Method for removing organic matters in reclaimed water by using in situ FeOxHy

Abstract

The invention relates to the field of treatment of reclaimed water, especially to a method for removing organic matters in reclaimed water by using in situ FeOxHy. Directed at the problem that secondary effluent of a municipal sewage plant has high content of organic matters, the invention brings forward the method of improving removal effects of coagulation, deposition and filtration units of a reclaimed water plant on organic matters by using combined action of an alkali salt and a ferric salt, wherein an alkali salt solution and a ferric salt solution are added according to a certain mol ratio and react with each other to produce in situ FeOxHy which enables organic matters in water to be agglomerated and adsorbed and settling properties of floc to be improved, and removal of the organic matters is further realized by using a solid-liquid separation reactor. The method can be used for deep purification of secondary effluent of the municipal sewage plant and is also applicable to a reclaimed water treatment project using effluent of the municipal sewage plant or rainwater as a water source.

Description

technical field [0001] The invention belongs to the technical field of regenerated water treatment, and in particular relates to a method of using in situ to generate iron hydroxyhydroxide In situ FeO x h y Method for removing organic matter in reclaimed water. Background technique [0002] There are often high concentrations of dissolved organic matter (DOM), low doses of estrogen and other small molecular organics in the effluent of urban sewage plants (ie, raw water for reclaimed water). Many reclaimed water purification processes cannot effectively remove the above-mentioned risk pollutants; on the other hand, some pollutants in the water may be converted into more toxic by-products in the purification and disinfection process, thereby significantly increasing the water quality safety risk. [0003] The coagulation and sedimentation method has remarkable effect in removing pollutants in water, stable operation, and can also effectively remove chroma, turbidity, SS, COD...

AI Technical Summary

Problems solved by technology

However, organic matter in the effluent of urban sewage plants often coexists with suspended particulate matter and ammonia nitrogen, and the above pollutants will also consume coagulants and greatly increase the dosage of iron salts

For the effluent of sewage plants with low alkalinity and weak buffer capacity, if the iron-salt coagulation process is used to remove organic matter, there will often be incomplete hydrolysis of iron-salt, small floc particle size, increased iron content in effluent, increased chroma, Problems such as poor sedimentation and filtration effect

The use of adsorbents such as iron oxyhydroxide, calcium hydroxyphosphate, diatomaceous earth-supported hydroxyl iron, and composite hydroxyl aluminum iron to absorb and remove organic matter can avoid the adverse effects of coagulation, but there are problems such as high cost, low adsorbent efficiency, and complicated regeneration operations.