Preservation of Wastewater Sedimentation Tanks by Using Proposed Types of Coatings

摘要

In Baghdad, Al- Rustamiya wastewater treatment plant was exposed to high and continuous drainage of sewage water, leading to weak in concrete parts of wastewater treatment plant. Protection of sedimentation tanks may be achieved by applying suitable coatings which resist the biological reaction and chemical effects of wastewater. Three types of coatings were prepared by using Siloxane polymer (SX5000WB) mixed with different amounts of micro titanium dioxide (TiO_2). Concrete cubes were covered with these coatings and partially immersed for 28 days in basins contain wastewater brought from Al- Rustamiya primary and secondary sedimentation tanks. Swabs from the cubes were also taken to monitor bacterial growth on cube's surfaces after applying different types of coatings. To determine the effects of coatings on concrete cubes strength, compressive strength was measured after 28 days of partially immersing in wastewater. According to the study's findings, coated concrete with 250 mg of micro TiO_2 per litre of the polymer is a suitable method of protection. At this concentration of TiO_2, bacterial growth was almost zero at concrete immersed in wastewater taken from primary and secondary sedimentation tanks, no obvious relationship was found between the type of coating and reduction of chloride and sulphate effect. Concrete compressive strength was increased by the increasing of coatings concentrations providing a thin film that may contribute in concrete protection.