Determination of hexabromocyclododecanes in sediments from the Haihe River in China by an optimized HPLC–MS–MS method

Hexabromocyclododecanes(HBCDs),a new type of persistent organic pollutants widely used as brominated flame retardants,have attracted wide attention due to their increasing level and toxicity. A method based on high-performance liquid chromatography mass spectrometry(HPLC–MS–MS)in electrospray ionization mode has been developed by optimization of various parameters,which effectively improved the separation degree and responsive intensity of α-,β-and γ-HBCD isomers. The concentrations and distribution profiles of three HBCD isomers were investigated in sediments from the Haihe River in China.It was observed that the concentrations of HBCDs varied in the range of 0.4–58.82 ng/g,showing a decreasing trend along the flow direction,possibly due to attenuation and biodegradation along the flow direction of the Haihe River. The distribution profile of α-,β-,γ-HBCD was 7.91%–88.6%,0–91.47%,and 0.62%–42.83%,respectively. Interestingly,α-HBCD dominated in most sample sites. This was different from the distribution profile in commercial industrial products,which might be attributed to the inter-transformation and different degradation rates of the three HBCD isomers. The potential ecological risk of HBCDs in sediment was characterized under the two-tiered procedure of the European Medicines Evaluation Agency for environmental risk assessment. Although the HBCDs in the selected section of the Haihe River presented "no risk" in the sediment compartment,its risk in sediment cannot be neglected since sediment is one of the important sinks and reservoirs of pollutants.     

Pollution characteristics of polycyclic aromatic hydrocarbons in common used mineral oils and their transformation during oil regeneration

The pollution characteristic of polycyclic aromatic hydrocarbons(PAHs) in common used mineral oils, semi-refined oils, refined oils and solid wastes produced during the used mineral oil regeneration process was analyzed. The results showed that total PAHs content in six common used mineral oils was as follows: used engine oil used quenching oil used casting oil used hydraulic oil used antirust oil used industrial lubricating oil. Furthermore, this order was dependent on the source of PAHs and oil working temperatures. Additionally, total PAHs content in regenerated oils was as follows: semi-refined oil refined oil crude oil, which was related to the catalytic cracking process of crude oil and adsorption refining process of semi-refined oil. The ranking of total PAHs content in regenerated wastes varied depending on the regeneration technology used as follows: waste adsorption sand acid sludge waste clay precipitation sludge cracked residue. In all types of used mineral oils and regenerated wastes, the maximum and minimum proportions of the total PAHs content were composed of 2–3 ring-PAHs and 5–6 ring-PAHs, respectively. The majority of PAHs in the used mineral oils entered into regenerated wastes during regeneration process, while a small number remained in the regenerated oil.     

遥感法用于车辆实际道路行驶污染状况评估

为了评估满足不同排放标准的在用车在实际道路行驶条件下的污染状况,以2013年3-11月间在北京市朝阳区收集的16.5×104组在用汽油车排放遥感测试大数据为基础,对北京市的在用车实际道路排放水平进行分析和评价.结果表明:新车排放标准升级明显降低了在用车的CO、HC和NO平均排放浓度.从国Ⅰ/国Ⅱ到国Ⅲ以及从国Ⅲ到国Ⅳ/国Ⅴ,每次标准升级使得在用车的CO排放浓度平均降低12%~15%,HC和NO排放浓度分别降低13%和40%左右.与2003年相比,北京市2013年机动车CO、HC和NO排放的平均浓度分别下降了52.1%、82.1%和65.3%,排放标准升级带来的减排效果十分明显.未来排放标准升级过程中应当强化对在用车实际驾驶过程排放的监管,同时积极引导老旧车辆的淘汰更新,加大对排放造假行为的执法和处罚力度.      

总磷TNT试剂在地表水环境监测中的应用研究

为有效监控地表水环境中总磷的变化趋势,落实环境保护水污染防治行动计划.选择稳定性好、分析高效、低能耗的总磷TNT试剂对南京市的长江流域水源地、城市内河道及湖泊治理监控区的地表水环境样品进行监测.应用该试剂测定总磷的方法检出限为0.008 mg/L,相对标准偏差为2.2%~7.4%(n=6),加标回收率为91.0%~110%,有证标准样品同步验证测试的相对误差为-1.3%~1.4%.试验证实总磷TNT试剂应用结果能够满足地表水环境中总磷监测的精密度、准确度要求.     

Isolation and Characterization of <Emphasis Type="Italic">Bacillus cereus</Emphasis> Bacteriophages from Foods and Soil

The aim of this study was to isolate and characterize Bacillus cereus bacteriophages of various origins. Twenty-seven bacteriophages against B. cereus were isolated from various Korean traditional fermented foods and soils. Plaque size, transmission electron microscopy, virulence profile, and in vitro lytic activity of bacteriophage isolates were examined. Transmission electron microscopy confirmed B. cereus bacteriophages belonging to the family Siphoviridae. Among B. cereus bacteriophages with broad host range, 18 isolates (66.7%) did not harbor any B. cereus virulence factors. Among them, bacteriophage strain CAU150036, CAU150038, CAU150058, CAU150064, CAU150065, and CAU150066 effectively inhibited B. cereus in vitro within 1 h. Therefore, they are considered potential candidates for controlling the contamination of B. cereus in food or other applications.     

Re-emergence of a GII.4 Norovirus Sydney 2012 Variant Equipped with GII.P16 RdRp and Its Predominance over Novel Variants of GII.17 in South Korea in 2016

Noroviruses are major causative pathogen of nonbacterial acute gastroenteritis worldwide. Of the seven genogroups of noroviruses suggested recently, genogroup II genotype 4 (GII.4) had been the most common genotype identified in hospitalized patients in the last few decades. However, since the latter half of 2014, new variants of GII.17 have been reported as the main causes of outbreaks over GII.4 in East Asia and have also occurred in America and Europe. In this study, we monitored norovirus GII in coastal streams at South Gyeongsang province and South Jeolla province of South Korea from March 2015 to May 2016. Norovirus GII.17 capsid sequences were predominantly detected until September 2015 in water samples. However, we found that the number of positive cases of the norovirus GII.4 Sydney 2012 capsid sequence has been increasing since December 2015, overtaking that of GII.17 in 2016. The RdRp genotype of this predominant GII.4 variant in 2016 was identified as GII.P16. The emergence and predominance of the GII.4 pandemic capsid sequence harboring a different RdRp genotype suggested the potential for a future pandemic.     

黄山夏季气溶胶吸湿性及与化学组分闭合

大气气溶胶的吸湿性对其光学性质、云凝结核的活性以及人体健康都有重要影响.利用2014年7月在黄山光明顶观测获得的气溶胶的吸湿增长因子(GF)和多尺度气溶胶离子化学成分的观测数据,进行气溶胶吸湿性与化学组分的闭合研究.结果表明,黄山夏季气溶胶(在70~230 nm范围内)中硫酸铵、有机物(OC)、不可溶的物质含量最多,硝酸铵含量次之,硫酸氢铵含量最少,其中主要无机成分含量随着粒径的增加而逐渐增加;气溶胶在白天的吸湿性强于夜间,并且气溶胶粒子的吸湿性随粒径增加有逐渐增强的趋势;根据所有粒径的气溶胶粒子化学组分计算出的吸湿性参数κ值与κ观测值呈现大致相同的波动变化趋势,并且较接近观测值,决定系数r~2达到0.60.     

不同pH值灌溉水对土壤Cd生物有效性及稻米Cd含量的影响

通过盆栽种植实验研究了pH值为3.5~6.5的灌溉水对稻田土壤pH值、土壤Cd生物有效性以及2种水稻品种各部位Cd含量的影响.结果表明:1不同pH值灌溉水对土壤pH值影响显著.灌溉水pH为3.5~6.5的处理下,湘晚籼土壤pH值下降了0.6~0.3个单位,威优46号土壤pH值下降了0.7~0.4个单位.2随着灌溉水pH值的升高,土壤交换态和TCLP提取态Cd含量(生物有效性)均有降低的趋势,但TCLP提取态Cd含量不显著.3随着灌溉水pH值从3.5上升到6.5,湘晚籼12号水稻植株各部位Cd含量均逐渐下降,而威优46号水稻植株各部位的Cd含量逐渐上升.与pH=3.5处理相比,浇灌pH值为4.5~6.5的灌溉水,湘晚籼12号根系、茎叶、谷壳和糙米中Cd含量分别下降32.3%~48.0%、16.5%~48.0%、40.0%~56.2%和45.6%~73.9%;相反,威优46号根系、茎叶、谷壳和糙米中Cd含量分别上升30.5%~446.3%、5.3%~201.1%、70.3%~316.7%和71.0%~177.2%.显然,升高灌溉水的pH值有利于降低湘晚籼12号(常规稻)糙米中的Cd含量,但不利于降低威优46号(杂交稻)糙米中的Cd含量.     

钙镁磷肥对土壤Cd生物有效性和糙米Cd含量的影响

通过水稻盆栽试验,研究了施用钙镁磷肥对Cd污染稻田中Ca、Mg、Cd生物有效性的影响和种植水稻(湘晚籼12号、威优46号)后水稻各部位Ca、Mg、Cd含量的差异.结果表明,施用钙镁磷肥能显著提升土壤pH值,降低土壤TCLP提取态Cd含量,且降低效果随着水稻生育期的延长逐渐增强.与对照相比,施用0.8 g·kg-1的钙镁磷肥,使湘晚籼12号种植土壤和威优46号种植土壤TCLP提取态Cd含量在熟化期、灌浆期、分蘖期、成熟期分别下降了12.7%、15.6%、21.5%、61.9%和12.7%、72.6%、42.1%、59.7%.施用钙镁磷肥能显著增加水稻种植土壤中TCLP提取态Ca、Mg含量,降低TCLP提取态Cd含量,同时显著增加水稻各生育期各部位Ca、Mg含量并降低其Cd含量,水稻各部位中Ca、Mg含量与Cd含量均呈现负相关关系,表明外源Ca和Mg的加入对水稻累积Cd产生了拮抗作用.施用钙镁磷肥能显著降低水稻糙米中Cd含量并提高水稻产量.与对照相比,施用0.2~0.8 g·kg-1的钙镁磷肥,水稻湘晚籼12号和威优46号糙米中Cd含量分别下降了36.8%~52.6%和53.3%~75.6%.威优46号比湘晚籼12号更易将土壤Cd向水稻籽粒中转运.     

硫自养反硝化处理高含氟光伏废水可行性

为了研究硫自养反硝化处理高含氟光伏废水的可行性,室温(20~25℃)下,采用驯化后的硫自养反硝化生物膜反应器,探究了不同进水F-浓度对硫自养反硝化脱氮效能的影响.结果表明,当进水F-浓度为0~700 mg·L~(-1)时,随着F-浓度的提升,反应器的脱氮效能逐渐提升,且当F-浓度为700 mg·L~(-1)时,可获最大TN去除速率1.0 kg·(m3·d)-1.当进水F-浓度在700~900 mg·L~(-1)时,经短期驯化,TN去除速率可稳定在0.81~0.87 kg·(m~3·d)~(-1).当进水F-浓度提升至900 mg·L~(-1)以上时,反应器的TN去除速率随进水F-浓度的提升而下降,最低至0.4~0.5 kg·(m~3·d)~(-1).以光伏废水为研究对象,在进水F-浓度为800 mg·L~(-1)左右,进水NO_3~--N浓度为390~420 mg·L~(-1),HRT为8.8 h的条件下,经50 d运行后,获得稳定的脱氮效能,TN去除速率为1.1 kg·(m~3·d)~(-1),出水TN为15~25 mg·L~(-1),达到污水接管排放标准.采用传统反硝化工艺和硫自养反硝化工艺脱氮处理光伏废水的成本分别为2.468元·t~(-1)和2.072 8元·t~(-1),硫自养反硝化工艺更节约脱氮处理成本.