Category Archives: Quality test

Determination of chemical oxygen demand of water

Chemical Oxygen Demand indicates the amount of oxygen required to oxidize all soluble and particulate organic substances in water under specific conditions. All organic compounds may convert into carbon dioxide, water and ammonia. It is a significant parameter to determinate water characteristic. The COD value depends on oxidizing agent, pH, temperature, and period of time. It is expressed as Read more

Biochemical Oxygen Demand – BOD determination

There is a close relationship between dissolved oxygen and biochemical oxygen demand. BOD is the amount of dissolved oxygen required to break down the organic material of the sample water by aerobic biological organisms at certain temperature over a specific time period. Generally this parameter is determined with the consumption of oxygen by the micro organism during 5 days of incubation at Read more

Dissolved oxygen in water

Dissolved oxygen (DO) means the amount of oxygen that is dissolved in the water. Oxygen is the essential element to all animals. No animals can survive without it. Dissolved oxygen in water makes aquatic life possible. Human being takes oxygen from the air with the lungs. On the other hand, Fishes take dissolved oxygen through their gills. Gills work better if the water contains more oxygen. Read more

Determination of permanent hardness of water

The available methods for determination of permanent hardness of water are O’Heners method, EDTA method and Soap titration method. Initially we have to know; what is hardness? –Hardness is due to presence of bicarbonate, sulphates, chlorides and nitrates of calcium and magnesium. It is expressed in ppm (part per million) as calcium carbonate. There are two types of hardness: Temporary Read more

Determination of total hardness of water

To determine the Total Hardness of Water, EDTA is the easiest method. Reason, EDTA reacts with all metal without alkali metal and the proportion is 1:1. The main cause of water hardness is dissolved salts of calcium and magnesium. Moreover the other ions like Strontium, Iron, Barium and Manganese also contribute of water hardness. Traditional it is measured by the amount of soap that is Read more

Determination of total amount of cations in water

Different types of metal salt are dissolved in natural, industrial or any other water. Therefore, the water contains different type of cations. The cations in water can be determined by using cation exchange resin. They are electron donors and consequent positively charged. Some common cations are Na+, K+, Mg2+, Ca2+, Fe2+ or Fe3+, Mn2+, Al3+. On the other hand, cation exchange resin contains Read more

Determination of chloride in water by mohr method

Mohr method is one of the significant methods for determination of chloride in water. It is also known as Argentometric method. Chloride ion is a negatively charged ion. This method is appropriate for neutral or slightly alkaline water. Water sample is titrating against standard AgNO3 solution by using potassium chromate indicator. It is a precipitation titration method. Table of Read more

Water testing kits

The water testing kits are used for monitoring the quality of drinking water and controlling the important operational parameters. The kit is not given high level accurate result but it given a warp idea. This kit can help us by providing the idea about what is the condition of our water or check out how the treatment working on. Although we are not get exact result but this result is very Read more

Determination of hardness of water by EDTA method

Determination of hardness of water by EDTA method is one of the three main methods for determination of hardness of water. EDTA means Ethylenediaminetetraacetic acid. This EDTA reagent can be forming edta-metal complexes by the reaction with metal ions except for alkali metal ions. This reagent can forms a stable complex with the alkaline earth metal like calcium ion and magnesium ion in Read more