Evaluation of Ferrate(VI) as a conditioner for dewatering wastewater biosolids

Land application of sludge/biosolids is a commonly used practice for final utilization. Therefore, adequate conditioning and stabilization of wastewater solids is very critical for safe land application. The addition of ferrate (FeO₄^2-) has the potential to improve the dewaterablity of solids, destroy pathogenic organisms, and reduce certain endocrine disrupters. In this study, the dewaterbility and stabilization of thickened sludge treated with ferrate was evaluated under controlled laboratory conditions. To evaluate dewaterbility, three different techniques; belt-press, centrifugation, and vacuum filtration, were applied to dewater a mixture of solids. In addition, once biosoilds are generated, their safety and quality especially in terms of reduced endocrine disrupting compounds (EDCs) as well as pathogens become an important issue to the public. Therefore, the effectiveness of ferrate (FeO ₄^2-) in disinfecting microorganisms and in oxidizing EDCs, i.e., Nonylphenols and polybrominated diphenyl ethers, is briefly discussed.