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Purpose: to study physical-chemical parameters of sludge and the possibility of its application as a biomeliorant for increasing soil fertility in Volgograd region. Materials and methods. The object of research is light chestnut solonetzic soil of heavy loamy granulometric texture, silt sludge of domestic waste water. The analysis of soil samples was carried out according to generally accepted methods. Results and discussion. Comparative data of various sludge sediments in terms of physical-chemical parameters allow for the conclusion that the sewage sludge processed by the enzymatic-cavitation method has optimal moisture content (11 %), contains the main nutrients: nitrogen (3.3 %), phosphorus (4.27 %), potassium (0.31 %). The content of organic matter in the sludge was 32 %, which fully complies with the specifications of GOST R 54651-2011. The data of the water extract analysis show that in the variant with the processed sludge sediment there is a higher content of sulfate anions (5.40 mmol/100 g soil) in comparison with the variant of light chestnut soil (0.30 mmol/100 g soil), and increased content of calcium cations (8.40 mmol/100 g soil) and magnesium (5.10 mmol/100 g soil). As a result of the study of soil samples, it was found that after the introduction of sewage sludge in soil, the content of organic matter was 2.28 %, while in soil samples without the introduction of sediment it was 1.67 %. The content of nitrate nitrogen ranged from 8.3 to 30.9 mg/kg, ammonia nitrogen from 4.1 to 5.7 mg/kg, mobile phosphorus from 82.0 to 102.0 mg/kg, exchangeable potassium from 385 to 392 mg/kg according to the variants of the experiment. The conducted studies of the content of heavy metals in soil show that no excess was found for all standardized indicators. Conclusions: it is advisable to use sewage sludge after its biological treatment as a biomeliorant for increasing the productivity of slightly humic soils. |
