Methods for removing reduced sulfur compounds from groundwater

Abstract

Reduced sulfur compounds contained in natural waters adversely affect human health in wastewater, cause corrosion of collector materials and structures, and inhibit biological treatment processes. The methods to reduce the reduced sulfur compounds concentration in natural and waste waters are quite well known, however, in each case, in accordance with the requirements for the quality of treatment and the initial concentration of reduced sulfur compounds, it is necessary to adapt the methods used. This article presents the results of studies on the removal of reduced sulfur compounds from groundwater. The results of the reduced sulfur compounds oxidation method with hydrogen peroxide to sulfates with aeration and without aeration of the treated water are presented, as well as the results of studies on colloidal sulfur coagulation resulting from the incomplete oxidation of the reduced sulfur compounds. The expediency of using the reduced sulfur compounds of hydrogen peroxide with simultaneous aeration of the treated water as an oxidizing agent is shown. It was established that the contact duration of the treated water containing the reduced sulfur compound with hydrogen peroxide, both with and without simultaneous aeration, should be at least 30 minutes. The results of experiments on the colloidal sulfur coagulation are also presented, indicating that the use of sodium hydro-aluminate in proportion to aluminum sulfate, which ensures the ratio [OH+]: [Al3+] = 0,5, allows not only to achieve results in water purification with bringing the quality to the standards for drinking water, but also to reduce the coagulant dose in its active part by 30%, compared to other options. It has been analytically established that when using aluminum oxy sulfates or oxy chlorides for coagulation of colloidal sulfur, it is advisable to use the low-base coagulants.