Complex Alumina-Ferrous Coagulant for Effective Wastewater Purification from Hydrogen Sulfide

Erzhan I Kuldeyev,Ruslan E Nurlybayev,Aysha E Tastanova,Fardila M Zaihidee,Bibigul S Botantayeva,Igor V Bondarenko,Saniya S Temirova,Gianfranco Carotenuto

doi:10.1155/2021/5595599

Abstract

The article provides an overview of studies on the causes of the formation of hydrogen sulfide in anaerobic conditions of urban sewage systems and methods for neutralizing toxic reagent sulfur-containing compounds. It is noted that the presence of sulfur compounds and organic components in sewage flow leads to the formation and release of hydrogen sulfide into the atmosphere of settlements. Three main categories of methods for purifying sewage wastewater from hydrogen sulfide are presented. In this work, a complex alumina-ferrous coagulant has been developed from Kazakh raw materials. Based on natural ferruginous diatomite and middlings of sintered alumina, a complex alumina-ferrous coagulant has been synthesized, which is effective in purifying wastewater from hydrogen sulfide, accelerating the processes of sedimentation and clarification of sewage slurries. Experimental results also show that with the supply of increased amounts of coagulant, oil and oil films disappear from the surface of the cylinder, an almost complete purification of effluents from hydrogen sulfide compounds occurs, and the color of the liquid part is greatly reduced. In addition, the advantage of the developed reagent is that it is presented in the form of fine powder and can be easily dosed and added to a canalization pump station to interact with diluted hydrogen sulfide and be transported to sewage fields. Compared to other proposed methods in previous works, the reagent is suitable to be used directly in sewage systems such as sewage waters treatment plants and collectors to prevent hydrogen sulfide emission into the air atmosphere of populated areas, as well as at city sewage water treatment stations after air tanks and before secondary clarifiers to obtain better purified water suitable for watering agricultural plants.

Highlights

Hydrogen sulfide is a toxic, flammable, and corrosive gas that belongs to class II of compressed gas safety level (CGSL) hazard classification
Several other previous works support this finding by concluding that the reagent prepared from mixture of grained ferrous hydroxide, grained iron oxide, and depleted matte scrap can remove hydrogen sulfide from residuals and water in sewage systems and can be regenerated when brought in contact with diluted oxygen [12]
Speed and completeness of neutralizing diluted hydrogen sulfide with iron compounds are to a great extent defined by the form in which iron hydroxides are present in water solutions. e most efficient forms are colloid compounds that appear during hydrolysis of different iron-containing compounds such as sulphates, nitrates, and chlorides

Summary

Introduction

Hydrogen sulfide is a toxic, flammable, and corrosive gas that belongs to class II of compressed gas safety level (CGSL) hazard classification. Previous works have abundantly proposed various physical, chemical, and biological methods to diminish negative consequences of hydrogen sulfide in sewage water purification systems (reference). These methods are mainly to be implemented at industrial areas of sewage WWTP, which are situated beyond the borders of populated areas and equipped with all necessary premises and devices. It is crucial and more practical to develop an efficient reagent that is capable of neutralizing and suppressing hydrogen sulfide formation directly inside the sewage systems, where the gas emission into the atmosphere of populated areas occurs

Hydrogen Sulfide Neutralization Methods

Methodology

Results and Discussion

Conclusions