By:Nibedita Saha Form One TMA
Submitted to:Mr. Pervez
Due on: 27-05-08

We were all very excited to go to the Ma On Shan
Water Treatment Plant but it didn’t turn out as good as we thought it would. There were lots of mosquitoes and it was too hot on that day.
Everyone was whining and it wasn’t that great. It wasn’t as interesting as the other treatment work as well. It was much smaller and was too empty, but we still saw quite a bit of things and gained some knowledge as well.

When we entered the treatment work, our tour guide was waiting for us. He took us all into a large room and showed us the same video as the one we saw in Sha Tin but it wasn’t that bad at all. The video contained a lot of information which I have missed out in Sha Tin. I still liked it. It showed us how the department treats raw water and turns it into to drinkable water. There are many different processes to treat raw water.
Sedimentation, chlorination, filtration and fluorination are some of them. The water also has chemicals in it to kill the germs and bacteria in it. Through the video, I got to know that the workers are doing an excellent job in treating the water at their level best and I hope they keep it up in the future as well.

The guide showed and told us how the treatment process works and also about the treatment of sludge. There is a separate sludge house in which sludge is treated. He told us about all the different processes and explained it to us.

After his information, the guide took us around to tour the real machines of water treatment. It was huge and there was water everywhere. There were many rectangular holes in which water was put in and treated. Chemicals were also added in those holes to kill the bacteria and keep the drinking water safe.
We saw one of the processes but couldn’t really make out which process it was. Air was coming out from underneath. After taking a look at the sludge treatment plant, our tour ended and we went back to the hall.

After our tour ended, we all went back to the original hall from where we started our day. Over there, we got a pen, a ruler and some leaflets as a souvenir. When we received that, it was time for us to go back. I am glad the workers are working so hard to keep our drinking water safe and clean. This will be a memorable trip for me.

Flocculation/Sedimentation
Flocculation refers to water treatment processes that combine or coagulate small particles into larger particles, which settle out of the water as sediment. Alum and iron salts or synthetic organic polymers (used alone or in combination with metal salts) are generally used to promote coagulation. Settling or sedimentation occurs naturally as flocculated particles settle out of the water.
Filtration
Many water treatment facilities use filtration to remove all particles from the water. Those particles include clays and silts, natural organic matter, precipitates from other treatment processes in the facility, iron and manganese, and microorganisms. Filtration clarifies water and enhances the effectiveness of disinfections.

Ion Exchange
Ion exchange processes are used to remove inorganic contaminants if they cannot be removed adequately by filtration or sedimentation. Ion exchange can be used to treat hard water.
It can also be used to remove arsenic, chromium, excess fluoride, nitrates, radium, and uranium.
Adsorption
Organic contaminants, unwanted coloring, and taste-and-odorcausing compounds can stick to the surface of granular or powder activated carbon and are thus removed from the drinking water.

Disinfections (chlorination/ozonation)
Water is often disinfected before it enters the distribution system to ensure that potentially dangerous microbes are killed. Chlorine, chloramines, or chlorine dioxide are most often used because they are very effective disinfectants, not only at the treatment plant but also in the pipes that distribute water to our homes and businesses. Ozone is a powerful disinfectant, and ultraviolet radiation is an effective disinfectant and treatment for relatively clean source waters, but neither of these are effective in controlling biological contaminants in the distribution pipes.