Bismuth molybdate has attracted extensive attention as a visible semiconductor photocatalyst with great application potential, but bismuth molybdate is suffering rapid charge recombination and lower catalytic activity. Therefore, a rod-shaped Bi2MoO6/Bi14MoO24 homoelemental heterojunction was successfully fabricated using hydrothermal treatment and high-temperature calcination combined method. This novel heterojunction shows an excellent photocatalytic activity and good stability. Degradation efficiency of the optimal catalysts is up to 86 % under visible light for 100 min, and remained above 80 % after four cycles. Kelvin probe force microscopy (KPFM) is adopted to further verify faster separation of photogenerated carriers on Bi2MoO6/Bi14MoO24 heterogeneous nanorods. The result of DFT calculations also further proves that Bi2MoO6/Bi14MoO24 homoelemental heterojunction has higher work function and lower Fermi level, which can prolonging photogenerated electrons and holes lifetimes. Free radical capture experiments suggest that super oxide anion (center dot O2-) and hydroxyl (center dot OH) are main active groups during photocatalytic degradation, which is proved by EPR result. Considering this, a possible S-scheme mechanism is proposed to illustrate this enhanced performance. This research enriches heterojunction system and provides a reference for the design of efficient photocatalysts in future.

Rational design of Z-scheme heterojunction is known to be a good strategy for promoting photogenerated charge efficient separation. In this paper, a direct Z-scheme Ag 2 O/Bi 2 MoO 6 heterostructured microspheres with good interfacial properties were successfully prepared by hydrothermal synthesis-coprecipitation-calcination decomposition. Various techniques such as TEM, XPS, and XRD are used to reveal the structure, morphology, composition, electrochemical and optical properties of the target product. The catalytic activity of the as-prepared composites was evaluated by visible light degradation of Rhodamine B(RhB) and transient photocurrent. As expected, the results showed that 1:5 Ag 2 O/Bi 2 MoO 6 exhibited the optimal catalytic performance. And the visible degradation efficiency is up to 86% in 90 min, which was 2.69 times higher than that of Bi 2 MoO 6 (32%).Meanwhile the 1:5 Ag 2 O/Bi 2 MoO 6 exhibited the highest photocurrent efficiency. Meanwhile, the degradation efficiency of Ag 2 O/Bi 2 MoO 6 composites can still maintain more than 90% after four cycles. Its enhanced photocatalytic performance can be attributed to the formation of a good interfacial contact between Ag 2 O and Bi 2 MoO 6 , which can effectively promote the photogenerated charge transfer between the two semiconductors. In addition, hole and superoxide and were identified as the main active species and hydroxyl radicals as a secondary active species in the degradation process. Considering this case, a possible degradation pathway for RhB was proposed and discussed. This work may provide a new perspective for the rational design of excellent Bi 2 MoO 6 -based Z-type heterojunctions for environmental remediation.

Traffic activities release large amounts of trace metal(loid)s in urban environments. However, the impact of vehicle operation-associated emissions on trace metal(loid) enrichment in road dust and the potential migration of these trace metal(loid)s to the surrounding environment remain unclear. We evaluated the contamination, sequential fraction, and bioaccessibility of trace metal(loid)s in urban environments by assessing their presence in road dust, garden vegetables, and tree tissues, including bark and aerial roots, at a traffic-training venue impacted by vehicle operation emissions and, finally, calculated the bioaccessibility-based health risk. The results indicated a significant accumulation of trace metal(loid)s in road dust, with the highest lead (Pb), cadmium (Cd), and antimony (Sb) concentrations in the garage entrance area due to higher vehicle volumes, frequent vehicle starts and stops, and lower speeds. Aerial roots exposed to hill start conditions exhibited the highest Pb, Zn, and Sb levels, potentially caused by high road dust resuspension, confirming that this tree tissue is an appropriate bioindicator. Sequential extraction revealed high percentages of carbonate-, Fe/Mn oxide-, and organic/sulphide-associated fractions of Pb, copper (Cu), and zinc (Zn) in road dust, while most Cd, Cr, Ni, and Sb occurred as residual fractions. According to the potential mobilizable fractions in sequential extraction, the in vitro gastrointestinal method could be more suitable than the physiologically based extraction test to evaluate the bioaccessibility-related risk of traffic-impacted road dust. The bioaccessibility-based health risk assessment of the road dust or soil confirmed no concern about noncarcinogenic risk, while the major risk originated from Pb although leaded gasoline was prohibited before the venue establishment. Furthermore, the cancer risks (CRs) analysis showed the probable occurrence of carcinogenic health effects from Cd and Ni to adults and from Cd, Cr, and Ni to children. Furthermore, the Cd and Pb concentrations in the edible leaves of cabbage and radish growing in gardens were higher than the recommended maximum value. This study focused on the health risks of road dust directly impacted by vehicle emissions and provides accurate predictions of trace metal(loid) contamination sources in the urban environment.

The elimination of tetracycline hydrochloride (TC-HCl) from water has attracted extensive research attention. This study hydrothermally synthesized composite photocatalysts composed of BiVO4 microspheres containing coexisting phases of monoclinic scheelite (M-BiVO4) and tetragonal zircon (T-BiVO4), i.e., MT-BiVO4, loaded onto P-doped g-C3N4 nanosheets (PCNS). Furthermore, their morphology, structure, and photoelectrochemical properties were comprehensively characterized, and the performance and stability of photocatalytic degradation of TC-HCl were examined. Additionally, the effects of humic acid (HA), coexisting anions/cations, and actual water samples on the degradation efficiency of TC-HCl were investigated, and the degradation mechanism and pathways were examined. The findings indicated that the percentage of M-BiVO4 in MT-BiVO4 considerably influences the photocatalytic activity of the composite catalyst. Furthermore, the excellent photocatalytic performance of 5% BVO/PCNS was attributed to the synergistic effects of P-doping the modified g-C3N4, MT-BiVO4 isotype heterojunction effects, and the Z-scheme heterojunction constructed from MT-BiVO4 and PCNS, which can enhance the absorption range of the visible light and accelerate the transfer and separation of charge carriers between catalysts. The free radical capture experiments and electron spin resonance tests indicated that holes and O2- were the dominant active species in the photocatalytic degradation process. With high reusability and stability, the 5% BVO/PCNS composite has great potential for practical wastewater treatment applications. This study offers a new approach for preparing photocatalysts synergized by isotype and Z-scheme heterojunctions.

The problem of environmental pollution caused by the frequent use of antibiotics has attracted extensive attention. The heterojunction composed of various bismuth oxyiodide (such as BiOI, Bi4O5I2, Bi5O7I, etc.) were widely used in the treatment of antibiotic wastewater. Herein, a hollow BiOI/Bi5O7I hierarchical microsphere was constructed in-situ by annealing BiOI precursors synthesized by the solvothermal method. The phase transition temperature for the formation of heterojunctions has been investigated in detail. The obtained products were characterized by various technologies including transmission electron microscope (TEM), X-ray photon-electron spectroscopy (XPS), and so on. Experimental results suggested that 390-BiOI/Bi5O7I microsphere with hollow structure exhibits the optimal performance and maximum photocurrent response under visible light irradiation. The efficiency for degradation of tetracycline hydrochloride (TH) was up to 83 % in 100 min. The value still maintained at 95 % after the catalyst has been reused for four times. The capture experiment indicates that produced center dot O-2(-) played the most important role. But formed h(+) and center dot OH played a secondary role. The degradation intermediates were analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS). Accordingly, the possible degradation pathways are proposed. An S-scheme based heterostructure photocatalytic mechanism is proposed aiming to explain the enhanced catalytic performance. The BiOI/Bi5O7I heterojunction with exceptional activity and stability is bound to expand applications in the field of water treatment.

Road dust has been severely contaminated by trace metals and has become a major health risk to urban residents. However, there is a lack of information on bioaccessible trace metals in road dust, which is necessary for an accurate health risk assessment. In this study, we collected road dust samples from industrial areas, traffic intersections, and agricultural fields from a megacity (Guangzhou), China, and conducted a geochemical enrichment, speciation, and bioaccessibility-based health risk assessment of trace metals. In comparison with local soil background values, the results revealed a significant accumulation of trace metals, including Zn, Cd, Cu, and Pb in the road dust, which is considered moderate to heavy pollution. Sequential extraction indicated that most trace metals in the road dust were primarily composed of a Fe/Mn oxide-bound fraction, carbonate-bound fraction, and residual fraction, while the dominant fraction was the organic matter-bound fraction of Cu, and the residual fractions of As, Cr, and Ni. The in vitro gastrointestinal (IVG) method revealed that high percentages of Zn, Cd, Cu, and As were bioaccessible, suggesting the possible dissolution of trace metals from adsorbed and carbonate-associated fractions in road dust exposed to the biological fluid matrix. The IVG bioaccessibility-based concentration largely decreased the noncarcinogenic health risk to a negligible level. Nevertheless, the entire population is still exposed to the cumulative probability of a carcinogenic risk, which is primarily contributed to by As, Cd, Cr, and Pb. Future identification of the exact sources of these toxic metals would be helpful for the appropriate management of urban road dust contamination.

Bi2WO6-based heterojunction photocatalyst for antibiotic degradation has been a research hotspot, but its photocatalytic performance needs to be further improved. Therefore, 2D/2D P-doped g-C3N4/Bi2WO6 direct Z-scheme heterojunction photocatalysts with different composition ratios were prepared through three strategies of phosphorus (P) element doping, morphology regulation, and heterojunction, and the efficiency of its degradation of tetracycline hydrochloride (TC-HCl) under visible light was studied. Their structural, optical, and electronic properties were evaluated, and their photocatalytic efficiency for TC-HCl degradation was explored with a detailed assessment of the active species, degradation pathways, and effects of humic acid, different anions and cations, and water sources. The 30% P-doped g-C3N4/Bi2WO6 had the best photocatalytic performance for TC-HCl degradation. Its photocatalytic rate was 4.5-, 2.2-, and 1.9-times greater than that of g-C3N4, P-doped g-C3N4, and Bi2WO6, respectively. The improved photocatalytic efficiency was attributed to the synergistic effect of P doping and 2D/2D direct Z-scheme heterojunction construction. The stability and reusability of the 30% P-doped C3N4/Bi2WO6 were confirmed by cyclic degradation experiments. Radical scavenging experiments and electron spin resonance spectroscopy showed that the main active species were •O2− and h+. This work provides a new strategy for the preparation of direct Z-scheme heterojunction catalysts with high catalytic performance.

针对目前日益严重的多溴联苯醚污染问题,研究脱色希瓦氏菌S12在厌氧条件下对十溴联苯醚的利用及其降解特性.通过测定OD600值和电子显微镜观察分析S12菌的生长情况,并采用GC-MS分析十溴联苯醚(BDE-209)及其代谢产物的含量和组成.结果表明,在二甲基亚砜助溶条件下脱色希瓦氏菌S12能以BDE-209为厌氧呼吸的电子受体获得生长,且培养75d后,初始浓度为50mg·L-1的BDE-209降解率达81.07％,其降解产物主要为九溴代和八溴代产物.本研究为多溴联苯醚的污染生物修复提供了参考数据和指导作用.

纳米材料的大量生产和应用可能导致环境生态风险,纳米材料对水生生物的生态毒理效应已经引起了科学家的广泛关注.由于环境自身是一个非常复杂的介质,存在着的可能不是单一的纳米颗粒污染,而是多重性的.其中,当重金属与纳米颗粒在环境中共存时,两者之间可能产生复杂的效应.本文概述了纳米材料与重金属在水环境中的环境行为,总结了纳米材料对水生生物的毒理效应,并阐述了对其它有毒污染物的生态毒理效应的影响.最后,展望了纳米材料对水生生物的生态毒理效应这一研究领域的发展方向.

针对十溴联苯醚(BDE-209)难溶性和萃取方法的复杂性,通过从萃取剂和萃取条件上对BDE-209进行萃取优化.结果表明:①上清-沉淀复合法的萃取效率仅为21.8％.②烘干温度对样品的萃取效率影响不显著,在80、100和120℃条件下的萃取效率均达到95％以上,但高温条件有可能使BDE-209发生降解.③不同萃取剂和分步萃取对样品萃取效率影响显著,2次萃取比一次性萃取的萃取效率提高了13.6％～29.6％,正己烷萃取效率(100％)>乙酸乙酯萃取效率(84.87％)>异辛烷萃取效率(23.33％).④采用正己烷少量多次萃取,可短时间内最大程度回收水相样品中的BDE-209(97.82％).少量多次萃取法萃取效率高,操作简便,节省时间,适于大部分水相样品快速定量分析.

Developing monitoring system for paper industrial wastewater treatment system is an important route for wastewater reuse and recycling from wastewater, which are regarded as effective way for cleaner production. A novel hybrid deep leaning CLSTMA model, which based on sequential fusion convolutional neural network (CNN), long short term memory (LSTM) and attention mechanism (AM), was developed to monitor the water quality in a full-scale paper industrial wastewater treatment system for energy conservation and emissions reduction. The hybrid CLSTMA model for predicting water quality of paper industrial wastewater treatment system was divided into three steps: spatial information fusion by using CNN module, temporal information fusion by using LSTM module and variable weighted calculation by using AM module. Compare with other models (CNN, LSTM and CLSTM models), RMSE of CLSTMA model for the effluent chemical oxygen demand (CODeff) reduced by 23.3–31.55%, MAE of CLSTMA model reduced by 38.89–74.50%, R of CLSTMA model increased by 8.29–11.86%. For the effluent suspended solids (SSeff), compared with CNN and LSTM models, RMSE of CLSTMA model reduced by 10.26% and 9.92%, MAE of CLSTMA model reduced by 5.37% and 3.44%, R of CLSTMA model increased by 15.13% and 37.21%, respectively. While, R of CLSTMA was consistent with CLSTM model, but RMSE and MAE of CLSTMA model reduced by 16.07% and 7.49% than the CLSTM model. Simulation results demonstrate that the proposed CLSTMA model has a great potential in monitoring paper industrial wastewater treatment system for cleaner production.

Spodoptera frugiperda and Rhopalosiphum maidis, as main pests, seriously harm the safety of maize. At present, chemical pesticides are mainly used to control these pests. However, due to residue and resistance problems, more green, environmentally benign, simple preventive control technology is needed. In this study, we reported the reason for the antifeedant activity of azadirachtin on S. frugiperda and proposed that S. frugiperda treated with azadirachtin would turn from pest into natural enemy. S. frugiperda showed an obvious antifeeding phenomenon to maize leaf treated with various azadirachtin concentrations (0.5~20 mg/L). It was found that maize leaf treated with 1 mg/L of azadirachtin has a stimulating effect on the antenna and sensillum basiconicum of S. frugiperda, and azadirachtin can affect the feeding behavior of S. frugiperda. Additionally, after treating maize leaves or maize leaves + R. maidis with 1 mg/L of azadirachtin, the predatory behavior of S. frugiperda changed from a preference for eating maize leaves to R. maidis. Moreover, the molting of R. maidis can promote the change of this predatory behavior. Our results, for the first time, propose that the combined control technology of azadirachtin insecticide and biological control could turn S. frugiperda from pest into natural enemy, which can effectively eliminate R. maidis and protect maize. This combined control technology provides a new way for pest management and has good ecological, environmental, and economic benefits.

在"新工科"为理念的大背景下,针对目前存在的综合设计性实验项目少、科学研究性实验未计入考核、学生解决实际问题能力差等问题进行研究.探讨了实验课程内容、增设虚拟仿真实验,实验考核机制以及实验室条件和师资队伍等问题,以改变现有问题,提升学生创新能力、综合能力.

针对茂名石化产业园区精细化工集群的发展需要,分析了园区的精细化工产业现状,提出了以当地研发资源组建精细化工研发平台的多方共建模式,并从团队、实验室、研究方向、运行模式等方面讨论了研发机构的建设路径.

针对茂名石化产业转型发展的需要,分析了高校科研机构现有模式的存在的问题,提出了基于石化行业的高校新型产业研发机构的模式和机制,并从定位、组织、管理、产学研合作等方面讨论了高校研发机构的建设模式,确定了开放、共享、协同的创新运行机制.

An integrated OCO reactor was used to investigate the performance and microbial community successional changes under long-term exposure to relatively low levels of ZnO nanoparticles (NPs). Relatively higher concentrations of ZnO NPs (1.5 mg L-1) could adversely affect the nitrogen and phosphorus removal in the reactor. The diversity and richness of the microbial communities chronically declined with an increasing concentration of ZnO NPs higher than 1.5 mg L-1. With the elevated ZnO NPs, the phyla abundances of Proteobacteria, Firmicutes and Actinobacteria decreased slightly, whereas those of Bacteroidetes and Acidobacteria increased. Bacteroidetes and Proteobacteria were the predominant phyla in each phase (with a variation in abundance), together with some common taxa responses to ZnO NP stress as revealed by Venn diagram analysis. Some genera associated with the removal of nitrogen and phosphorus, such as Acinetobacter, Stenotrophomonas and Pseudomonas, decreased significantly. The present results are significant for expanding our understanding of the functional performance and microbial community successions of activated sludge which has experienced long-term exposure to environmentally relevant concentrations of ZnO NPs.

The strain TZ-1 was screened from five isolates from soil sample of oil shale exploration area in Maoming by comparing the data of zinc removal percentage at pH 7.0 and 30 degrees C with initial Zn2+ concentration of 2 mmol/L in nutrient broth and MICs. The isolate TZ-1 was identified as Burkholderia sp. based on its morphological, physiological-biochemical characteristics and the 16S rDNA sequence. The initial Zn2+ concentration of 16 mmol/L in nutrient broth inhibited the growth of TZ-1 obviously. The maximum zinc removal percentage of TZ-1 was up to 67.83% with the initial zinc concentration of 8 mmol/L in the broth. The results of heavy metals affecting Zn2+ adsorption indicated that Zn2+ removal was increased when other heavy metals existed in the broth. The surface characterization of the adsorbent was done through FTIR. The results suggest that the hydroxyl, carboxyl, amine and phosphate groups of biomass surface play a vital role in Zn2+ adsorption. The biosorption process conforms Langmuir and Freundlich isotherms and can be described by the pseudo-second-order kinetic model. The data of application in wastewater treatment indicate that the strain TZ-1 is suitable for wastewater purification.

目前,国内针对沙氏外硫红螺菌的研究鲜见报道.为了挖掘功能光合细菌新菌源,从茂名水东湾红树林潮间带泥样分离到1株能以硫化物作为电子供体营光合自养作用的紫色光合细菌HBL-1.根据菌株的形态、细胞色素光吸收特征及自动微生物鉴定系统检测的碳源利用结果,结合系统发育分析,鉴定该菌为沙氏外硫红螺菌(Ectothiorhodospira shaposhnikovii).该菌培养条件粗放,尤其在偏碱性、含盐、光照微氧条件下生长最快;该菌能耐受较高浓度的Na2S,在Na2S初始浓度为227.6 mg/L时,培养6d后,N赴S转化率达到66.9％.结果表明该菌在水质净化方面显示较好的应用前景.

Hollow graphene-like nanocages are prepared by an efficient and scalable quasi chemical vapor deposition technique. The structure and morphology of the product are investigated by X-ray diffraction, Raman spectrum, scanning electron microscopy, transmission electron microscopy, X-ray photoelectric spectroscopy and nitrogen adsorption-desorption analysis. The supercapacitive performances for the electrode are investigated by cyclic voltammetry and charging-discharging methods. The hollow graphenelike nanocages have a near hollow sphere morphology and nanoporous frameworks. When evaluated for supercapacitor electrode, relatively high specific capacitance of 165.7 F/g and 283.1 F/g are obtained at current density of 1 A/g in 1 M KOH and 1 M H2SO4 electrolytes, respectively. In addition, desirable rate performance and good cycling stability are also demonstrated for the hollow graphene-like nanocages. (C) 2016 Elsevier B.V. All rights reserved.

通过稳定运行一体化OCO工艺,研究了纳米ZnO长期暴露条件下系统处理污水过程中的脱氮、除磷和有机物降解效果受到的影响,并探讨了活性污泥对纳米ZnO的去除效能.结果表明,在工艺运行80 d的暴露时间里,系统脱氮除磷具有剂量效应:进水纳米ZnO的质量浓度低于0.8 mg/L时,NH4+-N、TN、TP的去除有轻微的促进作用;1.5、4.0 mg/L对系统的脱氮除磷有明显的抑制作用.系统对纳米ZnO的响应表现硝化过程比反硝化过程敏感度高.活性污泥可以通过富集作用去除水中的纳米ZnO;纳米ZnO的质量浓度为4.0 mg/L条件下活性污泥的富集强度可高达1.74 mg/g.