Assessment and potential sources of metals in the surface sediments of the Yellow River Delta,Eastern China

The Yellow River Delta is the most intact estuary wetland in China and suffers from great pressure of metals. Seventy-seven surface sediment samples were collected in the delta, and contents of Cu, Pb, Cd, Cr, Zn, Ni, and Mn were analyzed by inductively coupled plasma spectrometry and those of Hg and As by atomic fluorescence spectrometry. The results showed that means of metal contents (ppm, dry weight) were as follows: Hg, 0.04; Cr, 61.72; Cu, 20.97; Zn, 60.73; As, 9.47; Pb, 21.91; Cd, 0.12; Ni, 27.24; and Mn, 540.48. 43.8% of Hg and 14.3% of Cd were from the allogenic source while others from the authigenic source. The results of the geoaccumulation indexes appeared that 6.5% of sites from the estuarine and the Gudao areas were moderately polluted by Hg. All ecological risk index values of Hg and 37.7% of Cd were more than 40, which were the main factors of strongly and moderately potential ecological risks of 37.7% of sites in the delta. High Cd contents may be due to the alkaline conditions of the delta and the unreasonable management of the farmland, while the abnormal distribution of Hg to the wet or dry deposition and the erosion of the seawater. It was suggested to monitor Hg content in the atmosphere of the Yellow River Delta. The results were expected to update the pollution status of metals in the delta and created awareness of preserving the sound condition of the Yellow River Delta.     

Genetic diversity and population structure of the invasive plant <Emphasis Type="Italic">Solanum rostratum</Emphasis> in China

The level of genetic diversity of 13 Chinese populations of S. rostratum was investigated using nine microsatellite loci. The genetic diversity of the Weisanlu population in Hebei province was the highest and the Hohhot population was the lowest. The genetic differentiation among the populations was highly significant (P < 0.001). A total of 68.54% of the total genetic variation of population was within populations, and the genetic variation between populations accounted for 31.46%. The long-distance dispersal of its seeds by human transport mainly resulted in the rapid dispersal of S. rostratum in China.     

生活垃圾加载介质层填埋法对初期渗滤液污染抑制效果研究

以传统卫生填埋柱R2为对照,通过往生物反应器填埋柱R1内加载可渗透反应介质层1和2进行模拟试验,主要探讨了填埋柱R1垃圾渗滤液COD、总氮、氨氮及总磷的变化趋势,探索一种新型的加载介质层垃圾填埋处理方法。试验结果表明,填埋20周后, R1柱COD浓度基本维持在40 000～45 000 mg/L间,约为R2柱的20%～30%;第24周,R1柱总氮和氨氮分别为206.5 mg/L和167.3 mg/L,在16～24周内,R1总氮和氨氮分别约为R2的14.5%～17.5%和36.2%～43.6%;18周时,R1柱总磷达最大值1.704 mg/L,至第24周降为0.673 mg/L, 整个实验过程R1柱总磷约为R2的0.15%～0.56%。     

Size-fractionation and characterization of landfill leachate and the improvement of Cu2+ adsorption capacity in soil and aged refuse

Leachate was collected from an anaerobic lagoon at Shanghai Laogang refuse landfill, the largest landfill in China, and the sample was separated into six fractions using micro-filtration membranes, followed by ultra-filtration membranes. Several parameters of the samples were measured, including chemical oxygen demand (COD), total organic carbon (TOC), total solids (TS), pH, total phosphate (TP), total nitrogen (TN), fixed solids (FS), NH4+, orthophosphate, color, turbidity, and conductivity. These parameters were then quantitatively correlated with the molecular weight cutoff of the membrane used. Organic matter in the dissolved fraction (MW<1kDa) predominated in the leachate, accounting for 65% of TOC. Thermal infrared spectroscopy was used to characterize the filter residues. Asymmetric and symmetric stretching of methyl and methylene groups, and of functional groups containing nitrogen and oxygen atoms, were observed. In addition, the ability of two different samples to adsorb heavy metals was tested. Cu2+ was chosen as the representative heavy metal in this study, and the samples were soil; aged refuse, which had spent 8 years in a conventional sanitary landfill; and samples of soil and aged refuse treated for 48h with leachate in the ratio of 5g of sample per 50ml of leachate. Cu2+ uptake by the raw soil was approximately 4.60microg/g, while uptake by the leachate-contacted soil and leachate-contacted aged refuse were 5.66 and 5.11microg/g, respectively. These results show that the organic matter in the leachate enhanced the capacity of aqueous solutions to adsorb Cu2+.     

Assessment of tap water quality and corrosion scales from the selected distribution systems in northern Pakistan

Corrosion deposits formed within drinking water distribution systems deteriorate drinking water quality and resultantly cause public health consequences. In the present study, an attempt was made to investigate the concurrent conditions of corrosion scales and the drinking water quality in selected water supply schemes (WSS) in districts Chitral, Peshawar, and Abbottabad, northern Pakistan. Characterization analyses of the corrosion by-products revealed the presence of α-FeOOH, γ-FeOOH, Fe₃O₄, and SiO₂ as major constituents with different proportions. The constituents of all the representative XRD peaks of Peshawar WSS were found insignificant as compared to other WSS, and the reason could be the variation of source water quality. Well-crystallized particles in SEM images indicated the formation of dense oxide layer on corrosion by-products. A wider asymmetric vibration peak of SiO₂ appeared only in Chitral and Abbottabad WSS, which demonstrated higher siltation in the water source. One-way ANOVA analysis showed significant variations in pH, turbidity, TDS, K, Mg, PO₄, Cl, and SO₄ values, which revealed that these parameters differently contributed to the source water quality. Findings from this study suggested the implementation of proper corrosion prevention measures and the establishment of international collaboration for best corrosion practices, expertise, and developing standards.     

Landscape ecological security assessment based on projection pursuit in Pearl River Delta

Regional landscape ecological security is an important issue for ecological security, and has a great influence on national security and social sustainable development. The Pearl River Delta (PRD) in southern China has experienced rapid economic development and intensive human activities in recent years. This study, based on landscape analysis, provides a method to discover the alteration of character among different landscape types and to understand the landscape ecological security status. Based on remotely sensed products of the Landsat 5 TM images in 1990 and the Landsat 7 ETM+ images in 2005, landscape classification maps of nine cities in the PRD were compiled by implementing Remote Sensing and Geographic Information System technology. Several indices, including aggregation, crush index, landscape shape index, Shannon’s diversity index, landscape fragile index, and landscape security adjacent index, were applied to analyze spatial–temporal characteristics of landscape patterns in the PRD. A landscape ecological security index based on these outcomes was calculated by projection pursuit using genetic algorithm. The landscape ecological security of nine cities in the PRD was thus evaluated. The main results of this research are listed as follows: (1) from 1990 to 2005, the aggregation index, crush index, landscape shape index, and Shannon’s diversity index of nine cities changed little in the PRD, while the landscape fragile index and landscape security adjacent index changed obviously. The landscape fragile index of nine cities showed a decreasing trend; however, the landscape security adjacent index has been increasing; (2) from 1990 to 2005, landscape ecology of the cities of Zhuhai and Huizhou maintained a good security situation. However, there was a relatively low value of ecological security in the cities of Dongguan and Foshan. Except for Foshan and Guangzhou, whose landscape ecological security situation were slightly improved, the cities had reduced values in landscape ecological security, with the most decreased number 0.52 in Zhaoqing. Results of this study offer important information for regional eco-construction and natural resource exploitation.     

Assessing water quality of drinking water distribution system in the South Taiwan

This investigation conducted a full-scale survey the drinking water distribution system in Kaohsiung city, Taiwan. The aim was to investigate whether the distribution system was capable of maintaining high water quality from the water treatment facilities through to the end user. The results showed that the distribution system can maintain high water quality, except for suitable chlorine residuals. The authors plotted chlorine residual contour maps to identify areas with low chlorine residuals, helping them prioritize sections that must be flushed or renewal. The contour maps also provide sufficient and clear information for locating booster chlorination stations. Contour maps enable water facilities to identify how water quality decays in the distribution systems and the locations of such decay. Water quality decay can be caused by properties of pipeline materials, hydraulic conditions, and/or biofilm thickness. However, understanding the exact reasons is unnecessary because the contour maps provide sufficient information for trouble-shooting the distribution systems.     

镉在不同土壤和蔬菜中残留规律研究

研究了镉在不同类型土壤和蔬菜中的残留积累规律.结果表明,含镉污水灌溉是造成农田土壤镉污染主要原因之一.土壤中镉残留量随污水镉浓度增加而增高.土壤镉含量与蔬菜中镉含量呈显著正相关.供试土壤及蔬菜可食部分镉的累积顺序为:粘土>壤土;壤土蔬菜>粘土蔬菜,小白菜(叶)>萝卜(根)>莴苣(茎)>辣椒(果)>豇豆(豆).     

A synergetic model for implementing an integrated management system: an empirical study in China

The implementation and certification of quality, environmental and occupational health and safety management systems have become a priority for many organizations. They are viewed as symbol for success and prerequisite for survival. However, it has been proved to be difficult to operate multiple parallel management systems covering quality, environment, and occupational health and safety and to ensure their alignment with the organization's strategy. To investigate the current status of integrated management system (IMS), a structured questionnaire survey was administrated. It is concluded that the major problems for enterprises to operate multiple parallel management systems include: it causes complexity of internal management, it lowers management efficiency, it incurs cultural incompatibility, it causes employee hostility, and increases management costs. The survey also examined the internal and external factors that affect the implementation of IMS. The internal factors include: (1) human resources, (2) organizational structure, (3) company culture, and (4) understanding and perception. The external factors consist of: (1) technical guidance, (2) certification bodies, (3) stakeholders and customers, and (4) the institutional environment. The article proposes a multi-level synergy model (strategic synergy, organizational structural-resource-cultural synergy, and documentation synergy) for an effective implementation of IMS.     

回注采出水深度除油复合配方的优选

胜利油田郝一站采出水在回注时油及悬浮物含量均不达标，采用正交实验对比了三种絮凝剂聚合铝、MAX-2、HLW003L的作用效果，确定最佳絮凝剂为MAX-2,50℃、pH 7．0时将其与反相除油剂FX复合后使用，可使处理后水中含油〈10mg／L，悬浮物〈5mg／L，能满足中低渗透油藏的注水水质指标。