A hybrid (cryptic growth & feasting/fasting) approach for biosolids reduction

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In Canada approximately 388,700 tons of dry sewage sludge (biosolids) are produced yearly and existing waste water treatment plants (WWTPs) are expanding to serve the demand of growing cities, which will result in an increase of sludge production in the future. Furthermore, the quality of waste sludge is worsening as a result of the presence of anthropogenic micro-pollutants, such as heavy metals, personal care products, endocrine disrupters, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) or dioxins, limiting agricultural and land reuse. New and practical WWTP sludge reduction approaches would not only reduce the operational and capital costs associated with sludge management and disposal, but also result in production of less biosolids and deleterious environmental effects when sent to landfill or agricultural land. This program builds on my expertise within the sludge line of MW pretreatment for sludge reduction, but shifts the focus of attention to wastewater line processes that lower sludge yield during wastewater treatment (one step earlier) rather than post-treatment after generation. The aim of this work is to study a hybrid (sonication followed by oxic-settling-anaerobic system) sludge reduction process as a viable technology for improved biodegradation and reduced sludge yield. The proposed research can be directly applied at the WWTP rather than in off-site post-treatments. The prior enhances biodegradation of sludge in aerobic/anaerobic bioreactors as a part of the carbon-oxygen cycle and leads to cost reductions in anaerobic biosolids digestion, dewatering, drying and transportation. Other benefits of this research will be improved sludge dewaterability and less biosolids returned to the environment as well as reduction of contaminants transferred to food crops grown on land and leaked into groundwater. If this research is successful, expansion of the sludge line treatment facilities (i.e., anaerobic digestion) could be delayed and Canada would be at the forefront of innovative wastewater line sludge minimization technology.