Phosphorus Concentration In Lake Water Research Articles

Fluctuation of phosphorus concentration in Lake Taihu in the past 70 years and future control strategy

分析湖泊中磷浓度的变化特征，揭示其变化的驱动机制，是有效实施湖泊水体磷浓度控制的前提.本文整理分析了太湖70年来（1949—2020年）水体磷浓度监测历史资料，对比了太湖不同湖区、不同时间尺度水体磷浓度的差异性及波动性，发现影响太湖磷浓度变化的原因既有人为的因素，也有自然的因素.无论是污染较轻的1950年，还是污染负荷相对较重的近30年，太湖水体磷浓度一直存在较大时空差异性.暴雨引发入湖河流携带磷污染的扩散、风浪扰动引起的内源释放及蓝藻水华期间藻类生物量的大幅时空变化，都加剧了太湖水体磷浓度的不稳定性.近20年的太湖水污染治理对磷浓度的时空分布影响明显，1998年的太湖水污染治理“零点行动”，2007年以来的水利调度等系列水污染治理工程，以及2017年以来的藻情变化等，都对太湖水体磷浓度的时空格局产生了影响.然而，高强度治理投入下太湖水体磷浓度依然偏高，其原因与流域建设用地比例增加、人口增加、耕地种植结构变化等外源负荷因素发生变化有关，也与湖体沉水植被退化、出入流结构发生变化、气候变化引发的蓝藻水华扩张等内源强度及水体表观磷浓度决定因素的生态环境变化有关.近70年来太湖水体磷浓度的变化过程对类似大型浅水湖泊的磷控制策略具有启示意义：大型浅水湖泊存在磷浓度较大波动的自然属性，在水环境保护目标考核中应充分考虑其不确定性，制定切实可行的控制目标；在控制策略上应将外源负荷控制放在首位，在流域污水处理厂深度除磷及流域土地利用调整等方面采取措施，实现入湖磷负荷的大幅削减，同时实施湖体生态修复与食物链调控措施，才能逐步实现湖泊水体磷浓度的控制目标.;Understanding the changing mechanism of phosphorus concentration in lakes is the precondition of strategic decision for lake restoration. Based on the 70 years (1949-2020) phosphorus concentration monitoring data at Lake Taihu, a large shallow lake, it is found that the phosphorus concentration was highly fluctuated temporally and spatially, owing to both human pollution and natural limnological changes. Phosphorus concentrations was largely different both in the relatively clean 1950 and in the relatively polluted recent 30 years. Heavy rain storm discharge plenty of external phosphorus into the lake, causing large spatial difference of water phosphorus concentration. Strong wind causing lots of phosphorus released from lake sediment, causing large temporal fluctuation of phosphorus concentration. And algal bloom materials re- distribution by wind driving also bring about large uncertainty of phosphorus concentrations. In the recent 20 years, pollution abatement projects have significantly changed the spatial-temporal change of phosphorus concentration in Lake Taihu. Zero Action of water pollution control in Taihu catchment since 1998, water resource diversion engineering since 2007, and the bloom situation aggravate since 2017 have significantly influenced the fluctuation intensity, spatial distribution and mean value of phosphorus in Lake Taihu. However, phosphorus concentrations in the whole Lake Taihu still keep high level even plenty of pollution treatment investigation. Its reasons are owing to both external loading factors, such as largely increase of construction land use ratios, population increases, and crop planting structure change in farmlands, and internal loading factors, such as submerged vegetation degradations, hydrological structure changes, and algal bloom aggravates under climatic change. The seventy years variation characteristic of phosphorus concentration in Lake Taihu should provide lessons for large shallow lakes management. Relatively large fluctuation of phosphorus concentration in lake water is the nature of large shallow lakes. Decision-maker should consider the natural characteristic when they formulate the protection target of large shallow lakes. External loading abatement should give priority, such as land use adjustment in Lake Taihu basin and deeply phosphorus removal in tail-water of urban sewage treatment plants. At the same time, internal loading control measures, such as submerged vegetation restoration and top-down food-web control of algal biomass by bio-manipulation of fishery should be undertaken to make sure the highly fluctuation of phosphorus being largely controlled.

Hedonic Price Estimates of Lake Water Quality: Valued Attribute, Instrumental Variables, and Ecological-Economic Benefits

We estimate the effect of lake water quality on residential housing prices using cross-sectional data on water clarity from 113 lakes across the United States. An instrumental-variables approach is developed to address potential endogeneity bias in the water-clarity variable. Three lake-based physical variables serve as instrumental variables: total nitrogen concentration in lake water, total phosphorus concentration in lake water, and water temperature near the lake surface. The econometric results include three methodological findings: the instruments are valid and strong; the ordinary-least-squares estimate of the coefficient on the water-clarity variable is unbiased; and water clarity is the attribute of water quality valued in the housing market. The estimated water-clarity effect shows that a one-tenth of a meter change in water clarity leads to a one-percent change in housing price, or an elasticity of 0.20 at mean clarity. Coupling this effect with estimates of an ecological production function, a lake-specific benefit index is developed that shows the effect on housing values of bringing lakes into compliance with the US Environmental Protection Agency's regional recommendations for phosphorous concentration in lake waters.

Determining the spatial variation of phosphorus in a lake system using remote sensing techniques

AbstractLakes are versatile ecosystems, with eutrophication being a serious problem affecting their condition and trophic status. Eutrophication can lead to an over‐abundance of macrophytes in lakes, producing favourable conditions for mosquito larvae. Increased eutrophication is attributed in most to excessive phosphorus concentrations in lake water. Satellite imagery analysis now plays a prominent role for quickly assessing water quality over a large area. The present study is an attempt to illustrate the variation of phosphate and total phosphorus concentrations in Akkulam–Veli Lake, Kerala, India, using Indian Remote Sensing satellite (IRS P6‐ LISS III) imagery. A multiple regression equation derived using radiance in the red and MIR bands in the imagery was found to yield superior results for predicting the phosphate concentration, whereas a simple regression equation using radiance in red band was found to yield good results for the total phosphorus concentration in lake water. Accordingly, the trophic status of the lake system can be determined easily from satellite imagery in this manner.

Diagenesis of settling seston: identity and transformations of organic phosphorus

Solution (31)phosphorus NMR spectroscopy and sequential fractionation were used to follow diagenetic changes in phosphorus forms during decomposition of settling seston in Lake Nordborg, a shallow eutrophic lake in Denmark. In a decomposition experiment, seston released >60% of their total phosphorus during ~50 days incubation, although seston collected during summer contained more phosphorus and released it over a longer period compared to seston collected during spring. Seston decomposition increased concentrations of potentially bioavailable polyphosphate and phosphodiesters, but also promoted the formation of refractory phosphorus forms that might be buried permanently in the sediment. Combining these results with in situ measurements of phosphorus concentrations in lake water and sediment traps revealed that the release from settling seston plays only a minor role in the accumulation of phosphorus in the hypolimnion of Lake Nordborg.

Laboratory-Scale Investigation of Ferrihydrite-Modified Diatomite as a Phosphorus Co-precipitant

The potential of ferrihydrite-modified diatomite as a phosphorus co-precipitant was investigated at a laboratory scale. Ferrihydrite-modified diatomite was demonstrated to effectively remove phosphorus from lake water as well as strongly bind phosphorus in sediment under anoxic conditions. Phosphorus removal from the lake water proceeded primarily through phosphorus adsorption onto ferrihydrite-modified diatomite and further phosphorus consumption by stimulated diatom growth. A total phosphorus removal efficiency of 85% was achieved when lake water was dosed with 250 mg/L ferrihydrite-modified diatomite; the residual total phosphorus concentration was 17.0 µg/L, which falls within the range for oligotrophic phosphorus levels. During a 30-day anoxic incubation period, total phosphorus concentrations in lake water treated with 400, 500, or 600 mg/L of ferrihydrite-modified diatomite slightly decreased and maximum total phosphorus concentrations remained below 15 µg/L. Addition of ferrihydrite-modified diatomite resulted in a marked increase in the iron-bound phosphorus fraction, a pronounced decrease in labile phosphorus and organic-bound phosphorus fractions, and stable aluminum-bound phosphorus, calcium-bound phosphorus, and residual phosphorus fractions in the anoxic sediments. Comparable iron-bound phosphorus concentration in the sediment treated by 400 mg/L of ferrihydrite-modified diatomite relative to that of the sediment treated by the combination of 400 mg/L of ferrihydrite-modified diatomite and alum solution at the concentration less than 532 mg/L indicated that ferrihydrite-modified diatomite exhibited a stable phosphorus-binding capacity when dosed at a similar amount. Ferrihydrite-modified diatomite had the potential to be used as an effective phosphorus co-precipitant.

Using aquatic macrophyte community indices to define the ecological status of European lakes

Defining the overall ecological status of lakes according to the Water Framework Directive (WFD) is to be partially based on the species composition of the aquatic macrophyte community. We tested three assessment methods to define the ecological status of the macrophyte community in response to a eutrophication pressure as reflected by total phosphorus concentrations in lake water. An absolute species richness, a trophic index (TI) and a lake trophic ranking (LTR) method were tested at Europe-wide, regional and national scales as well as by alkalinity category, using data from 1,147 lakes from 12 European states. Total phosphorus data were used to represent the trophic status of individual samples and were plotted against the calculated TI and LTR values. Additionally, the LTR method was tested in some individual lakes with a relatively long time series of monitoring data. The TI correlated well with total P in the Northern European lake types, whereas the relationship in the Central European lake types was less clear. The relationship between total P and light extinction is often very good in the Northern European lake types compared to the Central European lake types. This can be one of the reasons for a better agreement between the indices and eutrophication pressure in the Northern European lake types. The response of individual lakes to changes in the abiotic environment was sometimes represented incorrectly by the indices used, which is a cause of concern for the use of single indices in status assessments in practice.

Lake Maggiore (N. Italy) trophic history: fossil diatom, plant pigments, and chironomids, and comparison with long-term limnological data

The availability of long-term series of chemical and biological data and the eutrophication/oligotrophication history of Lake Maggiore allows an attempt to correlate the registered changes with sedimentary records in several sediment cores. Documentary and palaeolimnological data were used to calibrate two important suites of sedimentary indicators of phytoplankton, diatoms and algal pigments. Diatom assemblages in the sediment cores precisely reflect the pelagic diatom development for approximately the last century. Prediction of total algal biomass from the profile of the ubiquitous β-carotene and some algal groups in certain period of lake development (e.g. diatoms, Cryptophyta, cyanobacteria) was good, whereas the comparison of taxa-specific carotenoids and algal biomass standing stocks (as cell biovolume) in some case revealed poor correspondence. Selective carotenoid losses, taxa production, and mechanisms controlling pigment sedimentation are factors that biased the comparison. However, pigment concentrations and algal biovolumes are different units but equally valid. The use of fossil pigments complements other studies and provides more detailed information on algal development. A sub-fossil chironomid profile agrees well with the general trophic reconstruction as inferred from the pigment and diatom data, adding more details on changes in littoral substratum, water-level fluctuation and flood events. Models to infer primary productivity and total phosphorus concentration in lake water from sedimentary pigments and diatom assemblages are tested: in the case of the TP reconstruction, reliable results were obtained in this case for the period of high trophic state and for the last decade. During the recovery phase of the 1980s, unexpected high abundance of Stephanodiscus minutulus leads to strong overestimation of TP concentrations. Similarly, the reconstructed primary productivity only disagrees with the experimental data for some years in the last decade. Sensitivity of the sedimentary pigment model as well as the relatively reduced sampling dates likely explains this discrepancy. Similarities are also evident in the temporal diatom assemblage variations of an additional three sub-alpine Italian lakes. As well, the palaeolimnological reconstruction for Lake Maggiore parallels that for Lake Constance, another large sub-alphine lake located north of the Alps.

Lakes and reservoirs: reflecting waters of sustainable use

The International Lake Environment Committee (ILEC) has been conducting, in cooperation with the United Nations Environment Programme (UNEP), a project entitled the “Survey of the State of World Lakes” since 1986 with the aim of collecting and compiling environmental data on as many important lakes and reservoirs of the world as possible to be used as the basis for environmentally sound management of lakes. The results so far obtained from the survey have been published in five volumes as the “Data Book of World Lake Environments”, which contain sets of detailed data on 217 lakes from 73 countries all over the world. The survey carried out by ILEC and UNEP illustrated that the following six major environmental problems are now widespread among lakes and reservoirs around the world, leading to a crisis of water resources and aquatic ecosystems: 1) Lowering of water level, 2) Rapid siltation, 3) Acidification, 4) Toxic contamination, 5) Eutrophication, and 6) Extermination of ecosystems and biota. A preliminary analysis on surveyed lakes and reservoirs also demonstrated some interesting correlations between 1) the volume of lake water and transparency, 2) suspended solids concentrations and the ratio of forest area to the whole catchment area, 3) suspended solids concentrations and the area of farmlands in the catchment area per unit volume of lake water, and 4) total nitrogen and total phosphorus concentrations in lake water, indicators of the degree of eutrophication, and the catchment area population per unit volume of lake water.

Lakes and reservoirs: Reflecting waters of sustainable use

The International Lake Environment Committee (ILEC) bas been conducting, in cooperation with the United Nations Environment Programme (UNEP), a project entitled the “Survey of die State of World Lakes” since 1986 with the aim of collecting and compiling environmental data on as many important lakes and reservoirs of the world as possible to be used as the basis for environmentally sound management of lakes. The results so far obtained from the survey have been published in five volumes as the “Data Book of World Lake Environments”, which contain sets of detailed data on 217 lakes from 73 countries all over the world. The survey carried out by ILEC and UNEP illustrated that the following six major environmental problems are now widespread among lakes and reservoirs around the world, leading to a crisis of water resources and aquatic ecosystems: 1) Lowering of water level, 2) Rapid siltation, 3) Acidification, 4) Toxic cont 5) Eutrophication, and 6) Extermination of ecosystems and biota. A preliminary analysis on surveyed lakes and reservoirs also demonstrated some interesting correlations between 1) the volume of lake water and transparency, 2) suspended solids concentrations and the ratio of forest area to the whole catchment area, 3) suspended solids concentrations and the area of farmlands in the catchment area per unit volume of lake water, and 4) total nitrogen and total phosphorus concentrations in lake water, indicators of the degree of eutrophication, and the catchment area population per unit volume of lake water.

Information theoretical approach to comparative study of lakes

Information theoretical indices ( K , M , I ), introduced in a previous paper, are used for characterization and comparison of various types of lakes studied by IBP in Japan. The index K is a measure of distribution of matter among compartments in a system as compared with a reference system, the index M is a measure of concentration of matter in a system as compater with a reference system, and I = K + M . These indices are calculated for each lake; and the value M vs. K , the effect of changing reference system, the effect of aggregation of compartments, and the relation to nitrogen and phosphorus concentrations in lake water are investigated. The value of M becomes larger as eutrophication progresses. The value of K also increases with eutrophication with a large rate for oligo-mesotrophic lakes and with a small rate for eutrophic lakes.

Background aspects of lake restoration: water balance, heavy metal content, phosphorus homeostasis

Perturbations of the lake water balance, inputs of heavy metals to lakes, and intensifying fertilization of lakes through input and accumulation of phosphorus—these three classes of phenomena are among the more important background processes in lake restoration. Lake restoration consists of a series of measures animed at producing a homeostatic response of a lake system to external perturbations. The success of its implementation is affected by the morphometric and edaphic parameters of different types of lakes. The relationship between the volume (V) and mean-depth\((\bar z)\) of fresh-water lakes indicates a trend of\(V \propto \bar z^3 \). Glacial lakes occuring on or near crystalline shields have relatively shallow depths, whereas volcanic lakes, rift valley and deep valley lakes have relatively greater depths for the same volume. For saline lakes (21 lakes, V>1 km3) that undergo cycles of expansion and shrinkage, the V to\(\bar z\) relationship is closer to power 1. Water residence times (τ) of small and big fresh-water lakes show a trend of τ approximately linear in\(\bar z\) or τ∝V0.3. Volcanic lakes and Maare have longer residence times in comparison to other lakes of similar volumes. For the major inorganic chemical species and heavy metals, the regulatory upper-limit concentrations in drinking water in the USA and EEC are from several times to more than 100 times higher than their concentrations in a global mean river water. Only three elements (Fe, P, and Al) occur in river water at concentrations approaching such upper-limit recommendations. Rates of accumulation of phosphorus in lake water and sediments, computed as the difference between input and ouflow removal rates for 23 fresh-water lakes, are generally lower for lakes of longer water residence time. The rate of accumulation is a measure of homeostatic response of the lake system to input load: it is equivalent to the rate of all the removal processes needed to maintain phosphorus concentration in lake water at a steady state.

Improvements in Quantifying the Phosphorus Concentration in Lake Water

Vertical and horizontal patterns in limnetic phosphorus concentrations ([P]) were detected in an oligotrophic lake by dividing the total phosphorus pool into two fractions: dissolved and particulate matter smaller than 250 μm (smaller fraction) and particulate matter larger than 250 μm (larger fraction). The smaller fraction was estimated from samples collected with a water bottle, and the larger fraction was estimated with tow net samples taken at several stations and to various depths. Our samples were digested with potassium persulfate which gave less variable results than other acid digestion techniques. The average variance associated with the mean [P] (n = 3) for samples collected and analyzed according to our procedure was less than 0.05 mg P/m3. During summer stratification there was a consistent metalimnetic maximum in the smaller fraction, and there were small but significant differences in the concentrations found at two stations less than 1 km apart. During the same period the larger fraction was a significant portion (14–28%) of the phosphorus pool in the epilimnion which varied from 3 to 5 m in depth. It was a relatively constant portion of the phosphorus in the trophogenic zone (0–10 m) and in the 0- to 20-m portion of the water column i.e. 10–14% and 7.3–8.8%, respectively. In a separate experiment it was shown that by removing the larger fraction, the average variance associated with the mean [P] was reduced from 1.0, to 2.4 × 10−2 mg/m3. This reduction occurred because the larger fraction contained zooplankters with relatively high but variable amounts of phosphorus, and which occur in densities too low to be adequately sampled with the smaller fraction.Key words: phorphorus, lakes, phosphorus in zooplankton

A test of a simple model to predict short-term changes in the phosphorus concentration in lake water

A test of a simple model to predict short-term changes in the phosphorus concentration in lake water

Direct Determination of Apatite in Lake Sediments

Apatite is a common accessory mineral in the source rocks for the glacial debris supplying sediments to many Canadian lakes. A method has been developed which uses scanning electron microscopy and energy dispersive X-ray emission spectrometry for direct identification of apatite. This method has been used to examine the apatite content of various size fractions in Kamloops Lake sediments. Apatite concentrations obtained by this direct examination correlate well (r > 0.999) with apatite concentrations determined by chemical analyses and indicate that, in addition to comprising as much as 70% of the total phosphorus load, apatite may comprise as much as one-third of the "dissolved" (< 0.45 μm) inorganic phosphorus load. Consequently the use of classical (e.g. Vollenweider 1968; Vollenweider and Dillon 1974) methods of estimating lake trophic state from inorganic phosphorus concentrations in lake water must be done with care, recognizing that the bulk of inorganic phosphorus in lakes deriving sediment from glaciated igneous or metamorphic terrains may be in the form of apatite.Key words: apatite, lake, trophic state, phosphorus load, scanning electron microscopy

Applicability of Phosphorus Budget Models to Small Precambrian Lakes, Algonquin Park, Ontario

Phosphorus and hydrological budgets were constructed for four small lakes with Precambrian drainage in Algonquin Park, Ontario. Lake outflow discharge ranged from 21.7 × 105 to 177 × 105 m3∙yr−1. Annual phosphorus input to the lakes from terrestrial drainage and precipitation totaled 36.3–188 kg∙yr−1. The lakes retained 16–41% of the annual input. These data were used to test a series of models that predict the spring total phosphorus concentration in lake water and the mean summer chlorophyll a. The predicted spring phosphorus concentration agreed well with measured values (within 1.3 mg∙m−3) except where human-associated phosphorus input may have contributed to the phosphorus budget of the lake. Agreement between predicted and measured chlorophyll a was not as close. A figure of 0.48 kg P∙capita−1∙yr−1 was calculated as the human-associated supply. Key words: phosphorus budget, chlorophyll a, predictive model, Precambrian lake

A Test of a Simple Nutrient Budget Model Predicting the Phosphorus Concentration in Lake Water

The total phosphorus budgets for a number of lakes in the Haliburton–Kawartha region of southern Ontario were measured over a 20-mo period. These data, combined with the lakes' morphometry and water budgets, were used to test a simple nutrient budget model similar to that proposed by Vollenweider (1969) purporting to predict the total phosphorus concentration in lakes. Except in the case of two very shallow lakes [Formula: see text], the concentrations predicted by the model were very close to those measured in the lakes at spring overturn. Additional data from the literature supported the belief that this model could be used effectively for oligotrophic and mesotrophic lakes. Its value lies in the fact that quantitative changes in phosphorus loading can be interpreted in terms of changes in phosphorus concentration, which in turn, can be related to changes in parameters that reflect the lake's trophic state such as summer chlorophyll a concentration.