Arsenic removal filter

1. Product function

 

The arsenic removal filter is mainly used to remove the arsenide in the system and purify the water. It can also be used for water decolorization and odor removal.

 

2. Scope of application

 

It is often used as a special equipment for centralized removal of arsenic ions in drinking water with groundwater as its source.

 

3. Product characteristics

 

3.1 Unique multi-filter chamber structure, can achieve online backwashing (filtration, sewage and backwashing at the same time).

 

3.2 Simultaneous operation of the separately recycled processing process greatly improves the utilization rate of equipment and filter material.

 

3.3 According to the water pressure of the system, the tank material can be selected to use carbon steel, glass steel.

 

4. Technical parameter

 

4.1 Treatment effect:

 

①. Fluoride content: ≤0.05mg/L;

 

②. Effluent turbidity: < 3FTU;

 

③. Arsenic removal capacity: 10g/kg filter material.

 

4.2 Water Intake Requirements:

 

①. Arsenic content: ≤2.0mg/L;

 

2. Influent turbidity: < 50FTU;

 

③. Alkalinity: ≤2mg/L;

 

④.pH value: 6-6.5.

 

4.3 Working Environment Parameters

 

1. working temperature: 5-60℃ (special temperature can be customized);

 

②. Working pressure: ≤0.4MPa.

 

4.4 Operating Parameters

 

1. working mode: pressure type;

 

(2) Operation mode: water flow from bottom to bottom, series (high arsenic content) or parallel;

 

③. Filter material particle size: 0.5-2.5mm;

 

4. Filtration speed: 5m/h;

 

⑤. Operation cycle: 20 days (depending on the quality of raw water, the minimum is not less than 8 hours);

 

Backwash method: water washing, or air water combined backwash;

 

⑦. Backwash time: 10-15min;

 

⑧. Backwash water consumption: 1-3%;

 

⑨. Backwash strength: 18-25l/s·m2;

 

⑩ Regenerated liquid: 2.5-4% sodium hydroxide solution;

 

11. Regeneration time: 10h;

 

(12) Regeneration intensity: 8-10L/m2·s;

 

(13) Washing time: 8-10min.

 

5. Working principle

 

5.1 Process Flow

 

REDOX → Adsorption and ion exchange → repeated regeneration (back wash, suction, replacement, forward wash)

 

5.2 Running Process

 

①. REDOX

 

Studies have shown that the removal effect of iron salt is better than that of aluminum salt, and the removal effect of As(Ⅴ) is obviously better than that of As(Ⅲ), so the treated water is often pre-oxidized in the process of removing arsenic, and the trivalent As(Ⅲ) is oxidized to pentavalent As(Ⅴ).

 

②. Adsorption and ion exchange

 

In general, arsenic removal adsorbents have active molecular sieve, active alumina, bone charcoal and so on. Under the same conditions:

 

a. Active molecular sieve: removal rate of arsenic, 80%; Arsenic removal rate, 95%;

 

b. Activated alumina: removal rate of arsenic, 70%; Removal rate of arsenic pentavalent, 80%;

 

c. Bone charcoal: removal rate of arsenic, 25%; The removal rate of pentavalent arsenic is 50%, which is expensive and easy to cause excessive ammonia nitrogen.

 

In summary, the results show that active molecular sieve is an ideal and reliable material for arsenic removal.

 

③. Repeated regeneration

 

When the effluent reaches a certain amount, the active molecular sieve will be saturated, lose the exchange ability, and must be withdrawn from operation for regeneration. At this time, water is provided by other tanks to ensure continuous water discharge.

 

During regeneration, the molecular sieve is required to be backwashed first to remove impurities such as suspended solids that may be intercepted and loosen the molecular sieve at the same time. Liquid medicine is then injected from the upper part of the tank, and the recycled waste liquid is discharged through the blowdown valve. After the washing, the final washing process is carried out to completely remove the residual liquid in the molecular sieve layer.

 

The system can be controlled manually and automatically. The working state of each tank is successively: operation → regeneration (backwash, suction, replacement, washing) → operation; When the equipment fails, it automatically exits the operation, starts the regeneration program, and automatically puts into operation after the regeneration is finished. In order to ensure the need for production water, the control system prohibits the simultaneous regeneration of two devices.

 

6. Selection description

 

6.1 Equipment Selection

 

1. The demander must provide detailed water quality test report, water quality use, automation requirements, room size and other basic parameters, so that the supplier can provide detailed equipment selection and filter media.

 

2. According to the different water quality can choose a primary or secondary treatment system, according to the water quantity to choose a single or multiple parallel system.

 

(3) The process of defluorination shall be determined according to the following conditions:

 

a. When the arsenic content of raw water is less than 2mg/L, a single-stage treatment system is adopted;

 

b. When the arsenic content is > 2mg/L, the secondary treatment system or the treatment system using reverse osmosis as the main means of arsenic removal is used.

 

6.2 Device Installation

 

1. Provide the relevant operation data of the equipment (such as equipment weight, process flow chart, layout diagram, basic diagram, etc.).

 

2. Calibrate the equipment smoothly, and its error shall not exceed 10mm, so that the equipment can run evenly and stably.

 

③. Fill and smooth the filter material, and install the filter material according to the design index and filter material specifications.

 

(4) Install the supporting facilities of the pipeline valve and other equipment according to the design procedure, and check whether there is leakage. If yes, perform emergency maintenance. If no, perform commissioning.

 

⑤. Filter element and filter material cleaning, open the filter water and drainage valve in turn, clean before operation, until the filter layer cleaning water becomes clear. Check whether the device is running properly.

 

6. open the inlet pipe and control the water intake so that the water intake meets the design flow rate. Take a clean water sample, and open the clean water valve when the fluorine content is less than 1.0mg/L.

 

7. Debugging of backflush pump, close the filter inlet and outlet pipe valve, open the backwash water inlet pipe and backwash outlet pipe valve. When the discharge water from the outlet pipe becomes clear, the recoil ends. Restart and run normally.