How to determine the appropriate dosage of polyaluminum chloride?

How to determine the appropriate dosage of polyaluminum chloride?

Polyaluminum chloride (PAC), as a common water purification agent, plays an important role in the water treatment process. However, in order to ensure the best purification effect of water quality, it is important to determine the dosage of PAC reasonably. This article details how to determine the appropriate PAC dosage.

First, small test dissolve PAC to preliminarily determine the dosage range

Before using PAC for water treatment, a small test is first needed to determine the initial dosage range. The purpose of the pilot test is to observe the effect of water purification under different dosages by simulating the actual treatment process, so as to find the initial estimate of the best dosages.

Second, on the machine operation to adjust the PAC dosage ratio

After the completion of the pilot test, it is necessary to apply the PAC dosage ratio to the actual processing system according to the pilot test results. When the machine is running, the dosage ratio of PAC should be adjusted according to the weight ratio of solid PAC and water, and the general recommendation is between 1:9 and 1:15. If it is liquid PAC, it is recommended to use a ratio of 1:2 to 1:5 for mixed dissolution.It should be noted that the concentration of PAC solution has a significant effect on its dosing effect. When the alumina content is less than 1%, the solution is easy to hydrolyze, resulting in a decrease in purification effect. When the concentration is too high, it is not easy to evenly add, and it will also affect the purification effect. Therefore, when running on the machine, you should pay close attention to the concentration change of the solution and adjust it in time.

3. Observe the precipitation effect and adjust the dosage

In the process of dosing on the machine, it is necessary to closely observe the precipitation effect in the sedimentation tank, and adjust the dosage of PAC according to the actual situation. If there are few alum flowers and large residual turbidity in the sedimentation tank, it indicates that the dosage is insufficient. If the alum flower is too large and upturned, the residual turbidity is high, it indicates that the dosage is too large. At this time, the dosage of PAC should be adjusted in time to achieve the best purification effect.

Four, multiple experiments to determine the best dosage

Since water quality and PAC performance may vary over time and with environmental conditions, it is recommended that multiple experiments be performed to determine the optimal dosage of PAC. In the course of the experiment, the best dosage can be selected by observing the precipitation rate and the dosage of the drug used. At the same time, it is also necessary to convert the experimental results into the daily dosage of the drug consumption of the unit of use, so as to facilitate the subsequent practical application.

V. Summary

Determining the appropriate PAC dosage is a process that takes into account many factors. The optimal dosage can be gradually approximated by small test dissolution of PAC, adjustment of dosage ratio by running on the machine, adjustment of dosage by observing precipitation effect and determination of optimal dosage by several experiments. In practical applications, it is also necessary to flexibly adjust according to the actual situation of the site to ensure the best purification effect of water quality.