The difference between activated carbon filter and activated sand filter
The activated carbon filter pressure vessel is a pressure vessel filled with coarse quartz sand cushion and high-quality activated carbon.
Function: In the water pretreatment system, the activated carbon filter can absorb the residual chlorine that cannot be removed in the previous stage filtration to prevent the subsequent stage reverse osmosis membrane from being oxidized and degraded, and at the same time, it also adsorbs pollutants such as small molecular organics leaked from the previous stage , It has obvious adsorption and removal effect on peculiar smell, colloids and pigments, heavy metal ions, COD, etc. in water. The SDI value of RO influent can be further reduced to ensure SDI<5 and TOC<2.0ppm.
The work of the activated carbon filter is completed by the carbon bed. The activated carbon particles that make up the carbon bed have a lot of micropores and a huge specific surface area, and have a strong physical adsorption capacity. The water passes through the carbon bed, and the organic pollutants in the water are effectively adsorbed by the activated carbon. In addition, there are some oxygen-containing tube energy groups on the non-crystalline part of the activated carbon surface, so that the organic pollutants in the water passing through the carbon bed are effectively adsorbed by the activated carbon. Activated carbon filter is a kind of more commonly used water treatment equipment. As the pretreatment of water treatment desalination system, it can effectively ensure the service life of the subsequent equipment, improve the effluent water quality, and prevent pollution, especially to prevent the subsequent reverse osmosis membrane, ion exchange resin, etc. Free residual oxygen poisoning pollution.
The main factors that affect the adsorption effect and service life of the activated carbon filter are: the type and concentration of pollutants, the residence time of the airflow in the filter material, and the temperature and humidity of the air. In actual selection, the type of filter and the type of activated carbon should be determined according to conditions such as the type of pollutant, the concentration and the amount of air to be processed.
There should be good dust removal filters both upstream and downstream of the activated carbon filter, and their efficiency specifications should not be lower than F7. The upstream filter prevents dust from clogging the activated carbon material; the downstream filter blocks the dust generated by the activated carbon itself.
Activated sand filter is a continuous filtration equipment that integrates coagulation, clarification, and filtration based on the principle of countercurrent
Influent water enters the treatment system through the water distribution pipe at the bottom of the equipment, and overflows from the top outlet after being filtered by the sand bed. The impurities trapped in the sand bed during filtration are transported by aerodynamic force to the sand washer on the top of the filter tank. The contaminants are separated from the surface of the filter sand through mechanical friction and turbulence. The impurities are discharged with the sand washing water, and the sand is returned by its own weight. Sand bed.
- High efficiency: 24 hours of continuous work, no need to stop and backwash.
- Low operating costs: no high-lift and large-flow backwash pumps are required.
- Low maintenance cost: There are no rotating parts except the quartz sand filter material during operation, the failure rate is low, and the maintenance cost is low.
- Low one-time investment: There is no need to set up coagulation tanks, clarification tanks and other facilities alone, no backwash pumps, electric and pneumatic valves and other equipment, and the amount of engineering is small, and one-time investment is low.
- Small head loss: a single filter material and the filter material is cleaned in time, the head loss is small, and the total head loss is ≤0.5m.
- Influent water quality requirements are loose: it can withstand the 150mg/L concentration of SS influent water quality for a long time, and withstand the impact of 300mg/L concentration of SS in a short time without changing the effluent quality.
- The effluent quality is stable and the filtering effect is good. The filter material is clean and timely to ensure high-quality and stable water output without periodic water quality fluctuations.
- Easy to rebuild and expand: The adopted unit operation method can flexibly increase or delete the number of filters according to the change of water volume, which is easy to rebuild and expand.
- Small footprint and beautiful appearance: It integrates the traditional three-stage reclaimed water treatment process, saving about 70-80% of the land; the appearance is more beautiful and compact.
Vortex reactor, also called fast reactor, is a kind of cyanide suitable for lime softening reaction. The advantage is that the residence time of water in the reactor is short, the flow rate is fast, and the equipment is small in size. The applicable conditions of the fast reactor are: low suspended solids and low oxygen consumption in raw water, carbonate hardness not less than calcium hardness (rnmol/L); magnesium hardness in raw water less than 20% total hardness (mmol/L). High-purity lime should be used to prepare milk of lime with a concentration of 2%. It is best to pre-install marble or quartz sand filler (d=0.10-0.5mm) before operation. The filling height is 1/3^1/2 cone height from the bottom of the body. The granular substance can act as a contact agent and accelerate the reaction. Crystal, the reaction product is a calcium carbonate crystal with a diameter of 2 to 3 mm, and the pH value of the effluent is controlled between 9.5-10.3. The effluent turbidity and supersaturation of the reactor are high. Practice has proved that the supersaturation of Caz+ is 0.2~0.3mmol/L (calculated as 1/2 Ca’+). In order to prevent the post-filter from fouling, it is necessary to consider adding As a measure to adjust the pH value by acid, it is also suggested to use the reactor as the filter medium of the post filter to further reduce the supersaturation of water. The gravity reactor can be equipped with an air separator before the raw water enters. The effluent of the vortex reactor should be controlled at 2PM, and the amount of lime is appropriate at this time; the slag of the vortex reactor is relatively pure and granular CaCO3, and the density of 2.58g/cm3 can be effectively used.