Models to predict total phosphorus concentrations in coastal embayments of eastern Georgian Bay, Lake Huron

2018 ◽  
Vol 75 (11) ◽  
pp. 1798-1810 ◽  
Author(s):  
Stuart D. Campbell ◽  
Patricia Chow-Fraser
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Loading ◽  
Georgian Bay ◽  
Large Size ◽  
Capacity Model ◽  
Basin Morphometry ◽  
Coastal Embayments ◽  
Cottage Development ◽  
Shield Lakes ◽  
The Impact

Several coastal embayments of eastern Georgian Bay show signs of water-quality impairment thought to be caused by human activities. Here, we evaluate the ability of the Lakeshore Capacity Model (LCM), developed for Precambrian Shield lakes, to assess the impact of cottage development on the trophic status of ten Georgian Bay embayments. The LCM could only be applied to eight embayments due to the large size and complexity of two watersheds and produced unacceptably high estimates of mean seasonal total phosphorus concentrations ([TP]; i.e., exceeded 20% of measured values for five of eight embayments); accuracy of [TP] estimates could not be improved by accounting for internal phosphorus loading. We developed an additional model, the Anthro-Geomorphic Model (AGM), which uses building density and basin morphometry as variables. Estimates of [TP] for the AGM were within 20% of measured values for all sites. Compared with other aquatic systems, coastal embayments of Georgian Bay have significantly higher chlorophyll a concentrations per unit [TP]; we suggest that the TP–chlorophyll relationship presented in this study be used to estimate productivity in these systems.

Strategy for Phosphorus Control from Estimated Phosphorus Loads and Predicted Total Phosphorus Concentration in Penetang Bay, Georgian Bay, 1973 to 1992

1995 ◽  
Vol 30 (4) ◽  
pp. 619-634
Author(s):  
R. Keith Sherman ◽  
Sharon L. Brown
Keyword(s):  
Total Phosphorus ◽  
Open Water ◽  
Phosphorus Loading ◽  
Source Control ◽  
Phosphorus Concentration ◽  
Sewage Effluent ◽  
Total Phosphorus Concentration ◽  
Georgian Bay ◽  
Sewage Plant ◽  
Urban Storm

Abstract Cultural eutrophication has affected Penetang Bay, in southeastern Georgian Bay, since the 1960s. External sources of phosphorus were estimated and open water total phosphorus concentration was predicted in order to establish a rationale for an effective source control strategy for the bay. Seasonal loadings are greatest in the spring due mainly to the watershed sources, with 33-58% of the total annual load entering during the March to May period. Apart from this period, the two sewage plant effluent discharges are the largest sources of phosphorus loading to the bay. On an annual basis, the largest source of phosphorus to the bay is from treated sewage effluent (60%), followed by watershed, shoreline development and urban storm water, respectively. More than 80% of the estimated total annual loads was from sewage effluent, watershed and urban storm sources alone. These sources were estimated annually for the historical period of record (1973-1992). The trophic model predicted the long-term average total phosphorus concentration ([TP]) reasonably well. Predictions of [TP]Bay for individual years were within 1-49% of the measured [TP]Bay. The model predicted [TP]Bay to within 20% of measured values for 14 of the 20 years of record. The model as applied to Penetang Bay is sensitive to changes in sewage plant effluent loading and watershed loading. Model predictions indicate that significant reductions in open water [TP] can be expected following implementation of proposed source control actions. Total loading of phosphorus to the Bay of less than 1,000 kg/year should result in open water [TP]Bay of less than 15 µg/L.

scholarly journals Total Phosphorus Loading onto the Water Environment from Common Carp Fed Commercial Diets

1999 ◽  
Vol 65 (5) ◽  
pp. 712-716 ◽  
Author(s):  
Takeshi Watanabe ◽  
Parveen Jahan ◽  
Shuichi Satoh ◽  
Viswanath Kiron
Keyword(s):  
Common Carp ◽  
Total Phosphorus ◽  
Water Environment ◽  
Phosphorus Loading ◽  
Commercial Diets

scholarly journals Empirical Investigation of Symmetric and Asymmetric Target Adjustment Models: Capital Structure of Non-Financial Firms in Jordan

2017 ◽  
Vol 9 (3) ◽  
pp. 133 ◽  
Author(s):  
Bashar K. Abu Khalaf
Keyword(s):  
Capital Structure ◽  
Stock Exchange ◽  
Interaction Model ◽  
Firm Characteristics ◽  
Leverage Ratio ◽  
Financial Firms ◽  
Large Size ◽  
Amman Stock Exchange ◽  
Target Leverage ◽  
The Impact

The different capital structure theories propose the possible asymmetric behavior of capital structure. Thus, this paper empirically investigates whether non-financial Jordanian firms follow symmetrical or asymmetrical adjustment model. Then, an interaction model with the size and profitability (firm characteristics) investigated the impact of low/high profit and small/large size on the adjustment of leverage towards the target leverage ratio. This paper covered the period of 14 years (2002-2015) for a total of 110 companies listed on Amman Stock Exchange (75 industrial and 35 services). Results indicate that although Jordanian firms seek a target leverage ratio, their adjustment towards that target is Asymmetrical and high profitable and large companies tend to adjust faster than low profitable and small size companies.

scholarly journals 15. Clicker Lessons: Assessing and Addressing Student Responses to Audience Response Systems

2011 ◽  
Vol 1 ◽  
pp. 85
Author(s):  
Tim Pelton ◽  
Leslee Francis Pelton ◽  
Mary Sanseverino
Keyword(s):  
Audience Response ◽  
Evaluation Tool ◽  
Audience Response Systems ◽  
Self Evaluation ◽  
Perceived Need ◽  
Large Size ◽  
Response Systems ◽  
Support Teacher ◽  
The University ◽  
The Impact

This project began in response to a perceived need to assess students’ perceptions with respect to the emerging use of audience response systems (clickers) in several mid- to large-size undergraduate courses at the University of Victoria. We developed and validated a “Clicker Use Survey” to gather students’ opinions with respect to clicker utility and the impact of clicker use on their learning. With the collected data we generated a set of baseline distributions to support assessment of various clicker use protocols and created a self-evaluation tool to share with instructors to support teacher reflection on the efficacy of their clicker practices. We also provided a sample self-evaluation to model the use of the tool. Links to the survey instrument, baseline data and self-evaluation tool, and sample self-evaluation are provided.

scholarly journals Assessment of the Impact of Forestry and Settlement-Forest Use of the Catchments on the Parameters of Surface Water Quality: Case Studies for Chechło Reservoir Catchment, Southern Poland

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 964 ◽  
Author(s):  
Andrzej Bogdał ◽  
Andrzej Wałęga ◽  
Tomasz Kowalik ◽  
Agnieszka Cupak
Keyword(s):  
Water Quality ◽  
Total Phosphorus ◽  
Surface Waters ◽  
Forest Cover ◽  
Statistical Tests ◽  
Surface Water Quality ◽  
Anthropogenic Factors ◽  
Multivariate Statistical ◽  
Forest Use ◽  
The Impact

The aim of the study was to determine the impact of natural and anthropogenic factors on the values of 22 quality indicators of surface waters flowing out of two small catchments differing in physiographic parameters and land use, in particular forest cover and urbanization of the area. The research was carried out in the years 2012–2014 at four measurement-control points located on the Chechło river and the Młoszówka stream (Poland), which are the main tributaries of the retention reservoir. Basic descriptive statistics, statistical tests, as well as cluster analysis and factor analysis were used to interpret the research results. The water that outflowed from the forestry-settlement catchment of the Młoszówka stream contained higher concentrations of total phosphorus, phosphates, nitrite, and nitrate nitrogen and salinity indicators than outflow from the Chechło river. Water from the Młoszówka stream was characterized by more favourable oxygen conditions. Higher oxygen concentration in the catchment influenced a large slope of the watercourse and thus higher water velocity, which is promoted by the mixed process. In the case of the forest catchment of the Chechło river, the water quality was generally better than in the Młoszówka stream, mainly in cases of total suspended solids TSS, total phosphorus TP, phosphates PO43−, total nitrogen TN, nitrite N–NO2−, nitrate N–NO3−, and salinity parameters. Despite it being a short section of the river taken into the study, favourable self-purification processes like mixed, nitrification, and denitrification were observed in its water. The research shows that forest areas have a positive effect on the balance of most substances dissolved in water, and natural factors in many cases shape the quality and utility values of surface waters on an equal footing with anthropogenic factors. In the case of a large number of examined parameters and complex processes occurring in water, the interpretation of the results makes it much easier by applying multivariate statistical methods.

Impacts of agriculture on aquatic systems: lessons learnt and new unknowns in Northern Ireland

2001 ◽  
Vol 52 (1) ◽  
pp. 151 ◽  
Author(s):  
S. I. Heaney ◽  
R. H. Foy ◽  
G. J. A. Kennedy ◽  
W. W. Crozier ◽  
W. C. K. O' Connor
Keyword(s):  
Water Quality ◽  
Northern Ireland ◽  
Soluble Reactive Phosphorus ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
The European Union ◽  
Blue Green Algae ◽  
Lough Neagh ◽  
The Impact

Agriculture in Northern Ireland depends on grass-based production, but since 1980, expansion of output has been effectively constrained by production limits set by the European Union agricultural policy. Despite this, long-term monitoring over several decades has shown significant degradation of water quality in Lough Neagh, with persistent high biomass of blue-green algae. Similar long-term studies have revealed a marked decline in the freshwater survival of salmon in the nearby River Bush. These changes may be related and reflect the impact of farming on water quality and salmonid production. Regular sampling of the inflowing rivers to Lough Neagh has shown that continued increase in lake phosphorus concentration has been primarily due to an increase in the soluble reactive phosphorus loading from agricultural diffuse sources. Similar diffuse inputs of agriculturally derived nutrients to the River Bush, leading to increased plant growth together with the accumulation of fine sediment in salmon spawning redds, are considered to be important in the decline of freshwater survival of salmon from egg to smolt. The impact of farming practices on lakes and rivers is considered in relation to understanding of the complex and interacting factors that link land use to water quality.

scholarly journals Special features of elimination of phosphorus compounds in aeration tanks

2020 ◽  
Vol 163 ◽  
pp. 05016
Author(s):  
Nina Zaletova
Keyword(s):  
Total Phosphorus ◽  
Sewage Treatment ◽  
Phosphorus Compounds ◽  
Residual Concentration ◽  
Wastewater Treatment Process ◽  
Initial Concentration ◽  
Organic Mineral ◽  
Complex Forms ◽  
The Impact ◽  
Active Dose

In the sewage treatment plants, phosphorus compounds presented constantly, due to the sources of their appearance. In urban wastewater, phosphorus stays in various compounds – dissolved, insoluble, organic, mineral, simple and complex forms. Only phosphates and total phosphorus are monitored in wastewater chemicals laboratories. The data on phosphorus compounds containing in the wastewater of a number of cities is analyzed in the study. The impact of the biological wastewater treatment process on the efficiency of phosphorus removal was assessed. The research was carried out on an experimental technological installation. It is shown that in the original wastewater not only the concentration of total phosphorus and phosphates is constantly varying, but also their ratio. In the process of biological treatment, a number of complex biochemical and physical-chemical processes are parallel: assimilation, hydrolysis, and adsorption. The effectiveness of these processes is influenced by the magnitude of the initial concentration of total phosphorus and the amount of active dose of sludge. It has been recognized that the increased efficiency of the removal of total phosphorus has an effect on both the increase in the active dose of sludge and the size of the initial concentration of total phosphorus. However, the residual concentration of total phosphorus is affected by its original content, while the initial content of the total phosphorus is affected insignificantly.

scholarly journals Fitting geothermal energy into the energy transition

2019 ◽  
Vol 98 ◽  
Author(s):  
Daniel P. Smith
Keyword(s):  
Geothermal Energy ◽  
District Heating ◽  
Energy Transition ◽  
Heat Sources ◽  
Large Size ◽  
Energy Consideration ◽  
Seasonal Heat ◽  
The Impact ◽  
Base Load ◽  
Heating Networks

Abstract This article attempts to identify the main ‘above-ground’ factors which impact on the contribution that geothermal energy can make to the Dutch Energy Transition, and to draw conclusions about these factors. Recent literature sources are used to illustrate the size of Dutch heating demand, and the part of this which can be provided by geothermal energy. Consideration is given to the impact of off-take variability over time, showing that the base-load nature of geothermal doublets acts as a restraint on the share which they can take in the energy supply. The characteristics of district heating grids are discussed. Other potential sources of heat are considered and compared. The conclusion is that geothermal energy can provide a material contribution to the energy transition. This depends to a large extent on the existence of and design choices made for the development of district heating networks. Large size and standardisation, and the development of seasonal heat storage, are beneficial. Unlike most other renewable sources of heat, which have alternative ‘premium’ applications such as the provision of ‘peak capacity’ or molecules for feedstock, geothermal energy is not suitable for other uses. The emission savings that it can provide will be lost if other heat sources are chosen in preference as supply for district heating, so that it makes sense that district heating infrastructure should be designed to encourage the use of geothermal energy where possible.

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