As bio filter media, whether it is salt, oxide or other, all belong to polar substances. When they are dispersed in organic polymer resins with very small polarities, the compatibility between the two is easily caused by the difference in polarity. This is not good, thereby adversely affecting the processing properties of the filled plastic and the use properties of the product. Therefore, it is necessary to deal with the surface of bio filter media and to make its surface polarity close to the filled polymer resin through chemical reaction or physical method, so as to improve its compatibility.
The surface treatment of bio filter media can be divided into two major categories. One is surface physical effects, including surface coating and surface adsorption; and the other is surface chemical effects, including surface substitution, hydrolysis, polymerization, and grafting. The combination of the former filler surface with the treatment agent is the intermolecular force, and the latter agent surface is combined with the treatment agent through the chemical reaction.
In general, if the specific surface area of the plastic Mbbr bio filter media is large, the surface functional group has high reactivity, high density, and the selected surface treatment agent and the surface functional group of the filler have high reactivity, the space steric hindrance is small, and the surface treatment temperature is appropriate, the surface treatment of the bio filter media is chemical. The reaction is dominated, whereas the physical effect is dominant.
In fact, most of the mechanisms for the surface treatment of plastic Mbbr bio filter media exist at the same time. For example, if a surfactant is used, a long-chain organic acid salt, a high-boiling chain hydrocarbon, etc. are used as the surface treatment agent, the main treatment is It is through the physical application of surface coating or surface adsorption. When a coupling agent, a long-chain organic acid chloride or oxyphosphoryl chloride is used, a metal organic alkoxide compound, an epoxy compound, or the like is a surface treatment agent, the treatment is mainly performed by surface chemical action.
In the actual operation process, people can choose different surface treatment methods for bio filter media according to the different processing equipment and processing procedures used, such as dry method, wet method, gas phase method, processing method and other surface modification methods. and many more.