包河浮游植物与水质评价

根据对包河浮游植物群落调查,1987年共检出163种,分隶于67属、8门;藻总量年平均达42678.7×10~4个/升(细胞数,或个体数为38071.9×10~4个/升);以绿藻占绝对优势,在湖区各样点群落组成中均居各类群之首,其中小球藻(Chlorella spp.)为优势种;其次为蓝藻,其平裂藻(Merismopedia sp.)可为亚优势种。根据藻类数量、生物量及指示种评价,该水体已受到α—中度污染,属绿藻、蓝藻型α—富营养型湖泊,与理化指标评价结论基本相符。     

我国中亚热带典型海岛周边海域海水质量评价

根据我国中亚热带海岛生态特征及其地理分布,文章选取八个具有代表性的典型海岛作为研究对象。采用单因子评价方法和反映营养盐限制特征的海水富营养化评价方法,对我国中亚热带的八个典型海岛的周边海域海水质量展开了评价。研究结果表明,我国中亚热带典型海岛周边海域海水质量总体良好,但是氮磷含量普遍超标,无机氮和活性磷酸盐是主要污染指标;我国中亚热带典型海岛周边海域海水基本属于磷限制并且营养级程度不同;造成海水富营化的主要原因是陆源的流域污染和沿岸污水排放以及海上的养殖污染。     

Application of chemical fractionation and X-ray powder diffraction to study phosphorus speciation in sediments from Lake Hongfeng,China

Based on the techniques of sequential extraction and X-ray powder diffraction (XRD), the distribution characteristics of phosphorus speciation were investigated in 13 sediment samples from Lake Hongfeng, an important drinking water source for Guiyang with a typical karstic limestone environment. The total phosphorus (TP) concentrations in the sediments ranged from 973.36 to 2334.18 mg/kg with a mean concentration of 1635.87 mg/kg (dry weight), and it was evident that the phosphorus level in the sediments was high compared with other eutrophic lakes such as Lake Chaohu and Lake Xihu. The results of the two methods, sequential extraction and XRD, demonstrated the presence of different phosphorus species in the lake sediments. Being compatible with local geophysical characteristics, the results of sequential extraction techniques indicate that the average percentages of dissolved phosphorus (DP), aluminum-bound phosphorus (Al-P), iron-bound phosphorus (Fe-P), calcium-bound phosphorus (Ca-P) and organic phosphorus (OP) in the sediments were 0.40%, 7.06%, 5.07%, 45.48% and 38.49%, respectively. Notably, the concentrations of inorganic phosphorus (IP) were higher than those of OP, and the IP consisted primarily of Ca-P. The high concentrations of Ca-P may temporarily control the release of phosphorus from the sediments because it is a relatively stable, inert and non-bioavailable phosphorus fraction. The results of XRD analysis indicated that, among phosphorus species, AlPO₄ was found in all sediment samples at relatively high concentrations. Moreover, the TP concentrations in the sediments were high; thus the release potential and bioavailability of phosphorus in the sediments was important. Further statistical analyses of the results revealed significant correlations between phosphorus species in the sediments with two extractable principal components and four selectable cluster levels allowing interpretation of possible origins of phosphorus loading and transformation mechanisms of phosphorus species. Furthermore, available remediation measures were briefly assessed for the lake while considering its distinct environmental features.     

Establishing Submersed Macrophytes via Sinking and Colonization of Shoot Fragments Clipped off Manually

In this paper, sinking and growth of apexes and mid-stems of Myriophyllum spicatum L., Hydrilla verticillata （L.f.） Royle and Ceratophyllum demersum L. in concrete ponds containing eutrophic water and sediment were investigated. Sinking rates of apexes and mid-stems reached 34.8% and 4.4% at the 6 th day and 91.1% and 66.7% at the 22 nd day for M. spicatum, 57.8% and 55.6% at the 6 th day and 100% and 97.8% at the 22 nd day for H. vertieillata, 18.9% and 86.7% at the 6 th day and 95.6% and 100% at the 22 nd day for C. demersum, respectively. Most sunken fragments established themselves successfully with significant growth. Total shoot length ofplantlets developed from apexes and mid-stems increased by 399% and 61% for M. spicatum, 593% and 256% for H. vertieillata and 114% and 104% for C. demersum, respectively. The results showed that it was feasible to establish submersed macrophytes via sinking and colonization of shoot fragments clipped off manually.     

基于GA-SVM的渤海湾富营养化模型

为了更好地模拟和认知渤海湾富营养化的复杂行为,通过研究遗传算法(GA)和支持向量机(SVM)的结合形式,即参数寻优和特征选择,以渤海湾水质实测资料为依据,叶绿素a的质量浓度为输出,建立了GA-SVM的富营养化模型.无特征选择时,用遗传算法对支持向量机的参数(惩罚参数和核参数)进行自适应地优选,预测模型的均方误差可达到1.831μg/L,具有较好的认知、泛化能力.再利用遗传算法二进制编码及启发式寻优的优点,对所建模型的输入空间进行特征选择,提取出代表性的特征变量:DO%、pH值、水温、COD、盐度以及氨氮.特征提取后预测模型的均方误差可达到1.363μg/L,模型性能有了很大提高.分析表明,COD、盐度及氨氮可作为人为控制的首要指标.     

富营养水体中3种沉水植物的生长竞争及其净化效果

研究苦草、黑藻和马来眼子菜3种沉水植物在太湖富营养化水体中的生长竞争状况及其对水体的净化效果．结果表明：3种沉水植物短期内可以在混合种群中共存,但竞争优势差别明显．黑藻具有在水中形成上位冠层、根系发达的特性,与苦草、马来眼子菜相比在占领水体上层空间、获取光照和吸收营养方面优势明显,表现出较强的竞争优势;马来眼子菜与苦草之间的竞争不明显,其占据水面面积大,获取光照多,苦草则主要占据水体下层空间,地下部分发达,混种时两者生物量相当．它们对水体中总氮、总磷和藻类叶绿素a的降低作用明显,单种时以黑藻对总氮、总磷的去除率最高,苦草对藻类叶绿素a的降低效果最好;混种时以苦草＋黑藻组对总氮去除率最高,以苦草十黑藻＋马来眼子菜组对总磷去除率最高．     

邛海取水口水质现状分析

根据2006年邛海水厂取水口的实际监测资料,以地表水环境质量标准对邛海水厂取水口的水环境进行了质量评价。结果表明:邛海取水口全年总磷值为0.010～0.023m g.L-1,具有富营养化现象;各监测项目值均在生活饮用水水源地Ⅲ类水质标准之内。     

深水网箱养殖对海区水质影响研究

通过对箬跳、青山2个深水网箱养殖区的水质状况的调查数据分析发现,养殖海区的无机氮和氨氮含量明显升高,但是深水网箱养殖海区的总体污染状况要比海区小。在养殖产品起捕后,由于海流作用,深水网箱养殖海区的水质很快就达到与未开展养殖海区一致。     

生物组合对浮床污染物净化效能的影响

构建以水生植物(空心菜)单元、水生动物(三角帆蚌)单元及人工介质(微生物)单元组成的组合生态浮床.夏秋两季富营养水体净化实验显示,组合型生态浮床比普通水生植物浮床对NH+4-N,TN,CODMn平均去除效率的提高幅度:夏季水体交换时间5d时分别为22.6%,13.3%,13.7%;秋季水体交换时间7d时分别为19.5%...     

太湖富营养化的驱动因子分析

将太湖2001～2002年的水质监测数据与空间数据结合,采用基于因子分析的主成分方法将太湖的水质参数概括为5个主成分,提取并反证了湖泊水质各个主成分的科学内涵,即水体营养指数、富营养化指数、植物生长环境指数、水体色度指数和水体酸碱指数;研究了各主成分的空间分布特征、意义以及月均值随时间的变化规律．指出水体营养指数和植物生长环境指数是太湖富营养化的主要驱动因子,水体色度指数和水体酸碱指数是太湖富营养化的次要驱动因子并可作为富营养化的指示因子。