Bio oxygen demand (B.O.D) is the amount of oxygen required for the microorganisms (bacteria) present in the waster water to convert the organic substance to stable compounds such as CO2 and H2O. Bacteria placed in contact with organic materials will utilize it as a food source in the utilization the organic material will be oxidized to CO2 H2O. B.O.D is

Oxygen is required for all living organisms for growth (metabolism) 21% in air quantity directly related with atm pressure and inversly proportional to temp for trout 7.5 mgl required. Add 2ml alkali iodide azide if becomes yellow = oxygen present while no oxygen ppt will be created let it settle ( Na2S03, Sodium sulphride) brings oxygen to zero. Add NaS03 to another

Cement refers to material which acts as a binding substance. In construction and civil engineering cement is used to bind structural members for construction of buildings, pavements, bridges, tunnels, roads and highways etc. Cement bags should not be stored in an enclosed area where the walls, roof and floor is not completely weatherproof. Cement bags must not be

Concrete is made by mixing: Cement, water, course fine aggregates and admixtures (if required). The aim is to mix these materials in measured amounts to make concrete that is easy to: Transport, place, compact, finish and which will set, and harden, to give a strong and durable product. A concrete mix is designed to produce concrete that can be easily placed at the

Portland cement is a type of cement, not a brand name. Many cement manufacturers make Portland cement. Types IA, IIA and IIIA are cements used to make air-entrained concrete. They have the same properties as types I, II, and III, except that they have small quantities of air-entrained materials combined with them. Normal Portland cement. Type 1 is general use