Assessment of cadmium content of potato grown in Weining County,Guizhou Province,China

A total of 54 soil and 54 potato samples have been collected from Weining County to evaluate the accumulation of cadmium in potatoes. The concentrations of the total Cd and the available Cd in the soil samples have been detected. The total concentrations of Cd were from 0.41 to 10.0 mg/kg with an average value of 2.60 mg/kg in soil. The concentrations of available Cd in the soil were 0.07 to 3.47 mg/kg with an average value of 0.59 mg/kg. The concentration of the available Cd showed a good linear positive correlation with the total Cd content in the soil. For the 54 potato samples, the Cd concentrations were from 0.023 to 0.18 mg/kg with an average value 0.083 mg/kg (fresh weight).The bioconcentration factor (BCF) values of Cd in potatoes, based on dry weight, were from 0.02 to 0.96 with an average value 0.24. The uptake of cadmium by plants is dependent on various soil and environmental factors. A regression model to predict the concentration of cadmium in Weining potatoes based on soil properties and elevation was developed. The results showed the elevation and the soil pH played an important role and had a negative influence on the uptake of Cd by potato in Weining County. The mean intake of Cd by adults through consumption of potato from Weining would be 5.9 μg/day, and it is well below the provisionally tolerable daily intake for Cd (70 μg/day).     

Removal of nutrients and veterinary antibiotics from swine wastewater by a constructed macrophyte floating bed system

The potential of three varieties of Italian ryegrass (Lolium multiflorum Lam.), Dryan, Tachimasari and Waseyutaka, to improve the water quality of swine wastewater was evaluated using a constructed macrophyte floating bed system. With respect to reductions in levels of nutrients, chemical oxygen demand (COD), and sulfonamide antimicrobials (SAs, including sulfadiazine, sulfamethazine, and sulfamethoxazole), Dryan performed better than Tachimasari and Waseyutaka. For Dryan, total N was reduced by 84.0%, total P by 90.4%, COD by 83.4% and sulfonamide antimicrobials by 91.8–99.5%. Similar results were observed for Tachimasari and Waseyutaka. The results indicated that the treatment of swine wastewater using the constructed macrophyte floating bed system was effective in the removal of nutrients and veterinary antibiotics.     

Quinone profiles of microbial communities in sediments of Haihe River�CBohai Bay as influenced by heavy metals and environmental factors

A total of 11 sediment samples were collected from the sites along Haihe River?CBohai Bay, with site 1 at the beginning of Haihe River and site 11 in Bohai Bay, about 150 km away from site 1. Quinone profiles were used for the analysis of microbial community as influenced by pollutants in water and sediments, such as heavy metals, and other environmental factors. Nineteen species of quinones were found at site 1 while only six species at sites 10 and 11. Both the diversity of quinone species (DQ) and the number of quinones were higher in the sediments from Haihe River and the near-sea area of Bohai Bay than in those from the deep-sea area. The ?? diversity values were significantly higher, while Jaccard indexes of similarity were much lower among non-contiguous pairs of sites as compared with the contiguous ones. Cluster analysis indicated that quinone profiles may be grouped into two main clusters (sites 1?C7 and sites 8?C11), and there were higher similarities within the groups than between groups. Quinone species composition varied at different sites. Ubiquinones such as UQ-8, UQ-9, and UQ-10 and menaquinones such as MK-6, MK-7, MK-8 were isolated from all the sites and accounted for the largest proportions. Pearson correlation analysis revealed that both the number of quinone species and DQ correlated positively with total organic carbon contents in water and sediments, but negatively correlated with salinity and electroconductivity and did not correlate significantly with heavy metal contents in water.     

Distribution and enrichment of acid-leachable heavy metals in the intertidal sediments from Quanzhou Bay, southeast coast of China

The article presents the distribution and enrichment of acid-leachable heavy metals (ALHMs) Cu, Zn, Pb, Cr, Mn, and Fe in the intertidal sediments collected from Quanzhou Bay, southeast coast of China. The contents of ALHMs along with sediment texture, total organic carbon, S^2???, and CaCO₃ in surface sediments were analyzed to identify the input of heavy metals from various sources. The enrichment of ALHMs in the sediments is mainly attributed to the intense industrial activities around Quanzhou Bay and to the serried activities of intertidal breed aquatics along the seacoast. The results also illustrate the association between the ALHMs with the finer fractions, organic matter, and Fe oxyhydroxides in the sediments. The above results were very supported by the multivariate statistical analyses, including correlation, principal component analysis, and hierarchical clustering analysis. Comparative results of ALHMs in the intertidal sediments from Quanzhou Bay with those in other domestic bays and estuaries indicate that the study area has been enriched with heavy metals, especially with Zn, Cu, and Pb, during the past few decades. The results of the present study suggest that the authorities should pay attention to the current status and take some measures to control the heavy metal pollution in the study area.     

强化企业安全检查力度及效果的对策

安全检查是现代安全管理中最有效的手段 ,也是企业发现事故隐患、促进现场安全文明生产的好途径。介绍了安全检查作用及特性 ,并结合目前安全检查存在的不足 ,提出了一些强化安全检查效果的对策。     

Formation of submicron sulfate and organic aerosols in the outflow from the urban region of the Pearl River Delta in China

Size-resolved chemical compositions of non-refractory submicron aerosols were measured using a quadrupole Aerodyne aerosol mass spectrometer at a rural site near Guangzhou in the Pearl River Delta (PRD) of China in the summer of 2006. Two cases characterized as the outflows from the PRD urban region with plumes of high SO₂ concentration were investigated. The evolution of sulfate size distributions was observed on a timescale of several hours. Namely mass concentrations of sulfate in the condensation mode (with vacuum aerodynamic diameters (D_va) < 300 nm) increased at a rate of about 0.17–0.37 ppbv h^?1 during the daytime. This finding was consistent with the sulfuric acid production rates of about 0.17–0.3 ppbv h^?1, as calculated from the observed gas-phase concentrations of OH (～3.3 × 10⁶–1.7 × 10⁷ cm^?3) and SO₂ (～3–21.2 ppbv). This implies that the growth of sulfate in the condensation mode was mainly due to gas-phase oxidation of SO₂. The observed rapid increase was caused mainly by the concurrent high concentrations of OH and SO₂ in the air mass. The evolution of the mass size distributions of m/z 44, a tracer for oxygenated organic aerosol (OOA), was very similar to that of sulfate. The mass loadings of m/z 44 were strongly correlated with those of sulfate (r² = 0.99) in the condensation mode, indicating that OOA might also be formed by the gas-phase oxidation of volatile organic compound (VOC) precursors. It is likely that sulfate and OOA were internally mixed throughout the whole size range in the air mass.     

Establishment of Proper Land-use Assessment and Management Strategy for Deji Reservoir Catchment, Taiwan

Deji Reservoir is situated in the middle of Taiwan on the upstream catchment of the Dajia stream with an area of over 60,160 ha. The embankment stands 180 m high and is the tallest concrete arch dam in Taiwan. This dam stores 1.7 billion cubic meters of valid volume water. It provides over 370 million kilowatt-hours of electricity annually. It is also an important facility for operating flood control, hydroelectricity, irrigation, public water supply, etc. Seventy-two percent of the terrain is at 2,000- to 3,000-m altitude, and 5.2% is above 3,200-m altitude. More than 59% of the area is covered with steep topography of 55% slope. Only 7.9% of the area is shown with gentle slopes of less than 30% slope, which are located among the two banks of main streams with the altitudes ranging from 1,500 to 2,500 m. Most of the gentle slopes are used for temperate zone fruit, vegetable, and tea plantations. This land-use immediately adjoins a reservoir catchment region, resulting in an enormous impact on the mountainous environment. This study reviewed human-developed land-use area to properly address and evaluate norms for mitigating the impacts on the reservoir. The initial investigation brought up the parameters of gradient, slope movement types and processes, distance to the reservoir, location of developed area and distance with the farm road, etc. Local investigation and global information system technology were conducted in this research. We focused on segregating the terrain types of indisposed land-use. A different land-use management strategy is also analyzed.     

Prenatal evaluation and postnatal outcomes of fetal ovarian cysts

To evaluate the natural history and outcome of cases of fetal ovarian cyst under conservative prenatal treatment. A retrospective cohort study included patients diagnosed with fetal ovarian cysts was conducted between January 2008 to December 2016. Data including clinical data, sonographic feature and postnatal outcomes were obtained. One hundred and two cases were included for statistical analysis. The rate of spontaneous resolution was significantly higher among cases with simple than complex cysts (70/92 or 76.1% vs 2/10 or 20%, P < .01) and for cysts <4 cm than cysts ≥4 cm (50/56 or 89.3% vs 22/46 or 47.8%, P < .01). Ovarian torsion was confirmed in 5/102 (4.9%) cases; neither prenatal characteristics of cysts (complex: 2/10 or 20% vs simple: 3/92 or 3.3%, P = .07), nor their size ( ≥ 40 mm: 4/46 or 8.7% vs < 40 mm: 1/56 or 1.8%, P = .17) was predictive for ovarian torsion. 25/102 (24.5%) of cysts change in size or sonographic characteristics prenatally. Half of the complex cysts at the last prenatal scan are not ovarian in origin. 98/102 neonates (96.1%) were able to preserve both ovaries. Spontaneous resolution of ovarian cysts is predicted by cyst size and characteristics, whereas likelihood of torsion cannot be predicted.     

Crowding in platform staircases of a subway station in China during rush hours

Crowding during the morning peak hours at a platform staircase in a subway station in China was studied in this paper. Passenger flow was surveyed with normal evacuation time recorded. The evacuation process was simulated with the software buildingEXODUS. Predicted results on the total evacuation time and maximum flow capacity of the selected staircase were compared with the field observations. Two parameters, the width of staircase utilized per person and the maximum upstairs walking speed used in the software were identified to be noticeably different from the field studies. Predictions agreed better with the observations after tuning these two parameters. It is concluded that the evacuation simulation software can be applied for safety design with appropriate tuning on the key parameters through field tests.     

太钢安全工作新思路的尝试

太钢自1996年以来,开始了“大安全”工作思路,狠抓了人身安全,职业卫生安全,设备设施安全,生产组织安全,技术工艺安全,交通安全,消防安全,后勤保障安全,医疗卫生安全,环境保护,社会活动安全等,取得了很大效果。