基于概率神经网络的城市湖泊生态系统健康评价研究

概率神经网络(PNN)是一种结构简单、训练简捷、应用十分广泛的人工神经网络,并且在水质分类等环境领域已取得一定研究成果.本文选取广州市最大的人工湖——白云湖作为研究对象,结合其水质监测数据及生物监测数据,建立概率神经网络模型对其进行湖泊生态系统健康评价,得到不同监测时间点的湖泊生态系统健康评价结果.分析表明:1白云湖生态系统比较脆弱,目前净化水质的效果有限;2各监测点的评价结果均呈季节性变化,丰水期湖泊生态系统健康状态好于枯水期,年际变化不显著.实验结果表明,利用概率神经网络对湖泊生态系统健康状态进行评价是可行的,与传统评价方法相比,其具有训练时间短、权重确定客观、输出结果稳定等优势,可以运用到更多相关领域.     

Migration and transformation of Sb are affected by Mn(III/IV) associated with lepidocrocite originating from Fe(II) oxidation

Antimony (Sb) is a recognized priority pollutant with toxicity that is influenced by its migration and transformation processes. Oxidation of Fe(II) to Fe(III) oxides, which is a common phenomenon in the environment, is often accompanied by the formation of Mn(III/IV) and might affect the fate of Sb. In this study, incorporated Mn(III) and sorbed/precipitated Mn(III/IV) associated with lepidocrocite were prepared by adding Mn(II) during and after Fe(II) oxidation, respectively, and the effects of these Mn species on Sb fate were investigated. Our results indicated that the association of these Mn species with lepidocrocite obviously enhanced Sb(III) oxidation to Sb(V), while concomitantly inhibiting Sb sorption due to the lower sorption capacity of lepidocrocite for Sb(V) than Sb(III). Additionally, Mn oxide equivalents increased in the presence of Sb, indicating that Sb oxidation by Mn(III/IV) associated with lepidocrocite was a continuous recycling process in which Mn(II) released from Mn(III/IV) reduction by Sb(III) could be oxidized to Mn(III/IV) again. This recycling process was favorable for effective Sb(III) oxidation. Moreover, Sb(V) generated from Sb(III) oxidation by Mn(III/IV) enhanced Mn(II) sorption at the beginning of the process, and thus favored Mn(III/IV) formation, which could further promote Sb(III) oxidation to Sb(V). Overall, this study elucidated the effects of Mn(III/IV) associated with lepidocrocite arisen from Fe(II) oxidation on Sb migration and transformation and revealed the underlying reaction mechanisms, contributing to a better understanding of the geochemical dynamics of Sb.     

污水特质(水征)评价及其在污水再生处理工艺研究中的应用

近年来,在污水高标准处理研究和工程实践中,发现和遇到越来越多的现有常规水质指标、工艺理论和技术知识等难以解释的新现象和难以解决的新问题.以逐步建立水质复杂体系研究理论和方法体系,构筑科学、有效的污水处理风险管理和安全保障管理系统为目标,介绍了污水的复杂体系特征,阐述了污水高标准处理中工艺设计、运行和诊断面临系统理论方法缺失的问题及其根源,提出了可有效支撑污水工艺研究的污水特质,即"水征（water feature）"的概念.通过分析污水中污染物的浓度水平、组分特征、安全性和稳定性及其时空变化,定义了水征"四维度"内涵,即污染物污染程度、组分特征、毒害效应和转化潜势等4个维度.研究和实践案例表明,水征能有效支撑水质安全评价、处理特性预测、处理工艺设计和工艺诊断优化等.在以水环境质量改善和环境风险控制为目标的污水高标准处理新阶段,基于水征研究,发展高效处理工艺、构筑科学有效的风险管理和安全保障体系尤为重要.今后需深入、持续开展污水处理中水征指标评价方法与理论体系、水征与污染物处理关键技术开发与工艺优化、水征与风险评价管理等方面的研究.      

世界遗产价值分析与旅游开发对策研究——以武陵源自然遗产为例

武陵源自然遗产具有科考、生态、教育、文化、旅游等多重价值,是我国较早列入<世界遗产名录>的世界遗产之一.深入剖析武陵源的遗产价值,有助于纠正人们对自然遗产的认识偏差,从而重视自然遗产的保护,以保护遗产为前提进行遗产旅游的深度开发,重塑武陵源自然遗产的旅游核心竞争力.     

Distribution, sources, and potential toxicological significance of PAHs in drinking water sources within the Pearl River Delta

The Pearl River Delta (PRD) region is one of the most population-dense areas in China. The safety of its drinking source water is essential to human health. Polycyclic aromatic hydrocarbons (PAHs) have attracted attention from the scientific community and the general public due to their toxicity and wide distribution in the global environment. In this work, PAHs pollution levels from the drinking source water in nine main cities within the PRD were investigated. ∑15 PAHs concentrations during the wet season varied from 32.0 to 754.8 ng L(-1) in the dissolved phase, and from 13.4 to 3017.8 ng L(-1) in the particulate phase. During the dry season, dissolved PAHs ranged from 48.1 to 113.6 ng L(-1), and particulate PAHs from 8.6 to 69.6 ng L(-1). Overall, ∑15 PAHs concentrations were extremely high in the XC and ZHQ stations during the wet season in 2008 and 2009. In most sites, PAHs originated from mixed sources. Hazard ratios based on non-cancerous and cancerous risks were extremely higher in XC compared with the others during the wet season, though they were much less than 1. Nevertheless, risks caused by the combined toxicity of ∑15 PAHs and other organics should be seriously considered. PAHs toxic equivalent quantities ranged from 0.508 to 177.077 ng L(-1).     

秦皇岛市生态环境质量状况及保护对策

本文对秦皇岛市城市空气环境、水环境及声环境质量现状进行了全面评价和分析,并对主要环境问题进行了充分阐述,最后提出了合理开发利用水资源、努力改善水环境、加强海岸带和海洋环境综合整治以及加强城乡生态一体化建设三个方面生态环境保护的战略重点。     

苹果茎沟病毒对梨树幼苗生长及过氧化物酶活性的影响

Based on growth level and peroxidase activity, a comparative study and paried-samples t test were made between vires-free Zaosu pear seedlings and the seedlings inoculated with apple stem grooving virus(ASGV). The results showed : ( 1 )virus-free Zaosu pear seedlings grew better than inoculated ones. Of the seedlings the height, diameter, branches and autumn braches differed statistically significantly; (2)the peroxidase activity of inoculated seedlings was higher than that of virus-free ones, and the peak of peroxidase activity occurred on about d 7 and d 24 after inoculation. Fig 1, Tab 1, Ref 9     

胶州湾养殖区贝类生物体中多溴联苯醚的分布特征

对胶州湾养殖区贝类中的多溴联苯醚(PBDEs)的含量进行检测。结果表明,所采集的菲律宾蛤仔、长牡蛎和栉孔扇贝生物样品中9种PBDEs(BDE-15、BDE-28、BDE-47、BDE-75、BDE-99、BDE-100、BDE-138、BDE-153、BDE-154)的含量分别为(422.2～512.6)×10-12(干重)、(957.0～1102.7)×10-12(干重)和979.5×10-12(干重),其中位于海泊河口处的贝类生物体中的含量最高。所有样品中,BDE-47相对含量最高,其相对于∑9PBDEs的贡献率为38.8%～41.8%。贝类样品的9种PBDEs含量及组成的差别可能与它们对PBDEs的吸收和代谢能力的差异有关。胶州湾养殖区贝类生物体中BDE-47和BDE-99的含量远小于香港、美洲和欧洲等工业发达地区,和亚洲发达国家韩国等处于同一数量级,但相比于2002年青岛近岸紫贻贝中的含量有一定程度的增加,表明近年来青岛沿海地区PBDEs污染加重,这一点必须引起足够的重视。     

多溴联苯醚在胶州湾养殖水域含量水平与分布

2008年5月和8月,在胶州湾养殖区设置9个站位,分别进行水样和沉积物采集,利用5975气相色谱-质谱联用仪(GC/MS)进行多溴联苯醚测定。结果显示,在该水域水体中共检出4种多溴联苯醚单体,总浓度范围为ND～630.8 pg/L,其中BDE-47是主要污染物;沉积物中共检出8种多溴联苯醚单体,总浓度范围为(189.2～1349.7)×10-12。BDE-47、-99是沉积物中主要污染物。该海域多溴联苯醚的分布特征是靠近胶州湾东北岸的9号、8号站最高。另外,大沽河、桃源河入海口附近的1号站相对偏高,呈现出由东、西向中间方向逐渐递减的趋势。总体结果表明:多数站位8月份∑PBDEs含量高,5月份含量低。