On the Road to Cleaner Air

The air we breathe contains many particles, some naturally occurring and others created by human activity. The human body is equipped to deal with many of them but particulate matter or PM10 (particles measuring 10µm or less) is increasingly seen as a major health hazard.

As well as altering lung function and aggravating respiratory conditions such as asthma, there are now suggestions that PM10 can increase the risk of heart disease and lung cancer.

The PM10 standard has been defined to identify those particles that are likely to be inhaled by humans and is now widely accepted as the measure for levels of atmospheric dust in the UK and Europe.

One of the biggest sources of PM10 is road transport. All vehicles emit some PM10, but particularly those running on diesel.

While some sources of PM10 are declining – as seen in the UK, where coal combustion has fallen in recent decades – the volume of dust from road traffic is on the rise.

In some parts of the world the danger is greater than others, particularly in heavy industrial settings. Haul and transport roads are the major generating sources of particulate matter in, for instance, opencast mining areas in places such as India, where they can contribute over 90% of a mine’s total emissions.

In such environments various techniques have been used to limit the amount of road dust, but these have often had little effect, as they do not tackle the source of the emissions.

Dust pollution, however, is also a big problem in the towns and cities of Europe and the US. Whether it is paved road dust in urban areas or heavy traffic in industrial areas, the growing problem of dust pollution from our roads has been crying out for an innovative solution. Now, it seems that solution may be at hand.

BAM Infratechniek is the civil engineering technology division of the Royal BAM Group, based in the Netherlands. It is well known for its design, construction and service capabilities in pipe and cable networks for telecommunications, data, gas, water, electricity and heat, but also has a strong position in the market for traffic systems and tunnel installations. Among its latest innovations is the Fine Dust Removal System FDRS-PM10.

PRINCIPLE AND PRACTICALITY

The new system, which has not yet been released on the market, but is at an advanced stage of development, is focused on collecting PM10 emissions from road traffic. Based on a worldwide patent of Delft University of Technology in the Netherlands, the technology behind the new system relies on the principle that creating a charged space – or electrostatic roof – above or across a road will transfer a charge to all of the fine dust particles in the area beneath this roof.

Once the particles take on the charge it becomes possible to manipulate them, which means that passive, earthed screens installed at the roadside can collect the fine dust as it is repelled by the space charge. So far, test results show that this process can remove a substantial proportion of the fine dust from the air in the targeted area, and as the technology develops further its backers hope that it will improve its optimum performance level.

A further implication of the system’s design is that all other grounded or oppositely charged objects in the area – including trees, cars and buildings – will also attract the charged particles, with the result that they could play a significant role in the reduction of fine dust concentration in urban areas.

A key parameter of the design programme was to ensure that the dust removal system uses little power. Progress towards this goal has been good with the system now perceived to be environmental friendly. Furthermore, the system has the chance of succeeding in practical implementation because its electrostatic character ensures that it has no influence on communication systems or other technology in the immediate vicinity, and is harmless to both humans and animals.

A WINNING SOLUTION

Currently, the system cannot make any claims of cost-effectiveness as it is still being refined by developers and there is no accurate data on its long-term cost profile but the idea at its foundation is exciting. It is likely that the cost of the system will vary greatly depending on the specific site in which the technology is used, given that it requires bespoke design to ensure that it matches the local conditions and project goals for each location.

Nevertheless, it is certainly possible that such systems could have a positive impact on the long-term cost of road management, as they have the potential to reduce maintenance and upgrade costs through continuous dust control.

The technology certainly had enough potential to impress the judges at the 2008 Intertraffic event in Amsterdam, where the system won BAM Infratechniek the Innovation Award.

“Fine dust problems create a major threat to public health, which has resulted in tough European legislation; the jury considers this a very promising approach in an area which needs serious improvement,” commented Jury chair Fred Wegman, managing director of Netherlands National Road Safety Research Institute SWOV.

“This straightforward technology focuses on a major road environmental issue that could not previously be satisfactorily dealt with. The jury considered it a major breakthrough, being capable of installation in tunnels and urban canyons as well as in open-road locations.”

Controlling air pollution from roads is certainly a major concern, but until now little has been done to develop practical and cost-effective solutions.

BAM Infratechniek’s new system will be a big step forward, and will no doubt encourage more innovation among technology providers.