Modular cascade coupling type mine wastewater multi-stage treatment system and method

Abstract

This invention discloses a modular cascaded coupled multi-stage treatment system and method for mine wastewater, belonging to the field of environmental water treatment technology. It includes a filtration module filled with filter media for particle removal; an adsorption module filled with composite adsorption media for adsorbing heavy metal and organic pollutants; a reaction module filled with slow-release reaction media for removing heavy metal ions from wastewater through sulfide precipitation and reduction reactions; and a sedimentation module to slow down the reaction time and cause the water flow to reverse vertically. This invention achieves multi-stage synergistic removal of suspended solids, organic matter, and heavy metals from mine wastewater through a combination of sand, fly ash ceramsite, and heavy metal treatment agents; it relies on gravity flow due to the natural slope of the mine shaft for gravity-based operation; its modular design allows for flexible series connection to adapt to different pollution levels; and the semi-open tank facilitates media replacement, with heavy metals solidified in the reaction module, resulting in minimal secondary pollution.

Claims

1. A modular cascaded coupling multi-stage mine wastewater treatment system, characterized in that: It includes a filtration module, an adsorption module, a reaction module, and a sedimentation module connected in series; each module is an independent, semi-enclosed, waterproof long trough, connected sequentially by gravity flow formed by the natural slope of the mine or artificial elevation; wherein, The filter module is filled with filter media to remove particles; The adsorption module is filled with composite adsorption packing material and is used to adsorb heavy metal pollutants and organic pollutants. The reaction module is filled with slow-release reaction packing material and is used to remove heavy metal ions from wastewater through sulfide precipitation and reduction reaction. The sedimentation module is used to slow down the reaction time and cause the water flow to reverse up and down.

2. The modular cascaded coupled multi-stage mine wastewater treatment system as described in claim 1, characterized in that: The filtration module, adsorption module, reaction module, and precipitation module are all separate processing unit modules, and the filtration module, adsorption module, reaction module, and precipitation module are connected in series. The processing unit module is a semi-enclosed waterproof long trough; The processing unit module includes a top and two ends.

3. The modular cascaded coupling multi-stage mine wastewater treatment system as described in claim 2, characterized in that: The filter module includes two perforated partitions, which divide the filter module into three equal-length sections. The three equal-length sections are sequentially filled with gravel, coarse sand, and fine sand, which are used to remove large coarse mud and sand, medium-sized particles, and fine particles, respectively.

4. The modular cascaded coupled multi-stage mine wastewater treatment system as described in claim 3, characterized in that: The adsorption module includes a perforated partition, which divides the adsorption module into two equal-length sections. The two equal-length sections are sequentially filled with fly ash ceramsite and activated carbon granules, which are used to adsorb heavy metal ions and heavy metals and organic matter, respectively.

5. The modular cascaded coupling multi-stage mine wastewater treatment system as described in claim 4, characterized in that: The reaction module includes two perforated partitions, which divide the reaction module into three equal-length sections. The three equal-length sections are sequentially filled with a polyferric composite slow-release agent, zero-valent iron particles, and ferrous sulfide supported on ceramsite. The polyferric composite slow-release agent is used to remove heavy metal ions, the zero-valent iron particles are used to reduce high-valence heavy metals, and the ferrous sulfide supported on ceramsite is used to generate insoluble sulfides.

6. The modular cascaded coupling multi-stage mine wastewater treatment system as described in claim 5, characterized in that: The sedimentation module includes two under-suspended baffles to form a deflection sedimentation zone, allowing the water flow to bypass the bottom of the baffles and flow upwards.

7. The modular cascaded coupling multi-stage mine wastewater treatment system as described in claim 6, characterized in that: The top of the processing unit module includes a cover plate for observation, inspection, and packing replacement; The processing unit module includes an inlet and an outlet at both ends; The inlet is located on the upper part of the end face of the treatment unit module, and the outlet includes a stainless steel filter screen located on the lower part of the end face opposite to the inlet. The height difference between the inlet and the outlet forms a downward flow path, and the stainless steel filter screen is used to prevent the packing material from being lost. The connection between adjacent treatment unit modules includes a PVC short pipe or an open channel drop connection. One end of the PVC short pipe is connected to the outlet of the previous treatment unit module, and the other end of the PVC short pipe is connected to the inlet of the next treatment unit module. The overall hydraulic slope is formed by the natural slope of the mine tunnel or by artificial elevation, so that the bottom elevation of each treatment unit module is lowered in turn, ensuring that the outlet elevation of the previous treatment unit module is higher than the absolute elevation of the inlet of the next treatment unit module. The first 2 m of the PVC short pipe is an empty pipe, meaning it is not filled with any material and serves as a buffer for water inlet and a natural sedimentation section for coarse particles.

8. A modular cascaded coupling multi-stage treatment method for mine wastewater, based on the modular cascaded coupling multi-stage treatment system for mine wastewater according to any one of claims 1 to 7, characterized in that: Including the following Steps: Step 1: Allow the mine wastewater to flow into the filtration module by gravity, and then flow through the gravel zone, coarse sand zone and fine sand zone in sequence to remove suspended particles; Step 2: The filtered effluent enters the adsorption module and flows sequentially through the fly ash ceramsite zone and the activated carbon zone to adsorb heavy metals and organic matter. Step 3: The effluent after adsorption enters the reaction module and flows sequentially through the polyferric composite slow-release agent zone, the zero-valent iron particle zone, and the ferrous sulfide ceramsite-loaded zone to remove heavy metal ions through coagulation, reduction, and sulfide precipitation. Step 4: The effluent after the reaction enters the sedimentation module, where the water flow is reversed by the suspended baffle, which can slow down the reaction time. After sedimentation, the effluent is discharged.

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