A series of PowerPoint slides that will be useful when introducing students to the study of biogeochemistry: definitions, four main elemental cycles, isotopic techniques.
Bio 107 General Ecology
Objectives:
Identify and describe
the flow of nutrients in
each biogeochemical
cycle.
Explain the impact
that humans have on
the biogeochemical
cycles.
• Nutrient cycles referred to as biogeochemical cycles
• Gaseous forms of carbon, oxygen, and nitrogen occur in the atmosphere and cycle globally
• Less mobile elements, including phosphorous, cycle on a more local level
• Still, gains and losses from outside of the ecosystem are generally small when compared to the rate at which nutrients are cycled within the system.
Environmental science Module 1 Topic. This PPT is not a work of mine and was provided by our college professor during our graduation, so I am not sure about the original author. The credit goes to the Original author.
Biogeochemical Cycles and Human ActivitiesAmos Watentena
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A biogeochemical cycle is one of several natural cycles, in which conserved matter moves through the biotic and abiotic parts of an ecosystem. In geography and Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical substance moves through biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth. The following presentation discusses the role of humans in the biogeochemical cycles.
A series of PowerPoint slides that will be useful when introducing students to the study of biogeochemistry: definitions, four main elemental cycles, isotopic techniques.
Bio 107 General Ecology
Objectives:
Identify and describe
the flow of nutrients in
each biogeochemical
cycle.
Explain the impact
that humans have on
the biogeochemical
cycles.
• Nutrient cycles referred to as biogeochemical cycles
• Gaseous forms of carbon, oxygen, and nitrogen occur in the atmosphere and cycle globally
• Less mobile elements, including phosphorous, cycle on a more local level
• Still, gains and losses from outside of the ecosystem are generally small when compared to the rate at which nutrients are cycled within the system.
Environmental science Module 1 Topic. This PPT is not a work of mine and was provided by our college professor during our graduation, so I am not sure about the original author. The credit goes to the Original author.
Biogeochemical Cycles and Human ActivitiesAmos Watentena
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A biogeochemical cycle is one of several natural cycles, in which conserved matter moves through the biotic and abiotic parts of an ecosystem. In geography and Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical substance moves through biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth. The following presentation discusses the role of humans in the biogeochemical cycles.
Biogeochemical cycle, any of the natural pathways by which essential elements of living matter are circulated. The term biogeochemical is a contraction that refers to the consideration of the biological, geological, and chemical aspects of each cycle.
Nutrient cycling is one of the most important processes that occur in an ecosystem. The nutrient cycle describes the use, movement, and recycling of nutrients in the environment.
Multiple Benefits of SLCP Mitigation in Alpine and Polar RegionsInfoAndina CONDESAN
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Presentation of Johan C.I. Kuylenstierna, Director of the Stockholm Environment Institute York Centre
It describe the main findings of an Integrated Assessment developed under UNEP and WMO on tropospheric ozone and black carbon. This has been put together by key experts around the globe, with Drew Shindell of NASA-GISS as the Chair of the Assessment and which has been coordinated by the Stockholm Environment Institute. Tropospheric ozone is ozone which is formed in the lower atmosphere – different from Stratospheric ozone layer. This ozone is not emitted but created in the atmosphere from emitted precursors, of which methane and carbon monoxide are important ones. Black carbon is emitted as particles of carbon – essentially the main compnent of soot. These substances warm the atmosphere and act as air pollutants and there has been a lot of interest recently in the potential for reducing climate warming by addressing these substances.
Biogeochemical cycle, any of the natural pathways by which essential elements of living matter are circulated. The term biogeochemical is a contraction that refers to the consideration of the biological, geological, and chemical aspects of each cycle.
Nutrient cycling is one of the most important processes that occur in an ecosystem. The nutrient cycle describes the use, movement, and recycling of nutrients in the environment.
Multiple Benefits of SLCP Mitigation in Alpine and Polar RegionsInfoAndina CONDESAN
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Presentation of Johan C.I. Kuylenstierna, Director of the Stockholm Environment Institute York Centre
It describe the main findings of an Integrated Assessment developed under UNEP and WMO on tropospheric ozone and black carbon. This has been put together by key experts around the globe, with Drew Shindell of NASA-GISS as the Chair of the Assessment and which has been coordinated by the Stockholm Environment Institute. Tropospheric ozone is ozone which is formed in the lower atmosphere – different from Stratospheric ozone layer. This ozone is not emitted but created in the atmosphere from emitted precursors, of which methane and carbon monoxide are important ones. Black carbon is emitted as particles of carbon – essentially the main compnent of soot. These substances warm the atmosphere and act as air pollutants and there has been a lot of interest recently in the potential for reducing climate warming by addressing these substances.
Promoting lifestyle change can be challenging, but Social Marketing is a framework that can be useful to systematically address behavioural and social change. This is the presentation given at the 23rd Finnish Sport and Exercise Medicine Conference (Biomedicum Helsinki, 4 November 2015).
The health implications associated with short- and long-term exposure to particulate matter measuring less than 2.5 microns (PM 2.5) continues to raise concern. Certain health effects, such as asthma and chronic obstructive pulmonary disease (COPD), have long been associated with PM 2.5 exposure. Research into the association between respiratory conditions and PM 2.5 have been the basis for air quality regulations; however, recent literature suggests that PM 2.5 exposure may lead to far more adverse health effects such as cardiovascular disease, hypertension, and low birth weight. Additionally, it now appears that PM 2.5 may follow a non-threshold linear dose-response model, meaning there may be no safe level of PM 2.5. If this is the case, even stricter regulations will follow, putting more pressure on industry to lower the output of PM 2.5. It will also pave the way for unlimited litigation for personal harm and liability. As research involving PM 2.5 exposure and human health continues, businesses must be prepared for the coming onslaught of law suits and ever-increasing demands to remain in compliance with stricter regulations.
The environment provides humans with everything we need to survive. This presentation looks at the services ecosystems deliver humanity and the importance of conserving plant biomass and diversity in order to maintain those services
Nitrogen is important element of life. In importance it comes only next to carbon, hydrogen, and oxygen. The composition of protein, nucleic acid, growth hormones, and vitamins requires Nitrogen. Leaves consist of about 1 to 15% nitrogen of their dry weight but lesser % in another vegetative organ.
• The N2 is present in the atmosphere, in the form of gas. It is about 78%.
• Green plants unable to use this N2 directly in their metabolism. Only some micro-organism can convert this N2 gas directly into organic form.
• The N2 present in the soil is called soil nitrogen. The plants growing in the soil, mainly utilize the soil N2 for their metabolic requirements.
• In the soil the nitrogen is present in the form of nitrate nitrogen (NO3, NO2), ammonia nitrogen (ammonia, ammonium salt), organic nitrogen and molecular nitrogen (N2).
• The converging of the free nitrogen, by natural or physical process is called nitrogen fixation… when any biological system is involved in this process, then it is called as biological nitrogen fixation……
The Nitrogen cycle is defined as the biogeochemical cycle process that involves transforming the inert nitrogen that is available in the atmosphere, into a more usable or conventional form, that can be actively used by plants, and various living organisms. Enroll now at Tutoroot.
This is a comprehensive account of the nitrogen cycle in terrestrial environments. The nitrogen cycle is responsible for the circulation of nitrogen between inorganic and organic components of the environment.
nitrogen is the most abundant atmospheric gas,yet is a limiting factor. this presentation is a bird's eye view, of nitrogen cycle, its fixation, uptake and assimilation in plants
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
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In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
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Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
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Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
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The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
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Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Â
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
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Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
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Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
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Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
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As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
When stars align: studies in data quality, knowledge graphs, and machine lear...
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Ecology ecosystem
1. • The nitrogen cycle is the set biogeochemical processes by which
nitrogen undergoes chemical reactions, changes form, and moves
through difference reservoirs on earth, including living organisms.
• Nitrogen is required for all organisms too live and grow because it is
the essential component of DNA, RNA, and protein. However, most
organisms cannot use atmospheric nitrogen, the largest reservoir.
• The five processes in the nitrogen cycle -- fixation, uptake,
mineralization, nitrification and denitrification -- are all driven by
microorganisms.
• Humans influence the global nitrogen cycle primarily through the
use of nitrogen-based fertilizers.
2. • Nitrogen (N) is an essential component of DNA,
RNA, and proteins, the building blocks of life. All
organisms require nitrogen to live and grow.
Although the majority of the air we breathe is N2,
most of the nitrogen in the atmosphere is
unavailable for use by organisms.
• This is because the strong triple bond between
the N atoms in N2 molecules makes it relatively
inert.
3. • In fact, in order for plants and animals to be
able to use nitrogen, N2 gas must first be
converted to more a chemically available form
such as ammonium (NH4+), nitrate (NO3-), or
organic nitrogen (e.g. urea - (NH2)2CO).
• The inert nature of N2 means that biologically
available nitrogen is often in short supply in
natural ecosystems, limiting plant growth and
biomass accumulation.
4. • Nitrogen is an incredibly versatile element
existing in both inorganic and organic forms as
well as many different oxidation states. The
movement of nitrogen between the atmosphere,
biosphere and geosphere in different forms is
described by the nitrogen cycle (Figure 1), one of
the major biogeochemicalcycles. Similar to the
carbon cycle, the nitrogen cycle consists of
various storage pools of nitrogen and processes
by which the pools exchange nitrogen (arrows)
(see our The Carbon Cycle module for more
information).
5. The nitrogen cycle. Yellow arrows indicate human sources of nitrogen to the
environment. Red arrows indicate microbial transformations of nitrogen. Blue arrows
indicate physical forces acting on nitrogen. And green arrows indicate natural, non-
microbial processes affecting the form and fate of nitrogen. Ecology & Ecosystem
8. • Five main processes cycle nitrogen through
the biosphere, atmosphere, and geosphere:
nitrogen fixation, nitrogen uptake (organismal
growth), nitrogen mineralization (decay),
nitrification, and denitrification.
Microorganisms, particularly bacteria, play
major roles in all of the principal nitrogen
transformations
9. • . As microbial mediated processes, these
nitrogen transformations tend to occur faster
than geological processes like plate motion, a
very slow, purely physical process that is a part
of the carbon cycle. Instead, rates are affected
by environmental factors that influence
microbial activity, such as temperature,
moisture, and resource availability
10. Nitrogen fixation
• N2 NH4+ Nitrogen fixation is the process wherein
N2 is converted to ammonium, essential because
it is the only way that organisms can attain
nitrogen directly from the atmosphere. Certain
bacteria, for example those among the genus
Rhizobium, are the only organisms that fix
nitrogen through metabolic processes. Nitrogen
fixing bacteria often form symbiotic relationships
with host plants. This symbiosis is well-known to
occur in the legume family of plants (e.g. beans,
peas, and clover).
11. • In this relationship, nitrogen fixing bacteria
inhabit legume root nodules and receive
carbohydrates and a favorable environment
from their host plant in exchange for some of
the nitrogen they fix. There are also nitrogen
fixing bacteria that exist without plant hosts,
known as free-living nitrogen fixers. In aquatic
environments, blue-green algae (really a
bacteria called cyanobacteria) is an important
free-living nitrogen fixer.
12.
13. • In addition to nitrogen fixing bacteria, high-
energy natural events such as lightning, forest
fires, and even hot lava flows can cause the
fixation of smaller, but significant amounts of
nitrogen (Figure 3). The high energy of these
natural phenomena can break the triple bonds
of N2 molecules, thereby making individual N
atoms available for chemical transformation.
•
14. • Within the last century, humans have become
as important a source of fixed nitrogen as all
natural sources combined. Burning fossil fuels,
using synthetic nitrogen fertilizers, and
cultivation of legumes all fix nitrogen. Through
these activities, humans have more than
doubled the amount of fixed nitrogen that is
pumped into the biosphere every year , the
consequences of which are discussed below.
16. • Nitrogen uptake
• NH4+ Organic N The ammonia produced by
nitrogen fixing bacteria is usually quickly
incorporated into protein and other organic
nitrogen compounds, either by a host plant, the
bacteria itself, or another soil organism. When
organisms nearer the top of the food chain (like
us!) eat, we are using nitrogen that has been
fixed initially by nitrogen fixing bacteria.
17. • Nitrogen mineralization
• Organic N NH4+ After nitrogen is incorporated
into organic matter, it is often converted back
into inorganic nitrogen by a process called
nitrogen mineralization, otherwise known as
decay. When organisms die, decomposers
(such as bacteria and fungi) consume the
organic matter and lead to the process of
decomposition.
18. • During this process, a significant amount of
the nitrogen contained within the dead
organism is converted to ammonium. Once in
the form of ammonium, nitrogen is available
for use by plants or for further transformation
into nitrate (NO3-) through the process called
nitrification.
19. • Nitrification
• NH4+ NO3- Some of the ammonium produced by
decomposition is converted to nitrate via a
process called nitrification. The bacteria that
carry out this reaction gain energy from it.
Nitrification requires the presence of oxygen, so
nitrification can happen only in oxygen-rich
environments like circulating or flowing waters
and the very surface layers of soils and
sediments. The process of nitrification has some
important consequences.
20. • Ammonium ions are positively charged and
therefore stick (are sorbed) to negatively charged
clay particles and soil organic matter. The positive
charge prevents ammonium nitrogen from being
washed out of the soil (or leached) by rainfall. In
contrast, the negatively charged nitrate ion is not
held by soil particles and so can be washed down
the soil profile, leading to decreased soil fertility
and nitrate enrichment of downstream surface
and groundwaters.
21. • Denitrification
• NO3- N2+ N2O Through denitrification, oxidized
forms of nitrogen such as nitrate and nitrite (NO2-
) are converted to dinitrogen (N2) and, to a lesser
extent, nitrous oxide gas. Denitrification is an
anaerobic process that is carried out by
denitrifying bacteria, which convert nitrate to
dinitrogen in the following sequence:
NO3- NO2- NO N2O N2.
22. • Nitric oxide and nitrous oxide are both environmentally
important gases. Nitric oxide (NO) contributes to smog,
and nitrous oxide (N2O) is an important greenhouse
gas, thereby contributing to global climate change.
• Once converted to dinitrogen, nitrogen is unlikely to be
reconverted to a biologically available form because it
is a gas and is rapidly lost to the atmosphere.
Denitrification is the only nitrogen transformation that
removes nitrogen from ecosystems (essentially
irreversibly), and it roughly balances the amount of
nitrogen fixed by the nitrogen fixers described above.
23. Human alteration of the N cycle and its environmental
consequences
• Early in the 20th century, a German scientist named Fritz Haber
figured out how to short circuit the nitrogen cycle by fixing nitrogen
chemically at high temperatures and pressures, creating fertilizers
that could be added directly to soil. This technology has spread
rapidly over the past century, and, along with the advent of new
crop varieties, the use of synthetic nitrogen fertilizers has led to an
enormous boom in agricultural productivity. This agricultural
productivity has helped us to feed a rapidly growing world
population, but the increase in nitrogen fixation has had some
negative consequences as well. While the consequences are
perhaps not as obvious as an increase in global temperatures or a
hole in the ozone layer, they are just as serious and potentially
harmful for humans and other organisms.
24. • Not all of the nitrogen fertilizer applied to agricultural fields stays to
nourish crops. Some is washed off of agricultural fields by rain or
irrigation water, where it leaches into surface or ground water and
can accumulate. In groundwater that is used as a drinking water
source, excess nitrogen can lead to cancer in humans and
respiratory distress in infants. The U.S. Environmental Protection
Agency has established a standard for nitrogen in drinking water of
10 mg per liter nitrate-N. Unfortunately, many systems (particularly
in agricultural areas) already exceed this level. By comparison,
nitrate levels in waters that have not been altered by human
activity are rarely greater than 1 mg/L. In surface waters, added
nitrogen can lead to nutrient over-enrichment, particularly in
coastal waters receiving the inflow from polluted rivers. This
nutrient over-enrichment, also called eutrophication, has been
blamed for in
25. • creased frequencies of coastal fish-kill events,
increased frequencies of harmful algal blooms,
and species shifts within coastal ecosystems.
• Reactive nitrogen (like NO3- and NH4+) present in
surface waters and soils, can also enter the
atmosphere as the smog-component nitric oxide
(NO) and the greenhouse gas nitrous oxide (N2O).
Eventually, this atmospheric nitrogen can be
blown into nitrogen-sensitive terrestrial
environments, causing long-term changes
26. For example, nitrogen oxides comprise a
significant portion of the acidity in acid rain
which has been blamed for forest death and
decline in parts of Europe and the Northeast
United States.
Increases in atmospheric nitrogen deposition
have also been blamed for more subtle shifts
in dominant species and ecosystem function
in some forest and grassland ecosystems
27. • Currently, much research is devoted to
understanding the effects of nitrogen enrichment
in the air, groundwater, and surface water.
Scientists are also exploring alternative
agricultural practices that will sustain high
productivity while decreasing the negative
impacts caused by fertilizer use. These studies
not only help us quantify how humans have
altered the natural world, but increase our
understanding of the processes involved in the
nitrogen cycle as a whole.
32. • In 1958, atmospheric carbon dioxide at
Mauna Loa was about 320 parts per million
(ppm), and in 2010 it is about 385ppm.[3]
• Future CO2 emission can be calculated by the
kaya identity
33.
34.
35.
36. • The environmental sulphur cycle involves many physical, chemical
and biological agents.
• As such, the figure indicates the relationships between sulphur, S,
hydrogen sulphide, H2S, sulphur dioxide, SO2, and the sulphate ion,
SO4--. In mineral form sulphur may be present as sulphides (e.g.
pyrite, FeS2, chalcopyrite, FeS.CuS, pyrrhotite, FeS) and/or sulphates
(e.g. gypsum, CaSO4.2H2O, barite, BaSO4). Sulphur in minerals may
move through the cycle as a result of the oxidation of sulphides to
sulphate and/or the dissolution of sulphates. For example,
oxidation of pyrite to sulphuric acid may be immediately followed,
in situ, by acid neutralization by calcium carbonate (calcite) to form
calcium sulphate (gypsum). The reaction of hydrogen sulphide with
dissolved metal ions may precipitate metallic sulphides which are
chemically indistinguishable from naturally occurring sulphide
minerals.
37. • At some mines, sulphur is added to the cycle as
sulphur dioxide in processes such as the Inco/SO2
process for cyanide destruction in the treatment
of tailings. This added sulphur is oxidized to
sulphate ion (Ingles & Scott, 1987), most of which
remains free, but some of which combines with
lime, CaO, in the tailings to form gypsum.
• For information on the sulphur cycle with respect
to water quality monitoring see Canadian Council
of Environment Ministers (1987).
38. • The Role of Micro-organisms in the Sulphur Cycle
• Micro-organisms (most frequently bacteria) are often
integrally involved in the chemical alteration of minerals.
Minerals, or intermediate products of their decomposition,
may be directly or indirectly necessary to their metabolism.
The dissolution of sulphide minerals under acidic conditions
(ARD), the precipitation of minerals under anaerobic
conditions, the adsorption of metals by bacteria or algae,
and the formation and destruction of organometallic
complexes are all examples of indirect micro-organism
participation. Where minerals are available as soluble trace
elements, serve as specific oxidizing substrates, or are
electron donors/acceptors in oxidation-reduction reactions,
they may be directly involved in cell metabolic activity.
39. • There are three categories of oxidation-reduction reactions for minerals with micro-organisms:
• Oxidation by autotrophic (cell carbon from carbon dioxide) or mixotrophic (cell carbon from carbon
dioxide or organic matter) organisms. Energy derived from the oxidation reaction is utilized in cell
synthesis.
• Electron acceptance by minerals (reduction) for heterotrophic (cell carbon from organic matter)
and mixotrophic bacteria. Chemical energy is used to create new cell material from an organic
substrate.
• Electron donation by minerals (oxidation) for bacterial or algal photosynthesis (reaction is fuelled
by photon energy).
• Natural Oxidation in the Sulphur Cycle
• Oxidation of sulphur or sulphides for energy production is restricted to the bacterial genus
Thiobacillus, the genus Thiomicrospira, and the genus Sulfolobus. These bacteria all produce
sulphuric acid (i.e. hydrogen ions, H+, and sulphate ions, SO4-- ) as a metabolic product. Extensive
reviews of these bacteria and their behaviour have been written by Brierley (1978) and Trudinger
(1971).
• It is these bacteria that are known to accelerate the generation of Acid Rock Drainage (ARD) from
pyritic and pyrrhotitic rocks under suitable conditions. Evangelou & Zhang (1995) report that
sulphide oxidation catalysed by bacteria may have reaction rates six orders of magnitude (i.e.
1,000,000 times) greater than the same reactions in the absence of bacteria. Photomicrographs 1, 2
and 3, from LeRoux, North & Wilson (1973), illustrate the shape and appearance of T. ferrooxidans:
The bacteria develop flagella only if they are required for mobility in accessing energy sources.
• http://technology.infomine.com/enviromine/ard/microorganisms/roleof.htm
41. Almost all living things need oxygen. They use this oxygen during
the process of creating energy in living cells.
42.
43.
44. The flow of sulphur compounds in our environment.
Scheme: Elmar Uherek, adapted and modified from an water cycle
illustration of the Center for Space Research, Univ. of Austin, Texas
Please click the picture for a larger view! (150 K)
45. • We find many sulphur compounds on Earth.
• These include sulphur dioxide, elemental sulphur, sulphuric acid, salts of
sulphate or organic sulphur compounds such as dimethylsulphide and
even amino acids in our body.
• All these chemical compounds do not last forever. They are transported by
physical processes like wind or erosion by water, by geological events like
volcano eruptions or by biological activity.
• They are also transformed by chemical reactions. But nothing is lost.
Changes often take place in cycles. Such cycles can be chemical cycles in
which a sulphur compound A reacts to form B, B to C, C to D and D to A
again.
• At the same time there are spatial / geographical cycles. One example is
when sulphur compounds move from the ocean to the atmosphere, are
transported to the land, come down with the rain and are transported by
rivers to the ocean again.
•
46. • Oxidation and reduction
• In chemical cycles, sulphur is usually oxidised in the air
from organic sulphur or elemental sulphur to sulphur
oxides like SO2 and SO3 ending up as sulphate in
sulphate salts M(II)SO4, M(I)2SO4 or sulphuric acid
H2SO4. The sulphate compounds dissolve very well in
water and come down again with the rain, either as
salts or as acid rain.
• In chemical cycles oxidized compounds must also be
reduced again. This process does not take place in the
atmosphere but on the ground and in the oceans and is
carried out in complicated chemical reactions by
bacteria. The most important products are elemental
sulphur, hydrogen sulphide (H2S), which smells awful
and is very unhealthy, and organic sulphur compounds.
47.
48. • Sulphur compounds play a big role for our
environment and the climate system. On the one
hand they contribute to acid rain.
• But they are also important for the formation of
clouds. Finally, a lot of sulphur is brought into the
air by volcanic eruptions.
• If it was a strong eruption, the emitted particles
can go up to the stratosphere (9 - 12 km of
altitude) and cool down half our planet by 1-2°C.
http://www.atmosphere.mpg.de/enid/Nr_6_Feb
__2__6_acid_rain/C__The_sulphur_cycle_5i9.ht
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