Method and device for synchronously removing various heavy metals in agricultural non-point source sewage

Abstract

The invention relates to a method and a device for synchronously removing various heavy metals in agricultural non-point source sewage. The method comprises the following steps: enriching and culturing periphyton: after a purchased elastic filling is disinfected, adding the elastic filling into a natural farmland water body, and enriching and culturing periphyton; (2) inoculating the periphyton to a periphyton bioreactor; (3) debugging and operating single-electrode periphyton bioreactors arranged in an anaerobic reaction tank and an aerobic reaction tank of a periphyton reaction device: carrying out reaction on water and the periphyton to convert, adsorb and absorb heavy metal substances, wherein the pressure of the aerobic reaction tank (an aerobic section) of the periphyton reaction device is negative pressure; and (4) purifying water quality by virtue of a multi-stage periphyton bioreactor: connecting the single-electrode periphyton bioreactors in series, so that the inflow load is increased, the standing time is shortened, and the efficiency for removing various heavy metals is improved. The method has the characteristics of being simple, feasible and capable of avoiding a poisoning phenomenon and particularly has the characteristic that various heavy metals in the agricultural non-point source sewage can be removed.

Description

technical field [0001] The invention belongs to the field of ecology and environmental protection, relates to the field of agricultural non-point source pollution, in particular to a method for synchronously removing various heavy metal pollution in agricultural non-point source sewage by using a pericong bioreactor. The present invention also relates to the equipment used in this method: Zhoucong bioreactor. Background technique [0002] Heavy metal pollution is one of the most harmful water pollution problems. Heavy metals enter water bodies through man-made pollution sources such as mining, metal smelting, metal processing and chemical production wastewater, burning of fossil fuels, application of pesticides and fertilizers, and domestic garbage, as well as natural sources such as geological erosion and weathering. If these heavy metal wastewater is discharged into the natural environment without effective treatment, it is easy to accumulate in organisms and have an ampl...

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Problems solved by technology

[0004] (2). Refractory to degradation

Heavy metals cannot be degraded, and can only maintain stability or reduce toxicity by changing their valence and compound type; however, under the action of microorganisms, they may also be converted into more toxic organic compounds, such as inorganic mercury in natural water bodies, which can be destroyed Microbes convert to more toxic methylmercury

[0005] (3).Easy enrichment

[0006] (4). Toxic for a long time

However, the adsorption method is mainly non-selective adsorption, so it is not selective for the removal of heavy metal pollutants, and cannot remove specific heavy metal ions for special wastewater.

Invention patents (CN201410420016, CN102600777A, CN102583619A, CN104289185A) all improve the preparation of heavy metal ion adsorbents, including nano-iron ball adsorbents and plant biomass composite adsorbents. The fatal disadvantage is that these adsorbent materials are easy to be blocked during long-term use, resulting in unstable removal efficiency of heavy metals and even secondary pollution

However, these reactors mainly rely on a single microbial community or a few dominant microbial communities, and it is difficult to efficiently remove a variety of heavy metals in agricultural non-point source sewage with complex components, unstable discharge patterns, and uncertain discharge intensity.

Due to the complexity of agricultural non-point source sewage, a reactor composed of a single or a few microorganisms may also cause "poisoning"

And due to the need to maintain the "purity" or dominance of a single or a few microbial communities, these bioreactors have high operating and manufacturing costs and require more post-investment

At the same time, these reactors will add some chemical reagents more or less during the implementation process, which will cause harm to the environment, or the growth of individual plants (such as Centella asiatica) is restricted by the region, and its application range is greatly limited. Not suitable for application in agricultural non-point source sewage

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