Study of the Efficiency of Sludge Conditioning by the Method of Advanced Oxidation Process (AOP) During Dewatering of Excess Activated Sludge

Анотація

The issue of sludge disposal is a complex task that needs to be addressed, taking into account not only economic indicators but also local conditions, such as: the availability of existing sewage treatment plant infrastructure, energy availability, climatic conditions and so on. Currently, more and more municipal enterprises in European countries are building sludge incineration plants. Preparation of sludge for incineration occupies a significant part of the budget since its humidity and caloric content have the greatest impact on the parameters of the sludge incineration unit and its energy balance. Chamber-membrane filter presses are one of the few types of equipment that allows to ensure the maximum reduction of sludge moisture, and the possibility of its completion with heat treatment systems in one closed housing make it an even more attractive solution for small and medium wastewater treatment plants. Of great interest at the present stage of development of wastewater treatment and sludge disposal technology is the technology of advanced oxidation of AOR, which allows to remove biologically stable organic pollutants and leads to inactivation of pathogenic microorganisms. The purpose of this stage was to evaluate the possibility of using the technology of advanced oxidation of AOP for conditioning sludge of municipal treatment plants before their mechanical dehydration and to determine the technological parameters of the sludge filtration process. The studies included laboratory and industrial tests. Based on the research, it was found that AOP technology can be used to reduce the consumption of reagents (iron, lime) in the conditioning of municipal sewage sludge in the case of filtration on a chamber-membrane filter press. The most economically and technologically optimal ratio of Fe / Ca / H₂O₂ is equal to 2/5/1 at the dosage of hydrogen peroxide H₂O₂ at the level of 1 g / l. At the proposed dosages of reagents, it is possible to obtain a filtration sludge with a residual moisture content of 64–65% compared to 72–73% using only iron and lime (initial dry matter content in the sludge at 3%).