Bioflocculants as Alternative to Synthetic Polymers to Enhance Wastewater Sludge Dewaterability: A Review

The dewatering process reduces the water quantity in sludge, allowing decrease its volume, which facilitates storage, transport, stabilization, and improves post-treatment efficiency. Chemical polymers including aluminum sulphate polyaluminum chloride were applied as flocculants conditioning order to prepare sludge for dewatering. However, these synthetic may cause risks human health, should be substituted with ecofriendly safe materials. These materials include plant-based flocculants, animal-based microbial-based flocculants. Sludge dewaterability was evaluated by considering many parameters, such moisture content (MC), dry solids (DS), specific resistance filtration (SRF), capillary suction time (CST), volume index (SVI). use of microorganisms is an available option, since strains (R. erythropolis, A. ferrooxidans, P. mirabilis, T. flavus, etc.) demonstrated their ability produce useful from various origins (chemically treated primary activated anaerobically digested etc.). For only okra (Abelmoschus esculentus), cactus (Opuntia ficus Indica), moringa (M. oleifera), aloe (A. vera) plants are examined Compared polymers, showed a viable alternative chemicals step forward green treatment technology. Among chitosan aminated able reduce SRF (SRF reduction rate > 80%) sludge. A new strategy using methylated hemoglobin also significant enhancement cake solid (47%) bound 17.30%. Generally, extensive investigations needed explore optimize all related parameters (operating conditions, preparation procedure, production cost, choose appropriate large-scale application.