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

Determine the effect of iodine deficiency, Determine the Effect of Iodine D...

Determine the Effect of Iodine Deficiency? Iodine deficiency affects all populations at all stages of life, from the intrauterine stage to old age. However, pregnant women, lac

What is gene therapy, What is Gene therapy Gene therapy targets non ger...

What is Gene therapy Gene therapy targets non germ line cells, ie somatic cells, so will not directly affect gene pool. The frequency of the allele for the genetic disease w

What is the determination of vitamin B2, What is the Determination of vitam...

What is the Determination of vitamin B 2 In the chemical method, the yellow-green fluorescence of aqueous solution of riboflavin is measured. In the microbiological assay, tur

Altered protein metabolism - metabolic response to injury, Altered Protein ...

Altered Protein Metabolism - Metabolic Response to Injury? Urinary nitrogen loss is extensive following injury, Trauma accelerates nitrogen turnover. In unfed patients, tissue

How is hemophilia treated, Q. How is hemophilia treated? Why is hemophilia ...

Q. How is hemophilia treated? Why is hemophilia rare in females? Hemophilia is medically treated with administration of factor VIII in case of hemophilia A or of factor IX in c

Extended point within pulp chamber-endodontics principles, Extended point w...

Extended point within pulp chamber: Gripping action: -    Steglitz forceps or pin pilers. -    Access cavity flooded with chloroform to dissolve the sealer. -    Grasp the

What are pure culture techniques, What are Pure Culture Techniques? Mic...

What are Pure Culture Techniques? Microorganisms can be isolated from various natural environments like soil, food, water, sewage, decomposing matter and even from infectious m

Prognosis, The course and ultimate prognosis of ARF is usually directly rel...

The course and ultimate prognosis of ARF is usually directly related to the severity of carditis. The course and prognosis also depends upon recurrence of rheumatic fever. In pre-p

What a test tube brush and how is it used, What a test tube brush and how i...

What a test tube brush and how is it used? It is a method, made with nylon bristles attached to a twisted-wire shaft, used to knock the bottoms out of test tubes.

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