某铁路辖区创建标准化伙食团验收情况分析

按照《标准化伙食团管理评估考核表》4个类别18项工作任务,对某铁路辖区申报创建标准化伙食团的单位进行验收.结果显示,统一综合管理、设备卫生清洁、人员健康管理、场所卫生清洁工作较为到位,扣分较多集中在控制油盐食品、严格进货查验、统一资料台账和设备容器标识.结合考核验收情况,提出应进一步加强标准化伙食团创建工作、加强各部门...     

Mechanism study of electrochemical oxidation in the terylene diaphragm cell

Introduction T he dem and for new technologies to rem ove or to detoxify organics, especially those that are toxic to biological treatm ent processes from aqueous effluents, is w idely recognized. T he electrochem ical m ethod for treatm ent of such kinds of w astew ater has attracted a great deal of attention recently, m ainly because of its ease of control, am enability to autom ation, high efficiency and environm ental com patibility(C om ninel- lis and N erini, 1995). A t present, dim ens…     

Baseline ambient gaseous ammonia concentrations in the Four Corners area and eastern Oklahoma, USA

Ambient ammonia monitoring using Ogawa passive samplers was conducted in the Four Corners area and eastern Oklahoma, USA during 2007. The resulting data will be useful in the multipollutant management of ozone, nitrogen oxides, and visibility (atmospheric regional haze) in the Four Corners area, an area with growing oil/gas production and increasing coal-based power plant construction. The passive monitoring data also add new ambient ammonia concentration information for the U.S. and will be useful to scientists involved in present and future visibility modeling exercises. Three week integrated passive ammonia samples were taken at five sites in the Four Corners area and two sites in eastern Oklahoma from December, 2006 through December, 2007 (January, 2008 for two sites). Results show significantly higher regional background ammonia concentrations in eastern Oklahoma (1.8 parts per billion (ppb) arithmetic mean) compared to the Four Corners area (0.2 ppb arithmetic mean). Annual mean ammonia concentrations for all Four Corners area sites for the 2007 study ranged from 0.2 ppb to 1.5 ppb. Peak ambient ammonia concentrations occurred in the spring and summer in both areas. The passive samplers deployed at the Stilwell, Oklahoma site compared favorably with other passive samplers and a continuous ammonia monitoring instrument.     

Pesticide residues in soils, sediments, and vegetables in the Red River Delta, northern Vietnam

This study assessed pesticide residues in soils, sediments, and vegetables in the Xuan Khe and Hop Ly communes located along the Chau Giang River in the Red River Delta, northern Vietnam. Samples were collected from agricultural areas within and outside of embankments built to prevent flooding. In Xuan Khe, the soils outside of the embankment were more clayey with higher organic matter contents compared with the inside, due to selective deposition during river flooding. Many of the soils contained significant amounts of pesticides including dichlorodiphenyltrichloroethane (DDT), dicofol, isoprothiolane, and metalaxyl although their levels were below the maximum allowable concentration set by the Vietnamese government. The spectrum of DDT derivatives found suggested that the source of DDTs was not contaminated dicofol. Soils in Hop Ly resembled soils in Xuan Khe but were relatively sandy; one field showed appreciable contents of DDT derivatives. The ratios of (p,p ^′-dichlorodiphenyldichloroethylene + p,p ^′-dichlorodiphenyldichloroethane)/∑DDT in the surface and subsurface soils in Hop Ly were 0.34 and 0.57, suggesting that the DDTs originated from recent application. Pesticide residues in soils were not likely to translocate into vegetable crops, except for metalaxyl. High concentrations of cypermethrins in kohlrabi leaves could be ascribed to foliar deposition.     

Integrated assessment of brick kiln emission impacts on air quality

This paper presents monitoring results of daily brick kiln stack emission and the derived emission factors. Emission of individual air pollutant varied significantly during a firing batch (7 days) and between kilns. Average emission factors per 1,000 bricks were 6.35–12.3 kg of CO, 0.52–5.9 kg of SO₂ and 0.64–1.4 kg of particulate matter (PM). PM emission size distribution in the stack plume was determined using a modified cascade impactor. Obtained emission factors and PM size distribution data were used in simulation study using the Industrial Source Complex Short-Term (ISCST3) dispersion model. The model performance was successfully evaluated for the local conditions using the simultaneous ambient monitoring data in 2006 and 2007. SO₂ was the most critical pollutant, exceeding the hourly National Ambient Air Quality Standards over 63 km² out of the 100-km² modelled domain in the base case. Impacts of different emission scenarios on the ambient air quality (SO₂, PM, CO, PM dry deposition flux) were assessed.     

贵阳市夏季大气颗粒物及多环芳烃污染特征研究

采集贵阳市老城区夏季5个典型监测点(太慈桥、贵州师范大学、大西门、省政府及省植物园)的样品进行PM2.5、PM10质量浓度分析。同时对PM2.5中PAHs的质量浓度进行分析。结果表明:贵阳市夏季PM2.5和PM10浓度排序均为太慈桥省政府大西门贵州师范大学省植物园,且PM2.5和PM10之间有良好的相关性,PM10=0.931 3 PM2.5+0.019 4,R2=0.996 7,PM2.5污染较重。此外,5个监测点总PAHs和苯并(a)芘的分析结果均为太慈桥省政府大西门贵州师范大学省植物园,苯并(a)芘浓度均未超标。     

Indirect prediction of surface ozone concentration by plant growth responses in East Asia using mini-open top chambers

We developed small and mobile open top chambers (mini-OTC) measuring 0.6 m (W)?×?0.6 m (D)?×?1.2 m (H) with an air duct of 0.6 m (W)?×?0.23 m (D)?×?1.2 m (H). The air duct can be filled with activated charcoal to blow charcoal filtered air (CF) into the chamber, as opposed to non-filtered ambient air (NF). Ozone sensitive radish Raphanus sativus cv. Red Chime and rosette pakchoi Brassica campestris var. rosularis cv. ATU171 were exposed to NF and CF in mini-OTCs at different locations in East Asia. A total of 29 exposure experiments were conducted at nine locations, Shanghai, China, Ha Noi, Vietnam, Lampang, Phitsanulok and Pathumtani, Thailand, and Hiratsuka, Kisai, Abiko and Akagi, Japan. Although no significant relationships between the mean concentrations of ambient O₃ during the experimental period and the growth responses were observed for either species, multiple linear regression analysis suggested a good relationship between the biomass responses in each species and the O₃ concentration, temperature, and relative humidity. The cumulative daily mean O₃ (ppb/day) could be indirectly predicted by NF/CF based on the dry weight ratio of biomass, mean air temperature, and relative air humidity.     

Risk assessment for sustainable food security in China according to integrated food security—taking Dongting Lake area for example

Integrated food security covers three aspects: food quantity security, food quality security, and sustainable food security. Because sustainable food security requires that food security must be compatible with sustainable development, the risk assessment of sustainable food security is becoming one of the most important issues. This paper mainly focuses on the characteristics of sustainable food security problems in the major grain-producing areas in China. We establish an index system based on land resources and eco-environmental conditions and apply a dynamic assessment method based on status assessments and trend analysis models to overcome the shortcomings of the static evaluation method. Using fuzzy mathematics, the risks are categorized into four grades: negligible risk, low risk, medium risk, and high risk. A case study was conducted in one of China’s major grain-producing areas: Dongting Lake area. The results predict that the status of the sustainable food security in the Dongting Lake area is unsatisfactory for the foreseeable future. The number of districts at the medium-risk range will increase from six to ten by 2015 due to increasing population pressure, a decrease in the cultivated area, and a decrease in the effective irrigation area. Therefore, appropriate policies and measures should be put forward to improve it. The results could also provide direct support for an early warning system—which could be used to monitor food security trends or nutritional status so to inform policy makers of impending food shortages—to prevent sustainable food security risk based on some classical systematic methods. This is the first research of sustainable food security in terms of risk assessment, from the perspective of resources and the environment, at the regional scale.     

Arsenic contamination in groundwater and its possible sources in Hanam, Vietnam

This study investigated the arsenic (As) level in groundwater, and the characteristics of aquifer sediment as related to the occurrence of As in groundwater in Hanam, Vietnam. The deposition and transport of As-containing substances through rivers were also examined. Arsenic concentrations in 88% of the groundwater samples exceeded the As limit for drinking water based on the WHO standards. The dominating form of arsenic was As(III). The maximum total As content in bore core sediment was found in a peat horizon of the profiles and generally, elevated levels of As were also found in other organic matter-rich horizons. Total As contents of the bore core sediments were significantly correlated with crystalline iron oxide, silt and clay contents, suggesting that As in aquifer sediment was mainly associated with iron (hydr)oxides and clay mineral. In the groundwater, As concentration showed significant correlations with the total concentrations of Fe and HCO (3)(-). Significant correlations between HCl-extractable As and non-crystalline Fe oxide, total C, N, and S were also observed in the profiles. The results support the hypothesis that under favorable reductive conditions established by the degradation of organic matter, the dissolution of iron (hydr)oxides releases adsorbed As into the groundwater. The deposition of As in the sediments from the Red River were significantly higher than that in the Chau Giang River, suggesting that the Red River is the main source of As-containing substances deposited in the study area.