Q $4.(25$ marks$)$

Given the information of a mixed municipal solid waste in Table $4-1$:

a$.$ Calculate the moisture content and energy content of the commingled municipal solid wastes;

$(6$ marks$)$

b$.$ If $\backslash (50\backslash \%\backslash )$ of the food waste, $\backslash (50\backslash \%\backslash )$ of the paper, $\backslash (100\backslash \%\backslash )$ of cardboard, $\backslash (100\backslash \%\backslash )$ of the metals, and $\backslash (100\backslash \%\backslash )$ of the plastics are recycled, how would this affect the moisture content and energy content of the municipal waste collected?

$(8$ marks$)$

c$.$ Outline briefly typical composting and anaerobic digestion mechanisms for biowaste management. What operational aspects should be considered, in order to obtain a high quality of compost?

$(7$ marks$)$

d$.$ Draw a graph showing how temperature varies in a windrow composting process from the commencement of composting.

$(4$ marks$)$

Table $4-1$: Composition municipal solid waste

$\backslash$begin$\{$tabular$\}\{|$l$|$c$|$c$|$c$|\}$

$\backslash$hline Component & $\backslash$begin$\{$tabular$\}\{$c$\}$

Moisture $\backslash \backslash$

content $(\backslash \%)$

$\backslash$end$\{$tabular$\}$ & $\backslash$begin$\{$tabular$\}\{$c$\}$

Energy $($wet mass $\backslash \backslash$

based; kJ$/$kg$)$

$\backslash$end$\{$tabular$\}$ & $\backslash$begin$\{$tabular$\}\{$c$\}$

Percent by weight $\backslash \backslash$

$($wet mass$)$

$\backslash$end$\{$tabular$\}\backslash \backslash$

$\backslash$hline Food & $70$ & $2300$ & $13\backslash \backslash$

$\backslash$hline Paper & $6$ & $7200$ & $30\backslash \backslash$

$\backslash$hline Cardboard & $8$ & $7200$ & $11\backslash \backslash$

$\backslash$hline Plastics & $3$ & $14000$ & $9\backslash \backslash$

$\backslash$hline Yard waste & $75$ & $2640$ & $18\backslash \backslash$

$\backslash$hline Metals & $2$ & $200$ & $10\backslash \backslash$

$\backslash$hline Miscellaneous & $30$ & $2000$ & $9\backslash \backslash$

$\backslash$hline

$\backslash$end$\{$tabular$\}$

END