The water quality in the surface microlayer （SML） and subsurface water （SSW） in the Guangzhou segment of Pearl River, a eutrophic urban river section in China, were ana- lyzed. The spatial and temporal dynamics of...The water quality in the surface microlayer （SML） and subsurface water （SSW） in the Guangzhou segment of Pearl River, a eutrophic urban river section in China, were ana- lyzed. The spatial and temporal dynamics of nutrient concentrations, heavy metals and bac- teria were examined from two sampling sites in monthly samples throughout 2010. The mean concentrations of total nitrogen, ammonia, nitrate and nitrite were higher than 7.0 mg/L, 3.1 mg/L, 1.1 mg/L and 0.3 mg/L, while total phosphorus and orthophosphate were 0.5 mg/L and 0.1 mg/L, respectively. These results indicated that the water quality was rich in minerals and eutrophic. The mean concentrations of Mn and Fe were higher than 0.013 mg/L; and Ni, Cr and Pb were higher than 0.001 mg/L. The mean concentrations were in the order of Mn 〉Fe 〉 Ni 〉 Pb 〉 Cr. The concentrations of heavy metals in the Guangzhou segment were lower than the limit of the surface water quality standards in China and the World Health Organization （WHO）, but higher than the median values in the world＇s freshwater. The density of bacteria ranged from 3.30×10^5 to 5.23×10^6 cells/mL, and the amount of cultivable heterotrophic bac-teria ranged from 1.30×10^3 to 1.89×10^6 cfu/mL. Fecal coliform levels were beyond the V class of China water quality standard. The SML was enriched in nutrients, heavy metals and bac- teria, with the maximum enrichment factor of 3.84 for nutrients, 8.00 for heavy metals, and 3.04 for bacteria, suggesting that the water quality of the SML of the Guangzhou segment of the Pearl River was more serious than in the SSW.展开更多
广从断裂带在金沙洲段以3条近平行的北东向分支断裂展布,钻孔岩芯及显微构造分析表明,研究区基岩受断裂活动影响无疑,且断裂活动时代较新。以金沙洲基岩之上普遍存在的土黄色-褐黄色粉砂质黏土(或黏土)标志层为样品进行粒度分析,所得粒...广从断裂带在金沙洲段以3条近平行的北东向分支断裂展布,钻孔岩芯及显微构造分析表明,研究区基岩受断裂活动影响无疑,且断裂活动时代较新。以金沙洲基岩之上普遍存在的土黄色-褐黄色粉砂质黏土(或黏土)标志层为样品进行粒度分析,所得粒度参数及概率累积曲线表明,该层沉积物可与珠江三角洲其他区域进行对比,为晚更新世晚期(10~20 ka B.P.)沉积,该地层之上灰黑色-黑色淤泥质层(或细砂层)出现了明显的全新世高海面沉积异常,淤泥层中腐木的^(14)C年龄为6~7 ka B.P.,确认广从断裂金沙洲段的最新活动年龄为6~7 ka B.P.。展开更多
基金Foundation： National Natural Science Foundation of China, No.41173079 The Project of Department of Science and Technology, China, No.2012BAC07B05, No.2012BAD18B01 Jinan University Project, No.21612324
文摘The water quality in the surface microlayer （SML） and subsurface water （SSW） in the Guangzhou segment of Pearl River, a eutrophic urban river section in China, were ana- lyzed. The spatial and temporal dynamics of nutrient concentrations, heavy metals and bac- teria were examined from two sampling sites in monthly samples throughout 2010. The mean concentrations of total nitrogen, ammonia, nitrate and nitrite were higher than 7.0 mg/L, 3.1 mg/L, 1.1 mg/L and 0.3 mg/L, while total phosphorus and orthophosphate were 0.5 mg/L and 0.1 mg/L, respectively. These results indicated that the water quality was rich in minerals and eutrophic. The mean concentrations of Mn and Fe were higher than 0.013 mg/L; and Ni, Cr and Pb were higher than 0.001 mg/L. The mean concentrations were in the order of Mn 〉Fe 〉 Ni 〉 Pb 〉 Cr. The concentrations of heavy metals in the Guangzhou segment were lower than the limit of the surface water quality standards in China and the World Health Organization （WHO）, but higher than the median values in the world＇s freshwater. The density of bacteria ranged from 3.30×10^5 to 5.23×10^6 cells/mL, and the amount of cultivable heterotrophic bac-teria ranged from 1.30×10^3 to 1.89×10^6 cfu/mL. Fecal coliform levels were beyond the V class of China water quality standard. The SML was enriched in nutrients, heavy metals and bac- teria, with the maximum enrichment factor of 3.84 for nutrients, 8.00 for heavy metals, and 3.04 for bacteria, suggesting that the water quality of the SML of the Guangzhou segment of the Pearl River was more serious than in the SSW.
文摘广从断裂带在金沙洲段以3条近平行的北东向分支断裂展布,钻孔岩芯及显微构造分析表明,研究区基岩受断裂活动影响无疑,且断裂活动时代较新。以金沙洲基岩之上普遍存在的土黄色-褐黄色粉砂质黏土(或黏土)标志层为样品进行粒度分析,所得粒度参数及概率累积曲线表明,该层沉积物可与珠江三角洲其他区域进行对比,为晚更新世晚期(10~20 ka B.P.)沉积,该地层之上灰黑色-黑色淤泥质层(或细砂层)出现了明显的全新世高海面沉积异常,淤泥层中腐木的^(14)C年龄为6~7 ka B.P.,确认广从断裂金沙洲段的最新活动年龄为6~7 ka B.P.。
