Remediation of pharmaceutical and personal care products (PPCPS) in constructed wetlands: Applicability and new perspectives

Abstract

Nowadays, wastewater treatment plants (WWTPs) considered not very effective in removing all types of organic compounds, including pharmaceuticals and personal care products (PPCPs). The effluent discharged containing PPCPs shows negative impact on fresh/marine waters, even at vestigial concentrations. The integration of constructed wetlands (CWs) as a biological treatment technology in WWTPs may be an option to effective removal of PPCPs, which is crucial for water bodies protection. On the other hand, if they arrive to water bodies it is important to understand the self-restoration capacity of the system. This chapter makes an overview (based on literature and experimental data) about the effectiveness of CWs as a polishing step in WWTPs and the potential to remove contaminants if they arrive to salt marsh areas. In both cases, there is a same principle behind. CWs defined as artificially engineered ecosystems designed and constructed to control biological processes as in natural wetlands, but in a controlled natural environment. A case study highlights the remediation potential to remove target PPCPs in both environments. Simulated CWs (spiked wastewater) planted with Spartina maritima and light expanded clay aggregates (LECA) as substrate. Simulated salt marsh areas (spiked elutriate soaked in sediment) were planted with the same plant but with sediment as substrate. The presence of a physical support and/or S. maritima decreased contaminant levels either in WWTPs or in estuarine simulated environment. Plant uptake, adsorption to plant roots/sediments and bio/rhizoremediation are strong hypothesis to explain the decrease of contaminants either in CWs or in salt marsh environment. The chapter also discusses the concept of energy production in CWs as a way to increase the competitive advantages of CWs over other treatment systems, by coupling an efficient removal together with a profitable technology, which may decrease WWTP energetic costs.