SOLID WASTE MANAGEMENT -2
By Umar Bashir
A mature and responsible approach about the management of solid wastes begin in the later part of 19th century , as Watertight cans were used to collect the solid waste and in many areas of United States Sturdier vehicles were used to amass & transport solid wastes at Fixed patches. However a significant and valuable development was seen regarding the waste management , when the city of England got the construction of ist refuse incinerator in the year if 1874. And by the beginning of 20th century , 15% of American Big cities has got incinerating plants , however many are using previous equipments but the weightage of disposal is same.
While the going of time , the technology management of wastes also has been getting advanced and the many more instruments has come between the inception and disposal of wastes , like garbage grinders , compaction trucks and the pneumatic pipe system came into place , as disposing of wastes in the open fields creates more pollution , havocs Environment & jeopardized health of the living beings. For this a new system of has been processed , which is more advanced and sheild guard for any inconvenience of Environment , I;e sanitary landfill system.
This system Replaces the incineranations and dumping of wastes in open , which is really a mammoth system to mitigate adulterate of Environment. However the use of sanitary landfills protects and guards Environment from the noxious effects as emited by Incinerators and dumping and these landfills are well equipped. Now a days , the Incinerators are also made in such form , which deplete heats to go outside and have extensive air pollution control devices to satisfy the stringent quality of air . And now in the modern times , solid waste management plants are emphasized with recycling and waste reduction chambers at the sources.
SOLID WASTE CHARACTERISTICS
there are different kinds of solid wastes due to its different source of emitting and examption. These wastes may be from Residential houses , commercial properties , industries , institutions etc etc . However the main character and most decisive character which will make huge difference between them is , hazardous behaviour and non hazardous nature. The hazardous wastes are collected in the proper paved way , then disposed or recycled in the keen approach , a small mis handle may Cause huge or grieve damage , so one has to been very heedful and perform these things in well subordination and technological ways. These hazardous have good sources but not as much as non hazardous have , because these are emitted from many and Common sources , so for a Common management and at individual level one can easily manage non hazardous wastes , if follow the procedure in the very ethic way.
The non hazardous wastes while collected , should be segregated and divide them into wet and dry chambers , those who are wet should get decomposed into some manure form but those which are dry should be used for some other purpose after recycling.
This may also contain the garbage and rabbish components , however the garbage is compositable while as the trash or we can say rabbish is recycled and then Turned for other equipments , as they aren’t hazardous , so those can be recycled and then reused for other purposes. Such like trash adds about 20% of MSW in the USA in the municipal solid wastes. Such kind of waste is specifically called as Construction and demolition ( C & D) process and are Verily process across many developed nations.
The generation of the solid wastes varies from nation to nation as populace of the Respective area have Different behaviour and approaching towards Environment , so there may be difference in the generation of wastes at every nation level. Let we take an example of different nations , as America has very low wastes of paper than the nations of Japan , Europe . Or we can emphasize example of India , it has more wastes of plastics than other , so behaviour of people and coordination of people with Environment makes variation in the generation of wastes .
The rates of wastes generated per person per day also varies from nation , as taking the example of America , they generate 2kg per person per day , while in Canada they generate 2.5kg per day and in other nations they generate 0.5kg per person per day . However in few advanced nations , they generate lower than this because they some balanced behaviour with the Environment and management of wastes.
As many wastes are generated through the food residues or we can say wastes generated through houses and municipals . Those very wastes should be collected and then management very consciously because those very wastes are compositable and can be easily get degradated , which will deplete the generation quantity and will give protect Environment from sting smell , rodents and other things.
COLLECTING AND TRANSPORTATION
The solid wastes coming from houses or municipal means or any other means must be collected in healthy , hygienic way , so that the Environment will remain safe , neat and organized . However this very process is really expensive in labour basis but it has much more benefits by collected them in the advanced and technology methods. For the collection of the wastes , Respective authorities should use the advanced systems like pneumatic pipes , compactors . This will make the collection easy process and will make more simple . Also to compact and then collect them in the easy way , we should use grinders , which reduces the area of the wastes and then becomes easy to collect them.
For the transportation , authorities should use those typical trucks , which have enclosed and compact type system , which can sort & have capacity of 30 cubic metres. Also loading can be done from the front , rare side & compaction depletes the size of wastes and weight too. In the many advanced nations , the optimal selected routes have been used for the collection of regional wastes but this very process becomes more complex in the cities of low advance especially those which are congested and can’t make a good frame because this very optimal route is computer based but really hectic for the cities having congested areas.
While opting such advanced technology in the rural areas , it becomes very much costly because those areas are low in population density and it needs lot of labour and work , thus becomes more expensive.
The refuse collection should occur after small regular intervals as this garbage is degradable so it emits foul air , which may adulterate Environment and also within these interval days , the refuse is reduced in the size and then it will become easy to handle it.
A transfer station means ; the central facility which gets refuse from many other vechicals which can be called primary vechicals , when the community or any other patch doesn’t contain final destination near . It may be some tractor like or other vechicals which could hold 70 cubic metres of uncomposed wastes . And in many cities campact regional compactors are used because of closed lids and can unload by himself. These like closed compact systems are also used because of well equipped ejector systems and closed system.
In short we can say , the vechicals are ist emptied in the pit then the refuse or wastes are hoisted by mechinary into ahead transfer station.
TREATMENT AND DISPOSAL
When the solid or municipal wastes are collected , they are then treated in order to minimise the size , so that they could be holded in the organised manner and in high quantity. It have more beneficial assertions like reduced in volume , weight and few other mixtures can be separated . So this treatment changes the behaviour , which really gives some ideas about reuse and recycle things. In the process of Reducing size and volume , it requires many processes like ;
Incineration . Though we can reduce the size and volume by the burning process also but this process is very noxious , as it adds green house gases in the atmosphere , so this burning is not suitable way of reducing size . However in these new incinerators the wastes are reduced in size and volume by burning in a very advanced , controlled furnace which doesn’t add green house gases in the atmosphere. With this incineration process , the refuse gets 90% reduced in size , volume and weight , leaves behind the ash ,residues at the bottom called specifically as Bottom ash. And the other part called as fly ash should be maintained in the balanced way within incinerator , these incinerator should be guarded with high quality emission control devices , so that these may not sting atmosphere. Such devices should have modern equipment of controlling like electrostatic precipitator , gas scrubbers and many other , so that it could sheild the adulteration of Environment.
In the advanced incinerators , the wastes are burnt inside and the combustible portion admixes with oxygen , emits mostly CO2 , water vapour and heat but are processed in a very controlled equipments.
Modern day incinerator are guarded with well desired recieving and buring equipments , which can burn the refuses in the easy way and can hold one day refuse in a single attempt by having storage pit and stropping area. It’s taken out from the pit by the help of crane and is then putted into hopper and chute , charging in the grate in the furnace. Advanced incinerators also contain , rectangular furnace , rotatory kilns and other advanced technologies like vertical furnaces which maintain and controlled the refuses verily. These are made of refractory bricks , these can withstand with the high temperature and can’t emit those temperatures towards atmosphere. Thus these furnaces are very useful and are beneficial on environment presprective.
The combustion which is processed in these furnaces are grouped into processes , primary & secondary . In the primary combustion the refuses are turned dry by driven out moisture and then volitized , in the secondary the remaining unburnt residues are oxidized , eliminated , exhausted. In order to make both these processes very effective , it requires enough oxygen , which can be easily given by the mixing oxygen with refuse through the grates and admitted above. However the continuall supply of air can be maintained by making natural draft through forced draft fans.
Another method through which refuse can be treated , as refuse contains both kinds of matter organic as well as inorganic , However organic is decomposable , so this can be separated and putting into decomposition process by the use of microbes . This can reduce the volume n size by about 50% and then can be used for manure over the lands . During this process both types of wastes like garbage & sludge can be recycled & processed , with this the application of incineration may increase Upto good height.
SORTING & SHERDING
The decomposible wastes are separated in the refuse either on the basis of size , density , volume etc and are divided into glasses , metals and inorganic materials. These are done through physical separation or by the use of mechanical engineering magnetic properties or density.
The shredding is processed by hammering and rotatory approaches , reduces the size and results in the uniform mass of material.
This is the most common and acceptable method to deal with the refuse for management of wastes. A hygeinic area which is being selected for the deposition of refuses and is far away from the community population , also should be in the direction where the wind can go from population community towards that , so that foul air can’t bear to community . While burring the wastes , the pit shouldn’t be so deep as to get contacted with the water table , as it’s secretion may profine water.
To design such system , one has to liner the bottom and make desicion on the engineer confab based , then it will be more reliable and trustworthy towards Environment as well as for decomposition. The landfill surfaces Lucy be capped with impermeable covers to keep away from surface run off and bottom should be lined with plastic membranes too , which will not allow secretion downward . This very system will be reliable and accurate for the decomposition of wastes..