Eco‐efficiency,self‐sufficiency and sustainability in transport: The limits for Brazilian sugarcane ethanol policy

This paper examines the historic development of the Brazilian sugarcane ethanol sector and the largely successful attempt to create a sustainable, renewable fuel for the transport sector. The policy that resulted from this process is an example of meeting the need for sustainable transport through the consideration of location‐specific characteristics and appropriate policy. The paper then questions the current and expected trajectory of the sugarcane ethanol sector with the focus on one key question: can sustainability be exported? In this analysis, the paper identifies new threats to the sustainability of Brazilian sugarcane ethanol and potential “opportunity costs” incurred in further development and internationalization of the sector. The paper concludes that exporting sugarcane ethanol may bring unanticipated deleterious consequences, which in turn means that both policy and theory need to be more precise about how sustainable transport is defined and bounded by time and space.     

Reducing black carbon emissions from diesel vehicles in Russia: An assessment and policy recommendations

The paper assesses options and challenges of reducing black carbon emissions from diesel vehicles in Russia. Black carbon is a product of incomplete diesel combustion and is a component of fine particulate matter. Particulate matter emissions have adverse health impacts, causing cardiopulmonary disease and lung cancer; black carbon is also a large climate forcer. Black carbon emissions from Russian diesel sources affect not only the Russian territory but also contribute to overall pollution. This paper analyzes current ecological standards for vehicles and fuel, evaluates policies for emission reductions from existing diesel vehicle fleet, and assesses Russia's attempts to encourage the use of natural gas as a vehicle fuel. Based on best practices of black carbon emission reductions, this paper provides a number of policy recommendations for Russia.     

Efficient photocatalysis of tetracycline hydrochloride (TC-HCl) from pharmaceutical wastewater using AgCl/ZnO/g-C3N4 composite under visible light: Process and mechanisms

AgCl/ZnO/g-C₃N₄, a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochloride (TC-HCl) from pharmaceutical wastewater under visible light. The morphological, structural, electrical, and optical features of the novel photocatalyst were characterized using scanning electron microscopy (SEM), UV-visible light absorption spectrum (UV–Vis DRS), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and transient photocurrent techniques. All analyses confirmed that the formation of heterojunctions between AgCl/ZnO and g-C₃N₄ significantly increase electron-hole transfer and separation compared to pure ZnO and g-C₃N₄. Thus, AgCl/ZnO/g-C₃N₄ could exhibit superior photocatalytic activity during TC-HCl assays (over 90% removal) under visible light irradiation. The composite could maintain its photocatalytic stability even after four consecutive reaction cycles. Hydrogen peroxide (H₂O₂) and superoxide radical (^·O₂) contributed more than holes (h⁺) and hydroxyl radicals (^·OH) to the degradation process as showed by trapping experiments. Liquid chromatograph-mass spectrometer (LC-MS) was used for the representation of the TC-HCl potential degradation pathway. The applicability and the treatment potential of AgCl/ZnO/g-C₃N₄ against actual pharmaceutical wastewater showed that the composite can achieve removal efficiencies of 81.7%, 71.4% and 69.0% for TC-HCl, chemical oxygen demand (COD) and total organic carbon (TOC) respectively. AgCl/ZnO/g-C₃N₄ can be a prospective key photocatalyst in the field of degradation of persistent, hardly-degradable pollutants, from industrial wastewater and not only.     

泰乐菌素的微生物降解途径及其降解产物研究

研究了越南伯克霍尔德氏菌(Burkholderia vietnamiensis)对泰乐菌素的降解能力,并通过对降解产物的分析,推测了泰乐菌素的微生物降解途径.在自主筛选驯化分离到1株泰乐菌素高效降解菌B.vietnamiensis的基础上,采用高效液相色谱法测定其在不同条件下降解泰乐菌素的能力,并利用制备液相色谱分离纯化降解产物,质谱鉴定其结构.实验结果表明:B.vietnamiensis能高度耐受并快速降解泰乐菌素,用B.vietnamiensis处理初始浓度为50、100、200、300、400或500 mg·L-1的泰乐菌素培养基7 d,泰乐菌素的降解率均达到99%以上.B.vietnamiensis降解泰乐菌素的可能途径是:泰乐菌素A首先脱去碳霉糖转化为泰乐菌素B,然后分子中内酯键和醛基再经水解和还原生成2个新的降解产物.研究结果为泰乐菌素微生物降解机制的研究以及在此基础上降解酶的确定提供有价值的技术参考.     

饮用水中卡马西平的臭氧和二氧化氯降解研究

采用臭氧(O3)和二氧化氯(ClO2)2种消毒方式对饮用水中卡马西平(CBZ)进行氧化降解,考察了不同影响因素(pH值、温度)条件下的氧化动力学,并通过对CBZ降解副产物的确定推测了2种消毒条件下CBZ的降解途径.结果表明,序批式条件下O3和ClO2对CBZ的降解均遵循二级反应动力学.pH值的升高对CBZ的O3和ClO2降解有负面效果;在10 ～ 25℃范围内,温度对CBZ的O3降解速率常数影响较小,但CBZ的ClO2降解速率常数随温度升高显著升高.采用UPLC-Q-TOF-MS对CBZ的O3和ClO2降解前后样品溶液进行扫描,均检测到8种降解中间产物,2种氧化方式主要通过环化加成、亲电取代(羟基化和氯取代)及杂环上的重排等途径来实现对CBZ结构的破坏.     

Biodegradation of indole by a newly isolated Cupriavidus sp. SHE

Indole, a typical nitrogen heterocyclic aromatic pollutant, is extensively spread in industrial wastewater. Microbial degradation has been proven to be a feasible approach to remove indole, whereas the microbial resources are fairly limited. A bacterial strain designated as SHE was isolated and found to be an efficient indole degrader. It was identified as Cupriavidus sp. according to 16S rRNA gene analysis. Strain SHE could utilize indole as the sole carbon source and almost completely degrade 100 mg/L of indole within 24 hr. It still harbored relatively high indole degradation capacity within pH 4–9 and temperature 25°C–35°C. Experiments also showed that some heavy metals such as Mn^2 +, Pb^2 + and Co^2 + did not pose severe inhibition on indole degradation. Based on high performance liquid chromatography–mass spectrum analysis, isatin was identified as a minor intermediate during the process of indole biodegradation. A major yellow product with m/z 265.0605 (C₁₅H₈N₂O₃) was generated and accumulated, suggesting a novel indole conversion pathway existed. Genome analysis of strain SHE indicated that there existed a rich set of oxidoreductases, which might be the key reason for the efficient degradation of indole. The robust degradation ability of strain SHE makes it a promising candidate for the treatment of indole containing wastewater.     

Significance of adverse outcome pathways in biomarker-based environmental risk assessment in aquatic organisms

In environmental risk assessments (ERA), biomarkers have been widely used as an early warning signal of environmental contamination. However, biomarker responses have limitation due to its low relevance to adverse outcomes (e.g., fluctuations in community structure, decreases in population size, and other similar ecobiologically relevant indicators of community structure and function). To mitigate these limitations, the concept of adverse outcome pathways (AOPs) was developed. An AOP is an analytical, sequentially progressive pathway that links a molecular initiating event (MIE) to an adverse outcome. Recently, AOPs have been recognized as a potential informational tool by which the implications of molecular biomarkers in ERA can be better understood. To demonstrate the utility of AOPs in biomarker-based ERA, here we discuss a series of three different biological repercussions caused by exposure to benzo(a)pyrene (BaP), silver nanoparticles (AgNPs), and selenium (Se). Using mainly aquatic invertebrates and selected vertebrates as model species, we focus on the development of the AOP concept. Aquatic organisms are suitable bioindicator species whose entire lifespans can be observed over a short period; moreover, these species can be studied on the molecular and population levels. Also, interspecific differences between aquatic organisms are important to consider in an AOP framework, since these differences are an integral part of the natural environment. The development of an environmental pollutant-mediated AOP may enable a better understanding of the effects of environmental pollutants in different scenarios in the diverse community of an ecosystem.     

Peroxyacetyl nitrate observed in Beijing in August from 2005 to 2009

Measurements of peroxyacetyl nitrate（PAN） were made at a Beijing urban site each August from2005 to 2009. Over this 5-year period, the average PAN concentration for August in each year increased from 3（2005） to 11.7 μg/m3（2007）; however, it decreased rapidly in 2008（4.1 μg/m3）.Generally, the variation over the 5 years showed a rise in the first part of the study period,followed by a decline. We considered two categories of local and regional air masses in this study, which revealed that the PAN concentration in Beijing was affected mainly by southeastern air masses. The August PAN variation was influenced predominantly by local air masses in 2005,but by 2009 regional air masses had become more important. This study showed the level and variation of PAN in the month of August in 5 consecutive years for the first time, and proved that control measures are useful in decreasing photochemical pollution; hence, these measures are probably feasible for other megacities too. Furthermore, this method of analyzing regional and local impacts might be useful for other studies as well.     

微囊藻毒素微生物降解途径与分子机制研究进展

随着大量含氮和磷的废水流入湖泊和江河,导致淡水蓝藻水华污染现象日趋严重.蓝藻水华污染的最主要危害是产生和释放以微囊藻毒素(microcystins,MCs)为主的多种藻毒素.由于MCs对动植物具有很强的毒性,且其在水体中很难被传统的处理方法有效去除,因此如何有效控制蓝藻水华污染和去除MCs是摆在中外环境科学领域的一个难题.针对MCs的结构与毒性、降解菌株、酶催化降解、降解基因和生物降解途径与分子机制的研究进展进行了综述,并对今后微生物降解MCs的研究方向进行了展望,以期为解决我国日益严峻的湖库水体MCs污染和饮用水安全问题提供参考.