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Given the absorbability of nZnO and its inevitable coexistence with trace metals such as Cd and Pb in coastal environment, nZnO can adsorb these pollutants thereby affecting their distribution in different media of marine ecosystem. The marine copepod Tigriopus japonicus was applied in the present study to investigate the combined effect of nZnO and Cd or Pb on mortality and reproduction in marine organisms. For acute exposure, presence of 1.0 mg/L nZnO increased the toxicity of both Cd and Pb, as their LC 50 decreased from 5.9 and 75.4 mg/L to 3.95 and 48.0 mg/L, respectively. For 21 d chronic exposure, the reproduction of the copepod was influenced by Cd and Pb at environmental relevant concentrations, and the interaction between nZnO and Cd or Pb appeared to be antagonistic. The waterborne Cd and Pb concentration was affected by nZnO for neither acute nor chronic exposure, indicating no adsorption of these two metals to nZnO at relative low concentration. The overall findings of this study suggested the binary exposure to nZnO/Cd or nZnO/Pb might have potential different toxic mechanisms between acute and chronic exposure. Unlabelled Image • Acute toxicity of Cd and Pb increased at the presence of nZnO. • Reproductive toxicity decreased at presence of nZnO. • Reproduction of copepod was affected at environmental levels of Cd and Pb. • Feeding was not the reason for difference between acute and chronic exposure. • Acute and chronic binary mixtures might have different toxic mechanisms. [ABSTRACT FROM AUTHOR]

Species sensitivity distribution (SSD) method has been widely used to derive water quality criteria (WQC). However, the toxicity data of some environmental pollutants are not easily accessible, especially for endangered and threatened species. Thus, it would be very desirable and economical to predict the toxicity of those species not subjected to toxicity test with the aid of a mathematical model. The interspecies correlation estimation (ICE) model (developed by the US Environmental Protection Agency (USEPA)) uses the initial toxicity estimate for one species to produce correlated toxicity values for multiple species, and it can be utilized to develop SSD and HC (hazardous concentration, 5th percentile). In this study, we explored the applicability of ICE to predict toxicity of phenanthrene to various species. ICE-based SSDs were generated using three surrogate species ( Oncorhynchus mykiss, Lepomis macrochirus, and Daphnia magna) and compared with the metrical-based SSD. The corresponding HC of both models were also compared. The results showed there were no significant differences between HC derived from measured acute and ICE-based predicted values. The ICE model was verified as a valid approach for generating SSDs with limited toxicity data and deriving WQC for phenanthrene. [ABSTRACT FROM AUTHOR]

Tire wear particles (TWPs) are considered an important component of microplastic pollution in the marine environment and occur together with a variety of aquatic pollutants, including frequently detected bisphenols. The adverse effects of TWPs or bisphenols on aquatic organisms have been widely reported. However, the combined toxicity of TWPs and bisphenols is still unknown. In this study, the combined toxicity of both pristine (p-) and aged TWPs (a-TWPs) and four bisphenols ((bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS), and bisphenol AF (BPAF)) to Tigriopus japonicus was evaluated. TWPs increased the toxicity of BPA and BPF but decreased the toxicity of BPAF. For BPS, there was synergistic toxic effect in the presence of p -TWPs, but slightly antagonistic effect was observed in the presence of a-TWPs. This adsorption of BPAF by TWPs resulted in a reduction of its toxicity to the copepod. A-TWPs could release more Zn than p -TWPs, and the released Zn contributed to the synergistic effect of TWPs and BPA or BPF. The aggregation formed by TWPs in certain sizes (e.g., 90–110 μm) could cause intestinal damage and lipid peroxidation in T. japonicus. The synergistic effect of p -TWPs and BPS might be due to the aggregation size of the binary mixture. The results of the current study will be important to understand the combined toxic effect of TWPs and bisphenols and the potential toxic mechanisms of the binary mixture. [Display omitted] • The pattern of combined toxicity with TWPs was different among different bisphenols. • Adsorption of BPAF by TWPs led to antagonistic effect. • Released Zn from TWPs caused increased toxicity of BPA and BPF. • TWPs' aggregation at certain sizes led to synergistic effect between TWPs and BPS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Thermal NaBH 4 treatment is used to update the surface properties of ɑ-MnO 2. • BV is in situ formed via the wash-away of B dopant during dye elimination process. • BV transforms DO into ROS without extra energy input. • Strong acidity, free Mn3+ site and large pore contribute to adsorptive dye removal. • The treated MnO 2 shows excellent Pb2+ adsorption capacity especially in acid matrix. Oxygen vacancy (OV), one frequently designed structural anion defect, can transport active oxygen species towards multi-phase pollutant oxidation by activating oxygen molecules or chemical oxidants. However, dissolved oxygen (DO), a desirable oxidant source for water organics degradation, is very difficult to be directly utilized by OV-abundant metal oxides without extra heat or light input. To solve this problem, in this study another anion defect, i.e. , boron vacancy (BV), was successfully incorporated into ɑ-MnO 2 via a two-step method, i.e. , thermal NaBH 4 treatment for boron doping followed by in situ wash-away of boron during organic dye elimination process. The NaBH 4 -modified ɑ-MnO 2 exhibited much higher Rhodamine B (RhB) elimination than the original one. BV is capable of transforming DO into 1O 2 , OH and O 2 − radicals at 30 °C and without extra energy input, completely mineralizing RhB into inorganic carbon. Besides, NaBH 4 -induced strong acid sites, free Mn3+ species and large pore size contributed to adsorptive RhB removal. For the original ɑ-MnO 2 , surface lattice oxygen was the key oxidant for dye degradation. Malachite Green, Congo Red, Orange I and Methyl Blue were further tested as target substrates. The NaBH 4 -treated ɑ-MnO 2 presented superiority over the pristine sample in adsorptive Pb2+ removal as well. [ABSTRACT FROM AUTHOR]

Biochar was used as a heterogeneous activator for peroxymonosulfate (PMS), and the activation performance strongly depended on the structure, functional groups, and modification of the biochar. In this study, a new type of modified biochar was synthesized by utilizing the Mn(II) adsorption capacity of bacteria. After one-step pyrolysis of Mn(II)-adsorbed bacterial cells at 800 °C, a Mn-incorporated bacterial-derived biochar (Mn-BBC) was successfully produced. It exhibited structural heterogeneity, with MnO located at the surface of the BBC matrix, as shown on the result of SEM and XRD. Compared to BBC, Mn-BBC showed a 10-fold increase (0.0727 min−1 versus 0.0069 min−1) of pollutant removal rate. In addition, it also showed anti-interference capacity against common water matrix (except 10 mM CO 3 2-) and great stability/reusability. Chemical quenching, electron spin resonance, and pyrophosphate trapping indicated an indirect but important role of the superoxide, formed during the self-decomposition of PMS. The MnO on Mn-BBC can be oxidized by superoxide to produce surface Mn(III), which then binds to PMS and forms a surface complex. This complex promotes electron transfer from the pollutant to the Mn-BBC, facilitating the oxidation of the contaminants. Overall, this study confirmed the PMS activation capacity and mechanism of Mn-BBC, which expands the application of BBC-based materials derived from metal-adsorbed microbes. [Display omitted] • Metal ion-loaded bacterial cells can be a source of biochar. • Mn-incorporated biochar presents 10-folds higher activity than pristine biochar. • Surface Mn(III) is produced from the MnO oxidation by superoxide. • Electron-transfer from pollutant to PMS-Mn(III) complex is the dominant pathway. [ABSTRACT FROM AUTHOR]

[Display omitted] • A two-step protocol is applied to prepare active α-MnO 2 for HCHO oxidation. • "Structure-performance" relationship is interpreted by multiple characterizations. • Reactive oxygen vacancy is paramount to the excellent catalytic performance. • The reported sample outperforms a commercial purifier. • Reaction pathways are raised from an experimental angle. Defect engineering is a powerful way to achieve the structural manipulation of MnO 2 with rich surface active oxygen species for formaldehyde elimination under ambient conditions. Herein, a two-step protocol for consecutive modification of ɑ-MnO 2 structure by potassium insertion and ammonium treatment was successfully implemented, leading to a synergetic enhancement of formaldehyde oxidation efficiency. For K modification alone, only slight activity increase was realized at moderate K level and an even higher K addition jeopardized the catalytic performance. Neither did NH 4 + treatment alone work well for promoting formaldehyde oxidation. However, for the sample containing a higher K content (>3.07 wt%), the following NH 4 + treatment could induce structural deformation via substitution of lattice oxygen by N doping, resulting in the formation of abundant reactive oxygen vacancies that could continuously transform inert gaseous dioxygen into oxidative surface adsorbed oxygen. Catalyst characterizations proposed that activity of the oxygen vacancy was the main factor contributing to the excellent formaldehyde oxidation performance. The best-performed K-MnO 2 -NH sample with 76% removal efficiency for ∼ 400 mg/m3 HCHO at 30 °C not only surpassed a benchmark commercial purifier in terms of formaldehyde mineralization, but also was much more resistant to the interference from the concomitant benzene pollutant than the commercial catalyst. Reaction pathways were proposed through comprehensive experimental investigations on the surface intermediates of the spent catalysts. [ABSTRACT FROM AUTHOR]

Dibutyl phthalate (DBP) is a commonly used additive in plastic products, so it may potentially coexist with microplastics (MPs) in marine environment. The ingestion of MPs might affect the accumulation of DBP in marine organisms. In this study, the marine copepod Tigriopus japonicus was applied to study the combined effect of DBP and polystyrene microplastics (mPS) on the copepod through both acute mortality tests and chronic reproduction tests. The LC 50 of DBP was 1.23 mg L−1 (95% CI: 1.11–1.35 mg L−1), while exposure to mPS didn't have significant lethal effect on the copepods. Adsorption to MPs led to decreased bioavailability of DBP, resulting in decreased toxicity of DBP. In contrast to the results of acute toxicity tests, DBP didn't affect the reproduction of the copepods at lower exposure concentrations, while mPS reduced the number of nauplii and extended the time to hatch. Similar as acute toxicity tests, antagonistic interaction was observed for mPS and DBP in chronic reproduction tests, which might be attributed to promoted aggregation of mPS at presence of DBP. Overall, antagonistic toxicity effect between the two pollutants was observed for both acute and chronic tests, but the mechanisms of the interaction between DBP and mPS were different. Results of the present study highlighted the importance of long-term exposure when evaluating the toxic effect of MPs and their combined effect with other chemicals. Image 1 • T. japonicus was not acutely sensitive to polystyrene microplastic (mPS) exposure. • mPS reduced the number of nauplii and increased the hatch time of the copepod. • The combined effect between mPS and DBP to the copepods was antagonistic. • mPS reduced the waterborne concentration of DBP. • Presence of DBP promoted aggregation of mPS. [ABSTRACT FROM AUTHOR]

Heterogeneous activation of sulfite by synthetic lithium cobalt oxide (LCO) to treat simulated dye wastewater is developed in this study using Rhodamine B (RhB) as the model pollutant. Synergistic, independent and antagonistic interactions between LCO and Na 2 SO 3 were observed under acid (pH = 3), neutral and alkaline (pH = 10) conditions, respectively. A high mineralization rate of 84% was obtained with 200 mg of LCO and 50 mg of Na 2 SO 3 at pH = 3 for 50 mL of 5 mg L−1 RhB substrate. Even hand-shaking with 13 mg of LCO and 3 mg of Na 2 SO 3 for only 30 s could realize full de-colorization. Moreover, one-time dosage of 13 mg of LCO and 3 mg of Na 2 SO 3 worked effectively in twenty consecutive batches only if Na 2 SO 3 was periodically supplemented. The radical-trapping experiments determined the SO 3 • - radical as the dominant reactive species and oxygen vacancies were responsible for sulfite activation. In addition to RhB, the sulfite-enhanced protocol has been universally demonstrated with methyl blue and methyl orange. This paper reflects well the sustainability concept of reusing "wastes" for pollution control since LCO is a key component in the cathode material of abandoned lithium-ion batteries and sulfites are the byproducts of flue gas desulfuration. Image 1 • Synergy between LiCoO 2 and Na 2 SO 3 for efficient water treatment is reported. • A high mineralization is achieved for Rhodamine B degradation. • This protocol can effectively work for cycles via periodically re-adding Na 2 SO 3. • The reaction pathway involving oxygen vacancies was proposed. • It affords a new idea of reusing environmental wastes for water purification. [ABSTRACT FROM AUTHOR]