The catalytic effect of waterworks sludge on NOx removal in

pellets and sludge pellets combined packed-bed plasma reactor with plate-plate electrode geometry is measured for the various conditions. NOx removal rate is about 90[%] at

-sludge combined reactor used fresh sludge.

and

as byproducts are significantly generated in only

packed-bed plasma reactor, however, in

-sludge combined packed-bed reactor,

and

are completely removed while

as by-products are observed from FTIR spectra.

and

seem to react with metallic molecules, metal oxide, and organic compounds that are generally chlorophyll included in sludge. NOx removal rate increases with

concentration increasing. Removal rates

and

are independent of operating time and repetition measurement times.