The biological fate of 17α-ethinylestradiol (EE2; 500 ng/L to 1 mg/L) and trimethoprim (TMP; 1 μg/L to 1 mg/L) was evaluated with flow through reactors containing an ammonia oxidizing bacterial (AOB) culture, two enriched heterotrophic cultures devoid of nitrifier activity, and nitrifying activated sludge (NAS) cultures. AOBs biotransformed EE2 but not TMP, whereas heterotrophs mineralized EE2, biotransformed TMP, and mineralized EE2-derived metabolites generated by AOBs. Kinetic bioassays showed that AOBs biotransformed EE2 five times faster than heterotrophs. The basal expression of heterotrophic dioxygenase enzymes was sufficient to achieve the high degree of transformation observed at EE2 and TMP concentrations ≤ 1 mg/L, and enhanced enzyme expression was not necessary. The importance of AOBs in removing EE2 and TMP was evaluated further by performing NAS experiments at lower feed concentrations (500-1000 ng/L). EE2 removal slowed markedly after AOBs were inhibited, while TMP removal was not affected by AOB inhibition. Two key EE2 metabolites formed by AOB and heterotrophic laboratory-scale chemostats were also found in independent laboratory-scale mixed culture bioreactors; one of these, sulfo-EE2, was largely resistant to further biodegradation. AOBs and heterotrophs may cooperatively enhance the reliability of treatment systems where efficient removal of EE2 is desired.

Carbamazepine is one of the most persistent pharmaceutical compounds in wastewater effluents due to its resistance to biodegradation-based conventional treatment. Advanced oxidation can efficiently degrade carbamazepine, but the toxicity and persistence of the oxidation products may be more relevant than the parent. This study sets out to determine whether the products of advanced oxidation of carbamazepine can be biotransformed and ultimately mineralized by developing a novel methodology to assess these sequential treatment processes. The methodology traces the transformation products of the (14)C-labeled carbamazepine during UV/hydrogen peroxide advanced oxidation and subsequent biotransformation by mixed, undefined cultures using liquid scintillation counting and liquid chromatography with radioactivity, mass spectrometry, and UV detectors. The results show that the oxidation byproducts of carbamazepine containing a hydroxyl or carbonyl group can be fully mineralized by a mixed bacterial inoculum. A tertiary treatment approach that includes oxidation and biotransformation has the potential to synergistically mineralize persistent pharmaceutical compounds in wastewater treatment plant effluents. The methodology developed for this study can be applied to assess the mineralization potential of other persistent organic contaminants.

The effect of ozone oxidation on the second order reaction rate constant between effluent organic matter (EfOM) and hydroxyl radical (

Molecularly imprinted polymers (MIPs) have proven to be particularly effective chemical probes for the molecular recognition of proteins, DNA, and viruses. Here, we started from a filamentous bacteriophage to synthesize a multi-functionalized MIP for detecting the acidic pharmaceutic clofibric acid (CA) as a chemical pollutant. Adsorption and quartz crystal microbalance with dissipation monitoring experiments showed that the phage-functionalized MIP had a good binding affinity for CA, compared with the non-imprinted polymer and MIP. In addition, the reusability of the phage-functionalized MIP was demonstrated for at least five repeated cycles, without significant loss in the binding activity. The results indicate that the exposed amino acids of the phage, together with the polymer matrix, create functional binding cavities that provide higher affinity to acidic pharmaceutical compounds.