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

Explain behavioural counseling, Behavioural Counseling This evolved fro...

Behavioural Counseling This evolved froni tlie early theories  of  behaviourism.  The focus is on examining current behaviours and learning new ones.  It is believed that feeli

To test the effects of temperature on the activity of yeast, To test the ef...

To test the effects of temperature on the activity of yeast Make up a quantity of bread dough .Stir a yeast cake in water and methodically mix the yeast with the dough. Divide

Balloon aortic valvuloplasty for aortic stenosis, Q. Balloon Aortic Valvulo...

Q. Balloon Aortic Valvuloplasty for aortic stenosis? This is the procedure of choice in children and young individuals where the valve is not calcified. In elderly patients wit

Cation exchange capacity, Cation Exchange Capacity The adsorption of a ...

Cation Exchange Capacity The adsorption of a cation by a colloid nucleus or micelle and the accompanying release of one or more ions held by the micelle is termed as 'cation ex

Concentration gradient and passive and active transport, Q. What is the rel...

Q. What is the relationship between concentration gradient and passive and active transport? Passive transport is the movement of substances across membranes in favour of their

Respiratory system, describe the structure of a lung in terms of covering m...

describe the structure of a lung in terms of covering membranes and cavities

Determine the functional brain activity, Determine the functional brain act...

Determine the functional brain activity PET is powerful means of assessing functional brain activity, although it does not directly measures neuronal events. Rather it indicate

Enteric infectious viral disease, Match each item in Column A with the corr...

Match each item in Column A with the corresponding item in Column B regarding infectious diseases Column A Column B a. Pulmonary tuberculosis i. Enteric infectious protozoan diseas

Induction of antimicrobial substances, Induction of antimicrobial substance...

Induction of antimicrobial substances Phytoalexins are antimicrobial substances produced by plants in response to pathogen. They accumulate at the site of infection. For exam

When should eat a salad with lettuce, When you eat a salad with lettuce, cr...

When you eat a salad with lettuce, croutons, hard-boiled egg, bacon bits, and salad dressing, which one of those ingredients will be broken down the least by your digestive system?

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