Biology water

recycling

What is recycling of water?

• Treatment of wastewater is actually a remarkably simple process that utilizes very basic physical, biological, and chemical principles to remove contaminants from water.  Use of mechanical or physical systems to treat wastewater is generally referred to as primary treatment, and use of biological processes to provide further treatment is referred to as secondary treatment.  Advanced secondary treatment usually involves applying chemical systems in addition to biological ones, such as injecting chlorine to disinfect the water

How is it done..?• recycling graywater can also

be doncost-benefit analysis of a free, more labor-intensive system versus an installed, more expensive system is going to be a no-brainer: a free or cheaper system is usually the way to go. Many people who recycle their graywater bootleg it anyway (especially in California, where the legalities are so complex that it makes it almost impossible to recycle water for less than $5,000 or $7,000).e at home

How is it utilized?• Recycled water can be used for

almost any use, as long as it is treated to a level to make it fit for that intended purpose (i.e. fit-for-purpose) from a health and environmental perspective . However, the cost of treatment may make reclamation uneconomical for some uses. Australia now has more than 600 different recycled water schemes operating. The bulk of these schemes involve:

• Urban and municipal environments• Households, golf courses and

recreational parks.• Industry• Washing and cooling in power

stations and mills.

chemistryHardness of

water

what causes hard water?

• A compound called calcium hydrogen carbonate is the main cause of hard water. It forms when rain falls on limestone and chalk rocks. These rocks are made of calcium carbonate, which is insoluble in water. Because rain water contains carbon dioxide, dissolved from the air, this makes it acidic. The rain water reacts with the rocks to form calcium hydrogencarbonate which is soluble. This is the white solid that ends up in our kettles.

• An equation for the reaction is:

• water + carbon dioxide + calcium carbonate = calcium hydrogencarbonate

• H2O (l) + CO2 (g) + CaCO3 (s) = Ca(HCO3)2 (aq)

How to remove hardness of water?• Base exchange process' is

a chemical method by which, softening of permanent hardness in water can be done on a large scale or for household purposes. It is the most popular and effective means of softening hard water. It was discovered by Dr. Robert Gans, who found out the natural minerals called 'Zeolites', which is very effective in softening water,

Physics:water as an

energy resource

Tidal energy• Jump to: navigation, search • Tidal energy, sometimes called tidal

power, is the power achieved by capturing the energy contained in moving water in tides and open ocean currents.

• There are two types of energy systems that can be used to extracted energy: kinetic energy, the moving water of rivers, tides and open ocean currents; and potential energy from the difference in height (or head) between high and low tides. The first method - generating energy from tidal currents - is becoming more and more popular because people believe that it does not harm the environment as much as barrages or dams. Many coastal sites worldwide are being examined for their suitability to produce tidal (current) energy

Wave energy• Wave energy is the transport of

energy by ocean surface waves, and the capture of that energy to do useful work – for example, electricity generation, water desalination, or the pumping of water (into reservoirs). Machinery able to exploit wave power is generally known as a wave energy converter (WEC).

• Wave power is distinct from the diurnal flux of tidal power and the steady gyre of ocean currents. Wave-power generation is not currently a widely employed commercial technology, although there have been attempts to use it since at least 1890.[1] In 2008, the first experimental wave farm was opened in Portugal, at the Aguçadoura Wave Park.[2] The major competitor of wave power is offshore wind power.