1. Assistant Researcher, Dept. of Water Pollution Research, National Research Centre, El-Tahrir St., P.O. Box 12311, Cairo, Egypt (corresponding author).
2. Associate Professor, Dept. of Water Pollution Research, National Research Centre, El-Tahrir St., P.O. Box 12311, Cairo, Egypt.
3. Professor, Dept. of Water Pollution Research, National Research Centre, El-Tahrir St., P.O. Box 12311, Cairo, Egypt.