Sludge as a fertilizer. Cheremisinoff [4] also indicated that kitchen and other similar wastes
contain a high concentration of phosphorus . Furthermore , nitrogen and phosphorus level were high in
the wastewater of food industry [36]. Table 2 shows the mean total nitrogen content[28:8.26%
protein ¼ 13,217 mg / kg nitrogen calculated with a conversion factor of 6.25]of the sludge from
flotation as dry basis was slightly richer than that of pig manure [28:7.69%protein¼12,300mg/kg
nitrogen calculated with a conversion factor of 6.25]which is traditionally utilized as anorganic
fertilizer bymostfarmers [37]. Similarly, the mean total phosphorus level(1133 mg / k g¼ 0.11% )of the
sludge from flotation was nearly the same as that of the swine manures[37:1100mg/kg¼0.11%].