By: Sunny Wu（sunny7@juntaiplastic.com）
Post Date: June.22, 2022
Post Tags: How to choose biofilm carrier?
1. Mechanical Strength
In most biofilm processes there are different strengths of hydraulic shear and frictional collisions between carriers, so the biofilm carrier must have the mechanical strength corresponding to the biotechnology used. If the biofilm carriers themselves do not have a certain mechanical strength, they will inevitably break down to varying degrees in the reactor and lose their functionality, with the direct consequence of affecting the effluent quality.
Therefore, the first step in selecting the biofilm carrier is to consider the mechanical strength of the carrier, which is generally good for polymeric biofilm carriers.
2. Physical Form
The main point here is the specific surface area of the filter media or carrier. The specific surface area is the percentage of space held in the unit volume of the filter media, and the surface of the carrier is the part where the biofilm is formed and fixed.
3. Biological, chemical and thermodynamic stability
Biofilm will produce various metabolites in the process of metabolism, and these metabolites will have corrosive effect on the carrier, so metal, easily degradable and corrosive materials should be avoided as the carrier for microbial fixation.
4. Void rate
The void ratio is the percentage of space held in the unit volume of filter media.
The space between the filter media is the part of biofilm, sewage and air contact, is an important part of oxygen supply and oxygen transfer, a larger void ratio is conducive to the successful operation of biofilm reactor, filter media specific surface area and porosity of the two contradictory aspects, high specific surface area, the void ratio is low, the void ratio should not be too high or too low, to moderate is good.
5.Specific gravity
The specific gravity of the biofilm carrier is a factor that must be considered for the operation of the suspended carrier biofilm system, i.e. fluidized bed. If the specific gravity of the carrier is too large, the carrier will be difficult to suspend or the energy consumption will be too high; if the specific gravity of the carrier is too small, it will not be easy to maintain a certain flow state of the carrier in the reactor.
6. Effect on biofilm activity
The biofilm carrier must be harmless and non-inhibitory to the fixed microorganism. If the fixed cell or enzyme technology is applied to produce various biological products, the carrier itself must be harmless to human organism.
7. Reusability
From the economic point of view, biofilm carriers should be reusable, and from the engineering point of view, disposable materials should be avoided as carriers in wastewater biological treatment technology.
8.Price
When choosing biofilm carriers, price and performance should be balanced, and when it does not affect the design or research objectives, it is generally appropriate to use inexpensive carriers. For example, inorganic materials such as gravel, coke, cinder, etc. should be sourced locally as much as possible to facilitate processing and transportation.