Method for treating composite polluted underground water under low temperature condition

Abstract

The invention provides a method for treating composite polluted underground water under a low temperature condition, which is used for treating composite polluted underground water under the low temperature condition by a high efficiency aeration processing unit and a modified chitosan particle filtering technology. The high efficiency aeration processing unit employs an intermittent aeration manner which comprises: continuously aerating for 5min, stopping aeration for 1min, and controlling oxygen dissolving concentration in water being 6-7mg / L after aeration. Operation technologies of the modified chitosan particle filtering unit comprises that: a filtration rate is 5.5-6.5 m / h, stay time is 15-18min, a backwashing period is 48h, backwashing employs single-water flushing manner, and flushing intensity is 15L / m2s. The technology can maintain good operation efficiency when water temperature is lower than 5 DEG C, and has good treating efficiency for composite polluted underground water simultaneously containing high density iron, manganese, ammonia nitrogen and organic matters. The method has advantages of simple technology, flexible operation and low cost, and is not affected by temperature.

Description

technical field [0001] The invention relates to the technical field of chemical engineering and environmental protection, and is a process for treating compound polluted groundwater under low temperature conditions, and is especially suitable for synchronous removal of iron, manganese, ammonia nitrogen and organic matter in low temperature groundwater with a temperature below 5°C. Background technique [0002] 90% of my country's urban groundwater is polluted to varying degrees by inorganic and organic pollutants. The main pollution indicators are ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, iron, manganese, and organic pollution caused by sewage irrigation and pesticide fertilization. Taking the groundwater in the Liaohe River Basin as an example, the concentration of iron in some areas can reach 6-7mg / L, the concentration of manganese can reach 3-4mg / L, ammonia nitrogen 2-3mg / L, and there are trace organic pollutants such as phenol and polycyclic aromatic hydrocarb...

AI Technical Summary

Problems solved by technology

Taking the groundwater in the Liaohe River Basin as an example, the concentration of iron in some areas can reach 6-7mg / L, the concentration of manganese can reach 3-4mg / L, ammonia nitrogen 2-3mg / L, and there are trace organic pollutants such as phenol and polycyclic aromatic hydrocarbons. , belongs to the slightly polluted groundwater with high manganese, high iron, ammonia nitrogen, and organic matter. The complexity of the water quality has brought great difficulties to the existing water purification process

At present, the treatment process for complex micro-polluted groundwater mainly uses biotechnology, but because the annual temperature of groundwater in some northern regions is lower than 5°C, the biological activity is significantly reduced under low temperature conditions, which directly leads to the treatment process mainly based on biodegradation. Unsatisfactory removal of pollutants

Therefore, in order to solve the problem that it is difficult to achieve high-efficiency water purification effect in actual engineering when dealing with compound-contaminated groundwater under low temperature conditions, a complex-contaminated groundwater treatment technology based on high-efficiency aeration-modified chitosan particle filtration as the main body has been developed.

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