The factors that affect the flocculation effect are multifaceted, mainly including the type, concentration, dosage of flocculants, stirring conditions during coagulation treatment, pH value, temperature and its changes, etc. Different countermeasures should be adopted according to specific situations.

1. Types and dosages of flocculants: Different flocculants should be selected for different types of wastewater. The dosage of flocculant greatly affects the flocculation effect, and both excess and deficiency will lead to the dispersion and stability of sol particles. Therefore, the dosage should be determined through experiments.

2. The influence of stirring and reaction time: After adding a certain amount of flocculant to the wastewater, the first step is to make the flocculant quickly and evenly diffuse into the water. After the flocculant is fully dissolved, the generated colloids come into contact with the existing colloids and suspended solids in water, forming numerous tiny alum flowers. This process is also known as mixing. The mixing process requires the water flow to generate intense turbulence, allowing the agent to be fully mixed with the water in a relatively fast time. The mixing time generally requires a few seconds to 2 minutes.

3. The influence of pH value and alkalinity: pH value has a significant impact on the operation of flocculants, so when flocculation treatment is carried out on wastewater, it is necessary to fully pay attention to its effective pH value range. Organic polymer flocculants have less strict restrictions on pH values, but a lower pH value has a significant impact on the flocculation effect of the flocculant. Inorganic flocculants are sensitive to the pH value of wastewater. Due to the continuous production of hydrogen ions in the hydrolysis reaction of flocculants, it is necessary to maintain sufficient hydrolysis reaction.

4. The influence of temperature: Water temperature also affects the flocculation effect. The hydrolysis reaction of inorganic flocculants is an endothermic reaction. When the water temperature is low, it is not conducive to the hydrolysis of flocculants, and the viscosity of water is also related to the water temperature. If the water temperature is low, the viscosity of water is high, which weakens the Brownian motion of water molecules and is not conducive to the destabilization and flocculation of colloidal pollutants in water, making the formation of flocculants difficult. Therefore, the amount of flocculant used in winter is higher than in summer. An increase in temperature is conducive to the collision between colloids and the formation of coagulation, but temperatures exceeding 90 degrees Celsius can easily cause the flocculant to age or decompose, resulting in insoluble substances and ultimately reducing the flocculation effect.