Contamination and potential sources of polybrominated diphenyl ethers (PBDEs) in water and sediment from the artificial Lake Shihwa, Korea

Concentrations of polybrominated diphenyl ethers (PBDEs) were determined in water and sediment collected from the artificial Lake Shihwa and surrounding creeks. Total concentrations of 23 PBDE congeners in water and sediment ranged from 0.16 to 11.0 ng L⁻¹ and from 1.3 to 18 700 ng g⁻¹ dry weight, respectively. The concentrations of BDE 209 in water and sediment were 1-2 orders of magnitude higher than the total concentrations of other PBDE congeners. The concentrations of total PBDEs and BDE 209 in sediments were the highest compared to previously reported worldwide levels. The highest concentrations of PBDEs in water and sediments were found in creeks near industrial complexes. The PBDE concentrations gradually decreased with increasing distance from the creeks to the inshore and then offshore regions of the lake. BDE 209 was a major congener, accounting for 80% of the total PBDEs in water and sediment, consistent with a high consumption of deca-BDE for the brominated flame retardant market in Korea. Non-parametric multidimensional scaling ordination showed that surrounding creeks are major pathways of PBDE contamination associated with deca-BDE technical mixtures used in industrial complexes around Lake Shihwa. A significant correlation between total organic carbon and total PBDE concentration was found in sediments, and the correlation coefficients for individual PBDE congeners relatively increased from lower to higher brominated congeners.     

Biotic, temporal and spatial variability of tritium concentrations in transpirate samples collected in the vicinity of a near-surface low-level nuclear waste disposal site and nearby research reactor

The results of a 21 month sampling program measuring tritium in tree transpirate with respect to local sources are reported. The aim was to assess the potential of tree transpirate to indicate the presence of sub-surface seepage plumes.Transpirate gathered from trees near low-level nuclear waste disposal trenches contained activity concentrations of ³H that were significantly higher (up to ∼700 Bq L⁻¹) than local background levels (0-10 Bq L⁻¹). The effects of the waste source declined rapidly with distance to be at background levels within 10s of metres. A research reactor 1.6 km south of the site contributed significant (p < 0.01) local fallout ³H but its influence did not reach as far as the disposal trenches.The elevated ³H levels in transpirate were, however, substantially lower than groundwater concentrations measured across the site (ranging from 0 to 91% with a median of 2%). Temporal patterns of tree transpirate ³H, together with local meteorological observations, indicate that soil water within the active root zones comprised a mixture of seepage and rainfall infiltration. The degree of mixing was variable given that the soil water activity concentrations were heterogeneous at a scale equivalent to the effective rooting volume of the trees. In addition, water taken up by roots was not well mixed within the trees. Based on correlation modelling, net rainfall less evaporation (a surrogate for infiltration) over a period of from 2 to 3 weeks prior to sampling seems to be the optimum predictor of transpirate ³H variability for any sampled tree at this site.The results demonstrate successful use of ³H in transpirate from trees to indicate the presence and general extent of sub-surface contamination at a low-level nuclear waste site.     

Vegetation as an Indicator of Soil Properties and Water Quality in the Akarçay Stream (Turkey)

In this study, the relationship among water quality, soil properties, and plant coverage in the region of the Akarçay stream was examined. Correlation analyses were carried out between soil samples taken from each of four plant communities in the Akarçay basin and water in the Akarçay stream. The four plant communities in the study area are as follows: Limonium lilacinum (Boiss. et Bal.) Wag., Alhagi pseudalhagi (M. Bieb.) Desv. Peganum harmala L., and Hordeum marinum Huds. subsp. marinum. B, Cl, EC, K, Mg, Na, pH, and SO₄ data from both soil and water samples were subjected to statistical analysis, and significant correlations were obtained (p < 0.05). These correlations indicated that the chemical features of the soil had a major effect on water quality. The important parameters were B, Cl, EC, K, Mg, Na, pH, and SO₄ for Limonium lilacinum communities; Ca, K, and pV for Peganum harmala; and B, Cl, Mg, pH, and pV for Alhagi pseudalhagi. There were also statistically significant relationships (p < 0.05) among the parameters examined. These findings strongly suggested that these plant communities can be used as indicators for soil chemistry and water quality.     

环境噪声标准体系设计与相互关系研究

针对当前突出的环境噪声问题,提出了噪声管理需要3个层次不同的标准,每种标准有适用的对象、制订依据、作用和特征,在介绍不同层次标准相互关系基础上提出标准制订和修订的建议.     

Characterization of particulate matter from diesel passenger cars tested on chassis dynamometers

Emission characterization of particle number as well as particle mass from three diesel passenger cars equipped with diesel particulate filter(DPF), diesel oxidation catalyst(DOC)and exhaust gas recirculation(EGR) under the vehicle driving cycles and regulatory cycle.Total particle number emissions(PNEs) decreased gradually during speed-up of vehicle from 17.3 to 97.3 km/hr. As the average vehicle speed increases, the size-segregated peak of particle number concentration shifts to smaller size ranges of particles. The correlation analysis with various particulate components such as particle number concentration(PNC),ultrafine particle number concentration(UFPNC) and particulate matter(PM) mass was conducted to compare gaseous compounds(CO, CO_2, HC and NOx). The UFPNC and PM were not only emitted highly in Seoul during severe traffic jam conditions, but also have good correlation with hydrocarbons and NOxinfluencing high potential on secondary aerosol generation. The effect of the dilution temperature on total PNC under the New European Driving Cycle(NEDC), was slightly higher than the dilution ratio. In addition, the nuclei mode(DP: ≤ 13 nm) was confirmed to be more sensitive to the dilution temperature rather than other particle size ranges. Comparison with particle composition between vehicle speed cycles and regulatory cycle showed that sulfate was slightly increased at regulatory cycle, while other components were relatively similar. During cold start test, semivolatile nucleation particles were increased due to effect of cold environment. Research on particle formation dependent on dilution conditions of diesel passenger cars under the NEDC is important to verify impact on vehicular traffic and secondary aerosol formation in Seoul.     

建设节水型社会评价指标体系及赋权方法研究

针对某市10个县区节水的实际情况,依据层次分析法原理建立了节水型社会评价指标体系,分别采用两种客观性赋权方法(相关系数法、相似系数法)来确定指标体系中各层指标的权重,这样即保留了层次分析法分类清楚、解释性强的特点,又发挥了客观赋权法人为因素少的优点。     

嫩江齐齐哈尔江段高锰酸盐指数与化学需氧量相关关系的探讨

通过对嫩江齐齐哈尔段CODMn和CODcr值相关关系的分析,结果表明CODMn与CODcr显著相关,可以用CODMn值推算CODcr结果,减少CODcr的监测次数,降低分析中产生的Cr6+的二次污染。     

废塑料配煤炼焦机理研究及进展

基于高温干馏技术,利用煤与废塑料共焦化技术处理废塑料可将其转化为焦化产品,实现废塑料的资源化利用和无害化处理。在此从分析煤与废塑共焦化机理方面,探究共焦化对炼焦的影响,表明添加一定比例废塑料可略提高焦炭质量,增加焦油及焦炉煤气产率,同时降低化合水产率,说明废塑料的添加提高了煤中氢的利用率。     

碳排放与能源消费和经济增长的灰色关联分析

中国碳排放问题成为世界关注的焦点问题。研究碳排放与经济增长、能源消费关系有助于实现2020年碳减排目标。选取2001～2009年碳排放与能源消费、经济增长数据,运用灰色关联分析模型,分别计算碳排放与能源消费、经济增长的灰色关联度。研究结果表明,无论是从折线的相似程度还是相对于始点变化速率的接近程度来看,碳排放曲线与能源消费曲线、经济增长曲线十分相似,说明碳排放与能源消费、经济增长之间存在紧密联系。     

农业面源污染对我国农村地表水的影响与对策研究

基于2015—2021年我国农村地表水环境质量监测数据,分析了农村地表水环境质量状况特征;选取农业农村社会经济活动相关参数,与农村地表水中主要超标因子的超标比例进行了相关性分析;以2020年为基准年,对全国31个行政区,涵盖农村地表水水质状况、农业农村活动水平和污染压力、环境容量3个方面的9个指标进行了聚类分析。结果表明,我国农村地表水的变化趋势、季节特点和主要超标因子等表现出明显的农业面源污染特征;乡村人口、农业投入品使用量和经济作物种植比例等参数与主要超标指标具有较强的相关性（R＞0.9）;聚类分析将全国31个行政区划分为7种不同的农业面源污染类型。提出,应根据不同地区农业面源污染特点,因地制宜地推进标准化规模养殖、畜禽粪污资源化利用、化肥减量行动、高效低风险农药推广等农业面源污染治理措施,进一步加大农村生活污水处理设施建设,同时,完善农村环境质量监测网络,加强农业面源污染监测和评估。