Isnin, 8 Disember 2008

Waste Management [Part 1]

By definitions, waste is an unwanted or undesired material or substance. It is also refered to as rubbish, trash, garbage, or junk depending upon the type of material and the regional terminology. In living organisms, waste relates to unwanted substances or toxins that are expelled from them.(wikipedia-waste-1st may 2008)

Everybody in the world produce waste, either u r engineer, chidren, doctor or a housewife. We cant run away from waste. In life-cycle thinking, the is no term 'zero emission'. It is impossible for a human or machine not to produce waste where it means that efficiency is always less than 100%. But the important things as chemical engineer is to make people take waste a valuable things, not to be thrown away just like that. In hierarchy of waste management, the first things is prevention, then minimisation, reuse and recycling and the last option is disposal.


There are two types of waste;controlled waste and special waste. In controlled waste, waste can be divided into two parts,Municipal Solid Waste(MSW) and Industrial waste. MSW basically is a waste from household(domestic,schools,hospitals) and commercial(trade,business).Everybody produce MSW in household through individual activities. But both household and commercial usually have similar composition so they are classified as a same types of waste(MSW).

Another types of controlled waste is industrial waste which is basically from factories and transport. Generally most of this types of waste can be treated and more easier than Municipal Solid Waste(MSW). We will discuss about how to manage this waste later as controlled waste contributed a lot to enviroment (well, everybody produced controlled waste)

Last but not least is special waste where most part of it is hazardous. It is almost imposibble to treat this types of waste. For example is nuclear waste from diffusion of uranium factory to generate energy. At this time, we still didn't find the best way to decompose it. We just put nuclear waste into very thick concrete and buried it into deep sea. This is not good for future generation(not sustainable). Yes it is very toxic and radioactive and we give this 'gift' to our grandchild. How they will react later, say thanks? No way! For me, nuclear power is still not a choice to produce energy. Yes it produce lots of energy but it waste is very toxic. However there is a technology now to laser neutron into radioisotope the reduce its half-life. It have been done by Brit for iodine where its half life from something like 25million years to 25minutes. It is still very expensive and only in lab scale, not industrial scale.

30% of food that we buy in store will become spoiled food and then become waste. This statistic is SO TRUE. You go to Tesco and buy some food but you'll realised that most of the time u didn't finished it. Some you'll just throw it due to expired date has passed. Some because you dont like it taste bla bla bla. But won't you ever think that there is some part of our world(escpecially Africa and South America part) didn't have enough food. Some children just eat once a day. We can help them by giving donation and sort of things. In my opinion, we can reduce this household waste just by listing all the things that you want to buy first before go shopping. Differentiate between needs and demands. At least in this way we can reduce waste.

-Din-
1st May 2008

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