquired nutrients, indicates their high security with batteries (IO = 0.0009–0.1). It demonstrates that new biofertilizers on the basis of precipitation of sewage, suitable on microbiological indicators for their use in agriculture. On the obtained data which characterize advantages of new fertilizers — (active development of microorganisms of various specificity of action, specifics of functional orientation of a microbiota) can be predicted that use of biofertilizers on the basis of precipitation of sewage will have positive impact on functioning of an agrocenosis.

Comparison of anaerobic, cycling aerobic/anoxic, and sequential anaerobic/aerobic/anoxic digestion to remove triclosan and triclosan metabolites from municipal biosolids

The antimicrobial triclosan (TCS) is a pervasive and persistent environmental micropollutant which can contaminate land, biota, and water through the land application of biosolids. Many existing sludge management techniques have limited effectiveness against TCS and TCS metabolites including triclosan-sulfate (TCS-SO4). The objective of this study was to evaluate the impacts of different digestion types (anaerobic, aerobic/anoxic, and sequential anaerobic + aerobic/anoxic), temperatures, and digester sludge retention times (SRTs) on the destruction of organic matter, and on TCS/TCS metabolites. Conventional mesophilic anaerobic digesters (AD), room temperature cycling aerobic/anoxic digesters (AERO/ANOX), and sequential AD + AERO/ANOX digesters were all effective in removing organic matter. The optimum single-stage AD, and AERO/ANOX scenarios were both 20-day SRTs which had 52.3 ± 1.4 and 47.1 ± 3.7% chemical oxygen demand (COD) removals, respectively. Sequential AD + AERO/ANOX digesters improved organic matter destruction, removing up to 68.2 ± 2.1% of COD at an 8-day AD + 12-day AERO/ANOX second-stage (mesophilic) SRTs. While AD showed modest levels of TCS removals (all <40%), TCS was substantially more degradable aerobically with AERO/ANOX removing up to 80.3 ± 2.5% of TCS and nearly all TCS-SO4 entering the digester at a 20-day SRT. Sequential AD + AERO/ANOX removed virtually all TCS-SO4 entering the system and improved TCS removals from first stage ADs. However, they were less effective than a single-stage AERO/ANOX digester operating at the same overall SRT. These results demonstrate that AERO/ANOX and sequential AD + AERO/ANOX processes could be used to reduce the amount of TCS, TCS-SO4 and TCS-related compounds in digested sludge, minimizing the environmental burden of the land application of biosolids.

Effect of heating on some soil properties and potassium dynamics in calcareous soils of southern Iran

AbstractPrescribed burning of plant residues in agricultural lands may increase surface soil temperature and change the dynamics of soil potassium (K). In the current investigation, the effects of two hours heating of soil to 25, 100, 225, or 350°C and cycling (one and three cycles) on properties of eight calcareous soils from southern Iran and K dynamics (K forms, release, and fixation) were studied. Results indicated that heating to 100 or 225°C had no significant effect on pH,EC, or CEC but heating to 350°C increased soil EC (from 0.53 to 0.66 dS m−1) and decreased CEC (from 25 to 19 cmol kg−1). The heating to 350°C increased all forms of K including soluble (from 36 to 84 mg kg−1, 133% increase), exchangeable (from 285 to 490 mg kg−1), non‐exchangeable (from 598 to 686 mg kg−1), and HNO3‐extractable (from 922 to 1260 mg kg−1) decreased K fixation capacity of all soils (from 351 to 235 mg kg−1). Cumulative K release from soils to 0.025 M CaCl2 ranged from 114 to 438 mg kg−1 and increased significantly after heating of soils to 350°C and reached between 233 and 783 mg kg−1. Potassium fixation capacity of fine‐textured soils (soils 2, 6, 7, and 8) after 10 times extraction with CaCl2 was increased (65%–190%). Generally, heating of soils to 350°C caused combustion of organic matter and partial destruction or collapse of K‐bearing minerals and increased release of K.

Chemical and microbiological characteristics of the agrolandscape Zeya-Bureya plain small river

The article discusses the results of hydrochemical and microbiological studies of the waters of the small river Arguzikha, the left-bank tributary of the Amur River. The natural landscapes of the Zeya-Bureya plain, along the territory of which a small river flows, are transformed into agrolandscapes. Organic matter, nitrogen and phosphorus compounds accumulated in the waters of the Arguzikha river. The number of heterotrophic bacteria, the main function of which is the destruction of organic matter, in the summer reached 75 thousand cells / ml, which corresponded to the dirty water quality class. The content of nitrogen compounds in water and the number of ammonium-oxidizing bacteria experienced seasonal dynamics. The obtained results of the study of hydrochemical and microbiological indicators of aquatic ecosystems of the Zeya-Bureya plain are the basis for further study of the technogenic load on small rivers of the agrolandscape.

The number of cultured heterotrophic bacteria and the total bacterial number in the surface microlayer, water column and epilithic biofilms of the littoral zone of Lake Baikal

We have shown that the number of heterotrophic bacteria in the surface microlayer and periphyton is reliably higher than in the water column, which characterizes these biotopes as sites of intense destruction of suspended organic matter. Average values of the total bacterial number, the number of cultured heterotrophic bacteria and the K index indicate the elevated supply of labile organic matter at the stations near the Listvyanka settlement, the Olkhonskiye Vorota Strait and Aya Bay.

Runoff components of small catchments in Sikhote-Alin: summarizing the results of field measurements and tracer modeling

The article summarizes results of the systematic study of the streamflow formation of two small catchments in the upper part of the Ussuri River. The study was carried out by the hydrograph separation technique (using detailed data of the hydrochemical and hydrological monitoring) and the use of a tracer mixing model in conjunction with EMMA. Performed in the period from 2011 to 2016 the studies allowed to calculate the river runoff components of the summer-autumn period at 3 gauge-stations and evaluate their mutual dynamics at different time scales. It is shown that in the case of landscape uniformity of the catchment (the Medvezhiy Creek), the river flow can be represented as a result of 3 sources mixing. This, the most common, scheme for the hydrograph separation includes following sources: a direct rainfall flow, an organic soil water component, and an underground baseflow. If the catchments landscape structure is clearly heterogeneous (the Elovy Creek), the river flow can be represented as a result of 4 sources mixing. In this case, the fourth source appears as a result of the separation of soil water component into individual components organic and mineral. This separation is due to the spread in the basin of the cold upper belt of fir-spruce forests, whose soils are characterized by a lower rate of organic matter destruction and a deeper illuviation process of DOC. Statistically significant dependencies of the some runoff components proportions against river discharges were identified, systematization of which makes them promising for practice in hydrological monitoring and forecasting.

Vertical Distribution of Bacteria in Forest Lakes of Karelia

Abstract—The total abundance of bacteria, the number of saprophytic, oligotrophic, and sulfate-reducing microorganisms, the shapes of bacterial cells, the primary and bacterial production, the destruction of organic matter, and the rate of sulfate reduction were studied in small Karelian lakes during the stagnation period. It has been shown that the uneven vertical distribution of light, temperature, oxygen, and hydrogen sulfide creates ecological niches for the development of many various groups of microorganisms. In most lakes, the minimum abundance of microorganisms was found in the surface water layer, while its maximum was in the near-bottom layers. The trophic status of a water body has a great influence on the formation and function of microbial communities. Autochthonic organic matter in the closed forest lakes under study (the local term is “lamba”) was formed due to phytoplankton photosynthesis, but bacterial production exceeded primary production in the hypolimnion of eutrophic lakes. The content of hydrogen sulfide, the abundance of sulfate-reducing bacteria, and the rate of sulfate reduction were maximal in the bottom sediments of eutrophic lambas.