Impact of Cationic Polyelectrolyte Addition on Mesophilic Anaerobic Digestion and Hydrocarbon Content of Sewage Sludge

The agricultural spreading of treated sewage sludge is a valid strategy in terms circular economy for the management this nutrient-rich waste. Anaerobic digestion (AD) can be applied to stabilize and hygienize sludge, making it suitable reuse, while producing biogas utilized as an energy vector. However, presence contaminants, including petroleum hydrocarbons, could limit widespread utilization sludge. In context, impact dewatering agents, such cationic polyelectrolytes, on AD efficiency hydrocarbon biodegradation has been poorly investigated, although represents noteworthy aspect when conditioned digested use centralized plants. This work aims elucidate effect polyelectrolyte addition biomethanation well degradation extractability C10-C40 hydrocarbons during mesophilic 26.7 g/kgTS was observed extend lag phase, similar methane yields (573–607 mLCH4 per g degraded volatile solids) were both raw Furthermore, significant due chemical conditioning. Indeed, reveals that polyelectrolytes affect suggests moreover natural interferents (e.g., biogenic waxes) may lead overestimation potentially toxic concentrations, limiting application sludge-derived digestates agriculture.