Time-course uptake and elimination of benzo(a)pyrene and its damage to reproduction and ensuing reproductive outputs of Pacific oyster, <Emphasis Type="Italic">Crassostrea gigas</Emphasis>

The time-course of uptake and elimination of benzo(a)pyrene (BaP) for the Pacific oyster, Crassostrea gigas and reproduction damage and reproductive outputs were studied. Sexually immature C. gigas broodstock were fed for 28 days with live algae grown in four BaP solutions of 0, 50, 500, and 5,000 μg L⁻¹ (hereafter, control, 50, 500, and 5,000 oysters) and were subsequently conditioned to maturation by a feeding with BaP-free live algae under temperature manipulation for another 28 days. The 5,000 μg L⁻¹ oysters gained a steady state concentration, around 30,000 ng g⁻¹ d.w. for digestive gland, a week earlier compared to the 500 μg L⁻¹ oysters. The earlier gain or longer persistence of the steady state concentration influenced elimination of BaP, with an eliminating trend for 500 μg L⁻¹ oysters, while no elimination for 5,000 μg L⁻¹ oysters. The maternal persistence of the steady state concentration resulted in significant damages in the reproductive success and their reproductive outputs in terms of the hatching rate and larval growth, survival, and settlement. The 50 μg L⁻¹ oysters remained far below the steady state concentration, and showed a manifest eliminating behavior during the subsequent BaP-free 28 day maturation period. The reproductive success and initial larval events of 50 μg L⁻¹ oysters were comparable to those of control. However, the damage potential of the 50 μg L⁻¹ oysters might be more significant if their maternal exposure continued beyond 28 days, since the accumulation profile at this dose was linear.     

Assessment of soil and soil-gas radon activity using active and passive detecting methods in Korea

Radon ((222)Rn) is a carcinogenic gas produced by the radioactive decay of radium ((226)Ra). It has been reported that soil and soil-gas are primary factors that could cause indoor radon problems. Six sites were selected for this study--Sanbook, Gangcheon, Jikyeong, Choojung, Geumsung and Homyoung--each was classified according to bedrock type. In order to investigate soil-gas radon activities and radon emanating power, innovated active and passive detecting methods were developed and applied under both field and laboratory conditions. Statistical analysis of results confirmed that the radon activity values measured using either active or passive methods under field or laboratory conditions could be interchangeable with each other.     

Low-temperature CO oxidation over Au-doped 13X-type zeolite catalysts: preparation and catalytic activity

Au-supported 13X-type zeolite (Au/13X) was synthesized using a common deposition–precipitation (DP) method with a solution of sodium carbonate as a precipitate agent. Further testing was conducted to test for catalytic oxidation of CO. A study was conducted on the effects of different preparation conditions (i.e., chloroauric acid concentration, solution temperature, pH of solution, and calcinations temperature) on Au/13X for CO oxidation. In respect to the catalytic activity, the relationship between different the preparation conditions and gold particles in 13X zeolite was analyzed using X-ray diffraction, TEM and XPS. The activity of Au/13X catalysts in CO oxidation was dependent on the chloroauric acid concentration. From XRD results, a higher chloroauric acid concentration induced larger gold nanoparticles, which resulted in lower catalytic activity. Results revealed that higher temperatures induced higher Au loading, homogeneous deposit, and smaller gold clusters on the support of 13X, resulting in higher CO activity. Furthermore, a pH of 5 or 6 generated greater amounts of Au loading and smaller Au particles on 13X than at a pH of 8 or 9. This may be a result of an effective exchange between Au(OH)2Cl2- and Au(OH)₃Cl^- on specific surface sites of zeolite under the pH’s 5 and 6. The sample calcined at 300°C showed the highest activity, which may be due to the sample’s calcined at 200°C inability to decompose completely to metallic gold while the sample calcined at 400°C had larger particles of gold deposited on the support. It can be concluded from this study that Au/13X prepared from a gold solution with an initial chloroauric acid solution concentration of 1.5 × 10^-3 mol·L^-1 gold solution pH of 6, solution temperature of around 90°C, and a calcination temperature of 300°C provides optimum catalytic activity for CO oxidation.     

Physicochemical properties of chars at different treatment temperatures

In this study, the physicochemical properties of the char of Indonesian SM coal following heat treatment at various temperatures were evaluated using X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and morphological and specific surface area analysis. Based on these analyses, heat treatment of coal was determined to be the most effective in increasing the coal rank. In the XPS analysis, the C-O and C-O-C groups and quaternary-N species were found to be of a lower grade coal when the pretreatment temperature decreased, meanwhile the C-C group and pyridinic species increased. In the FT-IR analysis, the collapse of the C-O and C-O-C group was observed due to the collapse of the ether group. In SEM and Brunauer-Emmett-Teller (BET) analysis, a decrease in the ether group was shown to be accompanied with the formation of micropores.     

我国黑土地农田土壤除草剂残留特征研究及展望

粮食安全是“国之大者”.东北黑土地作为我国重要的粮仓,是保障国家粮食安全的“压舱石”.但黑土地农田除草剂的长期高强度施用,导致除草剂在土壤中积累和迁移,影响土壤质量、作物产量和品质,阻碍黑土地可持续利用和农业可持续发展.解决黑土地农田除草剂残留问题,既要从源头管控除草剂的施用,也要掌握除草剂的残留特征、时空演变和驱动因素,才能做到科学防控、精准施策.系统总结了我国黑土地农田除草剂的施用状况和存在的问题,全面梳理了除草剂的残留现状,指出了当前在黑土地农田除草剂残留特征、空间分布和污染诊断等研究上的不足,提出了我国黑土地农田除草剂残留诊断与风险管理研究思路与重点方向,为保障我国黑土地农田土壤健康、粮食安全和生态系统安全提供科技支撑.     

辽宁省机动车污染防治对策探讨

辽宁省机动车保有量大、增长速度快，机动车污染物排放总量不断增加，给城市环境空气质量改善带来巨大压力，本文根据辽宁省机动车污染实际情况，提出了辽宁省机动车污染的防治对策。     

Advanced molecular-fingerprinting analysis of dissolved organic sulfur by electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry using optimal spray solvent

Molecular level characterization of dissolved organic sulfur(DOS) by electrospray ionizationFourier transform ion cyclotron resonance mass spectrometry(ESI-FTICR MS) is necessary for further understanding of the role of DOS in the environment. Here, ESI spray solvent, a key parameter for ion production during ESI process, was investigated for its effect on the molecular characterization of DOS by ESI-FTICR MS. 100% MeOH as spray solvent was found for the first time to remarkably enhance the ioni...     

污泥生物炭去除水中重金属的研究进展

重金属带来的环境风险日益严峻,利用污泥生物炭去除水中重金属污染方面的研究得到了广泛关注。结合当前国内外研究现状,归纳了不同条件下制备的污泥生物炭对水中重金属,如Cd、Pb、Cr、As等的吸附机理,污泥生物炭对大多数重金属的吸附满足物理吸附和化学吸附的多重作用,可通过增加生物炭表面有效基团及有效吸附位点提升吸附性能。同时,总结了影响吸附效率的各种因素,探究了污泥生物炭的再生问题,并对今后污泥生物炭去除水中重金属的研究方向做出了展望。     

硅胶表面TEOS疏水化改性及吸附VOCs特性

以正硅酸乙酯（TEOS）为疏水改性剂,通过硅胶表面的羟基接枝反应,得到具备一定疏水性的改性硅胶;利用BET、FT-IR、XRD和TG-DTG等手段对改性硅胶的结构及稳定性进行了表征;在此基础上考察了改性硅胶对各类有机废气的吸附性能.结果表明,TEOS成功接枝在了硅胶表面,改性硅胶不仅具备一定的疏水性,而且机械强度增加到原来的66.85%,稳定性也都得到了提高; 550℃空气下焙烧后的改性硅胶仍具有疏水性且吸附容量是焙烧之前的2倍;在高湿度高浓度的废气治理中,TEOS改性硅胶表现出更高的吸附能力和优良的热再生性能.高浓度下改性硅胶的吸附容量是低浓度下的10倍且不受水汽的影响;改性硅胶循环10次的吸附/脱附几乎不变,且在一定条件下,15~30min就达到90%的脱附率.     

超高效液相色谱-串联质谱法测定污水中14种有机磷酸酯阻燃剂

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)联用法同时测定污水中14种有机磷酸酯阻燃剂(OPEs)的分析方法.样品采集后,经GF/C膜过滤,HLB固相萃取小柱净化后进样分析.以BEH C18色谱柱为分离柱,乙腈和水混合液为流动相(0.2 mL min-1)梯度洗脱,15 min内可完成14种OPEs的分离.在电喷雾正离子模式下,采用多反应监测模式(MRM)进行质谱测定.在加标浓度为1.0μg·L-1时,14种OPEs在污水处理厂进水和出水中的回收率分别为52.1%—119%、43.6%—114%,相对标准偏差(RSD)分别为1.2%—16.2%、0.4%—9.2%,方法的检出限(LOD)在0.3—6.0 ng·L-1间.方法精密度好,准确度高,可满足同时对污水样品中的14种OPEs进行定性及定量分析的要求.