The Role of MBBR Biological Fillers in Wastewater Treatment

MBBR biological packing, as an innovative wastewater treatment technology, significantly improves the efficiency and stability of wastewater treatment by combining the advantages of biofilm and activated sludge processes. Its core lies in using suspended fillers with high specific surface area as microbial carriers, degrading pollutants through the metabolic action of biofilms, and becoming an important solution for the treatment of municipal wastewater, industrial wastewater, and special scenarios (such as hospital wastewater)

1、Working principle of MBBR biological filler

MBBR fillers create an ideal carrier for the attachment and biofilm formation of microorganisms such as bacteria, nitrifying bacteria, and denitrifying bacteria by providing a large specific surface area (300-1000 m ²/m ³). When sewage flows through the reactor, the biofilm efficiently removes pollutants such as organic matter (COD, BOD), ammonia nitrogen (NH3-N), total nitrogen (TN), and phosphorus (TP) through adsorption, oxidation, and decomposition. For example, Leishenshan Hospital adopts the MBBR process to achieve efficient nitrogen and phosphorus removal of medical wastewater through biofilm enrichment on the surface of the packing material, and the effluent is stable and meets the standard. At the same time, the density of the packing material is close to that of water (0.94-0.97 g/cm ³), forming a dynamic fluidized state under aeration or stirring. This movement not only enhances the mass transfer efficiency between pollutants and biofilms, but also cuts bubbles, prolongs oxygen residence time, significantly improves oxygen utilization efficiency (reduces aeration energy consumption by more than 10%), thus forming a synergistic mechanism of "biofilm degradation fluidized mass transfer" and comprehensively improving sewage treatment efficiency

2、The Three Core Functions of MBBR Biological Fillers

MBBR fillers, with their ultra-high specific surface area (up to tens of times that of traditional activated sludge processes), can load high concentration biofilms of 10-30 g/L, significantly improving pollutant degradation efficiency. The anoxic/anaerobic microenvironment formed inside the packing promotes the synergistic symbiosis of heterotrophic bacteria, nitrifying bacteria, and denitrifying bacteria, constructs a multi microbial metabolic network, and enhances denitrification and phosphorus removal functions. In addition, the high stability of the biofilm endows the system with excellent shock resistance: it can still operate stably under influent COD fluctuations, low temperatures (such as 4 ℃), or high salt conditions (such as the case of Chifeng Wastewater Treatment Plant in Inner Mongolia); At the same time, the flow state of the packing material can physically break down filamentous bacteria, suppress the risk of sludge expansion, and reduce the remaining sludge production to 50% of the activated sludge process. In terms of process adaptation, MBBR can be flexibly added to the aerobic/anoxic/anaerobic sections of processes such as A/O, SBR, MBR, etc., and can be rapidly expanded by adjusting the packing filling rate (≤ 60% tank capacity), which can meet the upgrading needs of old sewage treatment plants without the need for civil engineering renovation, highlighting the technical advantages of "high efficiency, stability, and flexibility" in a trinity.

3.Application advantages and typical cases

In the field of municipal sewage treatment, MBBR technology significantly improves the efficiency of renovation by adding biological fillers. A typical case, such as a sewage plant, achieved a removal rate of 98% for ammonia nitrogen and over 90% for COD, while reducing the footprint by 30%, becoming the core solution for upgrading renovation. For industrial wastewater, its application presents differentiated advantages: it exhibits strong adaptability to high concentration organic wastewater such as meat processing (COD removal rate of 50-75%) and petrochemicals (COD removal rate ≥ 90%); At the same time, relying on the ability of biofilm to enrich and degrade complex pollutants, it can effectively treat difficult to degrade wastewater containing drug residues, dyes, etc. In special scenarios, MBBR highlights its emergency reliability - Leishenshan Hospital has successfully treated highly infectious medical wastewater and ensured the biological safety of the effluent through the intensive process of "regulating tank MBBR tank sedimentation", verifying its technical backup capability in public health emergencies

4. Challenge response and future evolution path

Despite the challenges of packing accumulation/loss and long-term operation and maintenance faced by MBBR technology, physical losses can be effectively controlled by optimizing screen design (such as stainless steel interception nets) and aeration layout (adding blowback aeration tubes); Cooperate with regular biofilm cleaning (high-pressure water gun or chemical method) and packing wear monitoring (designed for a lifespan of 30 years) to ensure long-term stable operation of the system. Facing future development, technological innovation focuses on two major directions: first, developing low temperature resistant and UV resistant modified fillers (such as polyurethane foam) to reduce the risk of microplastics; second, achieving intelligent and precise regulation of aeration/reflux through Internet of Things technology; At the application level, it extends to decentralized treatment (rural sewage, river treatment) and deep nitrogen and phosphorus removal (coupled with anaerobic ammonia oxidation, electrochemical technology) to support high standard discharge requirements such as Class III water. With the breakthrough of materials science and intelligent control technology, MBBR bio fillers will continue to release the advantages of "high efficiency, flexibility, and economy", providing sustainable solutions for water environment governance.