Repeated-dose toxicity attributed to aluminum nanoparticles following 28-day oral administration,particularly on gene expression in mouse brain

Nanotechnology is a rapidly growing industry that has elicited much concern due to the lack of available toxicity data. Aluminum oxide nanoparticles (AlNP) were listed as a high-priority group in the Organization for Economic Co-operation and Development (OECD) Steering Group for Test Guidelines. In this study, AlNP 35 ± 18.8 nm in size were administered daily at doses of 15, 30, or 60 mg k^?1 for 28 days. A significant decrease in white blood cells (WBC), neutrophils, lymphocytes, and monocytes was observed in the group treated with 60 mg kg^?1 of AlNP, accompanied by a significant increase in platelets. The concentration of aluminum (Al) rose significantly in the thymus, lung, and brain of the group treated with 60 mg kg^?1 of AlNP. However, no significant changes in histopathology were observed. The expression for feeding behavior, energy expenditure, and neurodegeneration-related genes were up-regulated more than twofold by 60 mg kg^?1 AlNP. Consequently, data suggest that exposure to AlNP may result in adverse health effects, including but not limited to growth inhibition, immunosuppression, and neurodegeneration.     

Removal of basic fuchsin dye from aqueous solutions using graphite oxide modified aromatic polyurethane foam material

Graphite oxide modified polyurethane foam (GO/PUF) was used for adsorption of basic fuchsin from aqueous solution and adsorption conditions were optimized to attain an efficiency of 99.5%. The adsorption isotherm was in agreement with the Langmuir model. Kinetic study followed pseudo-second order. Determination of Gibbs free energy and enthalpy change of adsorption indicated spontaneous and endothermic adsorption behavior, suggesting that the adsorbent had a potential for the removal of dyes from industrial wastewater.     

Effects of nano carbon black and single-layer graphene oxide on settlement,survival and swimming behaviour of Amphibalanus amphitrite larvae

The effects of two carbon-based nanomaterials, nano-sized carbon black (nCB), and single-layer graphene oxide (GO) on settlement of Amphibalanus amphitrite (Cirripedia, Crustacea) cypris larvae (cyprids) were assessed after 24, 48, and 72 h of exposure. Additionally, the effects of these nanomaterials on the mortality and swimming behaviour of the nauplius larvae (nauplii) of the same organism were determined after 24 and 48 h. The data indicate that nCB is more effective as a potential antisettlement agent than single-layer GO; moreover, nCB did not show any adverse effects on the larvae. The swimming behaviour of II stage nauplii of A. amphitrite exposed to a suspension of nCB was inhibited only at very high nCB concentrations (≥0.5 mg/mL). Single-layer GO, on the contrary, showed lower antisettlement effects and was more active in altering the survival and inhibiting the swimming behaviour of the nauplii. An indication of the toxic or non-toxic mechanisms of the antisettlement properties of both of these nanomaterials is provided by the reversibility of the antisettlement activity. In conclusion, we propose nCB as an innovative antifouling nanomaterial that shows low toxicity towards the model organism (crustaceans) used in this study.     

Validation of polymer-based nano-iron oxide in further phosphorus removal from bioeffluent: laboratory and scaledup study

The efficient removal of phosphorous from water is an important but challenging task. In this study, we validated the applicability of a new commercially available nanocomposite adsorbent, i.e., a polymer-based hydrated ferric oxide nanocomposite (HFO-201), for the further removal of phosphorous from the bioeffluent discharged from a municipal wastewater treatment plant, and the operating parameters such as the flow rate, temperature and composition of the regenerants were optimized. Laboratory-scale results indicate that phosphorous in real bioeffluent can be effectively removed from 0.92 mg·L^-1 to<0.5 mg·L^-1 (or even<0.1 mg·L^-1 as desired) by the new adsorbent at a flow rate of 50 bed volume (BV) per hour and treatable volume of 3500–4000 BV per run. Phosphorous removal is independent of the ambient temperature in the range of 15°C–40°C. Moreover, the exhausted HFO-201 can be regenerated by a 2% NaOH+ 5% NaCl binary solution for repeated use without significant capacity loss. A scaled-up study further indicated that even though the initial total phosphorus (TP) was as high as 2 mg·L^-1, it could be reduced to<0.5 mg·L^-1, with a working capacity of 4.4–4.8 g·L^-1 HFO-201. In general, HFO-201 adsorption is a choice method for the efficient removal of phosphate from biotreated waste effluent.     

氧化物载体对Ni-V催化剂催化燃烧二氯甲烷的影响

以Al₂O₃,TiO₂,ZrO₂ 3种氧化物为载体,通过溶胶凝胶法制备以Ni-V双金属氧化物为活性组分催化剂,在固定床反应器上研究了催化剂的二氯甲烷（DCM）催化燃烧性能.并通过XRD、BET、FTIR-Pyridine和H₂-TPR表征分析催化剂的物理化学特性,结果表明催化剂的氧化还原性能与酸性存在一定的协同能力促进DCM的催化氧化.10% Ni-V/Al₂O₃和10% Ni-V/TiO₂催化剂表面大量的酸性位点和强氧化性使得催化剂在催化燃烧DCM时拥有较好的活性,其中10% Ni-V/Al₂O₃在252℃时就有90%的转化率,但其在低温时易产生含氯有机副产物的CH₃Cl,并且50h连续稳定性测试发现其有失活现象.而10% Ni-V/TiO₂催化剂达到90%转化率时温度为274℃,且其在DCM降解中并没有CH₃Cl的产生,稳定性测试中也没有失活现象发生,这可能是与其拥有更多中强度B酸以及较强氧化还原能力有关.     

Removal of arsenic (V) from aqueous medium using manganese oxide coated lignocellulose/silica adsorbents

Arsenic (V) adsorption on manganese oxide coated rice wastes was investigated in this study. The modified adsorbents were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and pH measurements to determine the point of zero charge. Batch adsorption equilibrium experiments were conducted to study the effects of pH, contact time, and initial concentration on arsenic removal efficiency. The adsorption capacity of rice waste was significantly improved after modification with permanganate. The Langmuir isotherm model fitted the equilibrium data better than the Freundlich model which confirms surface homogeneity of the adsorbent. Maxima adsorption capacities are determined as 10 and 12 mg/g at pH 3 for manganese oxide coated rice husk and straw, respectively. The adsorption energy indicates that the adsorption process may be dominated by chemisorption. Pseudo-second-order rate equation described the kinetics sorption of arsenic with good correlation coefficients, better than a pseudo-first-order equation. Manganese oxide coated rice husk and straw appear to be promising low cost adsorbents for removing arsenic from water.     

氧化石墨烯存在下铜离子对大型溞的毒性研究

氧化石墨烯(graphene oxide,GO)作为一种具有独特物理化学性质的新型纳米材料被广泛应用,其进入环境后可能对传统污染物的毒性造成影响。选取大型溞为受试生物,研究了GO的存在对Cu在大型溞体内的富集、毒性和抗氧化系统的影响。结果表明,GO对Cu~(2+)具有良好的吸附效果,大幅降低了试验液中Cu~(2+)浓度。1 mg·L~(-1)和2 mg·L~(-1)GO存在下,大型溞暴露于19.2μg·L~(-1)Cu~(2+)溶液72 h后,体内的金属Cu富集量由360μg·g-1干重分别降低为308μg·g-1和215μg·g-1干重。GO的存在降低了Cu~(2+)对大型溞的毒性,Cu~(2+)对大型溞的72 h-LC50值由19.2μg·L~(-1)升高至56μg·L~(-1)。Cu~(2+)单独作用时,大型溞体内SOD活性和GSH含量表现为先诱导后抑制,而MDA含量逐渐升高;当GO存在时,大型溞体内酶活性的变化趋势与上述现象类似,但含量总体低于Cu~(2+)单独暴露时的活性和含量。研究表明GO的加入减少了大型溞体内Cu的富集量,降低了Cu~(2+)对大型溞的氧化损害,对Cu~(2+)的毒性存在一定的减轻效果。     

Comparing the adsorption behaviors of Cd,Cu and Pb from water onto Fe-Mn binary oxide,MnO2 and FeOOH

The adsorption potential of FMBO, FeOOH, MnO₂ for the removal of Cd²⁺, Cu²⁺ and Pb²⁺ in aqueous systems was investigated in this study. Comparing to FMBO and FeOOH, MnO₂ offered a much higher removal capacity towards the three metal ions. The maximal adsorption capacity of MnO₂ for Cd²⁺, Cu²⁺ and Pb²⁺ were 1.23, 2.25 and 2.60 mmol·g^-1, respectively. And that for FMBO were 0.37, 1.13, and 1.18 mmol·g^-1 and for FeOOH were 0.11, 0.86 and 0.48 mmol·g^-1, respectively. The adsorption behaviors of the three metal ions on the three adsorbents were all significantly affected by pH values and heavy metal removal efficiency increased with pH increased. The Langmuir and Freundlich adsorption models were used to describe the adsorption equilibrium of the three metal ions onto the three adsorbents. Results showed that the adsorption equilibrium data fitted well to Langmuir isotherm and this indicated that adsorption of metal ions occurred on the three metal oxides adsorbents limited to the formation of a monolayer. More negative charged of MnO₂ surface than that of FMBO and FeOOH could be ascribed by lower pH_iep of MnO₂ than that of FMBO and FeOOH and this could contribute to more binding sites on MnO₂ surface than that of FMBO and FeOOH. The higher metal ions uptake by MnO₂ than FMBO and FeOOH could be well explained by the surface charge mechanism.     

Ecotoxicological effect of zinc oxide nanoparticles on soil microorganisms

The widespread production and use of zinc oxide nanoparticles (ZnO-NPs) in recent years have posed potential threat to the ecosystem. This study aimed to investigate the ecotoxicological effect of ZnO-NPs on soil microorganisms using laboratory microcosm test. Respiration, ammonification, dehydrogenase (DH) activity, and fluorescent diacetate hydrolase (FDAH) activity were used as ecotoxicological parameters. The results showed that in the neutral soil treated with 1 mg ZnO-NPs per g soil (fresh, neutral), ammonification was significantly inhibited during the study period of three months, but the inhibition rate decreased over increasing time. Inhibition in respiration was observed in the first month of the test. In various ZnO-NPs treatments (1 mg, 5 mg, and 10 mg ZnO-NPs per g soil), DH activity and FDAH activity were inhibited during the study period of one month. For both enzyme activities, there were positive dose–response relationships between the concentration of ZnO-NPs and the inhibition rates, but the curves changed over time due to changes of ZnO-NPs toxicity. Soil type affected the toxicity of ZnO-NPs in soil. The toxicity was highest in the acid soil, followed by the neutral soil. The toxicity was relatively low in the alkaline soil. The toxicity was not accounted for by the Zn²⁺ released from the ZnO-NPs. Direct interaction of ZnO-NPs with biologic targets might be one of the reasons. The adverse effect of ZnO-NPs on soil microorganisms in neutral and acid soils is worthy of attention.     

不同培养介质中纳米氧化铜对小麦毒性的影响

采用琼脂培养和水培方法比较了纳米氧化铜(CuONPs)在不同暴露介质中的环境化学行为及其对小麦根生长的影响,并探讨了不同培养介质对CuONPs植物毒性的影响机制.结果表明,琼脂介质相对水相(营养液)环境可以减少CuONPs的团聚,增强其分散性.在琼脂和水相中Cu离子溶出随CuONPs浓度变化规律存在明显差异,在50～1000mg CuONPs·L-(1以Cu计)范围内,CuONPs在琼脂中无论是Cu2+的溶出浓度还是溶出比率均低于其在水相中的值.CuONPs在不同介质中表现出显著的小麦毒性差异.琼脂培养下小麦根生长半抑制效应浓度EC50(以CuONPs浓度表示)为108mg·L-1,而在水培方式下为9.0mg·L-1,说明琼脂介质极大缓解了CuONPs引起的植物毒性.分析表明,Cu2+溶出浓度较CuONPs投放量与小麦根生长抑制效应之间存在更好的指数相关关系,这说明该研究体系下CuONPs小麦毒性主要是由纳米颗粒释放Cu2+引起的.此结论较好地解释了当培养介质从水相变成琼脂时,Cu2+溶出减少,纳米毒性降低的现象.该研究结果认为,当前国内外使用水培法获得的纳米材料植物毒性研究结果在外推至实际土壤状况时将高估其环境安全性风险,推荐使用琼脂作为纳米材料土壤环境风险评价的模拟介质.