Construction method and application of phycomycete symbiotic denitrification biological filter

Abstract

The invention discloses a construction method and application of a phycomycete symbiotic denitrification biological filter, and relates to the technical field of mariculture tail water treatment. The construction method comprises the following steps: introducing the mariculture tail water into a filter containing filler for circulation to realize natural biofilm formation, then adjusting the alkalinity of the mariculture tail water to the alkalinity suitable for the growth of the seawater spirulina, taking the mariculture tail water as a growth water body, adding the seawater spirulina into the filter, keeping illumination, and after a phycomycetes biofilm grows on the inner wall of the filter, carrying out biofilm formation on the phycomycetes. Preliminary construction of the algal-bacterial symbiotic denitrification biological filter is completed; and gradually reducing the carbon source content of the mariculture tail water within the time not shorter than 15 days, gradually reducing the hydraulic retention time, and finally maintaining C / N to be 1 / 1 and the hydraulic retention time to be 2 hours, thereby completing the construction of the denitrification biological filter. According to the method, the addition of an organic carbon source is greatly reduced, the operation cost is reduced, meanwhile, efficient phosphorus removal is considered, and up-to-standard discharge of the mariculture tail water can be rapidly achieved within a short time.

Description

technical field [0001] The invention relates to the technical field of mariculture tail water treatment, in particular to a construction method and application of an algae-bacteria symbiotic denitrification biological filter. Background technique [0002] Mariculture tail water has the characteristics of low carbon-nitrogen ratio (C / N), high salinity, non-concentrated discharge, and large output, which makes its treatment difficult. [0003] Traditional physical treatment methods (mechanical filtration, foam separation, membrane separation, etc.) cannot carry out advanced treatment of aquaculture tail water, and it is difficult to meet the discharge standards. They are usually only used for pretreatment of aquaculture tail water; chemical treatment methods (ozone oxidation, flocculation, electrolysis Although high-efficiency, the cost is high, and by-products are produced, which increases the risk of eating aquatic products; while the biological treatment method has been ext...

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Problems solved by technology

[0002] Mariculture tail water has the characteristics of low carbon-nitrogen ratio (C / N), high salinity, non-concentrated discharge, and large output, which makes its treatment difficult

[0003] Traditional physical treatment methods (mechanical filtration, foam separation, membrane separation, etc.) cannot carry out advanced treatment of aquaculture tail water, and it is difficult to meet the discharge standards. They are usually only used for pretreatment of aquaculture tail water; chemical treatment methods (ozone oxidation, flocculation, electrolysis Although it is efficient, its cost is high, and by-products are produced, which increases the risk of eating aquatic products; while biological treatment has been extensively studied because of its low cost, low risk, and advanced treatment of aquaculture tail water.

[0004] At present, the traditional biological treatment methods mainly include activated sludge method, biofilm method, biological filtration method, etc., but the removal effect of nitrogen and phosphorus is not ideal.

The biggest problem is: ① The activated sludge method is still difficult to apply to the treatment of mariculture tail water. On the one hand, it is difficult to maintain the efficient growth of sludge due to the low tail water load, and often requires an external carbon source to maintain a suitable C / N. The treatment cost is increased; on the other hand, the removal of phosphorus in this method is realized by discharging excess sludge, and alternate anaerobic and aerobic / anoxic conditions need to be set to realize the storage of polyphosphate in phosphorus-accumulating bacteria. The larger the land area, the greater the processing cost

②Similar to the activated sludge method, the biofilm method is also limited by the low C / N ratio of the tail water. The phosphorus removal process depends on the growth or reproduction of microorganisms themselves, and the removal effect on phosphate in the tail water is not good, so it is mostly suitable for treatment Tail water with high concentration of organic matter

③ The biological filtration method represented by polyculture of shellfish and algae can remove inorganic nitrogen and phosphorus in tail water at low cost without adding exogenous substances, but its treatment effect is limited by the growth efficiency of macroalgae

But at present, most of the researches on algae-bacteria symbiosis wastewater treatment technology focus on the symbiotic system between autotrophic microalgae and aerobic bacteria. The oxygen released by autotrophic microalgae through photosynthesis is used by aerobic bacteria / nitrifying bacteria , so as to transform the ammonia nitrogen and nitrite nitrogen in the water body, and at the same time, the microalgae can remove part of the nitrogen and phosphorus through assimilation and absorption, but this method is not suitable for the high nitrate content in seawater land-based industrial farming If the symbiotic model of autotrophic microalgae and heterotrophic denitrifying bacteria is used for tail water treatment, the oxygen produced by photosynthetic microalgae will inhibit the denitrification efficiency of denitrifying bacteria, making it difficult to meet the discharge standards for mariculture tail water

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