The Influence of Phosphogypsum Addition on Phosphorus Release in Biochemical Treatment of Sewage Sludge

Abstract

The paper is focused on the research of biochemical treatment of sewage sludge and phosphogypsum under sulphate-reducing conditions with a phosphorus release process. The theoretical foundations of the work were based on the biochemical formalization using the principles of autocatalysis of natural systems. During the experimental research for the control of physicochemical parameters of the process spectroquantic, X-ray fluorescence analysis and other techniques were used. A schematic model of the dephosphatation process under anaerobic stabilization of sewage sludge and phosphogypsum was developed. The increase of phosphogypsum dosage had a close correlation with the release of phosphate ions. At the stimulating action of the phosphogypsum additive, a 2.5–5.0-fold increase in soluble phosphate concentration was observed. The rational dose of phosphogypsum was determined. Along with an increase the ratio of COD (Chemical Oxygen Demand)/phosphogypsum to 0.1, an increase in the phosphate ions in solution was observed. A further increase in the ratio of COD/phosphogypsum did not affect the concentration of phosphate ions in solution.

The Physico-Chemical and Mineralogical Characterization of Mg-Rich Synthetic Gypsum Produced in a Rare Earth Refining Plant

“…In addition, intense band at wavenumber 1099 cm −1 , in the gypsum containing by-product and deformations at 665.44, 594.08 and 457 cm −1 in MRSG could be attributed to the presence of sulphate functional groups [44]. Similarly, absorption peak in MRSG at 875 cm −1 corresponds to carbonate spectrum [44,45]. According to the FTIR spectroscopy, the most abundant components of MRSG are calcium hydroxide, calcium and magnesium carbonates, silicates, and calcium aluminates, which corroborates the XRD results.…”

Influence of Phosphogypsum Dump on the Soil Ecosystem in the Sumy region (Ukraine)

“…A large number of studies have been aimed at assessing of the impact of dumps on surface and groundwater resources [21][22][23]. Nevertheless, bio-monitoring is an important element in the analysis of the dump impact on the ecosystem [21,24].…”

Rationale for the Combined Use of Biological Processes and AOPs in Wastewater Treatment Tasks

“…For example, the analysis of industrial systems, in the case of a combination of basic methods (necessary for the treatment of industrial effluents), showed the overlapping effect of different equipment on the same pollutants: the cross-effect of different methods on one type of pollutant varies from 5 to 40% [7]. Based on the results obtained, the sequence of creating water treatment systems with enhanced functionality, and their ability to effectively counteract emergencies, the method of combining solutions for removing pollutants from effluents is justified [36,37].…”

“…Difficulties manifest themselves in the stabilization and formation of an equilibrium system between the processes of decomposition of complex organic impurities and preservation of the constancy of the biomass of the necessary ecological and trophic groups of microorganisms. It is important to stimulate the development of the desired dominant species composition of activated sludge, increasing their metabolic activity, which is possible with the use of physical and chemical methods of activation of biological processes [36].…”