Chemical dosing system in industrial life can be said to be a very common and necessary equipment, and there are many types of dosing device, among which water treatment dosing device is one of the more widely used. Sewage treatment is not only for environmental protection, but also after dosing treatment, we can get usable raw materials, which can be said to be industrial It's a powerful tool in our daily life. Let's take a look at the advantages of the water treatment dosing device and what is introduced in the calculation of the dosage of the water treatment dosing device.
Advantages of water treatment dosing device
1. The ability of resisting shock load is strong. The average residence time of contact oxidation method is more than 6 hours;
2. It has the ability of nitrogen and phosphorus removal, and can achieve the ability of treating industrial waste water, domestic sewage and urban sewage by adjusting the structure of the equipment;
3. Most of the fillers in the contact oxidation tank are composed of soft fillers with light weight, high strength, stable physical and chemical properties, large specific surface area, strong adhesion ability of biofilm, and high contact efficiency between sewage and biofilm;
4. In the contact oxidation tank, the aerator is used for blast aeration, which makes the fiber bundle float continuously, the aeration is uniform, and the microorganism grows mature, which has the characteristics of activated sludge process;
The effluent quality is stable, sludge production is small and easy to treat.
Calculation of dosage of water treatment dosing device
Dosage of scale inhibitor
The return water rate of the primary reverse osmosis system of the desalted water treatment system is calculated as 75%. Under the condition of 20-50 ℃, the water quality has a strong tendency of scaling, which indicates that an appropriate amount of dispersant for membrane must be added to ensure the long-term safe and stable operation of the reverse osmosis system and prolong the service life of the membrane. The influent of the second stage reverse osmosis is produced by the first stage reverse osmosis, which has low hardness and alkalinity and does not need to add scale inhibitor. Through the calculation of the special reverse osmosis software, it is known that the recommended dosage of the water quality under the recovery rate of 75% is 3ppm (based on the influent), and the daily dosage = reagent concentration × influent quantity × 24h ≈ 8.64kg (based on the influent quantity of 120m3 / h).
The pH adjustment system adopts x015 diaphragm pump and 120L water tank. Na0h solution with concentration of 0.1% ~ 0.5% is prepared in the water tank, and the drug is added through diaphragm pump. According to the pH value of the produced water and the conductivity of the produced water, adjust the amount of alkali to make the value of the produced water reach the moderate value, and determine the dosing concentration according to the actual secondary conductivity of the produced water. Diaphragm pump and two-stage reverse osmosis operate synchronously. General principles for adjusting the amount of alkali added
When the conductivity rises sharply, the amount of alkali added is large.
When the conductivity is stable but high, the amount of alkali added is too small.
When the amount of alkali added is too small, and then increase the amount of alkali added, the conductivity will drop sharply, but when it drops to a certain extent, it will rise immediately, then the amount of alkali added will increase too much.
When the scale of alkali diaphragm pump is adjusted to the maximum, the alkali dosage can not be reached, which indicates that the alkali concentration in the water tank is too small.
If the scale of alkali pump is below 20 and the adjustment sensitivity is too high, it means that the alkali concentration in water tank is too high.
Dosing of fungicides
Since the raw water is municipal tap water, there are few bacteria in the system, but with the increase of temperature, especially in summer, the normal operation of reverse osmosis membrane will be affected. Therefore, a certain amount of bactericide should be added to control the growth of bacteria and protect the reverse osmosis membrane from the invasion of microorganisms. The agent is continuously added to the pretreatment system to maintain the residual chlorine in the influent to inhibit bacteria Therefore, the dosage should be determined according to the actual biological pollution degree of the system, and the recommended dosage is 2ppm (based on the influent).
Daily dosing of desalted water treatment system = reagent concentration × water inflow × 24h ≈ 5.76kg (water inflow is 120m3 / h).
Dosage of reducing agent
In order to avoid oxidizing bactericide entering the reverse osmosis membrane to oxidize the membrane elements, a reducing agent dosing system is set up in front of the reverse osmosis system. The type of the dosing agent is dcl95, and the specific dosage should be determined according to the residual chlorine in the reverse osmosis system after adding the oxidizing bactericide, which is generally about 3-5 times of the residual chlorine, based on the dosage of 2ppm.
The daily dosage of desalted water treatment system = reagent concentration × influent quantity × 24h ≈ 5.76kg (influent quantity is 120m3 / h). Note that if the dosage of reducing agent is excessive, the system will be polluted and blocked. Therefore, daily residual chlorine monitoring must be strengthened to adjust the dosage ratio between oxidizing bactericide and reducing agent, so that the reducing agent can fully react the influence of oxidizing substances on membrane components At the same time, there is not too much residual to bring additional pollution to the system.
Most of the time, our demand for dosing device is relatively high. The quality of water treatment dosing device determines the effect of dosing treatment. Therefore, if we want to guarantee this link in industrial production, it is necessary to select a professional company to provide cooperation.