近期长江张家洲南水道强冲刷机理与趋势分析

2016年9月利用多波束测深仪调查了张家洲河段河床微地貌的高分辨率形态与分布特征,结合1998年和2013年水下地形资料,分析了三峡截流以来该河段河槽的冲淤变化与演变趋势。结果表明：（1）张家洲河段整体呈冲刷状态,净冲刷量17.2×10.6 m³。其中,张家洲南水道是强冲刷区,最大冲刷深度约9 m;（2）河槽表层沉积物中值粒径为149.1~226.3 μm,与历史资料相比呈粗化趋势;（3）张家洲河段约82.9％的主航道发育了沙波,约14.0％的主航道发育了冲刷坑与冲刷槽,平床地形仅占3.1％。流域来沙量减少是张家洲河段整体冲刷的主要原因,而河流控制工程稳定了河势,迫使水流归槽,加剧了张家洲南水道的冲刷。随着流域来沙量持续减少,张家洲南水道主航道有可能进一步冲刷     

Emission factors and particulate matter size distribution of polycyclic aromatic hydrocarbons from residential coal combustions in rural Northern China

Coal consumption is one important contributor to energy production, and is regarded as one of the most important sources of air pollutants that have considerable impacts on human health and climate change. Emissions of polycyclic aromatic hydrocarbons (PAHs) from coal combustion were studied in a typical stove. Emission factors (EFs) of 16 EPA priority PAHs from tested coals ranged from 6.25 ± 1.16 mg kg^?1 (anthracite) to 253 ± 170 mg kg^?1 (bituminous), with NAP and PHE dominated in gaseous and particulate phases, respectively. Size distributions of particulate phase PAHs from tested coals showed that they were mostly associated with particulate matter (PM) with size either between 0.7 and 2.1 μm or less than 0.4 μm (PM_0.4). In the latter category, not only were more PAHs present in PM_0.4, but also contained higher fractions of high molecular weight PAHs. Generally, there were more than 89% of total particulate phase PAHs associated with PM_2.5. Gas-particle partitioning of freshly emitted PAHs from residential coal combustions were thought to be mainly controlled by absorption rather than adsorption, which is similar to those from other sources. Besides, the influence of fuel properties and combustion conditions was further investigated by using stepwise regression analysis, which indicated that almost 57 ± 10% of total variations in PAH EFs can be accounted for by moisture and volatile matter content of coal in residential combustion.     

超高效气溶胶净化系统有效性现场检验研究

各类超高效气溶胶净化系统普遍存在的较为突出的问题是:缺乏系统工作有效性现场检测手段,难以判断系统防护是否失效。根据超高效滤料过滤特性和测试原理,并在分析了大气气溶胶对过滤效率测试影响的基础上,提出大气气溶胶背景下,基于粒数浓度测量和使用发生的高浓度单分散气溶胶作为实验气溶胶的净化系统防护有效性现场检验测试技术及系统组成,并进行了验证。     

采油废水的深度处理回用

采用溶气气浮—生物接触氧化—膜分离组合工艺深度处理采油废水。实验结果表明,出水水质满足热采锅炉进水要求。该法可年处理废水1.3×105m3,产水率按50%计,年节约新鲜水和废水回灌费用共计77.88万元,年节水效益为21.71万元。     

Persistent organic pollutants and heavy metals in adipose tissues of patients with uterine leiomyomas and the association of these pollutants with seafood diet, BMI, and age

Background, aim, and scope  

Persistent organic pollutants and heavy metals can cause diseases in women, however, the relationships of these pollutants and uterine leiomyomas (UL), which are non-cancerous tumors of the uterus, are unclear. This study focused on the quantification of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and heavy metals in subcutaneous and visceral fat obtained from patients with UL and in subcutaneous fat of a control group of women without UL to determine if there were any correlations between concentrations of persistent organic pollutants (POPs) and heavy metals and the incidence of UL.     

冷-干直接抽取法CEMS冷凝器的选型

探讨了烟气冷凝器的关键性能指标,提出烟气冷凝器脱水率、SO2组分丢失率和烟气出口露点温度等关键参数的计算公式,提出了适合不同工况条件下烟气冷凝器选型的依据和方法,为解决冷-干直接抽取法CEMS所面临的湿法脱硫后的高湿、低浓度SO2,及如何准确、客观地反映污染排放的现实问题,提供了一个合理的解决方案。     

城镇化过程对鄱阳湖流域生态系统的影响

城镇化是社会经济发展和现代文明的重要标志,但带来了严重的资源危机和生态环境问题。以鄱阳湖独特的流域特征为研究对象,以城市人口数量表征城镇化的进程,分类解析1990~2011年江西省统计年鉴数据,通过讨论鄱阳湖土地资源结构变化、水资源变化特征、湿地生态系统、生物多样性等资源消耗程度,以及大气污染和水污染为代表的城镇主要污染问题,探讨快速城镇化下鄱阳湖生态环境对干扰的响应。结果表明：鄱阳湖流域各城市的城镇化进展及其机制不同,南昌、九江和上饶城市扩张迅速,而景德镇和赣州发展较平缓;城镇化导致水资源日益紧缺,各城市年总用水量2003年以后均呈增加趋势,其中农业用水量逐年增加,工业用水量各城市年变化存在差异;生物多样性特征受到严重威胁,湖泊水面及湿地面积的持续减少,生物环境的组成和结构发生改变;九江等城市工业废气排放量加大、南昌等城市工业废水排放高,造成湖区环境恶化。根据分析,建议鄱阳湖流域未来从规划土地利用类型、统一调配水资源、制定生物多样性保护对策、加强环境污染治理、强化环保宣传和规划与政策法律化等多方面采取措施。本文为鄱阳湖生态系统可持续发展和生态经济区的城镇化建设提供理论参考     

我国畜禽集约化养殖环境压力及国外环境治理的启示

集约化养殖是我国畜禽产业发展的必然趋势,但畜禽集约化养殖带来的环境污染也日益严重。通过测算近10 a来的全国畜禽养殖废弃物产生总量及废弃物中氮、磷养分的排放总量,以欧盟畜禽耕地承载负荷为标准,建立畜禽粪便土地负荷警报值等级,分析得出我国全国及各区域畜禽养殖的环境压力:从近5 a全国层面看,以氮养分测算的耕地负载警报值在0.7左右,且2009~2011年的警报值已经超过07,畜禽氮养分的耕地负荷已经开始对环境产生污染威胁;而以磷肥测算的耕地负载警报值已经超过1,对环境造成了较严重的污染威胁。从2010年具体区域情况看,以氮养分测算的耕地负载警报值超过07的达到17个省份,其中河南、湖南、广东、四川污染较严重,北京的畜禽养殖氮养分环境污染已经到严重的程度;以磷养份测算的耕地负载警报值已有21个省份超过1,北京和广东的耕地负载警报值已接近3,磷养分的环境污染已很严重。最后,探讨了发达国家畜禽养殖环境压力及环境治理措施对我国的启示     

膜电解技术处理含氯及重金属的废酸

采用离子交换膜电解技术处理铜冶炼过程产生的含氯及重金属的废酸。考察了废酸处理工艺、电解温度、电解时间、电流密度和催化剂的添加等条件对处理效果的影响。实验结果表明：采用先沉淀重金属后脱氯的废酸处理工艺,氯离子和铜离子的去除效果均较好;当以钛盐为催化剂时,在电解温度为40 ℃、电解时间为2.0 h、电流密度为825 A/m²的最佳工艺条件下,处理后废酸中的氯离子质量浓度为0.22 g/L,氯离子去除率为98.59%,铜离子质量浓度为0.45 g/L,铜离子去除率为95.08%,其他重金属大部分也得到有效去除。净化后的废酸可回用至铜冶炼的生产过程中。     

A Comparison of Mass,Lead, Sulfate,and Nitrate Concentrations in a Field Study Using Dichotomous,Size-Selective,and Standard Hi-Vol Samplers

Air monitoring In the San Francisco Bay Area was carried out to measure outdoor community air concentrations of poly cyclic aromatic hydrocarbons (PAH) and mutagenlc activity (mutagenlclty) In participate organic matter (POM). Monitoring began In 1979 and Is currently conducted at six stations. PAH and mutagenlclty tests were performed on organic extracts prepared from high volume (hl-vol) filters composited every four months, by meteorological season. PAH were determined by high pressure liquid chromatography (HPLC) with fluorescence and ultraviolet detection. Mutagenlclty was measured In the Ames Salmonella bloas-say using strain TA98 with and without metabolic activation. The nine-year mean concentration of benzo(a)pyrene (BaP) was 0.4 ng/m³. The mutagenlcfty of this amount of BaP accounted for only about 0.2% of the observed mutagenicity In POM and other measured PAH accounted for even less. Concentrations of PAH and mutagenlclty were three to nine times higher during the winter than during other seasons. Year-to-year wintertime trends In several PAH were also seen. Early In the 1980s, winter concentrations of BaP and benzo (g,h,i)perylene Increased. However since the mld-1980’s, their concentrations have fallen. The decrease In PAH concentrations may be the result of an Increasing proportion of vehicles with relatively low organic emissions. In contrast to PAH, mutagenlcfty did not show significant year-to-year time trends.