Volume 2 December Volume 2012 RAJSHAHI UNIVERSITY JOURNAL OF ENVIRONMENTAL SCIENCE ISSN 2227-1015 Institute of Environmental Science (IES) University of Rajshahi Rajshahi‐6205 BANGLADESH Rajshahi University Journal of Environmental Science ISSN 2227-1015 Volume No. 2, December, 2012 IES Publication No. 2 Published by Institute of Environmental Science University of Rajshahi Rajshahi-6205, Bangladesh www.ru.ac.bd/ies @ All rights reserved by the publisher. The Journal is published yearly accommodating all aspects of environmental science both experimental and theoretical within the available scope after peer review. Subscriptions Institutions: Inside Bangladesh Tk. 500 per copy Out side Bangladesh US$ 50 per copy Individual: Inside Bangladesh Tk. 300 per copy Out side Bangladesh US$ 30 per copy Correspondence: All correspondence should be addressed to the Editor, Rajshahi University journal of environmental science, Institute of Environmental Science, University of Rajshahi, Rajshahi-6205, Bangladesh Website: www. ru.ac.bd/ies, e-mail:
[email protected], Tel. 880-0721 750930 Cover Design Dr. Md. Redwanur Rahman Printed at: Rajshahi University Press ISSN 2227-1015 RAJSHAHI UNIVERSITY JOURNAL OF ENVIRONMENTAL SCIENCE A Yearly Journal of the Institute of Environmental Science Vol. 2 No. 2 December, 2012 EDITORIAL BOARD Chief Editor Professor Dr. Md. Sarwar Jahan Members Professor Dr. Raquib Ahmed Professor Dr. Zahidul Hassan Professor Dr. Md. Golam Mostafa Dr. Md. Abul Kalam Azad Dr. Md. Redwanur Rahman Associated with us : Zakia Yasmin