Common Problems and Solutions in Water Treatment Process of Waterworks

In the water treatment industry, the waterworks shoulder the important responsibility of supplying water to the city. However, in the process of water treatment, a series of problems are often encountered, such as abnormal flocs in the sedimentation tank, changes in water quality, etc., which directly affect the production efficiency and effluent quality of the water plant. This paper will elaborate on several common problems and their solutions in the water treatment process of waterworks, and illustrate with examples.

Abnormality of floc in 1. sedimentation tank

Problem Description

As an important part of water treatment, the function of sedimentation tank is to precipitate suspended particles and colloidal impurities in water by gravity. However, in the actual operation, the sedimentation tank often appears floc anomalies, such as alum flower floating, too fine, etc., resulting in reduced precipitation effect, sedimentation tank water quality deterioration.

Solutions and Examples

1. The water is rich in gas, causing alum flowers to float up

Example: In a waterworks, a large number of fine particles of alum flowers were found floating on the water surface in the sedimentation tank, forming a layer of suspended alum flowers, while the water quality was significantly deteriorated.

Solution:

Find the gas source: check the water intake, water pump, mixing equipment and other system facilities one by one to find out the leakage point.

Treatment measures: repair the air leakage point found to ensure the tightness of the system; optimize the operation of the water pump to avoid operation under negative pressure conditions.

2. Effects of algae

Example: In the high algae stage, algae blooms in raw water, resulting in alum flower floating serious, sedimentation tank effluent quality decline.

Solution:

Adding algaecide: using algaecide such as copper sulfate to control the growth of algae. Additional measures should be taken for non-sensitive algae.

Enhanced coagulation: increase the dosage of coagulant, or use iron salt, activated silicic acid and other coagulant aids to improve the density of alum and precipitation effect.

Air floatation tank: when conditions permit, the sedimentation tank can be changed into an air floatation tank, and the algae particles can be floated and removed by air bubbles.

Effect of 2. Low Temperature and Low Turbidity on Coagulation Sedimentation Process

Problem Description

Under the condition of low temperature and low turbidity, the physical properties of water change, the hydrolysis of coagulant is difficult, the Brownian motion of particles is weakened, and the chance of collision is reduced, resulting in poor coagulation effect and substandard effluent quality of sedimentation tank.

Solutions and Examples

Example: In a water plant in the north, the water temperature is as low as 0~2°C in winter. Even if the coagulant dosage is increased, the precipitation effect is still not ideal and the effluent is turbid.

Solution:

Increase the dosage of coagulant: increase the dosage of coagulant in order to improve the coagulation effect.

Add coagulant aid: use activated silicic acid and other coagulant aids to improve the density and strength of flocs and speed up the settling speed.

Improve the water temperature: by preheating or adjusting the water source, the water temperature is appropriately increased to improve the coagulation conditions.

Effect of 3. Coagulation Process on Sedimentation Process

Problem Description

As a pretreatment step of sedimentation, the effect of coagulation process directly determines the treatment efficiency of sedimentation tank. Improper control of coagulant type, dosage and hydraulic conditions will lead to abnormal flocs and affect the precipitation effect.

Solutions and Examples

The example shows that the effect of the aluminum salt coagulant used in the treatment of low temperature raw water in a water plant is not good, and the turbidity of the effluent from the sedimentation tank is high.

Solution:

Select the appropriate coagulant: for low temperature water quality, switch to iron salt coagulant, using its better low temperature effect.

Optimize the dosage of coagulant: through the test to determine the better dosage, to avoid excessive or insufficient.

Control hydraulic conditions: reasonably adjust the mixing intensity and residence time to ensure that the coagulant and water are fully mixed, while avoiding the destruction of the generated flocs.

4. other factors

Problem Description

In addition to the above main factors, water quality mutation, unreasonable treatment process design is also an important reason for the precipitation process floc abnormalities.

Solution

Strengthen water quality monitoring: establish a sound water quality monitoring system, detect changes in water quality in time and take measures.

Optimized process design: According to the actual situation of the water plant, the existing process is evaluated and optimized to ensure the stable operation of the system.

Strengthen staff training: regularly conduct professional training for operators to improve their ability to operate equipment and deal with emergencies.

To sum up, the common problems encountered in the water treatment process of waterworks are various, but through scientific and reasonable analysis and countermeasures, the problems can be effectively solved to ensure the quality of water and the safety of water supply.

Focus on water treatment, only for the health of the world! henan elfolk chemical co., ltd. is a professional engaged in polymer flocculant research and development, production and sales of enterprises. The main products are "green water clean" brandPolyaluminium chloride,polymeric ferric sulfateSuch as water purification agent. With an annual output of 10,000 tons, the products are exported to all parts of the country and actively explore the international market. The company will continue to uphold the "integrity, innovation, win-win" business philosophy, to provide customers with quality products and services, to make due contributions to society.