the performance of iron nanocomposites as persulfate activators in permeable reactive barrier technology for treatment of landfill leachate

Landfill leachate contains a large organic load and a wide spectrum of pollutants, and it needs appropriate treatment to reduce the severity of these contaminants. therefore, the present study aimed to remove chemical oxygen demand (cod) and ammonia (nh3 ) as target contaminants from the landfill leachate. to this end, the zero-valent iron nanofibers/reduced ultra-large graphene oxide (zvinfs/rulgo) and converter sludge (cs) were used as persulfate (ps) activators in permeable reactive barrier (prb) technology for removing cod and nh3 . the box–behnken design (bbd) was employed to determine the possibility of using each activator and optimize three parameters: activator, pore volume (pv), and flow (ml/min) using target contaminants. in the batch process, the effects of ph, activator concentration, and ps/cod mass ratio on cod removal were examined. the bbd experiments provided a satisfactory predictive model, indicating that zvinfs/rulgo is superior to cs when used as activators of ps in prb technology. the biochemical oxygen demand (bod5 )/cod ratio increased from 0.24 in raw leachate to 0.67 in treated leachate, and leachate toxicity was reduced by more than 85%. additionally, the zvinfs/rulgo and cs contributed to the activation of ps.