The development of a selective removal method for group-targets of pollutants under the inhibition of nontoxic organic interferents is of great importance in environmental science. A novel TiO2 photoelectrode functionalized with dummy templates (PS-PAE-TiO2) is designed, exhibiting group-targeting selectivity for nine phthalate ester (PAE) analogs. In total, 90–99% of PAEs were removed from 30 μg L–1 in actual wastewater (chemical oxygen demand, 14.5 mg O2 L–1). The selectivity for PAEs originated from preferential enrichment close to the PS-PAE-TiO2 surface result in a twofold improvement in the apparent kinetic constant. The specific sites can be attributed to phenyl rings and o-ester carbonyl groups through the molecular recognition process. The intermediates were analyzed quantitatively, and a degradation pathway with lower toxicity was proposed, excluding ring-hydroxylated phthalates. Almost 100% of the estrogenic activity and acute aquatic toxicity were eliminated and the genotoxicity was reduced by 92.5%, which was about 40% higher than that at the nonselective photoanode. An enhanced removal at the PS-PAE-TiO2 photoanode with better economic benefits was confirmed, saving energy consumption by 2.5 kWh m–3 per order than that at the nonselective anode. The advanced removal method with group-targeting selective capability can provide a propagable strategy for the removal of a class of homologues from complex aqueous systems.

Preferential pretreatment of nonylphenol (NP) before biological treatment is of great significance due to its horizontal gene transfer effect and endocrine disruption activity. A novel molecular imprinting high-index facet SnO 2 (MI-SnO 2, HIF ) electrode is designed. NP was effectively removed from industrial wastewater at 1.8 V with totally suppressing human estrogen activity. The ratio of 5 day biological oxygen demand to chemical oxygen demand (BOD 5 /COD Cr ) was enhanced to 0.412 from 0.186 after preferential pretreatment. The effluent concentration of NP was 6.4 μg L −1 after further simulating anaerobic-anoxic-oxic treatment, which was about 1/10 of that without pretreatment. This preferential electrochemical pretreatment is interpreted as prior adsorption and enrichment of target pollutants on the MI-SnO 2, HIF surface. The reactive oxygen species and subsequent oxidation products were investigated by in situ electron paramagnetic resonance and electrochemical infrared spectroscopy. The degradation pathway of NP was further analyzed by liquid chromatography−mass spectrometry. This unique pretreatment method for a complex tannery wastewater system has irreplaceable status because no methods with similar advantages have been reported, expecting to be widely used in preferential pretreatment of toxic contaminants blended with highly concentrated nontoxic organics.

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Characteristic emerging pollutants at low concentration have raised much attention for causing a bottleneck in water remediation, especially in complex water matrices where high concentration of interferents coexist. In the future, tailored treatment methods are therefore of increasing significance for accurate removal of target pollutants in different water matrices. This critical review focuses on the overall strategies for accurately removing highly toxic emerging pollutants in the presence of typical interferents. The main difficulties hindering the improvement of selectivity in complex matrices are analyzed, implying that it is difficult to adopt a universal approach for multiple targets and water substrates. Selective methods based on assorted principles are proposed aiming to improve the anti-interference ability. Thus, typical approaches and fundamentals to achieve selectivity are subsequently summarized including their mechanism, superiority and inferior position, application scope, improvement method and the bottlenecks. The results show that different methods may be applicable to certain conditions and target pollutants. To better understand the mechanism of each selective method and further select the appropriate method, advanced methods for qualitative and quantitative characterization of selectivity are presented. The processes of adsorption, interaction, electron transfer, and bond breaking are discussed. Some comparable selective quantitative methods are helpful for promoting the development of related fields. The research framework of selectivity removal and its fundamentals are established. Presently, although continuous advances and remarkable achievements have been attained in the selective removal of characteristic organic pollutants, there are still various substantial challenges and opportunities. It is hopeful to inspire the researches on the new generation of water and wastewater treatment technology, which can selectively and preferentially treat characteristic pollutants, and establish a reliable research framework to lead the direction of environmental science.

Trace 17β-estradiol (E2) is persistent against advanced treatment when blended with higher concentrations of low-toxicity organics, thus wasting energy. A circulating-flow selective photoelectrocatalysis (CF-SPEC) system is established with a selective E2-TiO2-NR photoanode, accurately reducing 1 μg L–1 E2 to less than 0.1 ng L–1 along with eliminating estrogenic activity even when blended with natural organic matter (NOM) at a thousand times higher concentration. Such high efficiency is derived from the augmented selectivity and activity of E2-TiO2-NRs toward E2 during CF-SPEC. Under a flow, the difference in adsorption capacity between NOM and E2 is further amplified 5.6-fold. Furthermore, the higher initial •OH concentration and faster mass transfer jointly endow CF-SPEC with a stronger oxidation capacity. As a result, the removal of E2 increases by 58.7%, and the elimination of estrogenic activity increases 5.8-fold. In addition, deeper mineralization and less homo- and heterocoupling under CF-SPEC are observed, leading to more thorough estrogenic activity removal. Although additional energy is needed to maintain the flow, there is a 55% decrease in energy consumption due to the accurate removal capacity. This work suggests a combination of flow degradation and surface engineering that can be expanded for the selective removal of toxic trace pollutants in blended systems.