Questions

Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment.

Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. This removes material that will either float or readily settle out by gravity. It includes the physical processes of screening, comminution, grit removal, and sedimentation.

Secondary treatment removes the soluble organic matter that escapes primary treatment. It also removes more of the suspended solids. Removal is usually accomplished by biological processes in which microbes consume the organic impurities as food, converting them into carbon dioxide, water, and energy for their own growth and reproduction.

Tertiary treatment includes removal of nutrients such as phosphorus and nitrogen and practically all suspended and organic matter from waste water.

The photoelectric effect pointed to the particle properties of light, which had been considered to be a wave phenomenon. Particles like electron and protons have both particle like and wave like behavior. Thus, according to de Broglie, all the material particles in motion possess wave characteristics. Although the dual nature of matter is applicable to all material objects but it is significant for microscopic bodies only.

This is for the first time that no Literature Prize will be given in 70 years because of a #MeToo scandal.

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms.

The Seven Years’ War, a global conflict known in America as the French and Indian War, ends with the signing of the Treaty of Paris by France, Great Britain, and Spain.

The Seven Years’ War ended with the signing of the treaties of Hubertusburg and Paris in February 1763. In the Treaty of Paris, France lost all claims to Canada and gave Louisiana to Spain, while Britain received Spanish Florida, Upper Canada, and various French holdings overseas. The treaty ensured the colonial and maritime supremacy of Britain and strengthened the 13 American colonies by removing their European rivals to the north and the south.

The British victory in the French and Indian War had a great impact on the British Empire. Firstly, it meant a great expansion of British territorial claims in the New World. But the cost of the war had greatly enlarged Britain's debt.