Physico-chemical Characterization of Kaptai Lake and Foy’s Lake Water Quality Parameters in Chittagong, Bangladesh

In order to protect the quality of environment and human’s health, fresh water assets are tremendously important in various ways. To ensure the fresh water resources in Chittagong region of Bangladesh, we have studied the water quality parameters of Kaptai and Foy’s Lake. This research has done based on the essential surface water standard parameters such as pH, temperature, DO, BOD, COD, TDS, TSS, TS, EC, hardness, turbidity, salinity, total alkalinity, total acidity, SO4 2, PO4 3, NO 3-N, NO 2, CO2, and most of the heavy and toxic metals (As, Cd, Cr, Cu, Co, Fe, Pb, Mn, Ni, and Zn) of two lakes namely Foy’s (Chittagong) and Kaptai (Rangamati) Lakes in Chittagong , Bangladesh. The statistical approaches of sampling were utilized for collecting samples. The samples were assembled from ten different locations of each lake. Samples were conserved using satisfactory preservation procedure. Water samples from the surface-water assets were collected from various locations, and tide conditions and at various seasons for continual monitoring during the hydrological years 2014-2015. The results showed that Kaptai Lake, and Foy’s Lake all physicochemical parameters are within the permissible limit of WHO guideline. The results also supplied data to view, and quantify the enemy of the impact of climate alter on freshwater resources of this region. The outcomes further showed data for water quality of surface-water resources of greater Chittagong zone to match national and international quality for drinking, agricultural, manufacture and livestock requirements. A strategic water quality management plan has been proposed.

acquiring easy information that will guide the use, and shelter of the nation's water resources (WHO, 2004). That challenge is being represented by national, divisional, inter-district and local water resource agencies, and by large academic institutions (Hirsch, 2007). These institutions are collecting water standard data for a host of purposes that include compliance with authorizes and water supply standards; development of remediation plans for desire contamination problem; operational decisions on industrial, wastewater, or waste water supply facilities; and study on factors that affect water quality. An additional require for standard quality information is to provide a basis on which regional, and native level policy resolve can be based (Ahmed et al., 2018). Foy's Lake is one of the major significant man-made lakes in Chittagong, Bangladesh that was built by building a dam over the stream that decline from the slopes in the northern region of Chittagong in 1924. Intelligent decisions must be based on stable information (Hirsch, 2007). Because Bangladesh is fortunate enough having an extensive and huge water resources scattered all over the country in the form of small pond, beels (natural depression), lakes, canals, small and large rivers and estuaries covering an area of about 4.34 million hectares. In Bengali, Bangladesh is called as 'nodimatrik desh'. This is indeed literally true because rivers gave birth to this land.
Bangladesh is located in the low-lying Ganges-Brahmaputra River Delta, one of the greatest deltas in the world, is criss-crossed by different rivers, their tributaries and distributaries. Straddling the Tropic of Cancer prevalence, Bangladeshi environment is tropical with a mild winter from month of October to March, a dry, humid summer from the month of March to June. A hot and humid monsoon season lasts from the month of June to October, and distributes most of the country's rainfall. The hydroponic creating media allows sufficient root distribution of plants, and maintains homogeneous state of growing media, which is restricted in the pot plant experiments (Hossain et al., 2019;Salt et al., 1995). Now a critical need exists for accurate facts and rationale concept to provide approach for organizing our affairs. Pollution from human and industrial sources is the main water quality problem in the river systems near urban areas of Dhaka (WHO, 1991). However, any comprehensive assessment of Chittagong division's surface water quality parameters has yet to be completed. Some trace metals such as Cu, Fe, Mn, Zn, etc., at catalytic numbers as metalloenzymes and as cofactors of enzymes, are necessary to living organisms for their usual physiological activities. But the high concentration of Cu has been associates with liver damage, and Zn may create harmful nutrient interactions with Cu (Majagi et al., 2008).
Chittagong is generally called the business capital of Bangladesh. The challenges posed by climate alter, and growing economic improvement requires that the quantity and quality of water assets in Bangladesh be regulated by sustainable development policies. Without such an idea, Bangladesh will continue to face vital challenges to gain economic growth to help the growing population confined in a denselypopulated land with reducing water resources (Ahmed and Haque, 2010). At present, Kaptai Lake assists poor-scale fisheries, which is enrich in fish species diversity, and contributing approximately 8980 metric ton freshwater fish annually (FRSS, 2012). The main objectives of the study is to know the present status of physico-chemical parameters of water of the 2 selected lakes in Chittagong, to assess their interrelationship and to compare the present results with results obtained previously in the lakes of Chittagong as well as other lakes in home and abroad.

MATERIALS AND METHODS:
Sample Collection -A survey work was conducted fiscal year 2014-2016 for identifying sampling spots and the current quality conditions for a large part of Kaptai Lake and Foy's Lake in greater Chittagong region. The surface water samples were collected in the boat if possible in the middle of the flow. Two to four sub samples of equal volume were collected from vertical section. The water samples were collected within 3-9 inches from the surface of the water. Surface samples from different points of greater Chittagong district were collected for this study. Samples were piled up in amber color polyethylene bottle washed by rinsing thoroughly with 8M HNO 3 , followed by repeated washing with distilled water. The samples were mixed well and a sample of 1.0-1.5-L was transferred for analysis in the laboratory.
UniversePG l www.universepg.com Apparatus -A Shimadzu (Kyoto, Japan) (Model-1800PC) double-beam UV/VIS spectrophotometer and a Jenway (England, UK) (Model-3010) pH meter with a union of electrodes were used for determines of the absorbance and pH, respectively. A Varian Model-AA240FS quick sequential atomic absorption spectrophotometer (AAS) was used for studies of trace elements in water using a respective wavelength and hollow cathode lamp.
Sample Processing and Analysis -A glass thermometer was used for the measurement of temperature. pH, EC and TDS were studied at the sampling site by Hanna Combo meter, Model HI 98129. TS and TSS were studied by drying and weighing approach. Measurement of DO was done by Jenway 970 DO meter at the sampling area. BOD was studied from the differences of preliminary and 5 day, DO by DO meter. COD was estimated by titrimetric approach after 2 hours open reflux. Acidity, and dissolved carbon dioxide were studied by titrimetric approach using standard 0.02M NaOH. Total and phenolphthalein alkalinity were studied by titrimetric approach using phenolphthalein, and methyl orange as indicators.
Hardness was studied by complex metric titration approach. Dissolved hydrogen sulphide (DHS) was studied by iodimetric approach using standard iodine solution (WHO, 1991). Ammonia-N was studied by colorimetric nesslerization approach after distillation of collected samples. Total nitrate and nitrite-N was studied by colorimetric nesslerization procedure after reducing samples by Deverda's alloy (WHO, 1984). Sulphate S was studied by colorimetric barium chloride turbidimetric approach. Nitrite-N was studied by colorimetric method after formation of a reddish purple azo dye produced at pH 2.0 to 2.5 by coupling diazotized sulfanilamide with N-(1-naphthyl)ethylene diaminedi-hydrochloride (NED hydrochloride). Nitrate-N was estimated by colorimetric method in the ultraviolet range. Iron was studied by colorimetric method using 1, 10phenanthroline as chelating agent. Manganese was studied by colorimetric per-sulfate oxidation method. In colorimetric methods Zinc, copper, lead, cadmium, cobalt, nickel and chromium were studied by the measure of metals by UV-Visible and atomic absorption spectrophotometry samples were digested according to the wet-digestion method (EWD, 2009).
In colorimetric techniques a Shimadzu, Model-1800 UV-Vis spectrophotometer was used. Zinc, copper, lead, cadmium, cobalt, nickel and chromium were studied by Varian Model-AA240FS fast sequential atomic absorption spectrophotometer (AAS). For the determination of metals by UV-Visible Spectrophotometry, and atomic absorption spectrophotometry samples were digested as stated by to the wet-digestion method (Flanagan et al., 2001). Table 1: The parameters studied during the analysis and processing of water samples.
UniversePG l www.universepg.com No significant variation was observed in water quality among the ten points. Similar result was observed (Kabir and Naser, 2011) where they reported alkaline water in Chand bill Baor Oxbow Lake, Bangladesh and also described alkaline nature of Maheshara Lake water in Gorakhpur, India (Shukla et al., 2013).