Environmental Management of Wastewater Treatment Plants – the Added Value of the Ecotoxicological Approach

Abstract

Pollution control has been changed by advances in scientific knowledge, because there is a connection of environmental contamination with the ability to measure it. With greater understanding of the impact of wastewater on the environment and more sophisticated analytical methods, advanced treatment is becoming more common (Lofrano & Brown, 2010). The assessment of biological effects of wastewater discharges in the ecosystems is today considered relevant and ecotoxicological tests identifying the ecological hazard are useful tools for the identification of environmental impacts. Direct toxicity assessment, making use of ecotoxicological tests, can play an important role in supporting decision-making, either regulatory driven or on a voluntary basis. Within the Integrated Pollution Prevention and Control Directive IPPC, 2008/1/EC (European Commission [EC], 2008), the Direct Toxicity Assessment concept has been included as a suitable monitoring tool on effluent in several Best Available Techniques (BAT) Reference Documents. Also, in Water Framework Directive – WFD, 2000/60/EC (EC, 2000), direct toxicity assessment of Wastewater Treatment Plant (WWTP) effluents can contribute to attain or keep ecological quality objectives in water masses. So, for EU countries to comply with good ecological status, ecotoxicity evaluation of WWTP effluents is extremely relevant. In many countries ecotoxicity tests are already in use for wastewater management (Power & Boumphrey, 2004; Tinsley et al., 2004; United States Environmental Protection Agency [USEPA], 2004; Vindimian et al., 1999). Bioassays are also used for wastewater surveillance and BAT compliance by authorities in Germany (Gartiser et al., 2010a). A global evaluation of wastewaters should include ecotoxicological tests to complement the chemical characterization, with advantages especially in the case of complex wastewaters (Mendonca et al., 2009). This approach has advantages particularly to protect biological treatment plants from toxic influents (Hongxia et al., 2004), to monitor the effectiveness of WWTP (Cēbere et al., 2009; Daniel et al., 2004; Emmanuel et al., 2005; Libralato et al., 2006; Metcalf & Eddy, 2003) and in the impact assessment of complex wastewaters. Bioassays are considered a suitable tool for assessing the ecotoxicological relevance of complex organic mixtures (Gartiser et al., 2010b).