【Weekly Topic】- What types of fillers are used in contact oxidation?

Three-dimensional elastic fillers, soft fillers, combined fillers, semi-soft fillers,

There are four main categories: semi-soft packing, combined packing (combined double-ring packing, combined porous ring packing), elastic three-dimensional packing, and suspended packing (multi-faceted hollow sphere packing, internally mounted floating ball packing)

This post was last edited by hesonchang214 on 2015-10-14 09:33. Common types of packing include vertically arranged plastic honeycomb inclined tube packing, plastic regular mesh packing, and elastic packing. Plastic honeycomb tube fillers feature a large specific surface area and a high biomass yield per liter of filler, which has led to their widespread use. However, since the individual honeycomb tubes do not communicate with each other, sludge buildup can occur easily when the load is high or water supply is uneven, thus limiting their application. The plastic regular mesh packing has a mesh structure, allowing water flow to connect in all directions; this is equivalent to multiple redistribution processes, which effectively prevents uneven water distribution. The downside is that the surface of this filler is relatively smooth, making it difficult for organisms to form a biofilm on it. Elastic packing is composed of bundles of fibrous fibers tied to fiber ropes, offering a large surface area for biofilm formation; it has advantages such as resistance to clogging, low cost, and light weight. The elastic filler consists of several high-quality varieties from the polyolefin and polyamide families that are resistant to corrosion, heat, and aging. These materials are mixed with additives such as those that enhance hydrophilicity, adsorption capacity, and resistance to heat and oxygen. A special drawing process is used to create filaments, which are then fixed onto a corrosion-resistant, high-strength core strand. Thanks to the careful selection of materials and optimal processing techniques, the filaments arrange themselves in a uniform, three-dimensional pattern. This results in a hanging-type, three-dimensional elastic filler. Within its effective range, this filler can spread out evenly in all directions, allowing for thorough mixing, contact, and exchange between air, water, and biofilms. The biofilms not only attach evenly to each filament, maintaining good activity and the ability to adjust their structure, but they also gain an increasingly large surface area over time, enabling efficient metabolism. These characteristics make this filler superior to other fillers available in China. Features of elastic packing: Compared with rigid honeycomb packing, elastic packing has greater variability in its pores and does not get clogged ； Compared to soft-type fillers, it has a longer service life and does not cause clumping ； Compared to semi-soft fillers, it has a larger surface area, rapid biofilm formation, and lower cost. Therefore, this filler can be confirmed to be the fourth-generation, high-efficiency and energy-saving innovative filler, following various rigid, soft, and semi-soft fillers. Specifications of elastic packing: Φ150mm, Φ160mm, Φ180mm, Φ200mm. Uses of elastic packing: Widely used as biological packing in biological contact oxidation tanks and hydrolysis-acidification tanks.

What was said upstairs is very comprehensive; during operation, be aware of the possibility that an excessive thickness of biofilm could cause the packing to deform.

Our company once used elastic packing, which later collapsed due to the accumulation of microorganisms

There is currently a type of MBBR packing that performs well, overcoming the problem of packing collapse.

MBBR represents a transition from a fixed-bed to a fluidized-bed system.