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To enhance the catalytic activity of CuFe2O4 on PS, a nanoscale oxygen-vacancy CuFe2O4 was prepared by hydrogenation reduction technique to construct an advanced oxidation system of electrochemical-enhanced nanoscale oxygen-vacancy CuFe2O4-activated persulfate. Using Ebselen (EBS) as a model pollutant, the degradation efficiency, activation mechanism and degradation pathway were studied. The oxygen-vacancy CuFe2O4 was characterized and analysed by FESEM, EDS and XPS. The results show that under the optimal reaction conditions (PS = 0.8 g/L, oxygen-vacancy CuFe2O4 = 0.3 g/L, initial pH = 6.5), the removal rate of 20 mg/L EBS can reach 92% after reaction for 60 min, which proves that the formation of oxygen-vacancy changed the catalytic inertness of CuFe2O4 on PS. It is speculated that in the E/oxygen-vacancy CuFe2O4/PS system, the existence of oxygen holes enhances the electron transfer ability and reducibility of the catalyst, so the oxygen-vacancy CuFe2O4 can efficiently activate PS to degrade EBS. The quenching experiments show that both ${\rm SO}_4^{\cdot -}$ SO 4 ⋅ − and $\cdot {\rm OH}$ ⋅ OH are involved in the oxidation reaction as reactive radicals in the system, with ${\rm SO}_4^{\cdot -}$ SO 4 ⋅ − being the main reactive radical. In addition, both dissolved oxygen (DO) and anions in the solution inhibit the oxidative degradation of EBS by oxygen-vacancy CuFe2O4/PS system. Through GC-MS detection, a possible degradation pathway is proposed. [ABSTRACT FROM AUTHOR]

As emerging pollutants, pharmaceutical and personal care products (PPCPs) have received extensive attention due to their high detection frequency (with concentrations ranging from ng/L to μg/L) and potential risk to aqueous environments and human health. Advanced oxidation processes (AOPs) are effective techniques for the removal of PPCPs from water environments. In AOPs, different types of free radicals (HO·, SO4·−, O2·−, etc.) are generated to decompose PPCPs into non-toxic and small-molecule compounds, finally leading to the decomposition of PPCPs. This review systematically summarizes the features of various AOPs and the removal of PPCPs by different free radicals. The operation conditions and comprehensive performance of different types of free radicals are summarized, and the reaction mechanisms are further revealed. This review will provide a quick understanding of AOPs for later researchers. [ABSTRACT FROM AUTHOR]

Abstract Lomefloxacin, an antibacterial agent with known photo-induced toxicity in clinical studies, is frequently detected in aquatic environments. Investigating the photo-induced toxicity of lomefloxacin in aquatic organisms is therefore of importance for assessing its ecological risks. In this study, the effects of lomefloxacin on survival, growth and reproduction of Daphnia magna under simulated sunlight radiation (SSR) were investigated, and the mechanism of action was revealed. Results indicated that SSR containing UV radiation increased the acute toxicity of lomefloxacin to Daphnia magna relative to white fluorescent light irradiation. Under SSR, 100 μM lomefloxacin significantly enhanced reactive oxygen species (ROS) generation and lipid peroxidation, and decreased activities of superoxide dismutase and catalase. The biochemical observations and apparent effects on the organism indicate that oxidative stress plays a central role in the acute photo-induced toxicity. Chronic toxicity results showed that SSR significantly affected growth and reproduction of Daphnia magna , whereas lomefloxacin reduced the damage of UV radiation in SSR through light shielding. This study provides insight into the mechanism of photo-induced toxicity and can support the risk assessment of chemicals in the aquatic environment by including the impacts of sunlight irradiation on toxicity. Graphical abstract fx1 Highlights • Simulated sunlight radiation enhances toxicity of lomefloxacin to Daphnia magna. • Oxidative stress plays a central role in phototoxicity of lomefloxacin to daphnia. • UV and lomefloxacin display an antagonistic joint action on chronic toxicity. [ABSTRACT FROM AUTHOR]

A visible-light-excitable Eu3+ complex-based luminescent probe, [Eu(pdap)3(DPBT)], has been proposed for time-gated luminescence imaging of singlet oxygen in the mitochondria of living cells, as well as in tumor tissues and laboratory animals. Extension of the excitation window to the visible-light region makes the probe more favorable for practical usage. [ABSTRACT FROM AUTHOR]

Singlet oxygen ( 1 O 2 ) can be photogenerated by photoactive xenobiotics and is capable of causing adverse effects due to its electrophilicity and its high reactivity with biological molecules. Detection of the production and distribution of 1 O 2 in living organisms is therefore of great importance. In this study, a luminescent probe ATTA-Eu 3+ combined with time-gated luminescence imaging was adopted to detect the distribution and temporal variation of 1 O 2 photoinduced by fluoroquinolone antibiotics and carboxylated/aminated graphenes in Daphnia magna . Results show that the xenobiotics generate 1 O 2 in living daphnids under simulated sunlight irradiation (SSR). The photogeneration of 1 O 2 by carboxylated/aminated graphenes was also confirmed by electron paramagnetic resonance spectroscopy. The strongest luminescence signals of 1 O 2 were observed in the hindgut of daphnids, and the signals in different areas of the daphnids (gut, thoracic legs and post-abdominal claw) displayed a similar trend of enhancement over irradiation time. Mean 1 O 2 concentrations at different regions of daphnids within one hour of SSR irradiation were estimated to be in the range of 0.5 ∼ 4.8 μM. This study presented an efficient method for visualizing and quantifying the temporal and spatial distribution of 1 O 2 photogenerated by xenobiotics in living organisms, which can be employed for phototoxicity evaluation of xenobiotics. [ABSTRACT FROM AUTHOR]

Groundwater serves as a main drinking water source for rural residents in China. However, little is known regarding the pollution of organic micropollutants in groundwater that may pose health risks. In this study, more than 1300 organic micropollutants were screened in the groundwater samples collected from 13 drinking water wells distributed across five rural regions of Liaodong Peninsula in China. A total of 80 organic micropollutants including 12 polycyclic aromatic hydrocarbons, 11 alkanes, 9 pesticides, 7 substituted phenols, 7 perfluoroalkyl acids, 6 heterocyclic compounds, 5 alcohols, 5 phthalic acid esters, 5 pharmaceutical and personal care products, 3 ketones, 2 polychlorinated biphenyls (PCBs), 2 alkylbenzenes and 2 chlorinated benzenes were detected, with their total concentration of 32–1.5 × 10 4 ng/L. Noncarcinogenic and carcinogenic risks of a part of pollutants were assessed. Exposure through skin absorption and oral ingestion was considered in the assessment. Generally the risks are within the acceptable limits, except for that the carcinogenic risk at two sites in Jinzhou is higher than 10 −6 . To the best of our knowledge, this is the first report on health risks of groundwater micropollutants in China. [ABSTRACT FROM AUTHOR]

Abstract: The occurrence and distribution of organic pollutants were investigated and their initial aquatic ecological risks were assessed in water of the Yangtze River Estuary (YRE). A total of 18 samples were collected from South Branch of YRE during the flood season in August 2012. Out of 956 organic compounds, 23 organic pollutants were detected by GC-MS and NAGINATATM software which were dominated by phthalate esters (PAEs), petroleum hydrocarbons (PHCs) and substituted benzenes. The total concentration of detected 23 organic pollutants varied from 0.585 to 53.7μg/L in the studied sites. Moreover, the total amounts of PAEs (∑PAEs), PHCs (∑PHCs) and substituted benzenes (∑substituted benzenes) were in the range of 0.184-53.344μg/L, 0-0.164μg/L, and 0.196-1.559μg/L, respectively. The study revealed that PEC/PNEC ratios of 8 organic pollutants were higher than 1 (PEC: Predicted environmental concentration; PNEC: Predicted no effect concentration), while 3 of them Bis(2-ethylhexyl)phthalate, octadecane and nonadecane were found to be >100 and the remaining organic pollutants including diisobutyl phthalate, tridecane, dihexyl phthalate, methyl palmitate and methyl stearate ranged from 1 to 100. These results indicated significant ecological risks of the specific organic pollutants to the aquatic environment of YRE. [Copyright &y& Elsevier]

To enhance the catalytic activity of CuFe 2 O 4 on PS, a nanoscale oxygen-vacancy CuFe 2 O 4 was prepared by hydrogenation reduction technique to construct an advanced oxidation system of electrochemical-enhanced nanoscale oxygen-vacancy CuFe 2 O 4 -activated persulfate. Using Ebselen (EBS) as a model pollutant, the degradation efficiency, activation mechanism and degradation pathway were studied. The oxygen-vacancy CuFe 2 O 4 was characterized and analysed by FESEM, EDS and XPS. The results show that under the optimal reaction conditions (PS = 0.8 g/L, oxygen-vacancy CuFe 2 O 4  = 0.3 g/L, initial pH = 6.5), the removal rate of 20 mg/L EBS can reach 92% after reaction for 60 min, which proves that the formation of oxygen-vacancy changed the catalytic inertness of CuFe 2 O 4 on PS. It is speculated that in the E/oxygen-vacancy CuFe 2 O 4 /PS system, the existence of oxygen holes enhances the electron transfer ability and reducibility of the catalyst, so the oxygen-vacancy CuFe 2 O 4 can efficiently activate PS to degrade EBS. The quenching experiments show that both SO 4 ⋅ - and ⋅ OH are involved in the oxidation reaction as reactive radicals in the system, with SO 4 ⋅ - being the main reactive radical. In addition, both dissolved oxygen (DO) and anions in the solution inhibit the oxidative degradation of EBS by oxygen-vacancy CuFe 2 O 4 /PS system. Through GC-MS detection, a possible degradation pathway is proposed.

A visible-light-excitable Eu 3+ complex-based luminescent probe, [Eu(pdap) 3 (DPBT)], has been proposed for time-gated luminescence imaging of singlet oxygen in the mitochondria of living cells, as well as in tumor tissues and laboratory animals. Extension of the excitation window to the visible-light region makes the probe more favorable for practical usage.