scholarly journals Biogenic elements and organic matter production in the ecosystem of Lake Arey, Transbaikal region, Russia

2021 ◽  
Vol 908 (1) ◽  
pp. 012041
Author(s):  
G Ts Tsybekmitova ◽  
M O Morozova

Abstract Maintaining an ecological balance of Lake Arey is crucial in terms of nature conservation. Lake Arey is located in Eastern Siberia and is a central object of a designated conservation area of regional significance. The lake is used for recreation (organized and unorganized tourism, sport fishing, mud collection for balneological purposes) not only by residents but also by holidaymakers from other regions. In terms of mineralization level, Lake Arey is a freshwater body. Significant factors affecting the aquatic ecosystem are temperature, TDS, pH and dissolved oxygen, depth, and turbidity. High contents of ammonium ions are observed in the ecosystem. The concentration of dissolved inorganic phosphorus is 23.6% of total phosphorus. The ratio of PO (permanganate oxidizing ability of organic matter) to COD (chemical oxygen demand) indicates active processes of production, mineralization, and transformation of organic matter in the water body. Carotenoids prevail in planktonic pigments. The chlorophyll a amount is insignificant. The chlorophyll b content increases from July to September. Currently, Lake Arey belongs to the α-mesotrophic type of water body. However, increased anthropogenic load and high-water years can promote eutrophication processes.

2020 ◽  
Vol 24 (8) ◽  
pp. 22-27
Author(s):  
I.A. Arkhipchenko ◽  
L.G. Bakina ◽  
A.Yu. Bruhanov ◽  
O.V. Orlova ◽  
S.I. Tarasov

The results of a study of microbiological processes in controlled aerobic fermentation of litter dung was carried out. It was shown that the introduction of a microbial inoculum into the fermentable substrate allows to obtain an effective biofertilizer. It was found that in the process of transformation of organic matter a specific bacterial complex is formed, which significantly differs in quality composition from the microflora of the litter dung. The change in the composition of the microbial community affected the processes of humification and led to an increase in the proportion of humic acids by more than 3 times in comparison with initial substrate. Thus, along with the active processes of mineralization of organic matter, humification processes occur simultaneously, which is manifested in the formation and accumulation of humic acids. This allows us to justify the feasibility of the developed technology not only for the agro-industrial complex, but also for the microbiological processing of a wide range of organic waste into effective biofertilizers.


Author(s):  
G. Ts. Tsybekmitova ◽  
L. D. Radnaeva ◽  
N. A. Tashlykova ◽  
V. G. Shiretorova ◽  
A. K. Tulokhonov ◽  
...  

Lake Arakhley is located within the Lake Baikal basin in Eastern Siberia, Russia. The area is characterized by continental subarctic climate with considerate diurnal temperature range, long cold dry winters and short hot summers with more precipitation occurring during the latter half of the summer. Climatic shifts in high water years and low water years result in morphometric changes in the lake and in the chemical and physical parameters of the ecosystem. During low water years, concentrations of ammonium nitrogen and nitrite nitrogen are decreased, whereas nitrate concentration increases. High water years feature average concentrations of ammonium ions 1.5–2 times higher than the values of recent dry years. Redundancy analysis (RDA) of abiotic factors and biotic community indicated that the community structure shows the greatest correlation with physical and chemical parameters of water and biogenic elements (nitrites, ammonium, phosphates) along the first axis, and with the lake depth and transparency along the second axis. Changes in abiotic factors induce functioning and formation of characteristic communities of the primary producers in the trophic structure of the ecosystem. During low water years, with increased level of autochthonous organic matter, Lindavia comta dominance is observed, while during high water years, with increased allochthonous organic matter Asterionella formosa appeared as dominant. Currently, during low water years, the hydrophytes community is monodominant and composed of Ceratophyllum demersum. Meanwhile, such species indicating eutrophic conditions as Myriophyllum sibiricum, Potamogeton pectinatus are found in the lake vegetation.


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1998
Author(s):  
Vyacheslav Polyakov ◽  
Sergey Loiko ◽  
Georgiy Istigechev ◽  
Alla Lapidus ◽  
Evgeny Abakumov

The soils of Chernevaya taiga (tallgrass fir-aspen hemiboreal rainforest) have high fertility in comparison with oligotrophic analogs formed in boreal taiga. We have studied humic acids isolated from the soils of Chernevaya and oligotrophic taiga in the Novosibirsk, Tomsk, Kemerovo and the Altai regions of Russia and for the first time the structural and molecular composition of humic acids was determined using 13C CP/MAS and 1H-13C HETCOR NMR spectroscopy. According to data obtained in this study, up to 48% of aromatic compounds accumulate in the soils of Chernevaya taiga, which is higher than in the oligotrophic taiga and comparable with this rate of steppe Chernozems. In the course of active processes of transformation of organic matter, a significant number of aromatic fragments accumulates in the middle horizons of soil profiles. Using 13C CP/MAS spectroscopy, it was possible to identify the main structural fragments (aliphatic and aromatic) that formed in humic acids of the Chernevaya taiga. The HETCOR experiment made it possible to accurately determine the boundaries of chemical shifts of the main groups of structural fragments of humic acids. Our results demonstrate that the stabilization of organic compounds occurs in the soil of the Chernevaya taiga, which leads to the resistance of organic matter to biodegradation that is not typical for benchmark soils of boreal environments.


2020 ◽  
Vol 21 (1) ◽  
pp. 86-94
Author(s):  
Andri Warsa ◽  
Lismining Pujiyani Astuti

ABSTRACTIr. H. Djuanda or Jatiluhur reservoir as a multifunction water body with one of utilization as fish cultivation activity. Uneaten feed and fish excretion were organic matter sources. The number of floating net cages was increasing and it caused increasing in organic matter load. The objective of the research was to known organic matter load and decomposition rate (k) and BOD (Biochemical oxygen demand) ultimate (Lo) at Jatiluhur Reservoir. The research was done in February and August 2018 at three locations were Astap, Pasir Canar and Pulau Aki. The result of the research shown was organic load from cultivation activity was 70,595 tons/year. The decomposition rate of organic matter around 0.10-0.25 per day with BOD ultimate around 6.80-8.11 mg/L. The value of Lo was affected by organic matter concentration.Keywords: Ir. H. Djuanda Reservoir, organic matter, decomposition rate, BOD ultimateABSTRAKWaduk Ir. H. Djuanda atau yang dikenal dengan Waduk Jatiluhur merupakan waduk multifungsi yang salah satu pemanfaatannya untuk kegiatan budidaya ikan. Sisa pakan yang terbuang dan ekresi ikan merupakan sumber masukkan bahan organik. Jumlah keramba jaring apung (KJA) yang semakin bertambah akan menyebabkan beban masukkan bahan organik meningkat. Tujuan penelitian ini adalah untuk mengetahui beban masukkan bahan organik dari kegiatan budidaya dan laju dekomposisi bahan organik (k) serta BOD (Biochemical oxygen demand) ultimate (Lo) di Waduk Jatiluhur. Penelitian dilakukan pada bulan Februari dan Agustus 2018 pada tiga lokasi yaitu Astap, Pasir Canar dan Pulau Aki. Pendekatan yang digunakan dalam penentuan nilai k dan Lo adalah metode Grafik Thomas. Hasil penelitian menunjukkan bahwa beban masukkan bahan organik dari kegiatan budidaya sebesar 70.595 ton/tahun. Beban masukkan bahan organik telah melebihi daya dukung perairan. Nilai k untuk dekomposisi bahan organik di Waduk Jatiluhur berkisar 0,10-0,25 per hari dengan nilai Lo berkisar 6,80-8,11 mg/L. Nilai Lo dipengaruhi oleh konsentrasi bahan organik di perairan.    Kata kunci: Waduk Ir. H. Djuanda, bahan organik, laju peluruhan, BOD ultimate 


2019 ◽  
Vol 80 (12) ◽  
pp. 2310-2319 ◽  
Author(s):  
Prashant Dhanke ◽  
Sameer Wagh ◽  
Abhijeet Patil

Abstract Water generated from the fish processing industry is contaminated with organic matter. This organic matter present in wastewater increases the biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A new technology, hydrodynamic cavitation (HC) is used to deal with this wastewater produced in fish processing plants. The orifice plate is used in the HC reactor to generate a cavitation effect. The intensification of this technique was carried out with the help of hydrogen peroxide (H2O2) and TiO2. The treatment of this wastewater is reported in terms of percent degradation in BOD and COD and in biodegradability index (BI). Operating parameters like inlet pressure, pH, operating temperature and H2O2 doses were used to find the optimum condition. 15 g/L of H2O2 gave 69.5% reduction of COD in the 120 min of treatment that also increases BI value to 0.93 at inlet pressure 8 bar, Plate-5, temperature (30 °C), and pH 4. In the ultrasonic cavitation (UC) reactor, COD reduction is 68.7% without TiO2 and with TiO2 it is 71.2%. Also, this HC and UC reactor reduced CFU count to a great extent at the same operating conditions.


2021 ◽  
Vol 10 (5) ◽  
pp. 348
Author(s):  
Zhenbo Du ◽  
Bingbo Gao ◽  
Cong Ou ◽  
Zhenrong Du ◽  
Jianyu Yang ◽  
...  

Black soil is fertile, abundant with organic matter (OM) and is exceptional for farming. The black soil zone in northeast China is the third-largest black soil zone globally and produces a quarter of China’s commodity grain. However, the soil organic matter (SOM) in this zone is declining, and the quality of cultivated land is falling off rapidly due to overexploitation and unsustainable management practices. To help develop an integrated protection strategy for black soil, this study aimed to identify the primary factors contributing to SOM degradation. The geographic detector, which can detect both linear and nonlinear relationships and the interactions based on spatial heterogeneous patterns, was used to quantitatively analyze the natural and anthropogenic factors affecting SOM concentration in northeast China. In descending order, the nine factors affecting SOM are temperature, gross domestic product (GDP), elevation, population, soil type, precipitation, soil erosion, land use, and geomorphology. The influence of all factors is significant, and the interaction of any two factors enhances their impact. The SOM concentration decreases with increased temperature, population, soil erosion, elevation and terrain undulation. SOM rises with increased precipitation, initially decreases with increasing GDP but then increases, and varies by soil type and land use. Conclusions about detailed impacts are presented in this paper. For example, wind erosion has a more significant effect than water erosion, and irrigated land has a lower SOM content than dry land. Based on the study results, protection measures, including conservation tillage, farmland shelterbelts, cross-slope ridges, terraces, and rainfed farming are recommended. The conversion of high-quality farmland to non-farm uses should be prohibited.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1212
Author(s):  
Ao Liu ◽  
Aixi Han ◽  
Li Chai

Apparel manufacturing involves high water consumption and heavy water pollution in its supply chain, e.g., planting cotton, producing chemical fibers, and dyeing. This study employs a multi-regional input–output (MRIO) model to (1) assess the life cycle of blue and grey water (chemical oxygen demand (COD) specific) of China’s apparel manufacturing; (2) reveal the hidden linkage among sectors and regions in the whole supply chain; and (3) identify the key regions and upstream sectors with the most water consumption and heaviest water pollution. We found that the agricultural sector (i.e., planting fiber crops) is responsible for primary water consumption and water pollution. In addition, different provinces assume different production roles. Guangdong is a major output province in apparel manufacturing. However, its economic output is contributed to by other regions, such as blue water from Xinjiang and Jiangsu and grey water from Hebei and Shandong. Our research reveals the significance of taking an inter-regional perspective on water resource issues throughout the supply chain in apparel manufacturing. The sustainable development of China’s apparel manufacturing relies on improving water-use efficiency and reasonable industrial layout. The results are of significance and informative for policymakers to build a water-sustainable apparel industry.


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