Enhanced sludge dewatering and drying comparison of two linear polyelectrolytes co-conditioning with polyaluminum chloride

AbstractThis paper investigated the influence of polyaluminum chloride (PAX-14) co-conditioning with two linear polyelectrolytes on the dewatering and drying performances of urban residual sludge. Experiments were carried out on activated sludge samples collected after thickening from the Grosses Battes wastewater treatment plant. Dual conditioning implying PAX-14 coagulant and two cationic polymers, only differing by their molecular weight, were tested. The first part of the study was an experimental study of sludge dewatering improvement in terms of dry solids content of the dewatered cake and the evaluation of specific resistance to filtration (SRF) determined using a filtration–compression cell. The results showed that dual conditioning including PAX-14 addition has a positive impact on the dewatering process, based on the increase of cake dryness limit after PAX-14 addition. It was also found that the use of filtration theory based on Carman’s equation to determine the SRF parameter presents some lim...