Method for removing sulfide from wastewater

Abstract

The invention belongs to the technical field of water treatment, and relates to a method for removing sulfide from wastewater. In the method, a wastewater treatment container which is provided with a wastewater inlet and a wastewater outlet is arranged, wherein the top of the container is closed and provided with an air outlet; a dissolved air releaser is arranged below the liquid level in the container; an air dissolving device is arranged outside the container, and air is dissolved in the wastewater under high pressure; the wastewater which is needed to be treated passes through the container, and all of or part of the wastewater passes through the air dissolving device, so that a large amount of air is dissolved in the wastewater under the high pressure to form dissolved air water; anda large amount of oxygen dissolved in the dissolved air water reacts with the sulfide under the high pressure to oxidize the sulfide, the dissolved air water enters the container through the dissolved air releaser, pressure is suddenly reduced, the air dissolved in the dissolved air water and the sulfide in the form of hydrogen sulfide in the wastewater are separated out simultaneously to form small bubbles to be separated from the wastewater, and the residual sulfide is removed from the wastewater, so that the sulfide is removed from the wastewater. The process is simple, convenient to operate and stably operated.

Description

technical field [0001] The invention belongs to the technical field of water treatment and relates to a method for removing sulfide in waste water. Background technique [0002] Industrial wastewater discharged from industries such as dyestuffs, pharmaceuticals, pesticides, and petrochemicals usually contains a large amount of sulfides. When the wastewater containing sulfide is discharged into the water body, it will react with the iron metal ions in the water body to form precipitates, making the water body black and smelly; when the pH of the wastewater is acidic, it is easy to convert into highly toxic hydrogen sulfide, which is harmful to Organisms are highly toxic, therefore, sulfide-containing wastewater must be treated and discharged only after reaching the national discharge standard. [0003] At present, the removal methods of sulfide mainly include: air stripping or stripping method, coagulation precipitation method, chemical oxidation method and biological oxidat...

AI Technical Summary

Problems solved by technology

The air stripping or stripping method is used to treat sulfide-containing wastewater. It uses water vapor or air to separate hydrogen sulfide in the wastewater. The removal rate is high and the treatment process is mature, but the energy consumption and equipment investment are large, and the amount of waste gas generated Large, resulting in large investment in waste gas treatment

The coagulation-sedimentation method uses certain metal ions as precipitants to form precipitates, separate and remove them from sulfur ions, and then burn the precipitates at high temperature to recover the precipitants. The investment is small and the operation is simple, but there are problems of difficult precipitation and separation and high processing costs.

Commonly used chemical oxidation methods include air oxidation, wet oxidation, supercritical water oxidation and other oxidant oxidation methods, etc., which use air or other oxidants to oxidize sulfur ions in wastewater into elemental sulfur or sulfate, usually requiring the addition of catalysts or oxidants. Or oxidation under high temperature and high pressure, there are problems such as harsh reaction conditions, high requirements for equipment, and high operating costs

The biological oxidation method uses microorganisms to oxidize sulfide into elemental sulfur or sulfate. There are problems such as difficult separation of elemental sulfur, difficulty in microbial culture control, and inability to treat high-concentration sulfide wastewater.