1. Assistant Professor of Sanitary and Environmental Engineering, Dept. of Mechanics, Structures, and Environmental Engineering, Univ. of Cassino, via Di Biasio 43, 03043 Cassino (FR), Italy (corresponding author).
2. Professor of Environmental Biotechnology, Pollution Prevention and Control Core, UNESCO-IHE, P.O. Box 3015, 2601 DA Delft, The Netherlands.
3. Professor of Sanitary and Environmental Engineering, Dept. of Hydraulic, Geotechnical and Environmental Engineering, Univ. of Naples Federico II, Via Claudio, 21, 80125 Naples, Italy.