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1.
母乳与牛乳中微量元素的比较   总被引:2,自引:0,他引:2  
用ICP-AES法对母乳和牛乳中K、Na、Ca、Mg、P、Fe、Al、Zn、Sr、、Pb、Mn、Ba和Cu等13种元素含量进行了测定。结果发现母乳与牛乳的营养成分差异较大。研究了深入探讨微量元素在人体内重要的生理功能提供了有用的参考数据。  相似文献   

2.
含氟废水的混凝沉淀处理   总被引:10,自引:0,他引:10  
袁劲松  张在利 《污染防治技术》1999,12(4):217-218,221
研究了FeCl3,Al2(SO4)3,PFCS和APAM对含氟废水的混凝沉淀处理。结果表明:石灰乳,PFCS和APAM对废水中的氟及COD具有较好的处理效果,处理后水质达到国家二级排放标准。  相似文献   

3.
西湖北里湖沉积物磷形态分布及其与间隙水磷的关系   总被引:1,自引:0,他引:1  
杭州西湖是典型的富营养化浅水湖泊。经过环湖截污等工程措施,影响西湖的外污染源得到有效的治理,但西湖仍处于富营养化状态。在外污染源得到控制后,富含营养盐的沉积物成为西湖水质改善的主要限制因子。通过研究西湖北里湖沉积物中磷的赋存形态和丰度、间隙水磷含量垂向时空分布特征,分析沉积物磷形态与间隙水磷含量的相关性,探讨内源磷对西湖北里湖营养盐的贡献作用。结果表明,北里湖沉积物中活性磷含量较低,不同磷形态及其含量在垂向上呈现一定的波动,没有表现出明显的规律。间隙水总可溶性磷(TDP)和PO34-含量随沉积物深度的变化不明显,但其含量总体在垂向上都有先升高后降低的趋势,与沉积物中各形态磷均具有一定的正相关性。因此,沉积物磷对水体富营养化具有一定的贡献。  相似文献   

4.
本文对有机金属化合物形态分析的发展做了简单介绍,从本学科出发提出了有机金属化合物形态分析的概念和任务。分析了有机金属化合物形态分析常用的几种方法,包括GC-AAS,GC-MIP-AES,GC-FPD和GC-MS等的特点,对样品的采集,贮存和预处理方法以及形态分析中的质量控制进行了讨论。  相似文献   

5.
不同粒度飞灰中16种微量元素的含量分布   总被引:7,自引:0,他引:7  
研究了不同粒级的燃煤飞灰中的Ba、Be、Cd、Cr、Cu、Hg、Li、Mn、Ni、Pb、Sr、Ti、V、Zn、Zr元素的含量分布,煤中元素的含量比及富集因子。  相似文献   

6.
阳离子高分子絮凝剂用于印刷油墨废水处理   总被引:10,自引:0,他引:10  
聚二甲二烯丙基氯化铵(PDMDAAC)用于印刷油墨废水的处理,对共聚物中阳离子含量的选择,最佳投药剂量以及处理体系中温度等因素对处理效果的影响进行了研究,着重研究了絮凝剂的分子量和阳离子度对处理效果的影响,研究结果认为PDMDAAC适用于印刷油墨废水的处理。  相似文献   

7.
光催化氧化-混凝工艺处理化工废水   总被引:16,自引:0,他引:16  
探索了光催化氧化-混凝工艺处理废水的工艺条件,最佳光催化氧化处理条件为PH=3,催化剂为铁盐,氧化剂H2O2,低压汞灯,光照时间1.5h,废水温度45℃,温凝剂选用PAC和PAM(混凝剂的投加量为原水CODcr:PAC:PAM=7:1.5:0.01),混凝PH6,沉降时间0.5h,在该工艺条件对CODcr为173-70144mg/L的十二烷基苯磺酸钠废水、苯酐废水、富马酸废水、邻苯二甲酸二辛酯废水  相似文献   

8.
测定了用不同量的CAM助滤剂对不同煤泥的助滤脱水效果,结果说明了助滤脱水效果与助滤剂用量、粒度组成和煤泥种类等相关。  相似文献   

9.
监测了南京市的主要水系:长江、秦淮河和玄武湖水体表层的沉积物中Hg、Cd、Pb、Cu、As、Cr和zn等7种元素含量,分析了元素的富集程度,采用Hakanson潜在生态危害指数法对其生态危害程度进行了评价。结果表明:长江和玄武湖水系沉积物中,7种元素含量属于低潜在生态风险,秦淮河沉积物则呈较高潜在生态风险;7种元素的富集系数均为,秦淮河〉玄武湖〉长江,长江Cd元素的富集系数最大,为3.18,秦淮河和玄武湖两水系都是Hg的富集系数最大,分别为11.78和3.33;就元素的生态风险而言,长江水体表层沉积物中,7种元素属低潜在生态风险,玄武湖表层沉积物中,除Hg属中潜在生态风险外,其余6种元素属低潜在生态风险,秦淮河表层沉积物的7种元素生态风险由高到低,依次为Hg〉Cd〉Cu〉As〉Zn〉Pb〉Cr,Hg和cd分别属高潜在生态风险和较高潜在生态风险,其余5种元素属低潜在生态风险。  相似文献   

10.
用TPD,TPSR-MS活性评价等方法,用Cu-Zn-Al催化剂,对CO2加氢合成甲醇的原料气掺入适量CO2进行了研究。结果表明CO2能占据催化剂表面部分CO2的吸附位,能抑制CO2加氢的逆水汽变换反应和促进甲醇合成,从而大大提高了CO2加事成甲醇的选择性和收率。  相似文献   

11.
This study investigated the degradation of rizazole in water-sediment systems (West Lake system, WL; Beijing–Hangzhou Grand Canal system, BG) with two different types of sediments under aerobic and anaerobic conditions. The half-lives of rizazole in the WL water phase (14.59–15.13 d) were similar to those in the BG water phase (15.90–16.46 d). Within 3–7 d, the rizazole concentration in the sediments reached the maximum values, i.e., equilibrium. Rizazole dissipation was faster in the WL sediment phase with higher organic matter content (T1/2 = 18.99–19.09 d) compared with the BG sediment phase (T1/2 = 31.08–33.32 d). Rizazole degradation was slightly faster in the West Lake water-sediment system (WL system) (T1/2 = 17.11–18.05 d) than in the Beijing–Hangzhou Grand Canal water—sediment system (BG system) (T1/2 = 20.51–25.02 d). The aerobic degradation of rizazole was similar to its anaerobic degradation in the water-sediment system. The findings are useful to understand the behavior of pesticide in environment.  相似文献   

12.
Methane emissions from a coastal lagoon: Vembanad Lake,West Coast,India   总被引:6,自引:0,他引:6  
An attempt has been made to estimate methane fluxes from a tropical coastal wetland the Vembanad Lake, a lagoon along the West Coast of India. It has been found that Vembanad Lake contributes significant amount of methane to the atmosphere. Average emissions varied spatially within the lake. Methane emissions were 193.2 +/- 24.5 mg m(-2) h(-1) at Kumaragam (fresh water) as compared to 9.3 +/- 9.6 mgm(-2) h(-1) at Pullot (brackish water) site. Seasonal variation was significant between pre- and post-monsoons. Soil temperature, time of the day, salinity sediment organic carbon, all control the rate of methane emissions from the Vembanad Lake.  相似文献   

13.
Song J  Luo YM  Zhao QG  Christie P 《Chemosphere》2003,50(6):711-715
Small soil suction samplers have been used for several years to sample soil solution for chemical analysis in laboratory and glasshouse experiments. They are very cheap, effective and convenient. Here we describe for the first time their use in studies on sediment porewater. Bulk sediment from West Lake, a shallow hypereutrophic lake in Hangzhou, Zhejiang Province, China, was placed in laboratory microcosms and incubated in the dark at 25 degrees C for 182 days to evaluate the feasibility of using the samplers to extract sediment porewater and to estimate NH4+ flux across the sediment-water interface under anaerobic conditions. The results show that the samplers were capable of sequentially extracting sediment porewater, 15 ml of which could be readily extracted for analysis within 30-45 min by vacuum applied using a plastic syringe. The NH4+ flux under laboratory conditions was characterized by a fast phase during the initial 18 days of incubation followed by a slower linear phase, with average release rates of 11.6 and 3.6 mg N m(-2) d(-1), respectively.  相似文献   

14.
雨后入湖溪流磷污染对西湖的影响及其对策   总被引:6,自引:1,他引:6  
入湖径流是西湖磷的最主要污染源,尤其是暴雨后径流的磷污染最严重,梅雨(2001年)和台风雨后径流的磷净输入为1.77t,约占西湖全年磷总沉积量的42.5%。西湖流域内土壤表土的磷含量约是母土的两倍。西湖流域内土壤表土富磷和暴雨的冲刷和淋溶是导致雨后径流磷浓度提高的主要原因。提出了几种减小和消除径流磷污染的几种方案,通过分析比较,建渠排暴雨后径流水到钱塘江是比较彻底的消除径流磷污染的措施。  相似文献   

15.
Zhou Q  Gibson CE  Zhu Y 《Chemosphere》2001,42(2):221-225
The bioavailability of phosphorus (P) in sediments from West Lake and Lake Tai (China) and Lough Erne (Northern Ireland) was evaluated using total P (TP), water soluble P (WSP), readily desorbable P (RDP), algal available P (AAP) and Olsen-P. The results indicated that the TP content, the amounts of phosphorus extracted by each method and their proportions to TP varied widely between sediments of the three lakes. TP and chemical extractable phosphorus in the sediments of Lough Erne were considerably higher than those of the two lakes in China. Although TP in the West Lake sediments was similar to that of Lake Tai, the extractable phosphorus data suggested that the bioavailability of P in West Lake sediments was higher than that in sediments from Lake Tai. Nevertheless, the rank order of extraction efficiency was the same in all lakes and the amount extracted was in the sequence AAP > Olsen-P > WSP > RDP. There was a good correlation between extracted and TP in all the methods examined.  相似文献   

16.

Resuspended sediment is an important carrier of underwater material circulation, and bed shear stress is usually considered to be closely related to sediment resuspension. To analyze the resuspension dynamics in severely eutrophic Lake Chaohu, China, three fixed stations were set up to collect wave, current, and suspended sediment concentrate (SSC) data under windy weather, and two significant sediment resuspension events were recorded. Based on the Gaussian-shaped spectrum characteristics of waves in Lake Chaohu, the wave orbital velocity was estimated by using the wave parameter method. The selection of the general wave spectrum is important for the accurate estimation of wave orbital velocity. The results of the simple linear wave method were very similar to those of the wave parameter method with a Gaussian-shaped spectrum in Lake Chaohu. The total bed shear stress combining waves and currents during the observation period was calculated, and most of it was contributed by wind-driven waves. The bed material of Lake Chaohu has silt-enriched and weak cohesive features, and an examination of critical shear stress showed that the modified Shields curve method was still applicable to Lake Chaohu. When a sediment resuspension event occurred, the vertical gradient of SSC increased significantly, and the peak SSC value depended on the peak value of bed shear stress. As a predictor, bed shear stress only showed a good linear relationship during sediment resuspension events. At other times, the prediction of SSC using bed shear stress may be biased, especially at the time after a significant sediment resuspension event.

  相似文献   

17.
Tong Y  Lin G  Ke X  Liu F  Zhu G  Gao G  Shen J 《Chemosphere》2005,60(1):85-92
In order to investigate the role of the microbial community in aquatic ecology and nutrient transformations in the development of eutrophication in large shallow freshwater lakes along Yangtze River, the microbial community in the depth-related sediment in Lake Chaohu and Lake Longganhu were compared. Lake Chaohu is one of the three most polluted lakes in China. However, the neighboring Lake Longganhu, a mesotrophic lake, is relatively pristine. The total phosphorous (TP) and total nitrogen (TN) concentration in water was detected at 0.193 mgl(-1) and 3.035 mgl(-1) for Lake Chaohu, 0.051 mgl(-1) and 0.774 mgl(-1) for Lake Longganhu, respectively. The population of the microorganisms with various ecological nutrient transforming functions (e.g. phosphate solubilizing, denitrifying and cellulose decomposing) and a batch of environmental parameters concerning the nutrient accumulating and transforming (e.g. total organic carbon, total nitrogen, and total phosphorous concentrations) were assayed in the depth-related sediment samples from several defined points in both lakes. The sediment samples from Lake Chaohu showed higher density of actinomycetes (P<0.05) and phosphate-solubilizing bacteria (P<0.001) and less profusion of denitrifying bacteria (P<0.05) and cellulolytic microbes (P<0.001), compared with those of Lake Longganhu. The data suggested that the current microbial community in the sediment of Lake Chaohu is in favor of sustaining or further accelerating the process of the lake eutrophication. A possible positive feedback loop which consists of sustained growth of microorganisms and gradual decline of lake eutrophic status is worth further discussing.  相似文献   

18.
Rush Lake (WI, USA), the largest prairie-pothole lake east of the Mississippi River, has been contaminated with lead pollution as a result of over 140 years of waterfowl hunting. We examined: (1) the extent of lead pollution in Rush Lake sediments and (2) whether lead pollution in Rush Lake is affecting the abundance and community structure of indigenous sediment bacteria. Sediment lead concentrations did not exceed 59 mg Pb kg(-1) dry sediment. No relationship was observed between sediment lead concentration and the abundance of aerobic (P=0.498) or anaerobic (P=0.416) heterotrophic bacteria. Similarly, lead did not appear to affect bacterial community structure when considering both culturable and nonculturable community members. In contrast, the culturable fraction of sediment bacteria in samples containing 59 mg Pb kg(-1) exhibited a unique community structure. While factors other than lead content likely play roles in determining bacterial community structure in the sediments of Rush Lake, these data suggest that the culturable fraction of sediment bacterial communities is affected by elevated lead levels.  相似文献   

19.
Environmental Science and Pollution Research - The geographical location of West Taihu Lake determines that it is the entrance of the whole Taihu Lake, and the intensive industries around it pose a...  相似文献   

20.
西湖引水治理后的底栖动物群落   总被引:3,自引:0,他引:3  
1995年1月-1996年12月对西湖底栖大型无脊椎动物群落进行了连续监测与研究,共发现大型底栖无脊椎动物26种,其中寡毛类6种,多毛类1种,水生昆虫9种,蛭类,线虫和无节蠕虫各1种。  相似文献   

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