scholarly journals Phosphorous runoff risk assessment and its potential management using wollastonite according to geochemical modeling

2019 ◽  
Vol 4 (1) ◽  
pp. 787-794 ◽  
Author(s):  
Aneela Hayder ◽  
Stephen Vanderburgt ◽  
Rafael M. Santos ◽  
Yi Wai Chiang
Keyword(s):  
Risk Analysis ◽  
Algal Blooms ◽  
Agricultural Land ◽  
Algal Bloom ◽  
Risk Mitigation ◽  
Geochemical Modeling ◽  
Geochemical Modelling ◽  
Water Runoff ◽  
Phosphorus Pollution ◽  
Contaminate Drinking Water

AbstractLoss of phosphorus from agricultural land through water runoff causes serious detrimental effects on the environment and on water quality. Phosphorous runoff from excessive use of fertilizers can cause algal blooms to grow in nearby water systems, producing toxins that contaminate drinking water sources and recreational water. In this study, a risk analysis of the algal toxin micro-cystin-LR and the mitigation of phosphorus from agriculture runoff is discussed. A risk analysis was performed on the algal bloom toxin microcystin-LR considering the Lake Erie algal bloom event of 2011 as a case study. Toxicity risk analysis results show that relatively low concentrations of microcystin-LR compared to recent case studies pose an acute health risk to both children and adults, and a significant increase in the risk of developing cancer is suggested but subject to further study given the assumptions made. This study investigated the potential of using wollastonite to mitigate phosphorus pollution, considering thermodynamic conditions of a constructed wetland receiving influent water from agriculture runoff, by using geochemical modelling. Geochemical modelling results show that wollastonite can react with phosphorus and capture it in the stable mineral form of hydroxyapatite, offering a possible strategy for risk mitigation of phosphorous runoff. A removal efficiency of 77% of phosphorus using wollastonite is calculated with the help of geochemical modelling.

Cryogenic leakage risk analysis for FLNG and use of brittle crack arresting material as a risk mitigation measure

2015 ◽  
Author(s):  
Akio Usami ◽  
Naohiko Kishimoto ◽  
Hiroki Kusumoto ◽  
Fujio Kaneko ◽  
Takehiro Inoue
Keyword(s):  
Carbon Steel ◽  
Risk Analysis ◽  
Brittle Fracture ◽  
Risk Mitigation ◽  
Brittle Crack ◽  
Cryogenic Fluid ◽  
Mitigation Measure ◽  
Flammable Gas ◽  
Confined Environment

Leakage of cryogenic fluid can bring diverse consequences within confined environment like FLNG. In particular, leakage from pressurized refrigerant system is expected to form cryogenic pool, which could initiate brittle fracture of the structure as well as violent evaporation of flammable gas. The authors put the series of different leakage scenarios under light and quantitatively analyzed the potential consequences in an attempt to provide overall pictures of this hazard yet to have been made clear so far. Further, use of brittle fracture arresting steel – a new strain of carbon steel produced through special TMCP technology – was explored on its potential to mitigate the risk.

scholarly journals Interaction between simulated dense Scenedesmus dimorphus (Chlorophyta) bloom and freshwater meta-zooplankton community

2018 ◽  
Vol 77 (2) ◽  
Author(s):  
Zengling Ma ◽  
Hengguo Yu ◽  
Ronald Thring ◽  
Chuanjun Dai ◽  
Anglv Shen ◽  
...  
Keyword(s):  
Community Structure ◽  
Green Algae ◽  
Aquatic Ecosystems ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Photochemical Efficiency ◽  
Zooplankton Community ◽  
Post Inoculation ◽  
Zooplankton Community Structure ◽  
Scenedesmus Dimorphus

Algal bloom has been a subject of much research, especially the occurrence of blue-green algae (cyanobacteria) blooms and their effects on aquatic ecosystems. However, the interaction between green algae blooms and zooplankton community was rarely investigated. In the present study, the effects exerted by Scenedesmus dimorphus (green alga) bloom on the community structure of zooplankton and the top-down control of the bloom process mediated by the zooplankton were evaluated using a series of laboratory cultures. The results showed that a dense S. dimorphus bloom could change the zooplankton community structure by decreasing its diversity indices, leading to the enrichment of a particular zooplankton species, Brachionus calyciflorus. In the presence of mixed species of zooplankton, the density of S. dimorphus in the culture was decreased as determined by a change in total chlorophyll a (Chl a) concentration, which was about 200 μg L-1 lower than that of the zooplankton-free culture. Furthermore, the number of species belonging to Cladocera, Copepoda and Rotifera all decreased, with all the cladocerans disappeared in the co-culture within 2 weeks of culturing, while the density of rotifers increased from 818 (±243) ind L-1 at the time of inoculation to 40733 (±2173) ind L-1 on the 14th day post-inoculation. Grazing of S. dimorphus by the rotifer B. calyciflorus neutralized its growth, and the gradual increase in B. calyciflorus density eventually led to the collapse of the bloom. Furthermore, grazing by B. calyciflorus also led to a decrease in the maximal photochemical efficiency (Fv/Fm) of photosystem II (PSII). The combined changes occurring in the zooplankton community structure during the process of S. dimorphus bloom and the negative effects of grazing on algal growth, morphology and photosynthetic activities confirmed the key role of zooplankton in the control of algal bloom. The results of the study therefore indicated that dense algal blooms caused by non-toxic algae could still remain a threat to aquatic ecosystems.

scholarly journals The Ocean’s Elevator: Evolution of the Air-Seawater Interface During a Small-Scale Algal Bloom

2020 ◽  
Author(s):  
Mickey Rogers ◽  
Jennifer Neal ◽  
Ankur Saha ◽  
Abdullah Algarni ◽  
Thomas Hill ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Structural Changes ◽  
Organic Molecules ◽  
Algal Bloom ◽  
Small Scale ◽  
Surface Imaging ◽  
Brewster Angle Microscopy ◽  
Surface Active ◽  
Marine Algal ◽  
Late Stages

We explore in situ the surface properties of marine algal blooms of diatom monocultures by utilizing surface techniques of Brewster angle microscopy (BAM) imaging, vibrational sum frequency generation spectroscopy (SFG), and infrared reflection absorption spectroscopy (IRRAS). Over the course of the bloom, the marine algae produce surface-active biogenic molecules that temporally partition to the topmost interfacial layers and are selectively probed through surface imaging and spectroscopic measurements. BAM images show morphological structural changes and heterogeneity in the interfacial films with increasing density of surface-active biogenic molecules. Film thickness calculations quantified the average surface thickness over time. The image results reveal an ~5 nm thick surface region in the late stages of the bloom which correlates to typical sea surface nanolayer thicknesses. Our surface-specific SFG spectroscopy results show significant diminishing in the intensity of the dangling OH bond of surface water molecules consistent with organic molecules partitioning and replacing water at the air-seawater interface as the algal bloom progresses. Interestingly, we observe a new broad peak appear between 3500 cm<sup>-1</sup> to 3600 cm<sup>-1</sup> in the late stages of the bloom that is attributed to weak hydrogen bonding interactions of water to the surface-active biogenic matter. IRRAS confirms the presence of organic molecules at the surface as we observe increasing intensity of vibrational alkyl modes and the appearance of a proteinaceous amide band. Our work shows the often overlooked but vast potential of tracking changes in the interfacial regime of small-scale laboratory marine algal blooms. By coupling surface imaging and vibrational spectroscopies to complex, time-evolving, marine-relevant systems, we provide additional insight into unraveling the temporal complexity of sea spray aerosol compositions.

scholarly journals Then and Now: Understanding Change on an Agricultural Landscape

2021 ◽  
Author(s):  
Alexander Pardy
Keyword(s):  
Land Use ◽  
Great Lakes ◽  
Management Practices ◽  
Agricultural Landscape ◽  
Agricultural Land ◽  
Reference Group ◽  
Surface Water Quality ◽  
Laurentian Great Lakes ◽  
Phosphorus Pollution ◽  
Land Use And Management

Freshwater eutrophication typically driven by non-point source phosphorus pollution is one of the worlds’ most prevalent and vexing environmental problems with the Laurentian Great Lakes on the Canada – United States border. During 1975 – 1977, the Pollution from Land Use Activities Reference Group examined eleven agricultural watersheds in order to investigate the impacts of land use activities on surface water quality. This study examined how agricultural land use and management has transformed in two watersheds, Nissouri Creek and Big Creek. The goal of this study was to quantify the phosphorus mass balance change within the watersheds. During 2015 – 2019 land use and management practices survey data was collected. Results of this study showed Nissouri Creek is now depleting -2.19 kilograms of phosphorus per hectare of agricultural land, while Big Creek is still accumulating 4.77 kilograms of phosphorus per hectare of agricultural land. This study can guide efforts to limit the long-term losses of phosphorus in the Laurentian Great Lakes and elsewhere.

Conceptualization of a Critical Infrastructure Network – Model for Flood Risk Assessments

2021 ◽  
Author(s):  
Roman Schotten ◽  
Daniel Bachmann
Keyword(s):  
Risk Analysis ◽  
Flood Risk ◽  
Critical Infrastructure ◽  
Risk Mitigation ◽  
Mitigation Measures ◽  
Critical Infrastructures ◽  
Flood Exposure ◽  
Infrastructure Network ◽  
Flood Risk Analysis ◽  
De Bruijn

&lt;p&gt;&lt;span&gt;In flood risk analysis it is a key principle to predetermine consequences of flooding to assets, people and infrastructures. Damages to critical infrastructures are not restricted to the flooded area. The effects of directly affected objects cascades to other infrastructures, which are not directly affected by a flood. Modelling critical infrastructure networks is one possible answer to the question &amp;#8216;how to include indirect and direct impacts to critical infrastructures?&amp;#8217;.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;Critical infrastructures are connected in very complex networks. The modelling of those networks has been a basis for different purposes (Ouyang, 2014). Thus, it is a challenge to determine the right method to model a critical infrastructure network. For this example, a network-based and topology-based method will be applied (Pant et al., 2018). The basic model elements are points, connectors and polygons which are utilized to resemble the critical infrastructure network characteristics.&lt;/p&gt;&lt;p&gt;The objective of this model is to complement the state-of-the-art flood risk analysis with a quantitative analysis of critical infrastructure damages and disruptions for people and infrastructures. These results deliver an extended basis to differentiate the flood risk assessment and to derive measures for flood risk mitigation strategies. From a technical point of view, a critical infrastructure damage analysis will be integrated into the tool ProMaIDes (Bachmann, 2020), a free software for a risk-based evaluation of flood risk mitigation measures.&lt;/p&gt;&lt;p&gt;The data on critical infrastructure cascades and their potential linkages is scars but necessary for an actionable modelling. The CIrcle method from Deltares delivers a method for a workshop that has proven to deliver applicable datasets for identifying and connecting infrastructures on basis of cascading effects (de Bruijn et al., 2019). The data gained from CIrcle workshops will be one compound for the critical infrastructure network model.&lt;/p&gt;&lt;p&gt;Acknowledgment: This work is part of the BMBF-IKARIM funded project PARADes (Participatory assessment of flood related disaster prevention and development of an adapted coping system in Ghana).&lt;/p&gt;&lt;p&gt;Bachmann, D. (2020). ProMaIDeS - Knowledge Base. https://promaides.myjetbrains.com&lt;/p&gt;&lt;p&gt;de Bruijn, K. M., Maran, C., Zygnerski, M., Jurado, J., Burzel, A., Jeuken, C., &amp; Obeysekera, J. (2019). Flood resilience of critical infrastructure: Approach and method applied to Fort Lauderdale, Florida. Water (Switzerland), 11(3). https://doi.org/10.3390/w11030517&lt;/p&gt;&lt;p&gt;Ouyang, M. (2014). Review on modeling and simulation of interdependent critical infrastructure systems. Reliability Engineering and System Safety, 121, 43&amp;#8211;60. https://doi.org/10.1016/j.ress.2013.06.040&lt;/p&gt;&lt;p&gt;Pant, R., Thacker, S., Hall, J. W., Alderson, D., &amp; Barr, S. (2018). Critical infrastructure impact assessment due to flood exposure. Journal of Flood Risk Management, 11(1), 22&amp;#8211;33. https://doi.org/10.1111/jfr3.12288&lt;/p&gt;

Risk Analysis of Power-Gen Gas Turbines With GADS Outage Data

2017 ◽  
Author(s):  
Bin Zhou
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Risk Mitigation ◽  
Data System ◽  
Loss Prevention ◽  
The Past ◽  
The North ◽  
Effective Assessment

According to FM Global proprietary data, power-gen gas turbine losses have consistently represented a dominant share of the overall equipment-based loss value over the past decade. Effective assessment of loss exposure or risk related to gas turbines has become and will continue to be a critical but challenging task for property insurers and their clients. Such systematic gas turbine risk assessment is a necessary step to develop strategies for turbine risk mitigation and loss prevention. This paper presents a study of outage data from the Generating Availability Data System (GADS) by the North American Electric Reliability Corporation (NERC). The risk of forced outages in turbines was evaluated in terms of outage days and number of outages per unit-year. In order to understand the drivers of the forced outages, the influence of variables including turbine age, capacity, type, loading characteristic, and event cause codes were analyzed by grouping the outage events based on the chosen values (or ranges of values) of these variables. A list of major findings related to the effect of these variables on the risk of forced outage is discussed.

scholarly journals The Risk Analysis of Andalas University Hospital Construction Project

2018 ◽  
Vol 215 ◽  
pp. 01033
Author(s):  
Zaidir ◽  
Melani Novia Putri ◽  
Alizar Hasan
Keyword(s):  
Risk Analysis ◽  
Risk Mitigation ◽  
Construction Project ◽  
Risk Identification ◽  
University Hospital ◽  
Mitigation Measures ◽  
Ahp Method ◽  
Analytic Hierarchy ◽  
Goods And Services ◽  
Shop Drawing

Construction project activities have various risks during their implementation. Every work item on the project has different levels of risk and can affect the project so that it will have an impact on increasing cost and time of project completion. PT. Adhi Karya Tbk is carrying out the project of Andalas University Hospital, where in its implementation there will be many possibilities of risks that will occur. Therefore, it is necessary to identify and analyze the variables of risks that may occur as well as proposing appropriate risk mitigation measures for minimize the potential risks. Risk identification and risk analysis were done using Risk Breakdown Structure (RBS) and Analytic Hierarchy Process (AHP) method respectively. Based on data compilation, variables of risk are grouped in 4 types, namely risk of engineering consist of 8 variables, risk of production consist of 5 variables, risk of construction consist of 9 variables and risk of financial consist of 2 variable, with total of risk are 24 variables. Risk analysis with AHP method is obtained 5 (five) risk priority based on the highest value on each risk type. The five priority risks were a risks of increasing of material prices (extreme), a risk of increasing of procurement costs (high), workplace accidents risk in the project area (medium), mistaken translating the DED to shop drawing (medium) and a quality of goods and services produced by vendors not meet the specifications in contract (medium). To reduce the possibility and impact the risks posed mitigation measures for the risk priority highest were proposed.

The Hidden Impacts of Phosphorus Pollution to Streams and Rivers

BioScience ◽  
2020 ◽  
Vol 70 (4) ◽  
pp. 315-329 ◽  
Author(s):  
Michael A Mallin ◽  
Lawrence B Cahoon
Keyword(s):  
United States ◽  
Experimental Evidence ◽  
Health Risks ◽  
Algal Bloom ◽  
Harmful Algal Bloom ◽  
Oxygen Demand ◽  
The United States ◽  
Economic Losses ◽  
Phosphorus Pollution ◽  
Resource Managers

Abstract Phosphorus (P) enrichment to streams, lakes, and estuaries is increasing throughout the United States. P loading is typically viewed from a harmful algal bloom perspective; if added P causes excess growths of phytoplankton or macroalgae, it may become targeted for control. However, P loading also contributes to two other non–algae-based aquatic problems. Field and experimental evidence shows that P loading directly stimulates growth of aquatic bacteria, which can increase to concentrations that exert a significant biochemical oxygen demand on water bodies, contributing to hypoxia, a widespread impairment. Experimental evidence also demonstrates that fecal bacterial growth can be significantly stimulated by P loading, increasing health risks through exposure or the consumption of contaminated shellfish and causing economic losses from beach and shellfish area closures. Resource managers need to look beyond algal bloom stimulation and should consider the broader roles that excess P loading can have on ecosystem function and microbiological safety for humans.

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