The invention provides a method for strengthening the dewatering of the geotechnical pipe bag. The method organically combines sludge flocculation, electro-osmosis and the dewatering of the geotechnical pipe bag. The steps include adding a flocculant, injecting sludge into the geotechnical pipe bag, Electroosmotic dewatering, wherein the steps of the combined electroosmosis and geotechnical bag device include: (1) laying a drainage layer, (2) combining the geotechnical bag and laying electrodes, (3) disassembling the geotechnical bag, (4) removing the sludge solid. The invention effectively improves the dewatering efficiency of the geotechnical tube bag by adding flocculant and using electro-osmosis, and the vertical geotechnical tube bag not only reduces site occupation, but also can be reused, saving the cost of dehydration.

claims

1. a method for strengthening the dehydration of the geotextile bag is characterized in that comprising the following operation steps: (1) adding a flocculant, adopting a metering pump to add the flocculant in the conveying pipeline, and mixing through the pipeline mixer immediately thereafter , the flocculant can not only accelerate the sludge aggregation and dewatering, but also increase the conductivity of the subsequent sludge; (2) inject the sludge, the mixed sludge is injected from the opening above the geotechnical pipe bag, and the liquid level reaches the level of the geotechnical pipe bag. At the top, stop the injection, and the liquid level gradually rises to increase the internal pressure of the geotextile bag. After the water in the mud flows out of the geotechnical pipe bag, the liquid level in the geotechnical pipe bag will gradually decrease. Inject the mud and repeat the injection for 3 to 5 times; (3) Electroosmosis dehydration. After the last injection is completed for 1 to 3 hours, the electroosmosis equipment is turned on, and the mud in the geotechnical tube bag is electroosmotically dehydrated. The positive and negative electrodes in the electroosmosis Connect the adjustable DC power supply for power supply, increase the voltage with the decrease of the water content of the mud during the treatment process, power off after the power-on time lasts 15-20 hours, the power-off time is less than 15 hours, the positive and negative poles are short-circuited to discharge the charge , When the power is cut off, the geotechnical tube bag is manually beaten to accelerate the dehydration and loosen the cathode sludge, so that the subsequent power-on dehydration is easy to carry out.

2. a method for strengthening the dehydration of the geotextile bag, it is characterized in that the implementation step of electroosmosis and the geotechnical pipe bag combination device comprises:

(1) Laying the drainage layer: Lay an impermeable membrane on the flat foundation, set vertical pillars on the impermeable membrane, and then lay the drainage layer. After the drainage layer is laid, install the horizontal pillars;

(2) Combining geotextile bags and laying electrodes: lay a rectangular geotextile on the drainage layer, and set yin and yang electrodes on the geotextile. The bottom end of the electrode is fixed on the drainage layer through the horizontal geotextile. The rectangular vertical geotextile bag that has been sewn on five sides is placed in the bracket in a natural and vertical manner, the top is fixed on the hook on the bracket, and the bottom end of the vertical geotechnical tube bag is in contact with the horizontally laid geotextile and has overlapping parts, which will overlap. Partially folded in two and tightened with mechanical clamps to make it dense and rectangular;

(3) Dismantle the geotechnical tube bag, dehydrate, reduce volume and solidify into a solid under the action of electro-osmosis and natural gravity. After reaching the expected dehydration effect, loosen the mechanical clamp, and use the machine to pull up the vertical geotechnical tube bag to remove the sludge solids;

(4) Remove the solid, use the machine to remove the solid, be careful not to damage the electrode, the electrode and the geotextile bag can be reused after being washed with water.

3. The method for strengthening the dehydration of geotextile bags according to claim 2, wherein the arrangement of the yin and yang electrodes is that a graphite electrode is arranged every 80-200 cm on the rectangular center line, and each The cathode and anode electrodes are arranged at intervals of 80-200 cm.

4. A method for strengthening the dehydration of geotextile bags according to claim 2, characterized in that: the anode is made of graphite, the cathode is a PVC pipe wound with copper wires, and the PVC pipe is evenly provided with small holes, And wrap a layer of filter fabric on the outside of the tube, the lower ends of the anode and the cathode are wrapped with hard insulating material, and are fixed on the drainage layer through the horizontal geotechnical pipe bag. A small section of insulating hollow thin tube is fixed to the top of the cathode, and passes through the top of the geotechnical tube bag, and the wire is communicated with the electrode through the insulating thin tube.

  manual

A kind of method for strengthening the dewatering of sludge in geotechnical pipe bag

Technical field

The present invention belongs to the technical field of sludge reduction treatment, and relates to a method for dewatering urban sludge or lake and reservoir river sludge by using geotechnical tube bags, and in particular to a method for enhancing the dewatering effect of geotechnical tube bags by adding flocculants and electroosmosis.

  Background technique

The number of sewage treatment plants and sewage treatment stations in my country is increasing year by year, and the amount of sludge produced is also increasing sharply. In addition to the excess sludge generated by sewage treatment, the sludge generated by the annual dredging and dredging projects of urban rivers and lakes in my country With a volume of more than 70 million tons, how to deal with these sludges quickly and effectively has become an urgent problem that needs to be solved. Researchers at home and abroad have done a lot of research on sludge dewatering and reduction. The geotechnical tube bag dewatering technology is highly valued by the environmental protection community due to its low cost, large processing capacity, and easy operation. For example, the Sino-Singapore Eco-city Sewage Reservoir Treatment Project, Wuhan Sand Lake Treatment Project, etc. However, when the geotechnical tube bag is dewatered, the liquid seepage time is relatively long, and the water content of the sludge in the tube bag must reach below 60%, which requires a long time for dehydration and solidification, at least ten days. If the pressure in the tube bag is increased to increase the filtration speed, the compressive strength of the tube bag needs to be increased a lot, and more expensive raw materials must be selected, resulting in an increase in the cost of the tube bag.

Sludge dewatering through mechanical dehydration, gravity centrifugal force dehydration, etc. can only remove free water in the sludge, but the sludge still has a high water content, mainly composed of adsorbed water, the volume is still large, and the transportation and disposal are inconvenient. , Combining electroosmosis dehydration with geotechnical bag dehydration can make up for the deficiencies of geotechnical bag dehydration and speed up its dehydration efficiency. Electroosmosis can effectively remove adsorbed water in sludge capillaries, and the electroosmotic coefficient of sludge is much higher than Hydraulic permeability coefficient, electroosmosis is an efficient dehydration method. At present, electroosmotic dehydration is often combined with mechanical dehydration, which can improve the dehydration effect of mechanical dehydration, but the processing capacity is small, the equipment investment is large, and the processing cost is high. Combining electro-osmosis with the geotextile bag, and adding flocculant to the sludge to improve the dewatering performance of the sludge and increase the electrical conductivity of the sludge can greatly shorten the dehydration time of the geotextile bag dehydration, improve the dehydration efficiency, and make the electricity Osmotic dewatering can be applied to the dewatering of large areas of high water content sludge.

Invention content

The object of the present invention is to provide a sludge dewatering method with high dewatering efficiency and low processing cost, which solves the shortcoming that the geotechnical tube bag is time-consuming for dehydration and the geotechnical tube bag cannot be reused.

In order to achieve the above-mentioned purpose, the present invention organically combines sludge flocculation, electro-osmosis and geotechnical pipe bag dehydration, and the specific steps are:

(1) Add flocculant, use metering pump to add flocculant to the conveying pipeline, and mix it through the pipeline mixer next to it. The flocculant can not only accelerate the sludge aggregation and dehydration, but also make the subsequent sludge conductive Increase.

(2) Inject the sludge. The mixed sludge is injected from the opening above the geotextile bag. When the liquid level reaches the top of the geotechnical pipe bag, stop the injection, and the liquid level gradually rises to increase the internal pressure of the geotechnical pipe bag. After the water flows out of the geotechnical tube bag, the liquid level in the geotechnical tube bag will gradually decrease. At this time, the mud is repeatedly injected into the geotechnical tube bag for 3 to 5 times.

(3) Electro-osmosis dehydration. After the last injection is completed for 1-3 hours, the electro-osmosis equipment is turned on to conduct electro-osmotic dehydration of the mud in the geotechnical tube bag. The positive and negative electrodes in the electro-osmosis are connected to an adjustable DC power supply. During the treatment process Increase the voltage with the decrease of the water content of the mud. After the power-on time lasts for 15-20 hours, the power is turned off. The power-off time is less than 15 hours. When the power is off, the positive and negative poles are short-circuited to discharge the charge. , to accelerate dehydration and loosen the cathode sludge, so that the subsequent power-on dehydration is easy to carry out.

The implementation steps of the electro-osmosis and geotechnical tube bag combination device include:

(1) Laying the drainage layer: Lay an impermeable membrane on the flat foundation, set vertical pillars on the impermeable membrane, and then lay the drainage layer. After the drainage layer is laid, install the horizontal pillars.

(2) Combining geotextile bags and laying electrodes: Lay a rectangular geotextile on the drainage layer, and set a graphite anode and a PVC pipe cathode wrapped with copper wire on the geotextile. Small holes are evenly opened on the PVC pipe, and the The tube is covered with a filter fabric to prevent clogging of the pores and protect the copper electrodes. A graphite electrode is placed on the center line of the rectangle every 80-200 cm, and the cathode and anode electrodes are set at intervals of 80-200 cm from the center line to the two ends of the rectangle. The bottom end of the electrode is fixed on the drainage layer through the horizontal geotextile. After laying the electrodes, place the rectangular upright geotechnical tube bag that has been sewn on five sides into the support in a natural and vertical manner, with the top fixed on the hook on the bracket, and the bottom end of the upright geotechnical tube bag is in contact with the horizontally laid geotextile. If there is an overlap, fold the overlap in half and tighten with a mechanical clamp to make it dense and rectangular.

(3) Dismantle the geotechnical tube bag, dehydrate, reduce volume and solidify into a solid under the action of electro-osmosis and natural gravity. After the expected dehydration effect is achieved, loosen the mechanical clamp, and use the machine to pull up the vertical geotechnical tube bag to remove the sludge solids.

(4) Remove the solid, use the machine to remove the solid, be careful not to damage the electrode, the electrode and the geotextile bag can be reused after being washed with water.

In the combination device of the electrode and the geotechnical pipe bag, the drainage layer is set into a rectangle with an area larger than that of the horizontal geotechnical pipe bag, which is composed of well-permeable and hard graded particles, and a horizontal geotextile is laid on the rectangular drainage layer to drain water. There are drainage pipes around the layer to collect and discharge the protruding water into the river or sewage treatment plant.

In the electrode and geotextile bag combination device, the cathode PVC pipe has the function of a drainage pipe, the bottom ends of the cathode and the anode pass through the horizontal geotextile, and are fixed on the drainage layer, and the top end passes through the top geotextile, and The anode and cathode are connected in parallel respectively, and are the same as the cathode and anode of the DC power supply.

In the combination device of the electrode and the geotechnical tube bag, it is necessary to repeatedly inject the mud. When the water flows out of the rectangular tube bag, the liquid level will drop. At this time, the mud is repeatedly injected, and the injection is repeated 3 to 5 times. There is no need to turn on the power before the filling is completed. When the last injection of mud is completed for 1 to 3 hours, the power is turned on, and the voltage adjustment range is 20 to 60V.

Because the geotechnical tube bag of the present invention is vertical, the pressure of the mud in the geotechnical tube bag is relatively large, which accelerates the seepage time of the liquid in the geotechnical tube bag, and at the same time adds electro-osmosis, the cathode also has a drainage effect, which greatly shortens the time. The dehydration time of the geotechnical tube bag is shortened, the processing capacity is not reduced while the efficiency is improved, and the vertical geotechnical tube bag occupies less space and saves space.