The adsorption life of activated carbon is generally related to factors such as the quality of activated carbon itself, the usage environment of activated carbon, and the properties of the substances adsorbed by activated carbon.
Firstly, the properties of activated carbon adsorbents: the larger the surface area of activated carbon, the stronger its adsorption capacity;
Activated carbon is a non-polar molecule that easily adsorbs non-polar or very low polarity adsorbates;
The size of activated carbon adsorbent particles, modification and distribution of pores, and surface chemical properties also have a significant impact on adsorption.
Furthermore, the properties of activated carbon adsorbate depend on the solubility, surface free energy, polarity, size and unsaturation of adsorbate molecules, and concentration of adsorbate.
The pH value of wastewater: Activated carbon generally has a higher adsorption rate in acidic solutions than in alkaline solutions. The pH value of wastewater will affect the state and solubility of activated carbon adsorbates in water, thereby affecting the adsorption efficiency of activated carbon.
The effective period of activated carbon is the lifespan of activated carbon, and the lifespan of activated carbon has two meanings.
1. Store mission. It refers to the storage life of activated carbon, which means how long it can be stored in a storage room without opening.
2. Service life. It refers to the service life of activated carbon, how long it can be used in actual use with continuous filtration.
The storage life of activated carbon is generally 3-5 years, which mainly depends on the storage environment, temperature, humidity, and product quality of the activated carbon. If the sealing of activated carbon packaging is done well, activated carbon can be stored for 3-5 years. Generally speaking, in theory, the storage life of activated carbon is unlimited. However, in practice, due to objective reasons, an ideal storage environment does not exist. Therefore, the storage life of activated carbon should be set at 6 years. However, it should also be determined based on the actual situation of one's warehouse and the degree of sealing of activated carbon packaging.
The service life of activated carbon is not measured by usage time, but by the mass of adsorbate. It depends on how you use it and how much filtering is required. Suck up all the dirt, when it's saturated, it's at the end of its service life, it looks very new and useless. If there is a lot of filtering, it can be saturated in a day. In very clean conditions, it should not exceed one year.
So how to determine if coconut shell activated carbon has reached its service life? Should it be replaced?
Generally, in liquid-phase adsorption, which is the process of sewage treatment, it is possible to observe whether there is a change in the effluent water quality. If there is no change in the influent water quality, but the effluent water quality deviates significantly from before, it proves that coconut shell activated carbon should be replaced. The service life of coconut shell activated carbon varies in different sewage treatments and processes, and should be based on the actual on-site results.
Another aspect is gas-phase adsorption. It is easy to determine whether coconut shell activated carbon is saturated during the gas-phase adsorption process. Generally, coconut shell activated carbon has well-developed micropores, which can adsorb some small molecules of toxic and harmful gases during gas-phase adsorption. Based on the concentration of the inlet gas and the concentration of the outlet gas after adsorption, it can be determined whether the service life of coconut shell activated carbon has expired and whether it should be replaced.
Overall, the service life of coconut shell activated carbon is longer than other activated carbons, but it is still necessary to determine whether coconut shell activated carbon needs to be replaced or reach its service life based on its specific use and site.
https://www.naturecarbon.com/coconut-shell-activated-carbon/
