Mechanistic insight into Cu(II)-mediated transformation of oxytetracycline on Fe-bearing smectite: Evidence from kinetic modeling.

Heavy metals like Cu(II) and oxytetracycline (OTC) frequently coexist in livestock manure and wastewater due to their widespread use as feed additives, forming Cu(II)-OTC complexes that influence OTC transport and transformation in groundwater. This study investigates Cu(II)-mediated OTC transformation on Fe-bearing smectite under dark, anoxic conditions. Results show that OTC adsorption on Fe-bearing smectite undergoes further transformation.

Promotion of polyhydroxyalkanoates-producing granular sludge formation by lactic acid using anaerobic dynamic feeding process.

To promote the formation of granular sludge with high polyhydroxyalkanoates (PHAs) synthesis ability, an anaerobic dynamic feeding process (AnDF) was proposed. This process combines the feast-famine mode with an anaerobic plug flow feeding process and involving variations in cycle length and settling time. The effects of lactic acid (LA) content (0 %, 20 %, and 40 % COD) on sludge granulation and PHAs production were investigated using three AnDF reactors (R1, R2, and R3).