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Case Study: Pharmaceutical Wastewater — API Removal & Water Reuse

A European active pharmaceutical ingredient (API) manufacturer required full containment of trace pharmaceutical compounds in its wastewater, combined with 80% water reuse to meet its corporate water neutrality commitment.

PharmaceuticalMBRAOPWater ReuseAPI ContainmentEurope
99.9%API Removal
82%Water Reuse
<5 mg/LFinal BOD
1,200 m³/dayTreated Flow

The Challenge

A Central European facility manufacturing APIs for cardiovascular and oncology drugs generated 1,200 m³/day of complex mixed wastewater containing: (1) API-bearing process effluent at concentrations up to 50 mg/L API; (2) CIP and rinse water with high BOD and surfactants; (3) solvent-bearing condensates from distillation. Key constraints:

  • EMA guidance and local environmental permit required API concentrations in discharge <0.1 µg/L (5× PNEC margin)
  • Water neutrality target required 80% of treated water to be reused as cooling tower make-up and utility water
  • Mixed wastewater contained acetonitrile and methanol at 500–2,000 mg/L — inhibitory to standard activated sludge at these levels
  • COD variability: 800–25,000 mg/L depending on batch production schedule

The Solution

Reynolds & Bauhm designed a multi-stage treatment train combining solvent stripping, biological treatment, AOP, and membrane polishing:

  • Solvent stripping by steam distillation ahead of biological stage reduces acetonitrile from 1,500 to <50 mg/L; solvent recovered for reuse in production
  • Equalisation (500 m³) buffers batch discharges to a near-constant 1,200 m³/day average load
  • MBR (MLSS 12,000 mg/L; SRT 25 days; HRT 18h) achieves BOD <10 mg/L and degrades most API compounds by 85–99% through co-metabolism in the long-SRT system
  • UV/H&sub2;O&sub2; AOP (dose 1,500 mJ/cm²; H&sub2;O&sub2; 30 mg/L) destroys residual API compounds to <0.05 µg/L; H&sub2;O&sub2; quench with catalase
  • RO polishing (85% recovery) produces reuse-quality permeate for cooling tower; RO concentrate returned to head of plant for blending

Process Train

StageEquipment / ProcessKey Parameter
1Steam stripping columnRemoves solvents; condensate recovery to production
2500 m³ equalisation tankDampens batch peaks to ±20% of average COD
3MBR (hollow-fibre UF membranes, 0.04 µm)BOD <10 mg/L; TSS <1 mg/L; partial API degradation
4UV/H&sub2;O&sub2; AOP reactorUV 1,500 mJ/cm²; H&sub2;O&sub2; 30 mg/L; API destruction to <0.05 µg/L
5Catalase H&sub2;O&sub2; quenchResidual H&sub2;O&sub2; <0.5 mg/L
6RO polishing (85% recovery)Permeate conductivity <50 µS/cm; reused as cooling tower make-up
7GAC polishing (permeate stream)Trace organics insurance barrier; EBCT 10 min

Results Achieved

API Containment

All monitored APIs below 0.05 µg/L in final discharge, comfortably below 0.1 µg/L permit limit. Facility achieved EMA environmental risk assessment approval for the new discharge regime.

Water Reuse

82% of treated water returned to cooling tower make-up and utility use. Annual water procurement reduced by 360,000 m³, valued at approximately at local tariff.

Sustainability Target Met

Facility achieved water neutrality certification for its production site. Scope 3 water intensity KPI reduced by 81%, supporting group ESG reporting.

Regulatory Audit Compliance

Complete batch records, validation documentation, and environmental permit reporting aligned with FDA, EMA, and local regulatory requirements.

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MBR Systems

Membrane bioreactor systems for high-quality effluent and water reuse.

MBR Equipment

Discuss Your Project

Our engineers are available to review your site conditions and recommend the most appropriate treatment solution.

Why Pharmaceutical Wastewater Needs Specialist Treatment

Pharmaceutical wastewater combines high and variable organic loads with active pharmaceutical ingredients, solvents and constituents that are toxic or inhibitory to conventional biology — and it is produced under a regulatory spotlight that demands documented, validated performance. Treating it well means matching the train to the chemistry: equalisation to absorb batch variability, advanced oxidation or adsorption to address APIs and refractory organics, and robust biological treatment protected from inhibition. Because the sector requires evidence, we build in the monitoring and documentation that prove removal. The result is a treatment scheme that meets tight discharge limits reliably while standing up to the validation and audit expectations placed on pharmaceutical manufacturing.

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