Facile fabrication of three-dimensional hierarchical porous ZIF-L/gelatin aerogel: Highly efficient adsorbent with excellent recyclability towards antibiotics

Antibiotics are widely used in humans and animals, but there is a big concern about their negative impacts on ecosystem and human health after use. So far there is a lack of information on emission inventory and environmental fate of antibiotics in China. We studied national consumption, emissions, and multimedia fate of 36 frequently detected antibiotics in China by market survey, data analysis, and level III fugacity modeling tools. Based on our survey, the total usage for the 36 chemicals was 92700 tons in 2013, an estimated 54000 tons of the antibiotics was excreted by human and animals, and eventually 53800 tons of them entered into the receiving environment following various wastewater treatments. The fugacity model successfully predicted environmental concentrations (PECs) in all 58 river basins of China, which are comparable to the reported measured environmental concentrations (MECs) available in some basins. The bacterial resistance rates in the hospitals and aquatic environments were found to be related to the PECs and antibiotic usages, especially for those antibiotics used in the most recent period. This is the first comprehensive study which demonstrates an alarming usage and emission of various antibiotics in China.

Amoxicillin's traces within pharmaceutical effluents have toxic impact toward the algae and other lower organisms within food web. Adsorption, as an efficient process to remove contaminants from water was chosen; in particular with bentonite and activated carbon as adsorbents. The study was carried out at several pH values. Langmuir and Freundlich models were then employed to correlate the equilibria data on which both models equally well-fit the data. For kinetic data, pseudo-first and second order models are selected. While chemisorption is the dominant adsorption mechanism on the bentonite case, both physisorption and chemisorption play important roles for adsorption onto activated carbon. Also, several possible mechanisms for these adsorption systems were elaborated further.