Improvement of purification processes of polluted hydrogen sulfide-containing industrial effluents

Industrial facilities for the extraction and processing of oil and gas with a high sulfur content are a source of polluted highly concentrated hydrogen sulfide process waters. Industrial effluents at the Astrakhan gas condensate field are highly aggressive due to its features and undergo multi-stage purification. In view of the trends in resource conservation and environmental friendliness dictated by the complex environmental situation in the world, it is necessary to analyze in detail the existing wastewater treatment technologies for compliance with the principles of green chemistry and identify specific proposals. The article presents ways to improve the technological processes for purifying hydrogen sulfide-containing wastewater from the high-pressure reservoir gas separation plant of the Astrakhan Gas Processing Plant, which implements a combined method for purifying industrial wastewater and reservoir water from sulfides, carbonates and hydrogen sulfide. Its disadvantages are the unsatisfactory quality of water purification, the use of harsh reagents, multi-stage treatment, insufficient environmental friendliness and the preservation of risks to the environment. Advanced oxidation processes are a promising technology for wastewater treatment. When treating sulfide-containing wastewater, the Fenton reaction allows you to break down toxic sulfides to non-toxic compounds, remove hydrogen sulfide, and convert sulfides into sulfates, which are easier to remove from the water. Fenton's reaction reveals environmental and resource-saving benefits: high cleaning efficiency, carrying out the process at room temperature, and relative ease of implementation. A technological scheme is proposed for the treatment of highly concentrated sulfide-containing waters and local wastewater treatment with the transfer of hydrogen sulfide to a state of non-toxic, easily transported commercial sulfur. The requirements for the quality of effluents for the Fenton reaction are substantiated, the key factors determining the process are identified, and the technological scheme is adjusted. When making the proposed changes, such effects as greening production, shortening the length of the technological chain and reducing energy costs can be achieved by using the mild conditions of the Fenton process compared to steam.