Background The European Union's Water Framework Directive (WFD) states that its “ultimate aim is to achieve the elimination of priority hazardous substances and contribute to achieving concentrations in the environment near background values for naturally occurring substances”. Some of these substances are synthetic organic chemicals that come from industrial activities. A large amount of wastewater containing tetramethylammonium hydroxide (TMAH) is generated each year in Europe by electronics’ and semiconductor manufacturers. Because of the toxic properties of TMAH, the current limit of 7 milligrammes per litre (mg/L) is considered too high for adequate protection of aquatic ecosystems. Industrial streams containing TMAH require further treatment before they can be discharged into drainage systems. Current approaches to treatment of wastewater containing TMAH entail high costs for companies and negative environmental impacts. Objectives The LIFE BITMAPS project will establish a pilot plant that will demonstrate a new and never-before attempted process for the treatment of effluents from electronics and semiconductor manufacturing. The project will contribute to the implementation of the WFD by introducing more efficient treatment technologies that will help reduce TMAH pollution at source. By recycling wastewater, it will also demonstrate the application in practice of the circular economy priority of water reuse and savings in industrial processes. Moreover, in proposing a more efficient, effective and innovative solution for industrial wastewater treatment, the project will also contribute to one of the priority areas of the European Innovation Partnership on Water. The project's specific objectives are to: 1. Design, construct, and validate a pilot plant for treatment of effluent from electronics and semiconductor manufacturing that contains photoresist/TMAH (PR/TMAH), ammonium fluoride solution, and nitric, acetic and hydrofluoric mixed solutions; 2. Demonstrate the use of microorganisms to facilitate TMAH biodegradation; 3. Demonstrate the financial viability of the process using a life-cycle costing method; 4. Demonstrate more-efficient water management and evaluate the reuse of treated wastewater in the industrial plant; 5. Increase awareness of environmental issues among electronics and semiconductor manufacturers, influencing industrial investments in innovative and safer technologies. Expected results: Demonstrate biodegradation of PR/TMAH with an overall efficiency target of 99%; Demonstrate reduction of the TMAH level in wastewater by a factor of almost 20 (from 7 mg/L to 0.4 mg/L); Treat at least 500 cubic metres/year of wastewater containing PR/TMAH, 20 m3/year of ammonium fluoride and 5 tonnes/year of acid mixture; Show a reduction in site water consumption from 6 000 m3/year to 1 500 m3/year; Realise operational savings from a 100% reduction in TMAH waste disposal costs, and a halving of the cost of reagents; and Propose new quality standards and guidelines for wastewater discharged from electronics and semiconductor manufacturing plants, helping policy-makers to fill the regulatory gaps on TMAH emissions.