Soil carbon flux research!

21/11/2018
Measuring soil carbon flux gives an insight into the health of forest ecosystems and provides feedback on the effects of global warming. This article, from Edinburgh Instruments, outlines how soil CO2 efflux is determined and the applications of soil carbon flux research.

Soil is an important part of the Earth’s carbon cycle.
Pic: pixabay.com/Picography

The Earth’s carbon cycle maintains a steady balance of carbon in the atmosphere that supports plant and animal life. In recent years, concerns about the increasing levels of CO2 in the atmosphere, indicating a problem in Earth’s carbon cycle, has been a prominent global issue.1,2

As a part of a stable carbon cycle, carbon is exchanged between carbon pools including the atmosphere, the ocean, the land and living things in a process known as carbon flux. Carbon exchange typically takes place as a result of a variety of natural processes including respiration, photosynthesis, and decomposition.

Since the industrial age, humans have begun to contribute to carbon exchange with activities such as fuel burning, and chemical processes, which are believed to be responsible for increasing atmospheric CO2 concentrations and increasing global temperatures.1-3

Soil carbon flux provides feedback on environmental conditions
Soil is a vital aspect of the Earth’s carbon cycle, containing almost three times more carbon than the Earth’s atmosphere. Carbon is present in soil as ‘solid organic carbon’ including decomposing plant and animal matter. Over time, microbial decomposition of the organic components of soil releases carbon into the atmosphere as CO2.4,5

The amount of carbon present in soil affects soil fertility, plant growth, microbial activity, and water quality. Studying the carbon flux of soil gives an insight into an ecosystem as a whole and specific information about microbial activity and plant growth.4-6

Soil carbon flux can also help us to understand and predict the effects of global warming. As global temperatures increase, is it expected that microbial activity will also increase, resulting in faster plant decomposition and increased CO2 efflux into the atmosphere.5,6

Measuring soil CO2 efflux
Determining soil-surface CO2 efflux can be challenging. Researchers commonly employ a chamber combined with CO2 concentration measurements to determine CO2 efflux. A variety of chambers have been designed for such research, some of which are commercially available.7-10

Closed-chamber systems typically pump air through a gas analyzer, which measures CO2 concentration, before returning the air to the chamber. Soil CO2 efflux is then estimated from the rate of increase of CO2 concentration in the chamber.

Open-chambers pump ambient air into the chamber and measure the change in CO2concentration between the air entering the chamber and the air leaving the chamber to determine the soil CO2 efflux.

Of the two chamber types, open chambers are considered more accurate. Closed chambers tend to underestimate CO2 efflux as increased CO2 concentrations in the chamber cause less CO2 to diffuse out of the soil while the chamber is in place.10,11.

Often, CO2 concentrations in chambers are measured periodically and then extrapolated to give an estimation of CO2 efflux. This method can be inaccurate because CO2 efflux can vary significantly between measurements with changes in environmental conditions.

A further limitation of using chambers for CO2 efflux measurements is that chambers typically only provide measurements in one location, while CO2 efflux has been found to vary widely even in relatively homogeneous environments. The overall result is CO2 efflux data with limited temporal and spatial resolution, that does not reflect the environmental situation as a whole.10,12,13

Naishen Liang

A group of researchers from the National Institute for Environmental Studies (Japan) led by Naishen Liang has designed an automated, multi-chamber chamber system for measuring soil-surface CO2 efflux.

As CO2 concentrations are measured automatically using an infrared gas sensor, COefflux can be determined accurately throughout the experiment. The improved temporal resolution, combined with increased spatial detail resulting from the use of multiple chambers gives a better overview of how CO2 efflux varies with time, location, and environmental conditions within an ecosystem.10

Liang and his team have applied his method to gather information about a range of forest ecosystems. Their automated chambers have been used in a variety of forest locations combined with heat lamps to provide high-resolution, long-term data about the effects of warming on microbial activity and CO2 efflux.

Liang’s research has shown that soil temperatures have a significant effect on COefflux in a wide range of forest environments, information that is vital for understanding how global warming will affect forest ecosystems and the Earth’s carbon cycle as a whole.14-17

All chamber systems for determining CO2 efflux rely on accurate CO2 concentration analysis. Infrared gas analyzers are the most widely used method of instrumentation for determining CO2 concentrations in soil CO2 efflux measurement chambers.8,10,18

Infrared gas sensors, such as gascard sensors from Edinburgh Sensors, are well suited to providing CO2 concentration measurements in soil chambers, and are the sensors of choice used by Liang and his team.

The gascard sensors are robust, low-maintenance, and easy to use compared with other sensors. They provide rapid easy-to-interpret results and can be supplied as either complete boxed sensors (the Boxed Gascard) or as individual sensors (the Gascard NG) for easy integration into automated chambers.19,20


Notes, References and further reading
1. ‘The Carbon Cycle’
2. ‘Global Carbon Cycle and Climate Change’ — Kondratyev KY, Krapivin VF, Varotsos CA, Springer Science & Business Media, 2003.
3. ‘Land Use and the Carbon Cycle: Advances in Integrated Science, Management, and Policy’ — Brown DG, Robinson DT, French NHF, Reed BC, Cambridge University Press, 2013.
4. ‘Soil organic matter and soil function – Review of the literature and underlying data’ — Murphy BW, Department of Environment and Energy, 2014
5. ‘The whole-soil carbon flux in response to warming’ — Hicks Pries CE, Castanha C, Porras RC, Torn MS, Science, 2017.
6. ‘Temperature-associated increases in the global soil respiration record’ — Bond-Lamberty B, Thomson A, Nature, 2010.
7. ‘Measuring Emissions from Soil and Water’ — Matson PA, Harriss RC, Blackwell Scientific Publications, 1995.
8. ‘Minimize artifacts and biases in chamber-based measurements of soil respiration’ — Davidson EA, Savage K, Verchot LV, Navarro R, Agricultural and Forest Meteorology, 2002.
9. ‘Methods of Soil Analysis: Part 1. Physical Methods, 3rd Edition’ — Dane JH, Topp GC, Soil Science Society of America, 2002.
10. ‘A multichannel automated chamber system for continuous measurement of forest soil CO2 efflux’ — Liang N, Inoue G, Fujinuma Y, Tree Physiology, 2003.
11. ‘A comparion of six methods for measuring soil-surface carbon dioxide fluxes’ — Norman JM, Kucharik CJ, Gower ST, Baldocchi DD, Grill PM, Rayment M, Savage K, Striegl RG, Journal of Geophysical Research, 1997.
12. ‘An automated chamber system for measuring soil respiration’ — McGinn SM, Akinremi OO, McLean HDJ, Ellert B, Canadian Journal of Soil Science, 1998.
13. ‘Temporal and spatial variation of soil CO2 efflux in a Canadian boreal forest’ — Rayment MB, Jarvis PG, Soil Biology & Biochemistry, 2000.
14. ‘High-resolution data on the impact of warming on soil CO2 efflux from an Asian monsoon forest’ — Liang N, Teramoto M, Takagi M, Zeng J, Scientific Data, 2017.
15. ‘Long‐Term Stimulatory Warming Effect on Soil Heterotrophic Respiration in a Cool‐Temperate Broad‐Leaved Deciduous Forest in Northern Japan’ —Teramoto M, Liang N, Ishida S, Zeng J, Journal of Geophysical Research: Biogeoscience, 2018.
16. ‘Sustained large stimulation of soil heterotrophic respiration rate and its temperature sensitivity by soil warming in a cool-temperate forested peatland’ — Aguilos M, Takagi K, Liang N, Watanabe Y, Teramoto M, Goto S, Takahashi Y, Mukai H, Sasa K, Tellus Series B : Chemical and Physical Meteorology, 2013.
17. ‘Liang Automatic Chamber (LAC) Network
18. ‘Interpreting, measuring, and modeling soil respiration’ — Ryan MG, Law BE, Biogeochemistry, 2005.
19. ‘Boxed Gascard’
20. ‘Gascard NG’

@edinsensors #Environment #NIESJp

Why monitor dust?

17/04/2018
Josh Thomas of Ashtead Technology discusses the reasons for monitoring dust in the workplace.

Almost any place of employment can present a potential threat to health and safety from airborne particulates and aerosols. It is important to note, however, that dust hazards are not necessarily visible to the human eye and that the finest particles can represent the greatest threat because of their ability to travel deepest into the lungs. Effective monitoring is therefore key to the implementation of an effective risk management strategy.

There are two major reasons for monitoring dust in the workplace; to enable air quality management, and for regulatory compliance. The immediate effects of dust can be irritation to eyes, headaches, fatigue, coughing and sneezing. As such, poor indoor air quality can lower employee performance and cause increased absenteeism through sickness. In addition, particulates are known to create long-term deleterious effects, contributing to serious illnesses. In combination with outdoor exposure (to pollution form vehicles for example), the Government has estimated that 29,000 premature deaths occur in the UK every year as a result of particle pollution. This means that, particularly in urban areas, natural ventilation may not necessarily improve indoor air quality.

Dust-TrakEmployers are responsible for ensuring that staff and visitors are not exposed to poor air quality in the workplace, so it is necessary to conduct monitoring. Accurate and effective monitoring data can be used to check exposure levels and to help identify safe working practices.

Monitoring also helps to demonstrate compliance with relevant regulations. COSHH is the law that requires employers to control substances that are hazardous to health. According to the Health & Safety Executive (HSE), employers can prevent or reduce workers’ exposure to hazardous substances by finding out what the health hazards are; by deciding how to prevent harm to health; by providing effective control measures; by providing information and training; by providing monitoring and health surveillance, and by planning for emergencies.

In order to evaluate workplace safety, monitoring data is compared with Workplace Exposure levels (WELs) which prescribe the maximum exposure level to a hazardous substance over a set period of time. Failure to comply with COSHH and WELs can result in financial penalties, prosecutions and civil claims.

Indoor air quality is affected by both internal and external factors. Air pollution may arise from external sources such as neighbouring factories, building and development activities, or from vehicles – especially those with diesel engines. Internally, air quality is affected by working practices and business processes. For example, dust may arise from raw materials such as powders, or it may be produced by processes that generate particulates; including dust, mist, aerosols and smoke. In all cases, internal and external, it is important to identify both the source and the seriousness of the problem, so that appropriate and effective mitigation measures can be implemented. These might include, for example, ventilation, process dust prevention, the management of shift patterns, personal protection equipment (PPE) and alarm systems.

Regulatory requirements to monitor
Under the British Workplace (Health Safety and Welfare) Regulations 1992, employers have a legal duty to ensure, so far as is reasonably practicable, the health, safety and welfare of employees. Furthermore, the Management of Health and Safety at Work Regulations 1999 (GB) require employers to assess and control risks to protect their employees. A key element of this is the requirement to comply with the COSHH Regulations. The HSE says that exposure measurement is required:

  • For COSHH assessment, to help select the right controls
  • Where there is a serious risk to health from inhalation
  • To check that exposure limits are not exceeded
  • To check the performance of exposure controls
  • To help select the right respiratory protection equipment
  • To check exposure following a change in a process
  • To show any need for health surveillance; or
  • When an inspector issues an ‘Improvement Notice’ requiring monitoring

The COSSH Regulations include dust, mist, vapour, fumes and chemicals, but they do not cover Lead or Asbestos. Specific requirements exist for certain industries such as construction. Generally, WELs relate to particulate diameter because the health effects of particulates are heavily influenced by their size.

Inhalable dust is that which enters the nose or mouth during breathing and is available for deposition in the respiratory tract. It includes particles with a width between 2.5 and 10 microns (PM2.5 – PM10), and the WEL for this fraction is 10 mg/m3 as an 8-hour Time Weighted Average (TWA).

Respirable dust is the fraction that penetrates deep into the gas exchange region of the lungs. It includes particles with a width between 1 and 2.5 microns (PM1– PM2.5), and the WEL for this fraction is 4 mg/m3 as an 8-hour TWA. Lower specific WELs exist for particulates that present a greater threat to health. For example, Silica dusts have a WEL of just 0.1 mg/m3 respirable dust as an 8-hour TWA.

The costs of non-compliance
In addition to the enormous numbers of premature deaths that result from exposure to outdoor air pollution, there are also numerous well-documented instances demonstrating the harm caused by exposure to indoor pollution from dust, smoke, aerosols and vapour. For example, a 46-year-old cook developed breathing problems after working with flour in a school kitchen with poor ventilation. Her breathing problems became so severe that she could hardly walk and had to sleep sitting up. She became severely asthmatic and had to retire early on health grounds. With the support of her Union she made a compensation claim on the basis that decent working conditions were not provided, and the council admitted that it had not taken sufficient action despite repeated complaints. Consequently, the courts awarded the cook £200,000 (€230k) in damages.

In another example, between 1995 and 2004, a solderer was exposed to rosin based solder fumes and suffered health deterioration and breathing problems including asthma. An investigation conducted by the HSE found that the company did not have adequate control measures in place and failed to install fume extraction equipment. Furthermore, the company did not employ rosin-free solder until December 2003, despite an assessment having identified the need in 1999. The company was subsequently fined £100,000 (€116k) with £30,000 (€35k) costs, a punishment which attracted both local and national media attention.

Monitoring dust
A wide variety of methods exist for the measurement of dust, and the choice of equipment is dictated by the application. For example, it is obviously important to employ a technology that is able to measure the particulates that will be present. In addition, it will be necessary to determine whether monitoring should be continuous, at a single point, or whether portable instruments are necessary to check multiple locations. Monitoring might be conducted in a work space, or personal sampling might be undertaken in order to assess the exposure of an individual over an entire shift.

Personal Sampling Pumps represent the preferred method for workplace exposure monitoring where it is necessary to demonstrate regulatory compliance or where legal dispute is a possibility. An HSE document (MDHS 14/4) provides workplace exposure monitoring guidance for collecting respirable, thoracic and inhalable aerosol fractions. The samples collected by this process are analysed in a laboratory, which means that chemical analysis is also possible. However, the sampling method incurs a delay and incurs extra cost.

In response to the wide variety of applications and monitoring requirements, Ashtead Technology stocks a comprehensive range of monitors for both sale and rental, providing customers with complete financial and technical flexibility. As a TSI Gold Partner, Ashtead Technology provides a comprehensive range of maintenance and calibration services; helping customers to ensure that their monitoring equipment remains in optimal condition. Ashtead’s fleet of rental equipment includes large numbers of the latest TSI instruments, supported by the highest levels of service and technical assistance. Employing advanced light-scattering laser photometers, the TSI products are supplied with a calibration certificate and provide real-time, direct-reading aerosol monitoring and analysis of different particulate fractions in workplace, cleanroom, HVAC, fugitive emissions and environmental monitoring applications.

The TSI range of dust monitors is continually being developed to bring new levels of functionality to the market. For example, the new lightweight AM520 Personal Dust Monitor is able to measure and log PM10, Respirable (PM4), PM5 (China Respirable), PM2.5, PM1 or 0.8μm Diesel Particulate Matter (DPM), providing real-time audible and visual alarms, and running from a rechargeable battery for up to 20 hours. For outdoor applications, the MCERTS approved Environmental DustTrak is web-enabled, providing a quick and easy dust monitoring solution for applications such as building and development projects.

@ashteadtech #PAuto @TSIIncorporated

Ensuring pure air in Scottish towns.

15/01/2018

In North Ayrshire, Scotland, monitoring activities have demonstrated that the main local air quality issues are related to traffic congestion caused by a section of the High Street in Irvine, which is being used as a bus terminus, and by queuing traffic at New Street in Dalry. In both locations the pollutant of most concern is Nitrogen Dioxide.

Sensor on street in Irvine.

North Ayrshire Council operates a fixed continuous air quality monitoring station (AQMS) in Irvine High Street which supplies data to Scottish Air Quality website.

“Data from the AQMS is supplemented by portable monitoring equipment that is installed at key locations,” reports the Council’s Willie McNish. “Passive diffusion tubes provide approximate monthly average data, but over the last 2-3 years we have started using AQMesh air quality monitors. Three ‘pods’ have been installed in pollution hotspots and a further AQMesh pod is used as a mobile device; installed temporarily in key locations to assist with air quality strategy development, and planning and development control.”

AQMesh air quality monitoring pods, from Air Monitors, are small, lightweight, wireless, battery or solar -powered air quality monitors that are quick and easy to install. They are able to monitor the main pollutants simultaneously, delivering accurate cloud-based data wirelessly via the internet. “We use the AQMesh pods for air quality screening,” reports Willie McNish, one of the Council’s Officers responsible for air quality monitoring. “The beauty of these monitors is that they provide almost real-time data that we can access via PC. This is really useful for detecting and predicting trends. For example, I can look at the current air quality measured by a pod and then look at the Met Office website for information on wind speed and direction, and this helps us to better understand the factors that affect air quality.”

The ease and speed with which AQMesh pods can be installed in almost any location is a major advantage in air quality investigations related to planning applications. For example, Willie says: “Concerns about dust and fumes from trucks were raised in connection with an application to extend the life of a landfill site by ten years (as less waste is being landfilled more time was required to fill it), but by locating an AQMesh pod (measuring gases and particulates) in an appropriate location, we were able to support the planning decision by demonstrating that air quality would not be harmed by the extension.”

Monitoring is also informing the development of traffic management strategies to reduce exposure to air pollution. In Irvine, Willie says: “The prevailing wind direction is from the South West, which creates a canyon effect, whereby air pollution accumulates within streets that are confined by buildings on both sides. This effect is exacerbated by queuing double-decker buses, so we plan to undertake remedial measures and monitor their effects.”

As a consequence of the elevated levels of Nitrogen Dioxide in Irvine, the Council will undertake public realm works (streetscape improvements) to widen the pavement, and one of the bus stops will be relocated. This will not only move the source of pollution away from the receptor, but also allow better dilution and dispersion of pollutants, without affecting the frequency of service or convenient access to public transport. In Dalry, a new bypass is due to be constructed and it is anticipated that this will lower Nitrogen Dioxide levels. In both locations, modelling has indicated that air quality will improve, but existing monitoring data will be compared with data once the work is complete, so that an effective evaluation of the effects on air quality can be performed.

Summarising the advantages of the Council’s air quality monitoring strategy, Willie says: “The AQMS in Irvine employs standard reference methods or equivalent, to measure air quality, so it is able to provide definitive data for comparison with EU limits. The station is serviced and maintained by Air Monitors and delivers extremely high levels of data capture. Since 2015 it has also included a FIDAS 200 particulate monitor, so we are now able to monitor TSP, PM10, PM4, PM2.5, PM1 and Particle Number simultaneously, which provides greater insight into the types of pollution and their likely sources.

“To complement the AQMS we also operate 4 AQMesh pods which provide the flexibility we need to monitor air quality in precisely the location of greatest importance. Web connectivity combined with Air Monitors’ reliability of service provides us with continuous access to accurate air quality data, which means that we are able to fulfil our statutory obligations as a Council, and also find ways to protect the health of people in North Ayrshire.”

@airmonitors #Pauto @scotairquality @_Enviro_News #Environment

Train derailment prompts contaminated land investigation.

11/01/2018

A train derailment in Mississippi resulted in ground contamination by large quantities of hazardous chemicals, and environmental investigators have deployed sophisticated on-site analytical technology to determine the extent of the problem and to help formulate an effective remediation strategy. Here Jim Cornish from Gasmet Technologies discusses this investigation.

Jim Cornish

On March 30th 2015 a long freight train, transporting a variety of goods including lumber and chemicals, wound its way through the state of Mississippi (USA). At around 5pm, part of the train failed to negotiate a curved portion of the track in a rural area near Minter City, resulting in the derailment of nine railcars, one of which leaked chemicals onto agricultural farmland and woodlands. Emergency response and initial remediation activities were undertaken, but the remainder of this article will describe an environmental investigation that was subsequently conducted by Hazclean Environmental Consultants using a portable multiparameter FTIR gas analyzer from Gasmet Technologies.

Background
Over 17,000 gallons of Resin Oil Heavies were released from the railcar, and the main constituent of this material is dicyclopentadiene (DCPD). However, in addition to DCPD, Resin Oil Heavies also contains a cocktail of other hydrocarbons including ethylbenzene, indene, naphthalene, alpha-methyl styrene, styrene, vinyl toluene, 1, 2, 3-trimenthylbenzene, 1, 2, 4-trimethylbenzene, 1, 3, 5-trimethylbenzene and xylenes.

DCPD is highly flammable and harmful if swallowed and by inhalation. Its camphor-like odor may induce headaches and symptoms of nausea, and as a liquid or vapor, DCPD can be irritating to the eyes, skin, nose, throat or respiratory system. DCPD is not listed as a carcinogen, however DCPD products may contain benzene, which is listed as a human carcinogen. DCPD is not inherently biodegradable, and is toxic to aquatic organisms with the potential to bioaccumulate.

It is a colorless, waxy, flammable solid or liquid, used in many products, ranging from high quality optical lenses through to flame retardants for plastics and hot melt adhesives. As a chemical intermediate it is used in insecticides, as a hardener and dryer in linseed and soybean oil, and in the production of elastomers, metallocenes, resins, varnishes, and paints. DCPD-containing products are also used in the production of hydrocarbon resins and unsaturated polyester resins.

Emergency Response
Emergency response phase activities were performed from March 31 through May 2, 2015. Response objectives and goals were formally documented by utilizing Incident Action Plans for each operational period. Activities between April 11 and April 28, 2015 were summarized in weekly reports and submitted to the Mississippi Department of Environmental Quality (MDEQ) and the Environmental Protection Agency (EPA).

Approximately 10,189 gallons of the leaked product was recovered, leaving 5,458 gallons to contaminate the farmland surface and subsurface soil, surface waters, groundwater and ambient air. The site contamination problem was exacerbated due to heavy rainfall and associated stormwater runoff which caused the unrecovered product to migrate from the spill site.

Taking account of the high rainfalls levels that followed the event, it was calculated that contaminated stormwater runoff from the immediate project site (10 acres with 8.7 inches of rainfall) was 2,362,485 gallons less that retained by emergency retention berms. Approximately 207,000 gallons of contaminated stormwater were collected during the emergency response, in addition to approximately 7,870 tons of impacted material which were excavated for disposal. Following removal of the gross impacted material, the site was transferred into Operation and Maintenance status, conducted in accordance with a plan approved by MDEQ.

Ongoing site contamination
Groundwater and soil samples were collected and analyzed in 2015 and 2016, producing analytical data which confirmed that widespread soil and groundwater contamination still existed at the site. Further remediation was undertaken, but the landowners were extremely concerned about the fate of residual chemicals and contracted Hazclean Environmental Consultants to conduct a further investigation.

“The affected land is used for agricultural purposes, producing crops such as soybeans and corn,” says Hazclean President, E. Corbin McGriff, Ph.D., P.E. “Consequently, there were fears that agricultural productivity would be adversely affected and that chemicals of concern might enter the food chain.
“This situation was exacerbated by the fact that the landowners could still smell the contamination and initial investigation with PID gas detectors indicated the presence of volatile organic compounds (VOCs).”

Hazclean’s Joseph Drapala, CIH, managed and conducted much of the site investigation work. He says: “While PID gas detectors are useful indicators of organic gases, they do not offer the opportunity to quantify or speciate different compounds, so we spoke with Jeremy Sheppard, the local representative of Gasmet Technologies, a manufacturer of portable FTIR (Fourier Transform Infrared) gas analyzers.

Soil Vapor Analysis with FTIR

“Jeremy explained the capabilities of a portable, battery-powered version of the Gasmet FTIR gas analyzer, the DX4040, which is able to analyze up to 25 gases simultaneously, producing both qualitative and quantitative measurements. Gasmet was therefore contacted to determine whether this instrument would be suitable for the Mississippi train spill application.

“In response, Gasmet confirmed that the DX4040 would be capable of measuring the target species and offered to create a specific calibration so that these compounds could be analyzed simultaneously on-site.”

Site investigation with FTIR analysis
A sampling zone was defined to capture potential contamination, and measurements were taken for surface and subsurface soil, groundwater, and surface and subsurface air for a range of VOCs.

Vapor Well

The area-wide plan resulted in the installation of four permanent monitoring wells for groundwater sampling, twenty vapor monitoring wells, and twenty test borings for field screening. The test borings indicated the presence of VOCs which were further characterized by sampling specific soil sections extracted from the parent core.

In addition to the almost instantaneous, simultaneous measurement of the target compounds, the Gasmet DX4040 stores sample spectra, so that post-measurement analyses can be undertaken on a PC running Gasmet’s Calcmet™ Pro software, providing analytical capability from a library of 250 compounds. “The Gasmet DX4040 was manufacturer-calibrated for dicyclopentadiene, benzene, ethylbenzene, naphthalene, styrene, toluene, 1,2,3-trimenthylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene and m, o, and p and total xylenes at a detection range of 0.01 ppm to 100 ppm in air,” Joseph reports, adding: “The ability to compare recorded spectra with the Calcmet Pro library is a major advantage because it enables the measurement of unknown compounds.”

The operating procedures for the DX4040 indicate a simple, convenient requirement for daily calibration with zero gas prior to each monitoring activity. However, in addition to the use of nitrogen as the zero gas, Joseph also employed specialty gas (DCPD) certified for 1 ppm and 5 ppm as a calibration check and a response (akin to bump testing) gas.

Site screening
The test borings provided soil samples that were vapor-tested on-site as part of the screening process. Vapor from the extracted soil samples was analyzed by placing the soil samples in vessels at ambient temperature and connecting the DX4040 in a closed loop from the vessel, so that air samples could be continually pumped from the vessel to the analyzer and returned to the vessel. This screening activity helped to determine the location for vapor wells.

All soil samples were screened with the DX4040 and those with the highest reading from each boring were sent for laboratory analysis.

Vapor wells were fitted with slotted PVC liners and capped. Before monitoring, the cap was replaced with a cap containing two ports to enable the DX4040 to be connected in a similar closed-loop monitoring system to that which was employed for the soil samples.

Conclusions
As a result of this investigation it was possible for Hazclean to determine that the release of DCPD in the vapor state, as measured in the vapor monitor wells, is a result of surface and subsurface contamination in the soil and groundwater, and that this contamination will remain in the future.

Vapor analysis data provided by the DX4040 identified DCPD, benzene, styrene and xylene previously adsorbed on soil and/or wetted surfaces undergoing diffusion and evaporation. The adsorption, diffusion and evaporation of DCPD et al. released and spread across the farmland is a mechanism to explain the vapor concentrations found in vapor monitor wells as well as the ambient malodor problem.

The long term release of DCPD and other VOCs will continue to occur in the impact area unless a larger remediation project is conducted to remove soil and groundwater contamination. Furthermore, Hazclean recommends that, as a result of the effectiveness of the Gasmet DX4040 in this investigation, the same technology should be employed in any subsequent screening activities, using the same Gasmet calibration configuration.

Summarizing, Joseph Drapala says: “The Gasmet DX4040 was an essential tool in this investigation. Screening activities should have the ability to detect and identify the target compounds, as well as any secondary compounds that may have already been present on-site or could have been produced as a result of chemical interactions.
“As an FTIR gas analyzer, the DX4040 meets these requirements, providing enormous analytical capability through Gasmet’s Calcmet software. However, the instrument is also small, lightweight and battery powered which makes it ideal for field investigations.”


Towards a liveable Earth!

08/08/2017

Addressing global issues through co-innovation to create new value!

Yokogawa has developed sustainability goals for the year 2050 that will guide its efforts to make the world a better place for future generations.

Yokogawa’s efforts to achieve a sustainable society are in keeping with the Paris Agreement, which was adopted in 2015 by the 21st Framework Convention on Climate Change (COP21) to provide a basis for global efforts to tackle issues related to climate change. The agreement calls for the achievement of net-zero greenhouse gas emissions by the second half of this century. Also in 2015, the UN adopted the 2030 Agenda for Sustainable Development centering on the Sustainable Development Goals (SDGs). Through these initiatives, a global consensus is developing on how to address these issues, and the direction that companies should take is becoming clear.

Yokogawa’s efforts to achieve sustainability and build a brighter future for all are based on the company’s corporate philosophy, which states: “As a company, our goal is to contribute to society through broad-ranging activities in the areas of measurement, control, and information. Individually, we aim to combine good citizenship with the courage to innovate.” To ensure a flexible response to environmental and technology changes and guide its long-term efforts to address social issues, Yokogawa is committing itself to the achievement of goals that are based on a vision of where our society should be by the year 2050. Through the selection of products and solutions and the formulation of medium-term business plans and the like that are based on environmental, economic, and societal considerations, Yokogawa will carry out the detailed tasks needed to achieve these goals.

Commenting on this initiative, Takashi Nishijima, Yokogawa President and CEO, says: “Companies have a growing responsibility to respond to issues such as population growth and the rising use of fossil fuels that are addressed in the Paris Agreement and the SDGs. Yokogawa provides solutions that improve the stability, efficiency, and safety of operations at industrial plants and other infrastructure facilities by, for example, speeding up processes, reducing workloads, and saving energy. Yokogawa needs to work harder to broaden its solutions so that it can address other issues that impact our society. Yokogawa will establish key performance indicators (KPIs) to evaluate on a medium-term basis the achievement of its sustainability goals, and will continue to create new value through co-innovation with its stakeholders.”


Statement on Yokogawa’s aspiration for sustainability
Yokogawa will work , to achieve net-zero emissions, to make a transition to a circular economy, and ensure the well-being of all by 2050,  thus making the world a better place for future generations.

We will undergo the necessary transformation to achieve these goals by 1. becoming more adaptable and resilient, 2. evolving our businesses to engage in regenerative value creation, and 3. promoting co-innovation with our stakeholders.

Achieve net-zero emissions; stopping climate change
Climate change is an urgent issue that requires a global response. We aim for net-zero emissions, which means that the greenhouse gas concentrations in the atmosphere do not rise due to the balance of emissions and the absorption of greenhouse gases, which can be accomplished through the introduction of renewable energy and efficient use of energy. We are also working to reduce the impact of natural disasters and respond to biodiversity issues.

Make the transition to a circular economy; circulation of resources and efficiency
The transformation from a one-way economy based on the take, make, and dispose model to an economy where resources are circulated without waste, and the transition to businesses that emphasize services, is under way. We aim to realize a social framework and ecosystem in which various resources are circulated without waste and assets are utilized effectively. We are also contributing to the efficient use of water resources and the supply of safe drinking water.

Ensure well-being; quality life for all
With the aim of achieving the physical, mental, and social well-being described in the 2030 Agenda for Sustainable Development adopted by the United Nations in 2015, we support people’s health and prosperity through the achievement of safe and comfortable workplaces and our pursuits in such areas as the life sciences and drug discovery. We promote human resource development and employment creation in local communities, alongside diversity and inclusion.

 

@YokogawaIA #PAuto @UNFCCC

The ‘ins and outs’ of air quality monitoring!

20/02/2017
The British National Institute for Health and Care Excellence (NICE) recently issued draft guidance on ‘Air pollution – outdoor air quality and health.’ 

Here, Jim Mills, Managing Director of Air Monitors Ltd, explains why there will need to be more funding for monitoring if the mitigation measures mentioned in the guidance are to be implemented effectively. Jim also highlights the close relationship between outdoor air quality and the (often ignored) problems with indoor air quality.

The NICE guidelines are being developed for Local Authority staff working in: transport, planning, air quality management and public health. The guidance is also relevant for staff in healthcare, employers, education professionals and the general public.

Covering road-traffic-related air pollution and its links to ill health, the guidelines aim to improve air quality and so prevent a range of health conditions and deaths. Unfortunately, on the day that the draft guideline was published, most of the national media focused on one relatively minor recommendation relating to speed bumps. ‘Where physical measures are needed to reduce speed, such as humps and bumps, ensure they are designed to minimise sharp decelerations and consequent accelerations.’ Measures to encourage ‘smooth driving’ are outlined; however, the guidelines also address a wide range of other issues, which, in combination, would help tackle urban air pollution.

Public sector transport services should implement measures to reduce emissions, but this is an area that could involve the greatest financial cost.

Many local authorities would doubtless comment that they are already implementing many of the guideline recommendations, but refer to budgetary constraints on issues that involve upfront costs. This issue was raised on BBC Radio 4 when the issue was discussed on 1st December.

AQMesh Pod

AQMesh Pod

The NICE guidelines recommend the inclusion of air quality issues in new developments to ensure that facilities such as schools, nurseries and retirement homes are located in areas where pollution levels will be low. LAs are also urged to consider ways to mitigate road-traffic-related air pollution and consider using the Community Infrastructure Levy for air quality monitoring. There are also calls for information on air quality to be made more readily available.

LAs are also being urged to consider introducing clean air zones including progressive targets to reduce pollutant levels below the EU limits, and where traffic congestion contributes to poor air quality, consideration should be given to a congestion charging zone. The guidelines also highlight the importance of monitoring to measure the effects of these initiatives.

As part of the consultation process, NICE is looking for evidence of successful measures and specifically rules out “studies which rely exclusively on modelling.”

In summary, all of the initiatives referred to in the NICE report necessitate monitoring in order to be able to measure their effectiveness. However, most LAs do not currently possess the monitoring capability to do so. This is because localised monitoring would be necessary before and after the implementation of any initiative. Such monitoring would need to be continuous, accurate and web-enabled so that air pollution can be monitored in real-time. AQMesh is therefore the ideal solution; small, lightweight, quick and easy to install, these air quality monitors are able to monitor all the main pollutants, including particulates, simultaneously, delivering accurate data wirelessly via the internet.

Whilst AQMesh ‘pods’ are very significantly lower in cost both to buy and to run than traditional reference stations, they still represent a ‘new’ cost. However any additional costs are trivial in comparison with the costs associated with the adverse health effects caused by poor air quality, as evidenced in the recent report from the Royal College of Physicians.

Inside Out or Outside In?

Fidas® Frog

Fidas® Frog

The effects of air pollution are finally becoming better known, but almost all of the publicity focuses on outdoor air pollution. In contrast, indoor air quality is rarely in the media, except following occasional cases of Carbon Monoxide poisoning or when ‘worker lethargy’ or ‘sick building syndrome’ are addressed. However, it is important to understand the relationship between outdoor air quality and indoor air quality. Air Monitors is currently involved in a number of projects in which air quality monitoring is being undertaken both outside and inside large buildings, and the results have been extremely interesting.

Poorly ventilated offices tend to suffer from increased Carbon Dioxide as the working day progresses, leading to worker lethargy. In many cases HVAC systems bring in ‘fresh’ air to address this issue, but if that fresh air is in a town or city, it is likely to be polluted – possibly from particulates if it is not sufficiently filtered and most likely from Nitrogen Dioxide. Ventilating with outdoor air from street level is most likely to bring air pollution into the office, so many inlets are located at roof level. However, data from recent studies indicate that the height of the best air quality can vary according to the weather conditions, so it is necessary to utilise a ‘smart’ system that monitors air quality at different levels outside the building, whilst also monitoring at a variety of locations inside the building. Real-time data from a smart monitoring network then informs the HVAC control system, which should have the ability to draw air from different inlets if available and to decide on ventilation rates depending on the prevailing air quality at the inlets. This allows the optimisation of the internal CO2, temperature and humidity whilst minimising the amount of external pollutants brought into the indoor space. In circumstances where the outside air may be too polluted to be used to ventilate, it can be pre-cleaned by scrubbing the pollutant gases in the air handling system before being introduced inside the building.

Fidas200The implementation of smart monitoring and control systems for buildings is now possible thanks to advances in communications and monitoring technology. AQMesh pods can be quickly and easily installed at various heights outside buildings and further units can be deployed internally; all feeding near-live data to a central control system.

Another example of indoor air quality monitoring instrumentation developing from outdoor technology is the ‘Fidas Frog,’ a new fine dust aerosol spectrometer developed by the German company Palas. The Frog is an indoor, wireless, battery-powered version of the hugely popular, TÜV and MCERTS certified Fidas 200. Both instruments provide simultaneous determination of PM fractions, particle number and particle size distribution, including the particle size ranges PM1, PM2.5, PM4, PM10 and TSP.

Evidence of outdoor air pollution contaminating indoor air can be obtained with the latest Black Carbon monitors that can distinguish between the different optical signatures of combustion sources such as diesel, biomass, and tobacco. The new microAeth® MA200 for example, is a compact, real-time, wearable (400g) Black Carbon monitor with built-in pump, flow control, data storage, and battery with onboard GPS and satellite time synchronisation. Samples are collected on an internal filter tape and wireless communications are provided for network or smartphone app integration and connection to other wireless sensors. The MA200 is able to monitor continuously for 2-3 weeks. Alternatively, with a greater battery capacity, the MA300 is able to provide 3-12 months of continuous measurements.

In summary, a complete picture of indoor air quality can be delivered by a combination of AQMesh for gases, the Palas Frog for particulates and the microAeth instruments for Black Carbon. All of these instruments are compact, battery-powered, and operate wirelessly, but most importantly, they provide both air quality data AND information on the likely source of any contamination, so that the indoor effects of outdoor pollution can be attributed correctly.

@airmonitors #Environment #PAuto @_Enviro_News


Particulate monitors selling like hot cakes.

03/12/2016

Palas, the German manufacturer of particulate monitoring instruments, is expanding production to cope with demand for its fine particulate monitor, the Fidas® 200. In the following article Jim Mills explains why Air Monitors, the British distributor, is being kept busy by the demand for this exciting new technology.

fidas_200PM monitoring – the ultimate goal
We monitor PM because of its acute health effects. It irritates our eyes and lungs, and some of the finer particles were more recently shown to be able to move directly from the nasal cavity to the brain. Monitoring is therefore essential, but there are almost as many monitoring methods as there are types of PM, so it is vitally important to monitor what matters. If you are measuring dust from a construction site, the PM is relatively large in diameter and heavy, but if you are monitoring PM from diesel emissions in a city, the smallest particles with much less mass but high particle numbers, are of greater interest. Monitoring a single size fraction provides an incomplete picture of particulate contamination and risks ignoring the PM of most interest, particularly if the ignored fractions are the finer particles that travel deepest into the lungs. The ideal PM monitor would therefore reliably and accurately monitor all important PM fractions, with high data capture rates and low service requirements… hence the heavy demand for the Fidas 200.

Fidas® 200
The Fidas 200 is a fine dust ambient air quality monitoring device, developed specifically for regulatory purposes; providing continuous and simultaneous measurement of PM1, PM2.5, PM4, PM10, TSP (PMtot), as well as particle number concentration and particle size distribution between 180nm and 18µm (further non-certified size ranges are also available on request).

Employing a well-established measurement technology – optical light scattering of single particles – the Fidas 200 is equipped with a high intensity LED light source, which is extremely stable, delivering a long lifetime, with minimal service requirements. An optical aerosol spectrometer determines the particle size using Lorenz‐Mie scattered light analysis of single particles. These particles move through an optical measurement volume that is homogeneously illuminated with white light, and each particle generates a scattered light impulse that is detected at an angle of 85° to 95° degrees. The particle number measurement is based on the number of scattered light impulses, and the level of the scattered light impulse is a measure of the particle diameter.

The Fidas 200 operates with a volume flow of approx. 0.3m3/h and is equipped with a Sigma‐2 sampling head, which enables representative measurements even under strong wind conditions. The sampling system includes a drying system that prevents measurement inaccuracies caused by condensation from high humidity, which means that it will continue to function correctly in misty or foggy conditions but without the loss of semi-volatile fractions of the PM. It is also equipped with a filter holder for the insertion of a plane filter (47 or 50 mm in diameter) which enables subsequent chemical analysis of the aerosol.

Different versions of the Fidas 200 allow for stand-alone outdoors installation or for installation inside a measurement cabinet or air quality monitoring station.

Performance
The Fidas 200 is the only ambient continuous PM monitor in the UK to have passed TÜV and MCERTS. The MCERTS certificate (Sira MC16290/01) confirms that the Fidas 200 complies with the MCERTS Performance Standards for Continuous Ambient Air Quality Monitoring Systems, and with MCERTS for UK Particulate Matter. The instrument has type-approval to the Standards EN 12341 (PM10), EN 14907 (PM2.5) and is certified to the Standards EN 15267-1 and -2.

Importantly, the FIDAS 200 has half the uncertainty of many of its rivals and one third of the required uncertainty (25%).

Typical data capture rates exceed 99%. This has been achieved by a design approach that is focused on reliability. For example, two pumps operate in parallel, providing redundancy protection, and the instrument continuously monitors status and calibration.

Monitoring frequency has an adjustable time resolution ranging from 1 second up to 24 hours. However, high frequency data provides almost real-time access to readings when deployed with a remote web-enabled Envirologger. This enables the detection of short-term spikes, providing much greater insight into the causes of PM pollution.

The Fidas instruments have been proven in many countries as well as Britain; Air Monitors has been supplying Fidas PM monitors for around three years and there are now over 30 monitors in operation Britain alone.

Costs
One of the major financial considerations for Fidas 200 is its extremely low operating cost; the requirement for consumables is almost nil (no filter required) and its power consumption is around one fifth of its nearest rival. Calibration can be checked and adjusted, if necessary, quickly and easily in the field with a simple monodisperse powder test.

The purchase cost of a single Fidas 200 is a little more than some ambient PM monitors, but it is less expensive than others. However, for most instruments, a requirement to monitor two fractions, say PM2.5 and PM10, would necessitate two instruments and therefore double the cost. With budgets under pressure, Fidas therefore provides an opportunity to obtain better data for less cost.

In summary, the Fidas 200 offers better performance than all of its rivals; usually at significantly lower capital cost and always with dramatically lower operational costs. Consequently, it is no surprise that these instruments are selling like hot cakes.

@airmonitors #PAuto @_Enviro_News