MBR wastewater treatment equipment

Overview of Wastewater Treatment Equipment

Wastewater treatment equipment employing membrane bioreactor (MBR) technology represents a novel process that integrates biological treatment with membrane separation. It replaces the conventional secondary sedimentation tank, enabling highly efficient solid–liquid separation to produce stable reclaimed water suitable for direct reuse. Moreover, it maintains a high biomass concentration within the bioreactor, generates minimal excess sludge, and effectively removes ammonia nitrogen. The effluent exhibits nearly zero suspended solids and turbidity, with substantial reductions in bacteria and viruses. Additionally, the system features low energy consumption and a compact footprint.

Scope of Application for Wastewater Treatment Equipment

Suitable for treating domestic wastewater and similar industrial organic effluents—such as those from the textile, brewing, papermaking, leather‑tanning, food processing, and chemical industries—in residential communities, office buildings, shopping malls, hotels, restaurants, government agencies, schools, military units, factories, and other facilities.

Wastewater Treatment Equipment Process Flow

Raw water → Grille → Equalization tank → Lift pump → Bioreactor → Circulation pump → Membrane module → Disinfection unit → Reclaimed water storage tank → Reclaimed water distribution system

Process Flow Description of Wastewater Treatment Equipment

After passing through the screen, the wastewater enters the equalization basin and is then pumped into the bioreactor. The PLC controller activates the aeration system to supply oxygen. The effluent from the bioreactor is recirculated by a pump to the membrane separation unit, while the concentrated brine is returned to the equalization basin. The permeate undergoes rapid mixing‑based chlorination disinfection (using sodium hypochlorite, bleaching powder, or chlorine tablets) before being transferred to the reclaimed water storage tank. A backwash pump uses treated water from the cleaning tank to perform backwashing of the membrane filtration equipment, with the backwash effluent returning to the equalization basin. The lift pump is automatically started or stopped based on the water level in the bioreactor. Filtration and backwashing operations in the membrane unit can be controlled either automatically or manually. When chemical cleaning is required, the influent valve and the wastewater recirculation valve are closed, the chemical cleaning valve and the chemical recirculation valve are opened, and the chemical circulation pump is started to carry out the chemical cleaning process.

This integrated bioreactor is controlled by a programmable logic controller (PLC) and features the following functions:

• The membrane bioreactor employs an automated control system throughout the entire process, significantly reducing operating and management costs.
• When the water level in the bioreactor reaches the high‑level threshold, the lift pump stops; when the water level drops to the low‑level threshold, the lift pump automatically starts.
• Automatically start and stop the circulation pump based on the water level in the reclaimed water storage tank.
• Automatically starts and stops the dosing pump, with the dosing volume adjustable as needed.
• Automatically initiates membrane cleaning and disinfection procedures.
• The motor is equipped with overcurrent and overload protection.

Existing reclaimed‑water reuse projects commonly suffer from poor treatment performance, high operating costs, and large land footprints, with treatment facilities often failing to operate as intended. Consequently, China’s urban reclaimed‑water treatment sector urgently requires the development of cost‑effective, efficient, and practical treatment technologies and associated equipment.

Characteristics of the MBR Process in Wastewater Treatment Equipment

Membrane biotechnology for wastewater treatment, when applied to wastewater reuse, exhibits the following characteristics:

• It can efficiently perform solid–liquid separation, effectively separating suspended solids, colloidal substances, and microbial biomass lost from biological units from the treated effluent. The separation process is simple, requires a small footprint, and produces high-quality effluent that can typically be reused without the need for tertiary treatment.
• It enables the biomass in the biological treatment unit to be maintained at a high concentration, thereby significantly increasing the volumetric loading. Meanwhile, the high efficiency of membrane separation substantially shortens the hydraulic retention time of the treatment unit, correspondingly reducing the land footprint of the bioreactor.
• By preventing the loss of diverse microbial communities, it promotes the growth of slow-growing bacteria (such as nitrifying bacteria), thereby ensuring the smooth progression of various metabolic processes within the system.
• It prolongs the residence time of certain recalcitrant macromolecular organic compounds, thereby facilitating their degradation.
• 5Like other filtration and separation technologies, membrane treatment processes experience fouling of the membrane—acting as a filtration medium—over prolonged operation, leading to a gradual decline in permeate flux. Effective backwashing and chemical cleaning can mitigate this flux decline and help maintain the MBR system’s service life.
• When applied to municipal wastewater treatment, MBR technology, with its simple process and convenient operation, enables fully automated operation and management.