Conditioning of sewage sludge by prickly pear cactus (Opuntia ficus Indica) juice

The possibility of using a plant material, prickly pear cactus, Opuntia ficus Indica, juice (OFIJ), for conditioning the Beni-messous wastewater treatment plant sludge was examined. Optimum dosage of OFIJ was found to be 0.4 g kg−1 of dry matter. The residual turbidity, the dryness of filtration cake and the specific resistance of filtration were found to be 2.5 NTU, 24% and 0.13 × 1012 m kg−1 respectively. The results obtained with OFIJ were compared to those obtained with polyelectrolytes: Chimfloc C4346, a cationic polymer, Sedipur NF 102, a non-ionic polymer and Sedipu AF 400, an anionic polymer, and inorganic conditioners, FeCl3 and Al2(SO4)3. The optimum dosages of those conditioners were found to be 0.4 g kg−1 for OFIJ, 0.8 g kg−1 for Chimfloc C4346, 80 g kg−1 for FeCl3 and 60 g kg−1 for Al2(SO4)3.