Water Interaction with Fe2NiP Schreibersite (110) Surface: a Quantum Mechanical Atomistic Perspective

Phosphorus is an element of primary importance for all living creatures, being present in many biological activities in the form of phosphate (PO43-). However, there are still open questions about the origin of this specific element and on the transformation which allowed it to be incorporated in biological systems. The most probable source of prebiotic phosphorus is the intense meteoritic bombardment during the Archean era, few million years after the solar system formation, which brought tons of iron-phosphide materials (schreibersite) on the early Earth crust. It was recently demonstrated that by simple wetting/corrosion processes from this material various oxygenated phosphorus compounds are produced. In the present work, the wetting process of schreibersite (Fe2NiP) was studied by computer simulations using density functional theory, with the PBE functional supplemented with dispersive interactions through a posteriori empirical correction. To start disentangling the complexity of the system, only the most stable (110) surface of Fe2NiP was used simulating different water coverages, from which structures, water binding energies and vibrational spectra have been predicted. The computed (ana-)harmonic infrared spectra have been compared with the experimental ones, thus confirming the validity of the adopted methodology and models.

Performance improvement of aquaponics systems when using microbiological strains in them

The essence of the method of operation of the aquaponic system is to use the vital waste of aquatic animals as food for plants. At the first stage, the fish produces waste products. Then, in the second stage, microbes and worms convert the waste into fertilizers for plants. During the process, at the third stage, plants consume the necessary products of excretion of living organisms. Aquaponics is an artificial ecosystem in which three types of living organisms are key: aquatic animals (usually fish or shrimp), plants and bacteria. This technology works on the principle of an ecosystem of fish and plants: fish provides food to plants, and plants purify water and are environmentally friendly. The essence of this method is to use the vital waste of aquatic animals (fish, shrimp) as a nutrient medium for plants. These are chemicals such as nitrogenous, potassium, phosphorus compounds, carbon dioxide. Thanks to aquaponic farms, the costs of water and other natural resources, soil pollution and the use of insecticides are already being reduced in different places of our planet. Such systems are a sustainable ecosystem capable of producing organic matter that does not contain toxic substances often present in vegetables grown by traditional methods.

Diffuse Runoff from Agricultural Lands within a River Basin and Water Protection Measures

This paper is dedicated to the study of the pollutants coming from agricultural lands located within the catchment into the Yakhroma river, a third-order tributary of the Upper Volga. The area of the river catchment is 1437 km2. It is located in the north-eastern part of the Moscow region, which geographically belongs to the Klinsko-Dmitrov ridge (the upper part of the basin) and the Upper Volga Lowland. The slopes and floodplain included in the reclaimed lands (more than 9 th ha) are lined with cities, rural settlements, numerous kitchen gardens, and agricultural lands. Water quality, river profile from the source to the mouth, and sources of pollution within the reclaimed lands of the Yakhroma floodplain were studied from 2004 to the present. A geospatial intelligence system (GIS) was developed for the catchment area. Land areas are allocated according to the conditions of surface runoff formation, taking into account soil types and slopes. The studies of the river water quality, tributaries, and drainage network in the reclaimed lands showed biogenic pollution caused by insufficiently treated wastewater discharged from cities and agricultural land, especially within the reclaimed massif. The calculations of the removal of nitrogen, phosphorus, and potassium from surface and drainage waters revealed that the main role in the pollution of both surface and drainage waters is played by nitrogen and potassium compounds, and to a lesser extent by phosphorus compounds. For nitrogen, removal from surface runoff was 27.36 t/year; for phosphorus it was 6.06 t/year; for potassium it was 242.28 t/year; with drainage runoff, the removal of nitrogen was 98.88 t/year; the removal of phosphorus was 0.38 t/year; the removal of potassium was 37.04 t/year. To reduce the inflow of surface diffuse runoff and to purify collector and drainage waters from nitrogen and phosphorus compounds, including the creation of bioplateaus and biosorption structures, it was proposed to use a set of protective measures, which will significantly reduce the biogenic load on the river flow.

Response of Physicochemical and Microbiological Properties to the Application of Effective Microorganisms in the Water of the Turawa Reservoir

Effective microorganisms (EM) technology was used to find the optimal method of water restoration in the designated experimental area. The study aimed to evaluate the impact of EM biopreparation on selected physicochemical and microbiological properties using ISO methods. A week after the application of biopreparations, a slight decrease in the nitrates content (0.375–0.531 mg L−1) and a significant decrease in the content of phosphorus compounds (0.130–0.304 mg L−1) compared to the control date were observed. Moreover, on the second date, the decrease in most values of microbiological properties was noted. Two weeks after the application, in most cases, the values of water quality properties were shaped close to values obtained in the control date (before EM application). The EM effect was rather short-term, but optimization of application properties may prolong the effect and thus, include the EM technology among the best eco-friendly technologies used for freshwater ecosystem restoration.

INNOVATIVE METHOD OF NITRIFICATION AND DENITRIFICATION ON THE EXAMPLE OF WASTEWATER TREATMENT PLANT OF KOLOMYIA

The article is devoted to the unsatisfactory operation of biological wastewater treatment plants. At present in Ukraine there are no developments of equipment and devices to ensure the operation of treatment facilities using the technology of nitridenitrification of deep wastewater treatment from nitrogen and phosphorus compounds. The analysis of the equipment of biological treatment systems - nitri treatment plant - denitrifier, clarifier tanks is carried out. At the same time, the standards of the degree of purification of both Ukraine and the European Union were taken into account. On the example of treatment facilities in Kolomyia, Ivano-Frankovsk region, modern schemes of biological wastewater treatment for the removal of nitrogen and phosphorus have been proposed, namely, the re-equipment of single-corridor aerotanks into bioreactors of nitridenitrifiers by creating zones with different oxygen conditions in their volume.

Aquaculture Water Quality Improvement by Mixed Bacillus and Its Effects on Microbial Community Structure

Nutrients nitrogen and phosphorus pollution in aquaculture is one of the greatest challenges threatening the survival of aquatic organisms, which requires efficient and sustainable remediation approach. Microbial remediation, especially the application of probiotics, has recently gained popularity in improving the water quality and maintaining the health condition of aquatic animals. In the present study, two groups of mixed Bacillus (Bacillus megaterium and Bacillus subtilis (A0+BS) and Bacillus megaterium and Bacillus coagulans (A0+BC)) were applied to aquaculture system of Crucian carp to improve the treatment of nitrogenous and phosphorus compounds. The effects of mixed Bacillus on water quality, and the structure and function of microbial communities in aquaculture water were investigated. Our results showed that the improvement effect of mixed Bacillus A0+BS on water quality was better than that of A0+BC, and the NH4+-N, NO2--N, NO3--N and total phosphorus (TP) concentrations were reduced by 46.3%, 76.3%, 35.6%, and 80.3%, respectively. In addition, both groups of mixed Bacillus increased the diversity of bacterial community and decreased the diversity of fungal community. Microbial community analysis showed that mixed Bacillus A0+BS increased the relative abundance of bacteria related with nitrogen and phosphorus removal, e.g., Proteobacteria, Actinobacteria, Comamonas, and Stenotrophomonas, but decreased the relative abundance of pathogenic bacteria (Acinetobacter and Pseudomonas) and fungi (Epicoccum and Fusarium). The redundancy analysis showed that NH4+-N, NO2--N, and TP were primary environmental factors affecting the microbial community in aquaculture water. PICRUST analysis indicated that all functional pathways in the treatment groups were up-regulated, and all pathways in A0+BS group were richer than those in other groups. These results indicated that mixed Bacillus A0+BS addition produced good results in reducing nitrogenous and phosphorus compounds and shaped a favorable microbial community structure to further improve water quality.