Method for treating coking wastewater

Abstract

The invention discloses a method for treating coking wastewater. The method comprises the following steps: adding quick lime into the coking wastewater to adjust the PH value to 8 to 10, sufficiently stirring the coking wastewater and the quick lime, and then adding a plant coagulant to obtain the mixed solution; stirring the mixed solution obtained in the step 1), and then ensuring that the added plant coagulant fully reacts with the coking wastewater to obtain the layered solution; extracting the supernatant liquid in the layered solution obtained in the step 2) to carry out the sand filtration and the activated carbon filtration; and adding hydrochloric acid into the supernatant liquid filtered in the step 3) to adjust the PH value to 7 so as to achieve a discharge standard. In the method for treating the coking wastewater, plant seeds are used as the coagulant, the coagulant is a novel environmental-protection type coagulant low in cost, easy to obtain, safe, non-toxic and complete in biodegradation, avoids secondary pollution, and has the effective activity within a wider PH value range.

Description

technical field [0001] The invention relates to the technical field of water treatment, in particular to a coking wastewater treatment method. Background technique [0002] Coking wastewater is a typical toxic and refractory organic wastewater. Coking wastewater mainly comes from the production water and steam condensation wastewater in the initial cooling of coke oven gas and coking production. The concentration of pollutants in coking wastewater is high and it is difficult to degrade. Due to the presence of nitrogen in coking wastewater, the nitrogen source required for biological purification is excessive, which brings great difficulties to the treatment standard, and the polycyclic aromatic hydrocarbons contained in coking wastewater are not only difficult to degrade , and usually a strong carcinogen, causing serious pollution to the environment and directly threatening human health. [0003] The coking plant mainly produces chemical products such as coke, commercial ga...

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Problems solved by technology

[0007] Although the amount of organic coagulant is small, the coagulation speed is fast, it is less affected by the coexistence of salts, the pH value of the medium and the environment, and the fading effect is good, but the artificially synthesized organic polymer coagulant is expensive, and the residue will cause aggregation. Electrolyte toxicity, its application is limited