Dedicated Biological Treatment Technology for TMAH Wastewater (WH-TMAH)

Process Overview

Tetramethylammonium hydroxide (TMAH) wastewater is a highly toxic, refractory nitrogen-containing organic wastewater characterized by strong biological inhibition, high organic nitrogen content and difficult TOC degradation. Conventional biological systems struggle to treat it directly and are prone to microbial poisoning and loss of treatment efficiency. Designed to match the specific characteristics of TMAH wastewater, this process adopts an integrated solution combining PBR continuous-flow biological detoxification and degradation with combined A/O advanced treatment. It efficiently achieves wastewater detoxification, TOC removal and the ammonification of organic nitrogen, ultimately ensuring stable compliant discharge, and is well suited to industrial-scale continuous treatment scenarios.

Reference Raw Water Quality Parameters

Process Flow

Three Core Treatment Units

Pretreatment Unit (pH Adjustment + Homogenization Dilution)

• The collected TMAH waste liquid is subjected to precise pH adjustment, bringing the wastewater pH into the neutral range (6.5–7.5) and eliminating the inhibitory effect of an extremely acidic or alkaline environment on the downstream biological cultures.
• Once pH adjustment is complete, the wastewater is diluted with clean water at a fixed ratio to balance the wastewater concentration and reduce its toxic load, weakening the biological inhibition caused by high-concentration organic matter and creating a stable, suitable reaction environment for the subsequent biological reactions.

PBR Continuous-Flow Biological Detoxification Unit

• The homogenized wastewater from pretreatment enters the PBR continuous-flow biological system, where dedicated detoxification functional strains for TMAH wastewater are dosed. Developed through targeted acclimation and cultivation, these dedicated strains tolerate the toxicity of characteristic TMAH pollutants and possess a dedicated capability to degrade and convert the refractory organic components and nitrogen-containing pollutants in the wastewater.

This unit delivers three core treatment outcomes:

• Efficient degradation of Total Organic Carbon (TOC) in the water, substantially reducing the total load of organic pollutants.
• Completion of efficient organic nitrogen ammonification, converting complex macromolecular organic nitrogen into ammoniacal nitrogen; this achieves harmless conversion of the nitrogen form and matches the requirements of the subsequent nitrogen removal process.
• Continuous degradation of toxic substances in the water, significantly raising the wastewater biological toxicity indicator N-EC50, fully eliminating the biological toxicity of the wastewater and the inhibitory effect of the water on microorganisms, and completing the core step of harmless detoxification.

A/O Advanced Treatment Unit

• The low-toxicity, low-load wastewater that has undergone detoxification and degradation in the PBR system flows by gravity into the A/O biological treatment system, where it is homogenized and mixed with other production wastewater from the plant.
• Relying on the mature anoxic denitrification and aerobic nitrification degradation mechanisms of the A/O system, the unit achieves deep removal of residual trace organic matter, ammonia nitrogen, total nitrogen and other pollutants, further optimizing the effluent quality, closing the remaining gaps in pollutant treatment and ensuring that all water quality indicators fully meet the standards.

Four Key Technical Advantages

Strong Dedicated Detoxification Adaptability

• Equipped with dedicated TMAH-detoxifying bacterial strains, the process specifically overcomes the challenge of biological toxicity in the wastewater. It resolves the long-standing industry pain points of conventional biological systems being unable to operate and of microbial cultures losing activity, delivering detoxification performance that is both stable and controllable.

High Pollutant Removal Efficiency

• Efficient TOC degradation, ammonification of most organic nitrogen and complete elimination of water toxicity are achieved simultaneously, purifying the water across multiple dimensions with a high treatment load and a fast reaction rate.

Strong Process Continuity

• With its PBR continuous-flow process design, the system accommodates industrial continuous influent and continuous treatment conditions, requires no intermittent standing, operates with a high degree of automation and is easy to operate and maintain.

Excellent System Compatibility

• The combined process of pretreatment, dedicated biological treatment and conventional A/O can be seamlessly integrated with the existing plant wastewater treatment system without large-scale equipment modification, offering a low retrofit cost and strong implementability.

Treatment Performance

After treatment by this complete process package, the biological toxicity of the TMAH wastewater is completely eliminated, the N-EC50 indicator is significantly improved, and the water no longer exhibits biological inhibition. Core pollutants such as TOC and organic nitrogen are efficiently removed; following advanced treatment in the A/O system, the effluent quality can stably meet industrial wastewater discharge standards, achieving compliant discharge.

Three Core Treatment Units

Pretreatment Unit (pH Adjustment + Homogenization Dilution)

• The collected TMAH waste liquid is subjected to precise pH adjustment, bringing the wastewater pH into the neutral range (6.5–7.5) and eliminating the inhibitory effect of an extremely acidic or alkaline environment on the downstream biological cultures.
• Once pH adjustment is complete, the wastewater is diluted with clean water at a fixed ratio to balance the wastewater concentration and reduce its toxic load, weakening the biological inhibition caused by high-concentration organic matter and creating a stable, suitable reaction environment for the subsequent biological reactions.

PBR Continuous-Flow Biological Detoxification Unit

• The homogenized wastewater from pretreatment enters the PBR continuous-flow biological system, where dedicated detoxification functional strains for TMAH wastewater are dosed. Developed through targeted acclimation and cultivation, these dedicated strains tolerate the toxicity of characteristic TMAH pollutants and possess a dedicated capability to degrade and convert the refractory organic components and nitrogen-containing pollutants in the wastewater.

This unit delivers three core treatment outcomes:

• Efficient degradation of Total Organic Carbon (TOC) in the water, substantially reducing the total load of organic pollutants.
• Completion of efficient organic nitrogen ammonification, converting complex macromolecular organic nitrogen into ammoniacal nitrogen; this achieves harmless conversion of the nitrogen form and matches the requirements of the subsequent nitrogen removal process.
• Continuous degradation of toxic substances in the water, significantly raising the wastewater biological toxicity indicator N-EC50, fully eliminating the biological toxicity of the wastewater and the inhibitory effect of the water on microorganisms, and completing the core step of harmless detoxification.

A/O Advanced Treatment Unit

• The low-toxicity, low-load wastewater that has undergone detoxification and degradation in the PBR system flows by gravity into the A/O biological treatment system, where it is homogenized and mixed with other production wastewater from the plant.
• Relying on the mature anoxic denitrification and aerobic nitrification degradation mechanisms of the A/O system, the unit achieves deep removal of residual trace organic matter, ammonia nitrogen, total nitrogen and other pollutants, further optimizing the effluent quality, closing the remaining gaps in pollutant treatment and ensuring that all water quality indicators fully meet the standards.

Four Key Technical Advantages

Strong Dedicated Detoxification Adaptability

• Equipped with dedicated TMAH-detoxifying bacterial strains, the process specifically overcomes the challenge of biological toxicity in the wastewater. It resolves the long-standing industry pain points of conventional biological systems being unable to operate and of microbial cultures losing activity, delivering detoxification performance that is both stable and controllable.

High Pollutant Removal Efficiency

• Efficient TOC degradation, ammonification of most organic nitrogen and complete elimination of water toxicity are achieved simultaneously, purifying the water across multiple dimensions with a high treatment load and a fast reaction rate.

Strong Process Continuity

• With its PBR continuous-flow process design, the system accommodates industrial continuous influent and continuous treatment conditions, requires no intermittent standing, operates with a high degree of automation and is easy to operate and maintain.

Excellent System Compatibility

• The combined process of pretreatment, dedicated biological treatment and conventional A/O can be seamlessly integrated with the existing plant wastewater treatment system without large-scale equipment modification, offering a low retrofit cost and strong implementability.

Treatment Performance

After treatment by this complete process package, the biological toxicity of the TMAH wastewater is completely eliminated, the N-EC50 indicator is significantly improved, and the water no longer exhibits biological inhibition. Core pollutants such as TOC and organic nitrogen are efficiently removed; following advanced treatment in the A/O system, the effluent quality can stably meet industrial wastewater discharge standards, achieving compliant discharge.