对实验室污染问题的思考和建议

分析了目前实验室存在的污染种类及危害,阐明实验室是一种不容忽视的污染源,且污染种类复杂,毒害较大.提出实验室污染防治措施.     

企业逆向物流与循环经济立法之联系

逆向物流给企业带来效益的同时,也带来了生态物流的理念.逆向物流涉及了经济与生态环境两大系统,显现出了自身的特点与积极因素.逆向物流充分体现了循环经济发展之宗旨.加速循环经济的立法,并以相应立法来推动企业尽快实施物流活动是至关重要的.     

锰铜铈氧化物催化剂氧化NO性能及动力学研究

实验以TiO2为载体采用浸渍法制备CuOx/TiO2、CeOx/TiO2、CuCeOx/TiO2和MnCuCeOx/TiO2催化剂,考察这些催化剂氧化NO活性,探究Cu、Ce摩尔比和添加Mn元素对CuCeOx/TiO2催化剂氧化NO活性的影响,使用扫描电镜观察催化剂表面结构。研究发现,Cu、Ce元素配合后的CuCeOx/TiO2催化剂氧化活性明显好于单独含Cu、Ce的催化剂,当Cu、Ce摩尔比为Cu:Ce=1∶2时,CuCeOx/TiO2催化剂氧化活性最好,在NO浓度500×10-6,O210%,空速为24 000 h-1,350℃时,NO氧化度为0.62;添加Mn元素可以提高CuCeOx/TiO2催化剂低温氧化活性,250℃时,MnCuCe/Ti-3和MnCuCe/Ti-5催化剂氧化度为0.53和0.69,300℃时,MnCuCe/Ti-3和MnCuCe/Ti-5催化剂氧化度均为0.76;此外,实验还研究了NO在MnCuCe/Ti-3催化剂上反应的动力学方程。     

Histopathological changes in zebrafish embryos exposed to DLPCBs extract from Zhanjiang coastal sediment

Dioxin-like polychlorinated biphenyls (DLPCBs) are ubiquitous persistent pollutants that cause adverse effects in many environmental organisms. DLPCBs in marine sediments can be absorbed by benthic organisms, bioaccumulate, and biomagnify through the food chain and threaten animal and human health. There are no reports of DLPCBs concentrations in the Zhanjiang Gulf seabed. This study was designed to investigate the concentration of DLPCBs in the Zhanjiang coastal sediment and histopathological changes in zebrafish (Diano rerio) embryos exposed to environmentally relevant concentrations of DLPCBs. Of the five sites selected, two sites TS and JSW contained DLPCBs at concentrations of 0.08 and 22.54 ng/g dry sediment, respectively. Two groups of zebrafish embryos were used. One group was exposed to 3.75, 7.5, 15, 30, and 60 mg/ml of DLPCBs extracted from the sediments sampled from the TS site and the second group to 4.375, 8.75, 17.5, 35, and 70 mg/ml of DLPCBs from JSW site from 0.75 h post-fertilization (hpf) to 96 hpf. The zebrafish exposed to 60 and 70 mg/ml of DLPCBs at 96 hpf displayed gross histopathological changes with cardiac lesions including pericardial edema being the most deleterious. Other changes observed were hydropic degeneration of gill filaments and hepatocytes, loss of intestinal folds, and uninflated swim bladder. It appears that only a few sites of the Zhanjiang gulf are contaminated with DLPCBs. This is the first report of histopathological changes in the gills, hepatocytes, intestines, heart, and the swim bladder in zebrafish embryos exposed to DLPCBs from a coastal sediment. Further studies with sampling at different stages of development are required to identify which organ/tissue is most sensitive to DLPCBs.     

清水冲涮对向家坝以下金沙江河床及岸线资源的影响

随着金沙江下游梯级水电开发的蓬勃开展,清水下泄对下游河床及岸线的影响问题逐渐显露。通过实地观测,走访及清水下泄前后政府和民间数据、影像资料等对比分析,探讨问题的根源和避免问题严重化途径,为共抓长江大保护,为修复长江生态环境提供参考依据。结果发现:清水下泄对向家坝水电站坝址以下金沙江段部分河床及岸线资源造成了较为明显的影响。如该江段原来常见的砂滩、砾石滩除杨湾码头仅存一个沙岛外,其余全部消失;无防护设施的河段(如火焰村小岸组、火焰组和新桥组,豆坝村的马槽、娱乐、黄泥、丰收、中心三组,普安镇的13、12、7、5、4、3、2、1组,西郊街道白石社区新村组)受顶冲作用导致一半以上河漫滩地流失甚至引起滩岸坍塌;白家滩大堤一处坝垛根石将被掏蚀殆尽。此外,水富港三期扩能工程因侵占河道和开挖船池,进一步加剧了对四川安边镇小岸坝的不利影响。严重的下蚀侧蚀导致该江段同期水位明显下降,也对岸线两侧的居民生产生活带来安全隐患。相关各方对区域的特殊性及水电站修建造成的影响存在认识不足,各自的发展、利益和环境保护需求之间的矛盾等是问题产生的根本原因,问题出现后又缺少有效的沟通机制等。     

Influence of soil and hydrocarbon properties on the solvent extraction of high-concentration weathered petroleum from contaminated soils

Petroleum ether was used to extract petroleum hydrocarbons from soils collected from six oil fields with different history of exploratory and contamination. It was capable of fast removing 76–94 % of the total petroleum hydrocarbons including 25 alkanes (C₁₁–C₃₅) and 16 US EPA priority polycyclic aromatic hydrocarbons from soils at room temperature. The partial least squares analysis indicated that the solvent extraction efficiencies were positively correlated with soil organic matter, cation exchange capacity, moisture, pH, and sand content of soils, while negative effects were observed in the properties reflecting the molecular size (e.g., molecular weight and number of carbon atoms) and hydrophobicity (e.g., water solubility, octanol–water partition coefficient, soil organic carbon partition coefficient) of hydrocarbons. The high concentration of weathered crude oil at the order of 10⁵ mg kg^?1 in this study was demonstrated adverse for solvent extraction by providing an obvious nonaqueous phase liquid phase for hydrocarbon sinking and increasing the sequestration of soluble hydrocarbons in the insoluble oil fractions during weathering. A full picture of the mass distribution and transport mechanism of petroleum contaminants in soils will ultimately require a variety of studies to gain insights into the dynamic interactions between environmental indicator hydrocarbons and their host oil matrix.     

Contamination assessment of arsenic and heavy metals in a typical abandoned estuary wetland—a case study of the Yellow River Delta Natural Reserve

Coastal and estuarine areas are often polluted by heavy metals that result from industrial production and agricultural activities. In this study, we investigated the concentration trait and vertical pattern of trace elements, such as As, Cd, Ni, Zn, Pb, Cu, and Cr, and the relationship between those trace elements and the soil properties in coastal wetlands using 28 profiles that were surveyed across the Diaokouhe Nature Reserve (DKHNR). The goal of this study is to investigate profile distribution characteristics of heavy metals in different wetland types and their variations with the soil depth to assess heavy metal pollution using pollution indices and to identify the pollution sources using multivariate analysis and sediment quality guidelines. Principal component analysis, cluster analysis, and pollution level indices were applied to evaluate the contamination conditions due to wetland degradation. The findings indicated that the concentration of trace elements decreased with the soil depth, while Cd increases with soil depth. The As concentrations in reed swamps and Suaeda heteroptera surface layers were slightly higher than those in other land use types. All six heavy metals, i.e., Ni, Cu, As, Zn, Cr, and Pb, were strongly associated with PC1 (positive loading) and could reflect the contribution of natural geological sources of metals into the coastal sediments. PC2 is highly associated with Cd and could represent anthropogenic sources of metal pollution. Most of the heavy metals exhibited significant positive correlations with total concentrations; however, no significant correlations were observed between them and the soil salt and soil organic carbon. Soil organic carbon exhibited a positive linear relationship with Cu, Pb, and Zn in the first soil layer (0–20 cm); As, Cr, Cu, Ni, Pb, and Zn in the second layer (20–40 cm); and As, Cr, Cu, Ni, Pb, and Zn in the third layer (40–60 cm). Soil organic carbon exhibited only a negative correlation with Cd (P?I _geo values), which averaged less than 0 in the three soil layers, this finding indicates that the soils have remained unpolluted by these heavy metals. The mean concentrations of these trace elements were lower than Class I criteria. The degradation wetland restoration suggestions have also been provided in such a way as to restore the reserved flow path of the Yellow River. The results that are associated with trace element contamination would be helpful in providing scientific directions to restore wetlands across the world.     

区域水环境系统脆弱性指标体系及综合决策模型研究

目前水环境系统脆弱性研究主要局限于水环境系统的单方面脆弱性研究，过于片面化，需要综合考虑水资源、水环境质量、旱涝灾害、社会经济以及生态环境等方面的脆弱性。根据水环境系统脆弱性是系统状态受到系统压力引起的敏感性以及系统状态对系统压力的适应性响应的观点，采用“压力-状态-响应”模式构建区域水环境系统脆弱性指标体系。区域水环境系统脆弱性研究中客观存在诸多不确定性，利用联系数描述上述不确定性过程中差异度系数在［-1,1］上取值仍存在不确定性，为此，构造三角模糊数刻画差异度系数取值的不确定性，给出三角模糊联系数的基本形式，取置信水平得出置信区间联系数，采用期望-方差排序法对置信区间联系数进行决策分析，建立基于三角模糊联系数的系统综合决策模型。此模型用于安徽省水环境系统脆弱性评价的结果表明，安徽省区域水环境系统脆弱等级介于［2.731 3.620］之间，脆弱性状况不容乐观，应采取相应措施改善区域水环境质量，降低区域水环境系统脆弱性，保障区域社会经济及生态环境的可持续发展     

Spatial distribution and ecological risk assessment of sediment metals in a highly industrialized coastal zone southwestern Taiwan

Spatial variations of Cr, Cu, Hg, Ni, Pb, and Zn in the surface sediments from 34 stations of the Kaohsiung coastal zone southwestern Taiwan were studied to address the current pollution status, sediment quality, and potential ecological risk. The study revealed that the concentrations of sediment metals in Kaohsiung Harbor were alarmingly high compared to the other region of Kaohsiung coast. The concentrations of Cr, Cu, Hg, Ni, Pb, and Zn in the harbor sediments were as high as 351, 247, 1.93, 61.8, 60.9, and 940 mg kg⁻¹, respectively. The current situation of metal pollution was assessed by different pollution indices and results showed moderate to severe enrichment of Cu, Hg, and Zn in the harbor sediments. According to the degree of contamination, pollution load index, and contamination severity index, the sediments from the inner Kaohsiung Harbor show high degree and high severity of metal contamination, while the rest of Kaohsiung coastal areas show uncontaminated or low-level pollution. Results of mean ERM quotient and potential ecological risk index also indicated that the harbor sediments posed a 49% probability of biological toxicity and very high ecological risk. The toxic units indicated that the negative biological effects of the six metals in the harbor sediments were Zn > Cu > Cr > Ni > Hg > Pb. In contrast to Kaohsiung Harbor as a trap where considerable amount of anthropogenic metal loadings accumulated in sediments, low metal concentrations were observed in most Kaohsiung coastal sediments. It probably resulted from the limited fine-grained sediment deposition. In the wave-dominated Kaohsiung coastal zone, fine-grained sediments associated with polluted metals tend to be easily resuspended and transported offshore via waves and wave-induced currents. The results of this study can provide valuable information for river and coastal zone management.