Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Phytoplankton Density in Relation to Water Quality of the Wetland of Dhaka Export Processing Zone

Fouzia Akhter Khan
Department of Environmental Sciences, Jahangirnagar University, Savar, Dhaka-I342, Bangladesh.

Sirajul Hoque
Department of Soil, Water and Environment, University of Dhaka, Dhaka-I000, Bangladesh

A. K. M. Rashidul Alam
Department of Environmental Sciences, Jahangirnagar University, Savar, Dhaka-I342, Bangladesh.

Abstract/ Executive Summary:

Phytoplankton density in relation to water quality of the wetland of Dhaka export processing zone (OEPZ) was observed during August 2005 to February 2006. A total 36 taxa or phytoplankton belonging to Chlorophyceae, Bacillariophyceae, Cyanophyceae and Euglenophyceae was identified. Phytoplakton flora was dominated by Chlorophyceae (35.68%), Bacillariophyceae (34.35%), Cyanophyceae (26.74%) and Euglenophyceae (3.21 %). Chlorella (57.41 x 10³ cells/L), Navicula (52 x 10³ cells/L), Microcystis (50 x 10³ colony/L) and Euglena (11 x 10³ cells/L) were the dominant species of Chlorophyceae, Bacillariophyceae, Cyanophyceae and Euglenophyceae, respectively. Microcystis aeruginosa is an indicator species or polluted water which was found in the wetland. The mean value of temperature, electric conductivity (EC), total suspended solids (TSS), pH, dissolved oxygen (DO), biochemical oxygen demand (BOD₅), chemical oxygen demand (COD), total - N, total - P, total - K and total - S contents of water were 42°C, 2252 μS cm^-1, 256mg/L, 8.71, 2.74mg/L, 53.63 mg/L, 237.34 mg/L. 26.0 mg/L, 3.94 mg/L, 555.0 μg/L and 129.6~ mg/L, respectively. Phytoplankton was absent in point-source where the maximum water temperature was 5(rc. The strong negative significant correlations were observed between temperature and COD with phytoplankton.

Keywords: Phytoplankton, Physico-chemical characteristics, Water, Wetland

Location: Dhaka export processing zone (DEPZ), Ganakbari area, Savar, Dhaka, Bangladesh

Start Date: 00-08-2005

End Date: 00-02-2006

Program Area: Crop-Soil-Water Management

Commodity: Plankton

Objectives:

To determine phytoplankton density in relation to water quality of the wetland.

Methodology:

This is the main waste disposal site of the industries of the DEPZ. The sampling site was divided into four stations at each corner and designated as: A, B, C and D as north - east, north - west, south - east and south - west corner of the wetland, respectively. The sampling was carried out at 90 days interval from August 2005 to February 2006. To have representative samples, 1 liter water sample was collected from each of the four stations in the wetland at 10.00 a.m. From this sample, half were fixed with 5% formalin in a sample bottle for phytoplankton sedimentation. Another half liter was acidified with HCI and used for the determination of nutrient parameters of water. However, fresh sample (unacidified) were used to determine pH of the sample. After sedimentation of plankton, water of the bottle was sucked out carefully keeping the sedimented layer of plankton undisturbed and the final volume was adjusted to 20 ml. For qualitative analysis of phytoplankton the water sample were observed under a compound microscope (Olympus CH-2) on a glass slide. The observed phytoplankton specimens were identified at least generic level by consulting national and international standard literatures. For quantitative analysis, I ml of well shaken plankton concentrate was taken in a standard Sedgewick Rafter counting cell. Water temperature of the surface water was measured by using a degree centigrade thermometer, electric conductivity was measured by using an EC meter total suspended solid was measured by Gravimetric method, pH was determined by using a glass electrode pH meter (Jenway pH meter, Model no.3305), dissolved oxygen (DO) was determined by using the DO meter (HANNA I STRUMENTS: H 19143, Microprocessor, Auto Cal, DO meter, Portugal), BOD5 was determined by Winkler method, COD was determined by titrirnetric method, total nitrogen was measured by Micro-kjeldahls distillation method, total phosphorus (P) was determined by Vanadomolybdophosphoric yellow color method, potassium (K+) by Flame Photometer (Gallen Camp, Model no. PEP7, SI. No. 6(68) and total sulpher (S) by turbidrnetrically. Pearson Correlation was done by Statistical Package for Social Sciences (SPSS) to correlate between phytoplankton and physicochemical properties.

Source of Information: Banglade h J. Life Sci. 20(2): 45-51, 2008 (December)

Article Link (Online Journal):

Funding Source:

Total Budget (Tk.) :

Achievement/Findings:

Alkaline pH was observed in the station 0 (12.63), where phytoplankton was not found during February. The maximum temperature was observed in station C (50°C) and no phytoplankton was observed there. The lowest DO was 1.15 mg/L in the station C, where phytoplankton was absent. The maximum amount of COD content in the station 0 of the wetland was 592 mg/L and phytoplankton was absent in that station. Chlorophyceae showed a weak negative correlation with EC (I' = -0.362). COD showed a strong negative significant correlation (r = -0.649*) with Cholorophyceae. Bacillariophyceae showed a moderate positive correlation with total phosphorus (P) content (r = 0.402).The average highest temperature (42°C) observed in water of the wetland of DEPZ area may be due to discharge of heated effluent from the industries. Organisms may hardly survive there. The average DO of water of the wetland of DEPZ area was observed 2.47 mg/L below the standard of the Department of Environment, Bangladesh which is harmful for the aquatic life. It is urgently needed to treat the wastewater precisely in order to reduce the harmful impact of effluent on aquatic life and surrounding environmental condition on a sustainable basis.

Knowledge Management: Journal