Environmentally Friendly Waste System

We have wanted to run our first run of the experiment for quite sometime, however, due to circumstances, we have not been able to run the experiment proper.


We met with difficulties when the coupling of the vacuum truck and the digester did not fit, also he second time we went down to the SVF, we realised that there was no sludge available nor will there be any available anytime soon. This was due to the camps being cancelled in view of the H1N1 situation. After much discussion, we took Dr Han's idea of using municipal waste instead.




In summary, these are the problems that we have faced:


1. Lack of planning for our first experimental run; not fully prepared
2. Coupling of the vacuum truck and the digester did not fit
3. Cancellation of camps due to H1N1 situation
4. No sludge is available at Singapore Vision Farm (SVF)




Classification of various causes leading to the main concern of not able to carry out the first experimental run is done using a cause and effect analysis.

Furthermore, in this project, we are trying to collect the methane gas produced during the anaerobic stage of digestion. That is the main focus at the moment. Hence, although municipal waste is used instead of human waste, methane gas will still be produced and the collection can be done. The only problem is that we still cannot prove that the human waste that is digested is fit to use as fertilizers for plants.



In addition, since we are also thinking of introducing a wetland system, it doesn't really matter what kind of sludge is used. The only concern may be the extra contaminants contained in the municipal waste that needs to be properly dealt with.



Right now, we are doing calculations on the sizing of the methane collector. Our idea is to use the solubility of the other gases like CO2 and H2S and calculate that in relation to the residence time. From the residence time, we can gauge the height of the tank needed. The initial thought of design will is a thin but tall tank, that way, the other gases can be dissolved more easily as compared to a larger tank. This is because the bubbles that come through the tank will only be in a straight line and hence there isn't a need for a large tank.



More on the calculation will be updated