Seasonal Variation of Water Quality in Gowain River near Ratargul Swamp Forest, Sylhet, Bangladesh

Abstract

This article is based on a study that was conducted to investigate the physicochemical properties of water in Gowain river at pre-monsoon (February to May), monsoon (June to September) and post-monsoon (October to January) seasons and to determine the relationships between water quality parameters. The water samples were collected from five different sampling stations of Gowain river and analyzed in the laboratory of Department of Environmental Science and Resource Management, Mawlana Bhashani Science and Technology University, Bangladesh. The results also showed that most of the water quality parameters were suitable for aquatic organisms as well as fish. However, runoff from upstream and waste generated from anthropogenic sources could be the main causes of degradation of water quality and aquatic organisms.

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“…The standard limits of pH for inland surface water are 6.5 to 8.5 (EQS, 1997) and the study revealed that the pH values of all sampling stations were within the standard Pre-monsoon Monsoon Post-monsoon limit. Nahian et al (2018) found that pH value was 8.14, 7.76 and 7.44 for pre-monsoon, monsoon and postmonsoon, respectively, in Gowain River. The average pH in wet and dry seasons was found 7.73 and 8.03, respectively, in the Tista River (Islam et al, 2014), which is more or less parallel to the present study.…”

“…When dissolved oxygen becomes too low, fish and other aquatic organisms cannot survive (Islam et al, 2017). Nahian et al (2018) found their study in Gowain River the mean concentration of DO was 4.86, 5.18 and 4.42 mg/L in premonsoon, monsoon and post-monsoon season, respectively. Adequate DO is needed to maintain good water quality, aquatic organism endurance, and microorganism putrefaction of waste (Islam, Suravi and Meghla, 2010;Rahman et al, 2012).…”

“…On an average, the highest alkalinity of 122.01 mg/L was found in post-monsoon and the lowest alkalinity of 100.0 mg/L was observed in monsoon season (Table 2). According to Nahian et al (2018), the mean alkalinity was 279.30, 163.95 and 188.16 mg/L in premonsoon, monsoon and post-monsoon season, respectively. According to Rahman (1992), standard value of alkalinity is >100 mg/L for fresh water and most of the water samples.…”

“…Presently, the Chalan Beel, like many other beels, is at the risk of partial or total degradation due to manifold reasons like agricultural encroachment including pesticide usage, siltation along with other anthropogenic (Rahman, 2012;Nahian et al, 2018), however, a detailed study on seasonal variation of the water quality (physical, chemical, biological and anionic) parameters and trophic state index (TSI) in Chalan Beel is evidently lacking. Therefore, the present study aimed to provide data on variations of water quality parameters and TSI of Chalan Beel over a period of one year to provide baseline information for assisting management decisions of the Beel ecosystem.…”

Assessment of Physicochemical Properties and Comparative Pollution Status of the Dhaleshwari River in Bangladesh

“…In each polypropylene bottle, 1 mL of ultrapure nitric acid was added to achieve a pH of ~1 [47] before transferring to the Department of Soil, Water and Environment Laboratory of the University of Dhaka for heavy metals analysis. The standard sampling procedure was followed to collect all samples at every single sampling station [48][49][50][51][52].…”