Method for treating sulfur-containing waste water

Abstract

The present invention relates to a method for treating the sulfur-containing sewage. The industrial process of the invention is firstly adding sulfuric acid into the sulfur-containing sewage, adjusting pH value to 4-6, aerating with appropriate amount of air, facilitating the escaping of the H2S along with the air, and discharging the discharged water to the sewage treatment plant after adding alkali for neutralization. The aeration end gas containing H2S enters the incineration furnace or catalyzing burning reactor to generate SO2 and SO3, the SO2 and SO3 are absorbed by the absorption liquid to form a diluted acid. The generated diluted acid can be used back for adjusting pH to the sulfur-containing sewage, when the system operates normally basically no fresh sulfuric acid is added into the sulfur-containing sewage, the entire technique forms a closed system for treating the sulfur-containing sewage, the application range is broad and the cost is low.

Description

technical field [0001] The invention relates to a treatment method for sulfur-containing wastewater, in particular to a treatment method for refinery sulfur-containing wastewater. Background technique [0002] When refineries process sulfur-containing crude oil, devices such as atmospheric and vacuum, catalytic cracking, delayed coking, and hydrofining must discharge a large amount of sulfur-containing wastewater. Sulfur-containing wastewater cannot be discharged directly or directly into the sewage treatment plant for centralized treatment. There is H 2 S production causes personnel poisoning. [0003] The existing sulfur-containing sewage treatment methods include: acid neutralization method, precipitation method, steam stripping method, air oxidation method, wet oxidation method, etc. Yin Guiying reported a method of adding acid to treat sulfur-containing alkali slag wastewater in the article "Application of High Pressure Wet Air Oxidation Technology in Refinery Alkali ...

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Problems solved by technology

[0004] There are following problems in this technique: 1 does not adopt air to blow off H 2 S, leading to poor treatment effect; 2. Big smell on site; 3. SO produced by exhaust gas after incineration 2 Acid rain will be formed; 4. The consumption of concentrated sulfuric acid is large during the treatment process, and the economy is poor; 5. Salt and elemental S crystallization block the pipeline

[0008] CN1326899A proposes to use air oxidation method to treat sulfur-containing and ammonia-containing wastewater, the sulfide concentration range is 1000mg / L-2000mg / L, the temperature range is 40°C-80°C, the air is stirred for 4h-8h, the sulfide removal rate is 98%, and the ammonia removal efficiency 96%, the ammonia-containing tail gas produced is incinerated into the incinerator to produce N 2 and SO 2 , there are two problems here: one is that the treatment range of this method of oxidative desulfurization is limited, and it is impossible to deal with sulfide (S 2- ) Sulfur-containing wastewater with too high concentration, such as sulfide (S 2- ) concentration exceeds 10000mg / L waste water; Second, this method has limited deammonization efficiency

[0015] CN1394818A proposes that at first the reaction temperature is 255-260°C, the reaction pressure is 6.6-7.0MPa, and the space velocity is 1-2h -1 Under certain conditions, high-sulfur-containing organic wastewater is treated, and then treated with electric heterogeneous catalytic oxidation. This method consumes a lot of energy and requires high investment. It is even less economical if it is used for treatment of low-concentration sulfur-containing wastewater.

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