Effluent assessment index

Advantages of the PEEP index scheme for effluent assessment... 

Blaise, C. and J.F. Ferard. 2005. Effluent assessment with the PEEP (potential ecotoxic effects probe) index. In C. Blaise and J.F. Ferard. (eds), Small-scale Freshwater Toxicity Investigations, Vol. 2, pp. 69-87. New York Springer. 

Heikkila et al. (1996) have expanded the work of Hurme and Jarvelainen (1995) with environmental and safety aspects (Fig. 11). The alternatives are simulated to determine the material and heat balances and to estimate the physical properties. Then the alternatives are assessed in economic terms for which the internal rate of return is used. The environmental effects are estimated by equivalent amount of pollutant that takes into consideration the harmfullness of the different effluent substances. With environmental risks are also considered aspects of occupational health to choose inherently healthier process. Even though most health related rules are considered later in the work instructions, health effects should also be a part of the decision procedure. The inherent safety is estimated in terms of the inherent safety index as described later. 

Costan, G. Bermingham, N. Blaise, C. Ferard, J.F. Potential Ecotoxic Effects Probe (PEEP) a novel index to assess and compare the toxic potential of industrial effluents. Environ. Toxic. Water Quality 1993, 8 (1). 

Approximately 20 min will be needed to assess effluents that range between 700 and 1800 retention index. 

The extract of the volatiles is separated by high resolution gas chromatography (HRGC) and the odor of the compounds is assessed by sniffing the effluent of the GC column in parallel with the FID-detection. This technique allows the detection of odor-active volatiles, the determination of their odor qualities and, most important, the combination of these sensory data with an analytical parameter, the retention index (RI). In Figure 2, the results of... 

Originally, the PEEP index was designed to assess industrial and municipal effluent toxicity (Section 3). Because the PEEP index formula can accommodate any number and types of bioassays, it could also be applied in other versatile ways (Section 8). 

Table 1. Summary of the PEEP index hazard assessment scheme for effluents.

Requiring low-sample volume micro-scale tests for its cost-effective application, the PEEP index has thus far employed bioassays with bacteria, algae and microinvertebrates. While well-standardized toxicity tests using freshwater fish existed at the time of the PEEP s conception in the early 1990 s (e.g., the Environment Canada fingerling rainbow trout 96-h lethality test to assess industrial wastewaters), they were excluded because of their large sample volume needs (e.g., close to 400 L of effluent sample required to undertake a multiple dilution 96-h LC50 bioassay in the case of the trout test). In addition to effluent sample volume, the cost of carrying out salmonid fish acute lethality bioassays for the 50 priority industrial effluents identified under SLAP I (the first 1988-93 Saint-Lawrence River Action Plan) was prohibitive. 

The proposed hazard assessment scheme (HAS) used in Colombia is a ranking system where toxicity data obtained from the application of a test battery enables one to determine the degree of toxicity of liquid samples on a relative basis. Test battery results are then integrated into the Potential Ecotoxic Effects Probe (PEEP) index formula developed by Environment Canada for the comparison of wastewaters (Costan et al., 1993). This index can be applied to evaluate the potential toxicity of industrial and municipal wastewaters, and to assess the effectiveness of toxicity abatement measures for effluents. This procedure is easy to apply and can be used with different batteries of tests (see Chapter 1 of this volume). 

In brief, the PEEP index is a useful HAS to apply in comparative studies of wastewater effluents to assess their ecotoxicity and toxic loading. Some of its advantages include the fact that it considers results from different toxicity tests and endpoints, while integrating all possible antagonistic, additive or synergistic interactions that can occur between toxicants in a complex liquid sample. Furthermore, the use of a single PEEP value becomes very useful for decisionmakers who are then able to take science-based decisions to prioritize corrective actions on industries whose effluents are the most toxic for the aquatic environment. It is also noteworthy to point out that the PEEP index can be applied anywhere with any number or type of tests and endpoints to suit the needs and expertise of laboratories internationally. 

Table 5 illustrates the grouping of effluents and emissions to water, air, and solid waste. 2 ft is important to note that the mass in these categories cannot be simply added to produce a meaningful environmental index because some are associated with much more significant environmental impacts than others. The process of converting all of these outputs to useful burden index measures is a part of the inventory assessment process. 

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