American Journal of Applied Chemistry 2016; 4(5): 164-169 http://www.sciencepublishinggroup.com/j/ajac doi:10.11648/j.ajac.20160405.11 ISSN: 2330-8753 (Print); ISSN: 2330-8745 (Online) A Study on Total Dissolved Solids and Hardness Level of Drinking Mineral Water in Bangladesh Mohammad Rafiqul Islam 1, * , Mohammad Khairul Islam Sarkar 1 , Tanzina Afrin 2 , Shafkat Shamim Rahman 3 , Rabiul Islam Talukder 4 , Barun Kanti Howlader 5 , Md. Abdul Khaleque 1 1 Department of Environmental Science, Independent University, Bangladesh (IUB), Dhaka, Bangladesh 2 Department of Civil Engineering, Dhaka University of Engineering & Technology (DUET), Dhaka, Bangladesh 3 Department of Mathematics & Natural Sciences, BRAC University, Dhaka, Bangladesh 4 Departmentof Biochemistry, Primeasia University, Dhaka, Bangladesh 5 Department of Quality Control, Everest Drinks and Dairy Products Ltd, Dhaka, Bangladesh Email address: sad.safwan@yahoo.com (M. R. Islam) * Corresponding author To cite this article: Mohammad Rafiqul Islam, Mohammad Khairul Islam Sarkar, Tanzina Afrin, Shafkat Shamim Rahman, Rabiul Islam Talukder, Barun Kanti Howladar, Md. Abdul Khaleque. A Study on Total Dissolved Solids and Hardness Level of Drinking Mineral Water in Bangladesh.American Journal of Applied Chemistry. Vol. 4, No. 5, 2016, pp. 164-169. doi: 10.11648/j.ajac.20160405.11 Received: July 21, 2016; Accepted: July 29, 2016; Published: August 17, 2016 Abstract: Natural water is being processed by the Reverse Osmosis purification system in the different area of Bangladesh for drinking purposes. Most of the water processing companies fill the 500 mL, 1000 mL, 2000 mL and 5000 mL bottles with this processed water and sell widely in the different parts of Bangladesh. However, the dissolved minerals in their purified drinking water are not sufficient for human health. Total Dissolve Solids (TDS) is a parameter that counts all dissolved minerals in the water. Calcium, magnesium and potassium are minerals that are introduce as a “Beneficial Minerals” for human health. Calcium is an important mineral for bone development, potassium is needed for muscles and nervous system and magnesium is helpful protect cardiovascular disease. The objective of the study is to examine the Total Dissolved Solids (minerals) and the Total Hardness (TH) in selected bottled water samples. The selected samples have been marketed by the local branded companies in Bangladesh. TDS and TH are measured in total eight of bottled water samples collected from the local confectionery shops in Dhaka city. The obtained results show that the levels of dissolved minerals in the drinking water samples are very low, which is quite alarming. Particularly, calcium and magnesium are found in very low amount in water samples of three companies. It can be assumed that those bottled water do not bring additional benefits to human health. The TDS of sample of one company was alarming low (9.44 mg/L. It may pose negative effects on human health especially malnourished people’s health. Keywords: Drinking Water, Mineral, Dissolved Solid, TDS, BDS, BSTI, WHO 1. Introduction Dhaka, the capital of Bangladesh is one of the mega cities in the world with the population of over fifteen million [Figure 1]. [1]. It is one of the rising cities in Bangladesh. The demand of drinking water is increasing in all cities of Bangladesh. One cannot think about life without water. Everyone use water in their daily life for drinking, washing, flashing, bathing and cooking. In addition, water is widely used in irrigation, building construction, electricity and steam generating etc. Different properties of water are important for users though it is depend on the purposes for which water is used. The properties of drinking water must suitable for health. The safe drinking water is also considered to be a pre-requisite for developing public health and economic growth. Always, every thirsty people seek the safe and pure mineral containing drinking water for filling their body demand. In Bangladesh,