Muncipal water treatment , Biology

Assignment Help:

The modern water treatment plan is often called upon to perform wonders with the water fed to it.  The clear, safe , even tasteful water that comes from a faucet may have started as a murky liquid pumped from a polluted river laden with mud and swarming  with bacteria. Or, its source may have been well water, much   too hard for domestic use and containing high levels of stain-producing dissolved iron and manganese. The water treatment plant operator's job is to make sure that the water plant product presents no hazards to the consumer.

A schematic diagram of a typical municipal water treatment plants is shown in fig. 2.1. This particular facility treats water containing excessive hardness and a high level of iron. The raw water taken from wells first goes to an aerator. Contact of water with air removes volatile solutes such as hydrogen sulfide, carbon di-oxide, methane, and volatile odorous substances such as methane thiol (CH3SH) and bacterial metabolites. Contact with oxygen also aids iron removal by oxidizing soluble iron (II) to insoluble iron (III). The addition of limes as CaO or Ca(OH)2 after aeration raises the pH and results in the formation of precipitates containing the hardness ions Ca+2 and Mg+2. These precipitates settle from the water in a primary basin. Much of the solid material remains in suspension and requires the addition of coagulants (such as iron III and aluminum sulphates) to settle the colloidal particles. The setting occurs in a secondary basin after the addition of CO2 to lower the pH. Sludge from both the primary and secondary basins is pumped to a sludge lagoon. The water is finally chlorinated, filtered and pumped to the city water mains.

 

 


Related Discussions:- Muncipal water treatment

Ilustrate about corvous caurinus, When we watch animals in the wild, most o...

When we watch animals in the wild, most often we see them foraging for food. The foraging behaviour of animals has been a focus of behavioural studies for many decades. Natura

Carditis, It has been shown by prospective studies that Rheumatic heart dis...

It has been shown by prospective studies that Rheumatic heart disease (RHD) is linked to the occurrence of carditis during the first episode of ARF. If the first episode is accompa

Formation of pronuclei , Formation of pronuclei : Information of pron...

Formation of pronuclei : Information of pronuclei, micronucles which is one of the conjugants, plays an important role. Micronucleus undergoes meiosis and forms four haplo

Explain lane eynon method procedure, Q. Explain Lane Eynon Method procedure...

Q. Explain Lane Eynon Method procedure? You will be carrying out the procedure in two steps using Lane Eynon Method. Step 1 It involves the standardization of copper s

Significant for chromosomes, Q. Why is it significant for chromosomes to be...

Q. Why is it significant for chromosomes to be condensed during mitosis and decondensed during interphase? During mitosis the major problem to be solved is the correct separati

How is the cerebrum anatomically divided, How is the cerebrum anatomically ...

How is the cerebrum anatomically divided? The cerebrum is divided into two cerebral hemispheres, the right and the left. Each hemisphere is made of four cerebral lobes: frontal

Determine what is the dose to the thyroid, 1. Compute the mean energy per n...

1. Compute the mean energy per nuclear disintegration, A, for 99m TC if 2.0 x 10 9 Bq of this isotope is injected into a patient. Assume that one-half of the administered dose is

Diffusion, applications of diffusion

applications of diffusion

Impact of technological change on the cost of health service, Impact of Tec...

Impact of Technological Change on the Cost of Health Service Technological developments entail improvement in production/service frontiers either by providing cost benefit adv

Types of cardiac dopler, There are two types of Doppler examination: 1) ...

There are two types of Doppler examination: 1)  Pulse wave Doppler 2)  Continuous wave Doppler Both these modalities are necessary part of Doppler echocardiography and pro

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd