Extensive comparison of methods for removal of organic halogen compounds from pharmaceutical process wastewaters with life cycle, PESTLE, and multi-criteria decision analyses

Abstract

Recycling and disposing wastewater from the pharmaceutical industry are of utmost importance in mitigating chemical waste generation, where unmanaged hazardous waste fluxes could cause massive environmental damage. Air stripping, steam stripping, distillation, and incineration offer significant emission reduction potentials for pharmaceutical applications; however, selecting specific process units is a complicated task due to the high number of influencing screening criteria. The mentioned chemical processes are modelled with the Aspen Plus program. This study examines the environmental impacts of adsorbable organic halogens (AOX) containing pharmaceutical process wastewater disposal by conducting life cycle impact assessments using the Product Environmental Footprint (PEF), IMPACT World + Endpoint V1.01, and Recipe 2016 Endpoint (H) V1.06 methods. The results show that the distillation-based separation of AOX compounds is characterized by the most favourable climate change impact and outranks the PEF single score of air stripping, steam stripping, and incineration by 6.3%, 29.1%, 52.0%, respectively. The energy-intensive distillation technology is further evaluated by considering a wide selection of energy sources (i.e., fossil fuel, nuclear, solar, wind onshore, and wind offshore) using PESTLE (Political, Economic, Social, Technological, Legal, Environmental) analysis combined with multi-criteria decision support to determine the most beneficial AOX disposal scenario. The best overall AOX regeneration performance and lowest climate change impact (7.25 × 10−3 kg CO2-eq (1 kg purified wastewater)−1) are obtained by supplying variable renewable electricity from onshore wind turbines, reaching 64.87% carbon emission reduction compared to the baseline fossil fuel-based process alternative.