Identify $X$ and $Y$ from the figure representing an Electrostatic Precipitator:
$X-Y$

Give differences: $BOD$ and $COD$.

Electrostatic Precipitator $(ESP)$:
$I.$ Is an electrical device to remove particulate matter present in the exhaust of thermal power plant.
$II.$ More than $99\, \%$ particulate matter can be removed by this method.
$III.$ $ESP$ has electrode wires and a stage of collecting plates.
Which of the statements given above are correct?

What does a high $BOD$ of water indicate?

Which of the following is not used in catalytic converters?

What was the cause of the 'Yusho' disease which occurred in $1968$ due to a leak in a canning factory?