THE LIMNOLOGY OF LAKE WABUKAYNE,A STORM-WATER IMPOUNDMENT1

ABSTRACT The limnology of a 1.9-ha storm-water detention pond is described. The eutrophic nature of this impoundment is attributed to the nutrients in runoff from the surrounding residential area. During the summer, photosynthetic activity of the phytoplankton caused surface waters to become super-saturated with oxygen, while decomposing organic material greatly reduced dissolved oxygen concentrations in the deeper water. Sediment derived from construction activity within the drainage basin caused the impoundment to be turbid. The use of road deicing salts within the drainage basin produced high chloride concentrations and a temporary meromixis during the winter and early spring. The benthic fauna consisted primarily of oligochaetes, chironomids, and chaoborids. High densities of oligochaetes were present in the settling basin. Chaoborid larvae were abundant in the deep basin where low oxygen concentrations reduced the numbers of other benthic macroinvertebrates.     

WATERFALL REAERATION IN THE PASSAIC RIVER1

The effects of waterfall-induced turbulence on the dissolved oxygen concentration of the Passaic River (New Jersey) at two mostly natural waterfalls were observed during a five-month period encompassing high to low temperature and flow. A parameter defined by past investigators as the “deficit ratio” was found to be useful for mathematically describing the results. The Great Falls system showed the deficit ratio to be an inverse function of temperature for all events, with good correlation. A relationship was developed for the Little Falls system under low flow showing the deficit ratio to likewise be an inverse function of temperature and a power function of flow.     

MATERIALS INPUT OF LAKE CHAMPLAIN: A SYNOPTIC APPRAISAL1

ABSTRACT: The complex morphometry of Lake Champlain requires that detailed, regional studies be made, and the results integrated, to yield total lake conditions. Using specific conductance measurements, and values of total dissolved solids calculated from them, we present an approach to assessing the materials budget of the lake. The sampling program involved inventorying all 319 tributaries, determining the watershed area for each, and dividing the Champlain basin into appropriate hydrographic regions. Data were obtained from samples collected from 41 selected streams (representing 97.5% of the annual water input), sampling occurring in all seasons of the year since 1970. Results indicate that over one million metric tonnes of total dissolved solids enter Lake Champlain annually, about two-thirds (63%) from the eastern (Vermont) portion and almost one-fourth (22%) from the western (New York) part of the drainage basin, the remainder (15%) entering from the south end. Of the total quantity added annually, 17.4% is retained in the lake, indicating that a solids build-up is occurring, at a significant rate. We suggest that specific conductance, and therefore total dissolved solids, be utilized as a convenient indicator of water quality conditions, and results applied to permit more efficient watershed management.     

福建省九龙江江东库区沉积物微藻分布研究

沉积物既是营养盐的储存库,也是藻类的休眠场所.本研究以九龙江北溪江东水库为研究对象,于2011年4月、6月、9月、12月采集表层沉积物,对其营养盐含量、表层沉积物微藻分布及丰度进行分析.结果表明,沉积物大部分为粉砂质粘壤土,该区域沉积物总碳含量为9140.2~17760.4 mg·kg~(-1),总氮含量为950.0~1600.4 mg·kg~(-1),总磷含量为483.7~856.2 mg·kg~(-1).库区表层沉积物微藻细胞丰度范围在7.41×105~2.17×106cells·g~(-1)底泥(以干重计),主要为硅藻门和绿藻门,分别占微藻比例的45.52%~86.42%和5.96%~35.55%.沉积物微藻总丰度与上覆水体浮游植物总丰度及隐藻、裸藻丰度呈显著负相关,反映了沉积物微藻对上覆水体浮游植物的影响.沉积物中蓝藻、隐藻、甲藻孢囊丰度分别与水温呈显著负相关,分别与溶解氧呈显著正相关,因而冬季沉积物中有相对高的微藻丰度.沉积物微藻丰度与含水率、粉粒分别呈显著性正相关,反映了沉积物微藻沿着水流方向的积累.     

溶解氧及碳氮比对SBR处理猪场厌氧消化液脱碳除氮效能的影响

猪场厌氧消化液因C/N低,常规的生物脱氮工艺存在COD去除效率低、脱氮效果差等问题.文章以模拟猪场厌氧消化液为处理对象,考察了不同溶解氧浓度(DO浓度均值为2.0和4.0 mg/L)及进水C/N(C/N=2.7、4和6)对SBR工艺脱碳除氮效能的影响.结果表明:CODcr去除率随C/N的增加而升高,并且提高C/N有利于氨氮和总氮的去除,它们的去除率随进水C/N值的增加均呈上升趋势,在C/N =6时分别达到86％和94％.     

三阶段温度控制接种法对堆肥有机物质变化影响

为提高堆肥效率,利用生活垃圾,采用三阶段温度控制技术进行微生物接种堆肥试验,并对堆肥过程中有机物的动态变化进行分析.结果表明,在堆肥336 h,与普通接种法(CK)比较,三阶段温度控制接种法(TSCT)堆肥总有机碳(TOC)、水溶性有机碳(DOC)含量依次降低6.37%、6.57%;而腐殖质(HS)、胡敏酸(HA)、腐殖化指数(HI)分别增加了8.61%、16.75%、18.40%.通过对胡敏酸分子元素组成分析证实,堆肥后,普通接种法处理胡敏酸分子中C/H、O/C依次增加8.33%、6.25%;而三阶段温度控制法堆肥中胡敏酸C/H、O/C依次增加了18.33%、11.48%.以上结果表明,三阶段温度控制法可明显加快堆肥腐殖化进程,进而提高堆肥效率.     

活性污泥培养初期溶解氧(DO)的控制

活性污泥培养初期,由于污泥尚未大量形成,细菌消耗的营养和溶解氧少,曝气量大大少于稳定运行期间的曝气量。以缙云污水处理厂为例,对培养初期污泥沉降比(SV30)与溶解氧(DO)以及化学需氧量(COD)去除率之间的关系进行了探讨。     

粘土矿物对重金属有害元素吸附性研究

文章从粘土矿物主要性能出发,结合粘土矿物吸附能力试验和已知采矿污染区粘土矿物吸附能力测试,研究了蒙脱石、高岭石、伊利石等粘土矿物对Pb、Zn、Cr、Cd、Hg等重金属有害元素的吸附性,探讨了粘土矿物在水污染治理中的应用。     

土霉素残留对模型池塘生态系统代谢的影响

按生态学方法建立和培育模型池塘生态系统,选择符合要求的生态池,设立一个空白对照池和4个不同浓度用药池,用药后定期观测生态池溶解氧(DO)、pH值、初级生产力(P/R)等参数的变化.结果表明,100mg/L用药造成系统不可逆性的破坏;20mg/L和4mg/L浓度的用药对系统参数造成的影响比较短暂,系统参数分别在2wk后和1wk后恢复正常;0.8mg/L用药对系统参数几乎不造成可测定的影响.图3参8     

Mineral status of soils and forage in the Mole National Park,Ghana and implications for wildlife nutrition

Geochemical mapping of soils and selected plant species has been carried out in the Mole National Park, Ghana. The distribution of the essential nutrients: cobalt, copper and manganese is largely controlled by bedrock geology, while the geochemical dispersion of Ca, I, Fe, Mg, Mo, P, K, Se, Na and Zn has been modified by soil and hydromorphic processes. From selective extraction experiments, Fe, Mn and Co are found to be largely fixed in the soil mineral fraction. Larger proportions of Cu, I, Mo, Se and Zn are EDTA extractable and have a high chelation potential.Cobalt, Cu and Mn were preferentially concentrated in grass species while molybdenum and selenium are concentrated in browse plants. Copper uptake is antagonistic to Fe, Mo and Zn accumulation in all plant and grass samples. Similarly, Se and Mn appear antagonistic and Fe uptake is antagonistic to Co, Cu, Mn, Mo and Zn.The low concentration of P points to a potential dietary deficiency of this element throughout the park. Cobalt deficiency may also occur due to a love extractability of these elements in the soils and low concentration in plants. However, the lack of data on the elemental requirements of wildlife allows only tentative conclusions to be drawn.