PARAMETERS AFFECTING CONDITIONING ENHANCEMENT OF BIOSOLIDS BY ELECTRON-BEAM TREATMENT

High-energy radiation has been investigated as an alternative method f or sludge conditioning. Since the efficiency of sludge disinfection an d toxic organic chemical destruction due to irradiation is well docume nted, this study concentrated on theoretical and experimental aspects of sludge dewatering enhancement (conditioning) due to irradiation. Th e primary parameters used for evaluation of conditioning were specific resistance of filtration, bound water current, and zeta potential of sludge. Experimental results showed that the scavenging power of sludg e systems was higher at larger absorbed radiation doses. When the scav enging power exceeded 10(9) (s(-1)), the scavenger (KCNS), could compl etely eliminate the effect of conditioning of liquid sludge by radiati on-absorbed doses up to 2,000 krads. It was observed that bound water content was reduced by irradiation processes, and sludge zeta potentia l became more positive with increased doses. The experimental results also showed that larger absorbed radiation doses yielded better treatm ent results, but generally with a lower efficiency within the tested d ose range. These findings confirm that irradiation can reduce sludge b ound-water content and enhance agglomeration by altering sludge partic le surface charges.