Yuri Gagarin State Technical University of Saratov

Abstract-A general characteristic of the river basin of the interstate Ural River and data on the economic use of the Ural River in its upper, middle, and lower reaches are given. Information on the hydrol. of the liquid and solid flow of the Ural River is presented. Hydrochem. monitoring of the water bodies of the Ural River basin was performed during the flood period, the summer low-water period, and the autumn low-water period in the years 2017-2018. The hydrochem. monitoring of the water quality in the natural water bodies of the Ural catchment basin has revealed an excess in the MPC of heavy metal ions in the water of the studied water bodies for drinking water and for fishery water bodies. An excess in the MPC of cadmium ions for drinking water by 1.2-1.4 has been recorded in the Ilek River during low water periods, as well as in the Ural River near the border with the Russian Federation in the amount of 3.1-3.4 MPC for drinking water during the flood period and near the village of Zharsuat in the amount of 1.5-2.6 MPC for drinking water during summer and autumn low water periods. An excess in the MPC of lead ions for fishery water bodies by 1.2-1.4 has been revealed in the middle and lower reaches of the Ural River in different seasons of the year. Excessive concentrations of ions of different heavy metals compared to their MPC for fishery water bodies have been found in all water bodies in different periods of the year. The greatest excess of zinc ions compared to the MPC for fishery water bodies was observed during the low water period.

Abstract-The status of the photosynthetic pigments in the aquatic plants Lemna minor L. and Elodea canadensis Michx. under the action of Ni²⁺, Co²⁺, Cu²⁺ and Pb²⁺ acetates in concentrations of 5.00, 2.50, 1.25, 0.62, 0.31, 0.15, 0.07, and 0.03 mg/L was assessed by changes in the fluorescence intensity of chlorophyll a and b and their ratio. It was established that nickel acetate in original solutions in all the above concentrations caused an increase in the fluorescence intensity of chlorophylls a and b in L. minor in relation to the control while the lead salt suppressed it. Co²⁺ acetate inhibited the fluorescence of chlorophyll a with concentrations in the initial solutions of 0.03 to 0.15 and 2.50 mg/L and that of chlorophyll b at all concentrations, except 0.62, 1.25, and 2.50 mg/L. For E. canadensis, it was found that the salts of all metals at all concentrations caused a reduction of the fluorescence intensity of chlorophyll a relative to the control and increased it in the case of chlorophyll b. The exception was the effect of copper and lead acetates with a concentration of 1.25 mg/L, when the fluorescence intensity of chlorophyll b was maintained at the control level. The presence of Ni²⁺, Co²⁺, Cu²⁺, and Pb²⁺ acetates in all concentrations in the culture medium influenced the quant. and qual. characteristics of chlorophyll a and b, which indicated a violation of the photosynthesis process. Our data on the change in the chlorophyll a/b ratio led to a conclusion about degradation of chlorophyll a relative to chlorophyll b after the effect of heavy metals.

Abstract-One of the most promising methods of industrial wastewater treatment is flocculation using polyacrylamides. The purpose of our research was to estimate the efficiency of the use of new types of polyacrylamide-based flocculants for industrial wastewater treatment. The objects of the study were wastewaters from the Saratov Chem. Plant of Acrylic Polymers Akripol, as well as several flocculants (water-soluble polymers) based on acrylamide, acrylic acid, and chitosan. It has been established that the optimal dose of H600^TM nonionic flocculant was 5 mg/dm³. The efficiency of industrial wastewater treatment was studied on two samples of weakly cationic flocculants (215-2 and 233-2) synthesized in a laboratory way, as well as on a sample of nonionic H600^TM flocculant. It has been revealed that the tested flocculants do not significantly influence the pH value and content of sulfate ions in water. Flocculant 233-2 with the highest chitosan content was the best in terms of COD, dry residue, and the amount of suspended solids. Flocculant 215-2 with the lowest chitosan content had a slightly worse performance. The worst of the tested flocculants was the nonionic H600^TM, which does not contain chitosan.