三峡库区大宁河流域非点源污染研究

以大宁河流域巫溪水文站控制流域为研究对象,应用分布式非点源污染模型SWAT,利用实测流量、泥沙负荷及氮、磷负荷数据对模型进行了率定和验证,并模拟了大宁河流域的径流量和营养物质氮、磷的排放.结果表明,月平均流量在率定期和验证期的效率系数分别达到了0.93和0.62;泥沙负荷的效率系数分别为0.70和0.34;氨氮和总磷的效率系数分别达到了0.31和0.37.大宁河流域污染物质的排放存在着较大的空间差异,有机氮和有机磷的5年平均排放量区间分别为2.01～38.15和0.35～5.89 ks/(hm2·a),其中,流域西南部子流域的有机氮和有机磷平均排放量最大,分别为38.15和5.89 ks/(hm2·a),是大宁河流域污染物排放的最敏感区域.     

Comparison of vehicle activity and emission inventory between Beijing and Shanghai

Vehicle emission inventory is a critical element for air quality study. This study created systemic methods to establish a vehicle emission inventory in Chinese cities. The methods were used to obtain credible results of vehicle activity in Beijing and Shanghai. On the basis of the vehicle activity data, the International Vehicle Emission model is used to establish vehicle emission inventories. The emissions analysis indicates that 3 t of particulate matter (PM), 199 t of nitrogen oxides (NO(x)), 192 t of volatile organic compounds (VOCs), and 2403 t of carbon monoxide (CO) are emitted from on-road vehicles each day in Beijing, whereas 4 t of PM, 189 t of NO(x), 113 t of VOCs, and 1009 t of CO are emitted in Shanghai. Although common features were found in these two cities (many new passenger cars and a high taxi proportion in the fleet), the emission results are dissimilar because of the different local policy regarding vehicles. The method to quantify vehicle emission on an urban scale can be applied to other Chinese cities. Also, knowing how different policies can lead to diverse emissions is beneficial knowledge for other city governments.     

Characteristics of real-world vehicular emissions in Chinese cities

On-board emission measurements were performed on 49 light-duty gasoline vehicles in seven cities of China. Vehicle-specific power mode distribution and emission characteristics were analyzed based on the data collected. The results of our study show that there were significant differences in different types of roads. The emission factors and fuel consumption rates on arterial roads and residential roads were approximately 1.4-2 times those on freeways. The carbon monoxide, hydrocarbon, and nitrogen oxides emission factors of Euro II vehicles were on average 86.2, 88.2, and 64.5% lower than those of carburetor vehicles, respectively. The new vehicle emission standards implemented in China had played an important role in reducing individual vehicle emissions. More comprehensive measures need to be considered to reduce the total amount of emissions from vehicles.     

Cell wall surface layer (S-layer) promotes colony formation in Microcystis: comparison of S-layer characteristics between colonial and unicellular forms of Microcystis and function conformation

Colony is a key to Microcystis becoming a dominant population and forming blooms. To find the mechanism of colony formation, we investigated cell wall structures of colonial and unicellular strains. Results showed that colonial strains had significant surface layer protein (S-layer) on the surface of cells than unicellular strains by transmission electron microscopy. Western blot showed colonial strains had more S-layer than the unicellular strains. When the S-layer gene (GenBank accession number CAO89090.1) of Microcystis aeruginosa PCC7806 was expressed in Synechocystis sp. PCC6803, PCC6803 aggregated into colonial morphology. The results indicated that the S-layer could promote colony formation in Microcystis. Based on the S-layer sequences of PCC6803 and PCC7806, nine S-layer genes in other Microcystis strains were screened from the GenBank. Sequence comparing showed that the S-layers conserved regions were all located in N-terminal. The S-layers contain repeats-in-toxin (RTX) sequences with Ca²⁺-binding site, and their amino acid composition, hydrophobicity, isoelectric point, etc. were consistent with the characteristics of RTX-type S-layer in bacteria.

     

Neurological effects of subchronic exposure to dioctyl phthalate (DOP), lead,and arsenic,individual and mixtures,in immature mice

Environmental Science and Pollution Research - Dioctyl phthalate (DOP) (200, 500, and 1000 mg kg?1 bw, i.g.), Pb (Ac)2 (50 mg L?1, p.o.), and NaAsO2 (10 mg L?1, p.o.) were...     

镁渣配料煅烧硅酸盐水泥熟料的研究

研究了镁渣矿物组成和镁渣配料煅烧硅酸盐水泥熟料的反应动力在数和物理性能。结果表明：镁渣的主要矿物组成为γ－Ｃ２Ｓ、β－Ｃ２Ｓ、ＭｇＯ、ＣＦ、Ｃ２Ｆ、ＦｅＯ、ＣａＦ２等，并且镁渣可降低熟料形成反应表观活化能，加速熟料矿物的形成，提高熟料的强度。     

Formation control of bromate and trihalomethanes during ozonation of bromide-containing water with chemical addition: Hydrogen peroxide or ammonia?

To ensure the safety of drinking water, ozone (O₃) has been extensively applied in drinking water treatment plants to further remove natural organic matter (NOM). However, the surface water and groundwater near the coastal areas often contain high concentrations of bromide ion (Br^?). Considering the risk of bromate (BrO₃^?) formation in ozonation of the sand-filtered water, the inhibitory efficiencies of hydrogen peroxide (H₂O₂) and ammonia (NH₃) on BrO₃^? formation during ozonation process were compared. The addition of H₂O₂ effectively inhibited BrO₃^? formation at an initial Br^? concentration amended to 350 µg/L. The inhibition efficiencies reached 59.6 and 100% when the mass ratio of H₂O₂/O₃ was 0.25 and > 0.5, respectively. The UV₂₅₄ and total organic carbon (TOC) also decreased after adding H₂O₂, while the formation potential of trihalomethanes (THMsFP) increased especially in subsequent chlorination process at a low dose of H₂O₂. To control the formation of both BrO₃^? and THMs, a relatively large dose of O₃ and a high ratio of H₂O₂/O₃were generally needed. NH₃ addition inhibited BrO₃^? formation when the background ammonia nitrogen (NH₃N) concentration was low. There was no significant correlation between BrO₃^? inhibition efficiency and NH₃ dose, and a small amount of NH₃N (0.2 mg/L) could obviously inhibit BrO₃^? formation. The oxidation of NOM seemed unaffected by NH₃ addition, and the structure of NOM reflected by synchronous fluorescence (SF) scanning remained almost unchanged before and after adding NH₃. Considering the formation of BrO₃^? and THMs, the optimal dose of NH₃ was suggested to be 0.5 mg/L.     

矿区含氡深井水作饮用水氡污染治理的试验研究

矿区含氡深井水通过实验室小规模除氡试验。结果表明：敞口贮存，曝气和活性炭吸附是除氡的三种有效方法。本文对试验各种过程和结果进行分析讨论。     

区域矿产资源开发的一般模式与应用——以赣江流域为例

本文首次将矿产资源开发作为一个能动型开放系统予以研讨,通过建立区域矿产资源开发数据库、计算矿产资源对国民经济发展的保证程度、计算矿产资源开发的价值贡献、经济地质区划和有限投资倾向的优选等5个方面实行宏观控制;通过组建矿产资源开发生产联合体进行中观调节;通过成立矿产资源开发综合研究机构获取微观反馈,建立了区域矿产资源开发的新模式,并以赣江流域为例进行了探讨,取得了有意义的结果。     

浙江省生态功能区划研究

在浙江省生态环境现状调查的基础上,运用GIS等先进技术,采用定性与定量相结合的方法,对浙江省生态环境现状、生态环境敏感性和生态服务功能重要性进行评价,形成浙江省生态功能区划方案,将浙江省划分为6个生态区、15个生态亚区、47个生态功能区,并确定了具有重要生态系统服务功能的5个重要生态功能区域.区划成果为浙江生态省建设规划的实施、资源的合理利用和工农业生产合理布局提供了科学依据.