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

Why urea is known to denature proteins, Urea is known to denature proteins ...

Urea is known to denature proteins Based on the structure of urea, how do you think this occurs?

Use mathematical calculations to justify the answer, Using an average wavel...

Using an average wavelength of 450 nm (0.45 um) can you resolve two objects that sit greater than 200nm apart from one another? Use mathematical calculations to justify your answer

Significance of apomixis, Significance of Apomixis Apomixis offers th...

Significance of Apomixis Apomixis offers the possibility of indefinite multiplication of especially favorable biotypes without any variation due to segregation or recombinati

Stds, define stds give 5 examples of stds give signs, symptoms, treatment a...

define stds give 5 examples of stds give signs, symptoms, treatment and prevention of each example

Explain positive staining technique, Explain Positive Staining Technique? ...

Explain Positive Staining Technique? Here, a stain has a positively charged chromophore that gets attached to the negatively charged outer surface of the microbial cell and thu

How much sds need for 50 ml, How much SDS do you need for 50 ml of a 20% SD...

How much SDS do you need for 50 ml of a 20% SDS solution in water(weight/ volume)? SDS is a solid.

Define deuterostomes in animal kingdom, Define Deuterostomes in animal king...

Define Deuterostomes in animal kingdom? Coelomate animals are thought to have separated into two divergent lines of evolution in terms of the way embryos develop. In the embryo

What is the plant hormone remarkable for stimulating, What is the plant hor...

What is the plant hormone remarkable for stimulating flowering and fruit ripening? What are the uses and practical inconveniences of that hormone? The plant hormone notable for

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