Determine whether the activated carbon in the activated carbon adsorption box needs to be replaced.

To determine whether the activated carbon in the activated carbon adsorption box needs to be replaced, you can start with the following aspects:
Visual observation method
Color change: Under normal circumstances, activated carbon is black. If the color is found to be significantly lighter during use, especially the surface color is gradually lighter, it may mean that it has absorbed a large number of impurities, and the adsorption capacity has decreased. For example, when treating organic waste gas, after the colored substances in the waste gas are adsorbed, the color of activated carbon may change due to the increase in adsorption amount.
Shape change: After the adsorption of a large number of substances, activated carbon may change shape due to the influence of adsorbed substances. For example, when dealing with humid gases, too much water is absorbed, which may cause activated carbon particles to expand, deform, and even break and pulverize, which may be a signal that needs to be replaced.
Performance testing method
Adsorption efficiency measurement
Gas detection: For the activated carbon adsorption box that treats exhaust gas, professional gas detection equipment can be used to detect the concentration of pollutants in the inlet and outlet gas of the adsorption box. If the import concentration is unchanged, but the export concentration is significantly increased and exceeds the emission standard or fails to achieve the expected treatment effect, it indicates that the adsorption capacity of activated carbon is reduced and may need to be replaced. For example, in the treatment of benzene series waste gas, when the export benzene series concentration exceeds the specified emission standards, the activated carbon should be considered for replacement.
Water quality testing: For the activated carbon adsorption box that treats wastewater, the water quality indicators of incoming and outgoing water can be detected, such as chemical oxygen demand (COD), chroma, heavy metal ion concentration, etc. If the effluent water quality deteriorates, the indicators increase significantly, indicating that the adsorption performance of activated carbon is reduced, and needs to be replaced.
Pressure drop detection: During the operation of the activated carbon adsorption box, the status of activated carbon can be judged by observing the change of pressure drop. With the increase of activated carbon adsorption, the resistance in the adsorption box will gradually increase, and the pressure drop will also increase accordingly. When the pressure drop exceeds the normal operating range, it may mean that the activated carbon has been blocked or saturated by adsorption and needs to be replaced or treated.
Running time judgment method
Reference experience time: According to the use of activated carbon experience and manufacturer's recommendations, determine the approximate replacement cycle. In general, under normal working conditions, the service life of activated carbon ranges from 3 months to 1 year. For example, when dealing with moderate concentrations of organic waste gas, if ordinary granular activated carbon is used, it may need to be replaced after about 6 months of operation.
Cumulative running time: Record the cumulative running time of the activated carbon adsorption box, combined with the amount and nature of pollutants treated, and comprehensively determine whether it needs to be replaced. If under the same operating conditions, the cumulative running time reaches or exceeds the previous time to replace the activated carbon, even if the current adsorption effect has not decreased significantly, the activated carbon should be considered for detection or replacement to ensure the stability of the adsorption effect.
Professional analysis method
Thermogravimetric analysis: The activated carbon sample is analyzed by a thermogravimetric analyzer to measure the change in activated carbon quality at different temperatures. If in the process of thermogravimetric analysis, the mass loss is found to be significantly lower than the new activated carbon or standard value, it indicates that the adsorption site inside the activated carbon has been occupied by a large number of, the adsorption capacity is reduced, and it needs to be replaced.
Specific surface area analysis: The specific surface area analyzer is used to determine the specific surface area of activated carbon. The specific surface area is an important indicator to measure the adsorption capacity of activated carbon. When the specific surface area of activated carbon drops to a certain extent, it indicates that its adsorption performance has been greatly reduced, and the activated carbon should be replaced at this time.