Agar gel particles and application thereof in biological nitrogen removal process of source water

Abstract

The invention discloses agar gel particles and application thereof in a biological nitrogen removal process of source water. The agar gel particles comprise the following components in part by weight: 5 to 10 parts of agar, 1 part of sodium alginate, 5 parts of ceramic aggregates and 100 parts of water. The application comprises the following steps of: feeding the source water polluted by nitrates from the bottom of an agar gel reactor; allowing the source water to pass through an agar gel particle packed bed and flowing the source water out of an overflow weir; performing natural inoculation by using microorganisms in the source water; and then performing biological denitrification and treatment of a biological aerated filter on the source water after a system is started. The agar gel particles have the advantages of obtaining a nitrate nitrogen removal rate of over 90 percent and over 300mg / (L.d) of nitrate nitrogen volumetric removal loads and not producing secondary pollution, along with simple components, easy preparation, high system adaptability and stable running and the like, and overcome the defects of low nitrate nitrogen removal rate, long hydraulic retention time, difficult control over amount of added carbon source and the like in the conventional biological nitrogen removal process of the source water.

Description

technical field [0001] The invention belongs to the field of environmental engineering water treatment, and relates to a method for removing nitrate in source water, in particular to an agar gel particle and its application in a biological denitrification process of source water polluted by nitrate. Background technique [0002] The application of agricultural nitrogen fertilizers, livestock and poultry excrement, improper treatment and discharge of domestic sewage and nitrogenous industrial wastewater, leaching and infiltration of solid waste, sewage recharge and acid rain, etc., make water source water, especially groundwater Nitrate concentration rises and becomes the main pollutant. Nitrate itself is not harmful to the human body, but it can be converted into nitrite by nitrate-reducing bacteria in the human body, which can cause methemoglobinemia, or form carcinogenic nitrosoamines or their compounds to cause cancer in the digestive organs, which is harmful to human hea...

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Problems solved by technology

Studies by Aslan et al. have shown that when wheat straw is used as a carbon source, a longer HRT (56.85h) is required, and the effluent COD is 50-100mg / L; Shao Liu et al.’s research by using wheat straw as a carbon source shows that ideal denitrification The effect also requires a longer HRT; when Jin Zanfang and others studied paper as a carbon source, the results showed that the system start-up was complicated and a relatively long HRT (9.8h) was required. After the denitrification effluent was treated by activated carbon adsorption, the final effluent DOC<11mg / L; when Mary et al. used chitin as the carbon source, a longer HRT (16.2h) was also required; when Zhou Haihong et al. used BDPs as the carbon source, activated sludge was used to start the reactor, and the release of carbon source was unstable and affected by the biofilm Constraints; Fan Zhenxing et al.’s research using polylactic acid as a carbon source shows that it takes a long time to start the reactor, the biofilm formed is not stable enough, denitrification is greatly affected by temperature, and a long HRT (13h) is also required

[0005] At present, the biological denitrification technology of solid carbon source water source water mainly has the following disadvantages: (1) the removal rate of nitrate nitrogen is not high; (2) the volumetric removal load of nitrate nitrogen is not high; (3) it needs a long hydraulic retention time (HRT ); (4) The release of organic matter is not stable enough, and there is a risk of organic secondary pollution in the effluent; (5) The system operation is not stable enough

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