An experiment for pathogen removal from a raw sewage sludge (55) by
composting and addition of cement kiln dust (CKD) was carried out at the
Experimental Farm of the Faculty of Agriculture, Suez Canal University, Ismailia
Governorate. 55 from the Wastewater Treatment Plant at 5 erabium, I smailia, was
mixed with ground rice straw (RS) on equal weight basis. The mixture of SS and RS
was composted individually or blended with CKD, on weight basis as follows: SS-RS
mixture, SS-RS mixture+5%CKD, SS-RS mixture+10%CKD, SS-RS
mixture+15%CKD and SS-RS mixture+20%CKD. Different compost mixtures were
regularly mixed in elongate piles 5 m long and 1 m high and wide. Temperature and
pH values were recorded, total coliforms, Salmonella spp < /em>., Shigella spp < /em>., Klebsiella
spp < /em>., Vibrio spp. and Ascaris humbericoides ova counts were counted at various
composting stages (0, 1, 2, 3, 5, 7, 15, 3D, 45 and 60 days). Data for all composting
treatments indicated that: Temperature was gradually increased by increasing composting period and
application rate of cement kiln dust till the 5 Ih or 7 Ih day and then again declined till
so" day (the end of the experiment).The pH decreased as composting progressed till
the end 0 f c om posting and increased by increasing application rate of cement kiln
dust at all composting stages. Total coliforms, Salmonella spp < /em>., Shigella spp < /em>., Klebsiella spp., Vibrio spp < /em>.,
and Ascaris humbericoides ova counts decreased as composting progressed till the
end of composting. Pathogenic bacteria and Ascaris parasite ova counts of mixtures
decreased and the reduction percentages increased by increasing application rate of
cement kiln dust. Ascaris parasites were more resistant tot he c omposting and CKD blending
than other pathogens. Also, total coliforms and Salmonella sp < /em>p < /em>. were less resistant to
destroy by compo sting and CKD blending than other pathogenic bacteria.