PREDICTION OF CHLOROPHYLL A CONCENTRATIONS IN FLORIDA LAKES: THE IMPORTANCE OF PHOSPHORUS AND NITROGEN1

ABSTRACT: Models for the prediction of chlorophyll a concentrations were developed and tested using data on 223 Florida lakes. A statistical analysis showed that the best model was log (Chl a) =?2.49 + 0.269 log (TP) + 1.06 log (TN) or log (Chl a) =?2.49 + 1.06 log (TN/TP) + 1.33 log (TP) where Chl a is the chlorophyll a concentration (mg m^-3), TP is the total phosphorus concentration (mg m^-3) and TN is the total nitrogen concentration (mg m^-3). The model yields unbiased estimates of chlorophyll a concentrations over a wide range of lake types and has a 95 percent confidence interval of 29–319 percent of the calculated chlorophyll a concentrations. Other models, especially the published Dillon-Rigler and Jones-Bachmann phosphorus-chlorophyll models, are less precise when applied to Florida lakes. The data support the hypothesis that nitrogen is an important limiting nutrient in hypereutrophic lakes.     

微波消解法测定农药废水中的总磷

介绍了一种测定农药废水中总磷的新的预处理方法－微波消解法。其消解时间从传统法的40min缩短到8min，精确度和准确度与传统的消解法相比无显著性差异。     

磷对环境的污染及防治对策

我国水体富营养化严重，其主要控制因子是磷。在分析磷污染的污染状况，污染源的基础上，介绍了防治对策，采用低磷循环冷却水处理剂，减少磷排放，是防止工业磷污染的有效方法。     

次氯酸钠氧化脱除黄磷尾气中的硫、磷杂质

采用次氯酸钠氧化工艺净化黄磷尾气，在次氯酸钠溶液中有效氯的质量分数为0．65％，PH为9、反应温度为285K，气体流速为0．6-0.8L/min的条件下，对尾气中H2S、PH3的脱除率分别达到99．9％，和99．8％，出口含量分别小于0.2mg/m^3和7mg/m^3，对有机硫也有30％的脱除能力。     

采用两级物化法去除黄磷废水中的氟化物

采用向含氟废水中加入适量石灰和聚合氯化铝，然后投加适量钙盐、磷酸和聚丙烯酰胺的二级处理工艺除氟，通过控制合适的pH、钙盐和磷酸的投加量、反应时间、反应温度、搅拌强度和絮凝剂的投加量，可使黄磷废水中氟的质量浓度降至5mg/L，氟的去除率达到99％以上，出水中氟的质量浓度达到GB8978－1996一级排放标准。     

Biological Pollutants: Alien Fishes in Mountain Lakes

Many lakes in the national parks of the Canadian Rockies were stocked with alien fish species in the early to mid 20th century. Changes to Parks Canada's mandate require the original communities of these lakes to be restored. We document the changes to invertebrate communities caused by the stocking of alien fishes into three fishless alpine lakes, and describe the results of two restoration experiments, one the reintroduction of Hesperodiaptomus arcticus, a planktonic predator that had been eliminated from Snowflake Lake by stocked fish, and the other the removal of brook trout (Salvelinus fontinalis) from Bighorn Lake. In both cases, there were great changes to the zooplankton communities, which required several years to complete, probably because of the cold water and unproductive nature of the lakes. Many of the invertebrate species extirpated by stocked alien fishes co-exist with native fish species in nearby lakes. Possible reasons are discussed.     

EFFECTS OF SLUDGE AND CHEMICAL FERTILIZER APPLICATION ON RUNOFF WATER QUALITY1

ABSTRACT: Simulated rainfall was used on experimental field plots to compare the effect of chemical fertilizer and sludge application on sediment, nitrogen, and phosphorus in runoff from no-till and conventional tillage systems. Chemical fertilizer application under the no-till system resulted in the least amount of total N and P in surface runoff. However, sludge application under the no-till system resulted in the least amount of NO₃-N and sediment in surface runoff. The worst water quality scenarios were observed when either sludge or chemical fertilizer were surface-applied under a conventional tillage system. Nitrogen losses from the conventional tillage system were minimized when sludge was incorporated into the soil. However, phosphorus and sediment yield from such a system were significantly higher when compared to phosphorus and sediment yield from the no-till system. The results from this study indicate that the use of sludge on agricultural land under a no-till system can be a viable alternative to chemical fertilizer for nitrogen and phosphorus control in runoff. A more cautious approach is recommended when the sludge is incorporated into the soil in a conventional tillage system because of potential for high sediment and phosphorus yield in surface runoff.     

毕节地区各土类水土保持树种的Fuzzy评价

根据毕节地区16个主要造林树种的生态生物学特性,结合本区气候和土壤生态条件,运用 Fuzzy 二级评价模型,对各土类水土保持树种的适宜程度进行了综合评价。     

Environmental regulatory compliance on army lands: A case study

A “finding of no significant impact” (FONSI) resulting from an environmental assessment (EA) was reported by the US Army in June 1986 for the construction and utilization of a multipurpose range complex (MPRC) at the Pohakuloa Training Area, Hawaii. There was little public response, and the US Fish and Wildlife Service and state agencies were consulted and had few comments concerning the results of the botanical surveys used in the assessment. Construction of the $24 million project was begun in 1988. Near the end of construction in 1989 a lawsuit was filed to halt construction because an environmental impact statement (EIS) had not been done for the project, and the plaintiff thought that significant damage had occurred to several unusual ecosystems. Judgment was against the plaintiff and construction continued. An appeal was filed with the 9th Circuit Court. As MPRC construction was nearly complete, and on advice of Department of Justice lawyers, the Department of Army agreed to settle out of court. The settlement in part called for: (1) the plaintiff to drop the appeal and allow construction to be completed as scheduled, and (2) the Department of Army to prepare an EIS for the operation of the MPRC. A subsequent botanical survey for the EIS discovered one endangered plant species, four category 1 candidate plant species (taxa with sufficient data to support listing as endangered or threatened), three category 2 candidate plant species (taxa with some evidence of vulnerability but insufficient data to support listing at this time), one category 3a species (presumably extinct taxa), and possibly three undescribed species growing within the MPRC boundary. The MPRC case study is an excellent example of why the National Environmental Policy Act (NEPA) must be modified to require in-depth and thorough environmental surveys.     

Management plan for an alkali sink and its endangered plantCordylanthus palmatus

Cordylanthus palmatus is a hemiparasitic annual of the family Scrophulareacae. It is on both the federal and state lists of endangered species. Only four widely separated populations remain, all of them in alkali sinks, where the plant thrives in saline-sodic soils. The largest population is at Springtown, Alameda County, California. This article reports on efforts to develop a management plan for both the plant and the alkali sink ecosystem. The plan is based on: (1) characterization of hydrology, soils and geomorphology of the site; (2) characterization of the land use impacts to the site; (3) analysis of plant distribution in relation to gradients of elevation and soil chemistry; (4) studies on water potential and water stress inCordylanthus palmatus and associated species. On the basis of this plan, both the State of California and private groups are cooperating to create, restore, and manage a preserve in the Springtown Alkali Sink.