Time lapse: construction of sludge treatment reedbed basins

From ARM Ltd comes this innovative use of video to show the stages of construction of a reedbed basin.

The camera, set in a fixed position, recorded a ‘time lapse’ over several weeks while contractors CA Blackwell constructed this reedbed, one of 16 built for Essex and Suffolk Water.

ARM Group Ltd carried out the design, which is the first time a reedbed has been used for drinking water sludge treatment. Covering 6 ha, the reed bed dewaters the sludge produced during the drinking water treatment process.

(c) ARM Group Ltd 2013 // www.armgroupltd.co.uk

Bürkert plays instrumental role in brewery expansion

Bürkert’s work with Stroud Brewery in 2011 enabled a small craft brewery to expand while maintaining the same award-winning quality. This great video shows the Bürkert products and systems that were provided and how they were used in a new semi-automated process.

There is more technical information about the project on ESI.info Environmental Engineering.

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Wastewater & sewage treatment: what’s NASA got to do with it?

Following on from my post about London’s most recent sewage incident, which killed over 3,000 fish, I take a look at NASA’s contribution to sewage treatment, improved air quality and biofuels …

In August this year, the third worst drought in Texas forced municipal water managers in Big Spring to consider recycling sewage water. The effluent, which would typically be discharged into a creek, would be treated and blended with potable water. In essence, shortening a process that would normally occur naturally, but with greater results.

This process isn’t as extreme as one might initially think, after all, a tank on the International Space Station collects and cleans urine to recover water for drinking, cooking and cleaning. Similar distillers and filters on the space shuttle Endeavor produced 6,000 pounds of potable water each year from the sweat and urine of astronauts!

In the 1970s NASA began to investigate the uses of sewage for this purpose. NASA’s research lead them to look at the environment’s ability to clean itself of pollutants. BC Wolverton, an environmental scientist who initially worked with the military to clean up environmental messes, was tasked with using plants to clean waste water at the NASA Center. It was identified that water hyacinths (commonly seen as invasive, nuisance weeds), thrive on sewage; absorbing and digesting the minerals in wastewater, giving clean water from sewage effluent!

Common water hyacinth

Today, water hyacinths are used to handle sewage in cities across the United States, such as in the city of Hercules, Georgia, where a 350,000-gallon-per-day water hyacinth wastewater treatment plant has been built. Despite this, water hyacinths still receive bad press, this year a water hyacinth invasion in California has caused the ‘weed’ to clog waterways, decreasing oxygen levels and killing plankton.

Solving London’s sewage problem: 3,000 fish killed by sewage in the River Crane

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The Angling Trust have described it as “devastating” and “tragic”, while Thames Water admit that it was regrettable. Thames Water issued an apology last week, after it was forced to allow sewage to spill into the River Crane near Twickenham after a sluice gate became jammed and engineers were unable to re-open it. Thames Water, who have acknowledged blame for this major pollution incident, said:

The six-tonne, cast-iron penstock, used for controlling flows, jammed closed on Saturday morning in a trunk sewer at Cranford Bridge on the A4 Bath Road while engineers carried out routine maintenance.

Attempts to re-open the sluice gate were not successful until 8am on Monday, when engineers used a custom-made lifting device to force it open.

With 3,000 fish now dead and an entire seven-mile span of the West London river uninhabitable, it is reckoned that it will be years, not months, before the river returns to its original, thriving state. The Environment Agency (EA) are in the process of carrying out a full investigation, intimating that prosecution may be an outcome. Since then, Thames Water have issued an apology with Chief Executive Martin Baggs pledging that the company is “committed to put things right over the long term.”

Dead fish in the River Crane and its tributary, the Duke's River, London

The EA have been working continuously with Thames Water in an effort to minimise any further environmental damage by taking water samples, as well as monitoring levels of dissolved oxygen and ammonia in the river. Although the pollution has now spread into the River Thames, it is reported as having had little impact.

Hydropower in the UK: untapped potential?

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With one-third of British electricity plants expected to be retired by 2025, and the UK required to meet stringent targets on renewable energy, the need for clean, renewable and sustainable technology is greater than ever.

Thorpe Marsh coal-fired power station, near Doncaster, was closed in 1994

In the previous post, which focused on the controversies surrounding the use of bioenergy, in particular biomass, it was noted that Britain could make better use of water in generating electricity (we are, after all, an island). In June this year, the government announced that it would be injecting £20million into the development of hydropower technology, recognising that it is an under-developed technology in the UK. Nevertheless, statistics published at the end of September by the Department of Energy and Climate Change (DECC) revealed that renewable energy has hit a record high in the UK, with the second quarter of 2011 providing 9.6% of electricity from renewable sources, a 50% rise on the previous year. But there is still plenty of untapped potential.

Hydropower projects in the UK

Despite the encouragement by the government to develop hydropower technology, there are numerous UK projects already in place.

•  Great River Ouse, Bedfordshire & Tees Barrage white water course, Teeside

Spaans Babcock have been contracted to provide hydropower technology for the River Great Ouse, Bedfordshire, as well as at a prestigious Teeside training camp for competitors of the London 2012 Olympic Games, with the multi-million pound upgrade of the Tees Barrage white water course.

Spaans Babcock Teeside project

Steve Garcia, Project Manager at British Waterways, responsible for the upgrade, said: “Once completed the new upgraded course will provide the UK’s first fully sustainable white water course.”(Download the full press release here).

Each project will use Spaans Babcock’s screw pump/generators. The generators work in the opposite direction of the company’s Archimedian screw pump, which pumps the water up. The generator screws rotate due to the flow of the water, transferring energy to the driver unit. The energy will then be transformed by a generator into electricity.

Biomass fuelled power station at Holyhead: is it sustainable? What do you think?

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Biomass has been a bone of contention amongst green campaigners of late, but why?

In the news:

Campaigners for biomass are encouraging the Government to support investment in biomass technology while reviewing renewable energy subsidies, with the Renewable Energy Association (REA) launching a Back Biomass campaign, which argues that biomass creates jobs, contributes to a low-carbon economy and produces affordable energy.

The most recent controversy surrounds the Government’s decision to allow a biomass fuelled power station to be built at Penrhos Works in Holyhead, Anglesey. Not only will the plant generate enough electricity to power 300,000 homes, almost a quarter of the homes in Wales, it will also provide 700 jobs, with 100 of those jobs remaining permanent after construction is complete. Praising the project, Charles Hendry, Minister of State for Energy said: “Biomass power stations such as this one in Anglesey will provide us a reliable, secure, flexible and renewable source of power.”

Llyn Bychan, North Wales

What the critics say:

However, Friends of the Earth (FoE) argue that the wood-burning power station would cause more environmental problems than it would solve. Although FoE largely supports the use of biomass, it does so only on the condition that it does not negatively impact the environment. For instance, the group will not support the use of biomass if it involves imported wood fuel, and states that the use of land for food production must be prioritised over the use of land for energy crop production, warning that “there are dangers” (Download FoE: Energy from Biomass: Position Statement).

Swimming the Thames: David Walliams vs. 500,000m3 of raw sewage

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Yesterday evening, comedian David Walliams completed an epic eight-day, 140-mile swim down the River Thames in aid of the 2011 Sport Relief Big Splash Challenge.

If swimming a colossal 140 miles isn’t quite enough, Walliams had to contend with the sewage ridden Thames. On Sunday, Thames Water advised the Little Britain star’s team against allowing Walliams to swim into the centre of London. The reason? Approximately 500,000m3 of raw sewage had been flushed into the river via combined sewer overflows since Monday. Thames Water sustainability director, Richard Aylard, said: “We’re not public health experts but I wouldn’t recommend swimming in it.”

David Walliams swimming the Thames (Flickr:FlickrDelusions)

Each year, about 32,000,000,000m3 of raw sewage overflows into the river Thames. Thames Water plans to invest £4.9 billion to upgrade London’s dated sewage systems from 2010 to 2015. Completed and planned improvements include:

Improving Britain’s Rivers: 10 Most Improved Rivers & Oxygenating the River Clyde

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Today, the Environment Agency published a list of the ten most improved rivers in England and Wales, which includes the the River Thames, Wear and Dee. This is great news for the people responsible for meeting stringent EU targets for water quality. By 2015, European Union Member States must achieve a good level of water quality for all rivers, lakes, estuaries, coastal waters and groundwater, as set out in the 2000 Water Framework Directive (WFD), which became law in the UK in 2003.

The top 10 most improved rivers in England and Wales are:

1. River  Wandle, London
2. River Thames, London
3. River Wear, County Durham
4. River Stour, Worcestershire
5. River Darent, Kent
6. River Dee, Wales and North West England
7. River Nar, Norfolk
8. River Taff, South Wales
9. River Stour, Dorset
10. Mersey Basin

Britain’s rivers are the healthiest they have been in 20 years: no longer a symbol of our industrial past, but a flourishing haven for wildlife. A number of factors have contributed to the regeneration of these rivers, including habitat improvement projects, better regulation of polluting industries, and the Environmental Agency’s review of thousands of abstraction licences, which are required for those impounding or taking more than 4,000 gallons of water each day from streams, rivers, canals and reservoirs.

The River Wandle in 1973. The river was subjected to extreme pollution by local industry and declared a sewer in the 1960s

Now, the River Wandle tops the list of most improved rivers

Ian Barker, Head of Land and Water at the Environment Agency, said:

Work that we have done with farmers, businesses and water companies to reduce the amount of water taken from rivers, minimise pollution and improve water quality is really paying off – as these rivers show. Britain’s rivers are the healthiest for over 20 years and otters, salmon and other wildlife are returning for the first time since the industrial revolution.

In Scotland, work is also being carried out to help reach the targets set out in the Water Framework Directive and successes are being noted. Only last month, populations of resident and migratory fish were found to be thriving in the Glasgow city centre’s River Clyde, which is commonly perceived as uninhabitable due to the city’s heavy industrial and shipbuilding past.

UK water companies and the rise of the zebra mussel

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The rise of the zebra mussel is no laughing matter: while Thames Water is currently investing millions of pounds upgrading London’s sewer systems, the water company spends approximately £1million each year tackling the problem of pesky, immigrant zebra mussels.

What are zebra mussels?

Zebra mussels, whose name derives from the pattern often found on their shell, are small freshwater mussels found in the Black and Caspian seas. Considered as an ‘invasive species’, they are often accidentally carried into UK waters via the ballast water of ships coming from Eastern Europe.

Zebra mussels live free from predators in the UK and they also breed at alarming rates, with females producing approximately 30,000 eggs in a single season. The mussels attach themselves to surfaces, and can live there for as long as five years. For UK water companies, this is a recipe for disaster.

What problems do zebra mussels create for water companies?

Zebra mussels have posed a serious problem to the power and water industries in the USA for over twenty years, costing them on average $500 million per year. The problem? Zebra mussels find their way into water systems, clogging up raw water and water treatment pipes.

Cardiff WwTW digesters shortlisted for the 2011 Prime Minister’s Better Public Building Award

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In July, David Cameron confirmed his commitment to the Prime Minister’s Better Public Building Award, sponsored by BIS (the Department for Business, Innovation and Skills) and the Cabinet Office.

But what, you may ask, does this have to do with environmental engineering? Well, this year, up against prestigious developments such as the Acacia Centre in London and the Theatre Royal Bath in the Small Civil Engineering Project shortlist (up to £3m), is Welsh Water‘s Cardiff WwTW digesters.

Designed to convert waste into biogas, the digesters were constructed at Welsh Water’s Cardiff and Afan WwTW to generate 5MW of power. The largest of these installations was at the Cardiff site, with two 22m-diameter, 22m-high reinforced concrete digester tanks sitting on 2,900m3 raft foundations. The principal designer on this project was Arup, with Morgan Sindall as principal contractors.

The Prime Minister’s Public Building Award is assessed as part of the British Construction Industry Awards, and it’s interesting, if not telling, that an industrial engineering installation could win a building award.