Fate and impact of pharmaceuticals and personal care products during septage co-composting using an in-vessel composter

The present study aimed at understanding the impact of pharmaceutical and personal care product (PPCP) load on compost dynamics and fate of PPCPs during the composting. In addition, the compost dynamics during single PPCP degradation and multiple PPCPs degradation were investigated. Results revealed that co-composting could degrade the pharmaceutical, carbamazepine (CBZ) up to 83% during single pollutant degradation while it was 66% during multiple pollutant system, at an initial concentration (IC) of 5 mg/kg dw. In case of personal care product, namely triclosan (TCS), single pollutant degradation resulted in 86% removal whereas the removal efficiency was 83% in multiple pollutant system. Relatively high concentration of CBZ showed a negative impact on compost dynamics compared to that of TCS. Higher IC resulted in lower temperature development and relatively lower pollutant removal. The study on pollutant transfer in compost solid surface and in leachate revealed that TCS was not leached out while the leaching of CBZ was significant during composting process. The various transformation products formed during composting were identified and tentative pathways for CBZ and TCS degradation were proposed.