Sweeter Smell Of Success For Wastewater Treatment

On the beach: Southern Water Environment Officer Adela Hepworth, with some of nature’s own products which are helping to give a green answer to the question of smell reduction at waste treatment works.
AN ENVIRONMENTALLY-friendly project by a United Kingdom water company is using natural elements like bark, wood chips, seaweed and seashells, lining water-filled tanks to provide a solution to a smelly problem – the unpleasant odour that can come from wastewater treatment works.
At Peel Common Wastewater Treatment Works in Hampshire, southern England – which serves nearly a quarter of a million people – Southern Water say they are on course for the lowest recorded number of odour complaints against the site.
Feasting bugs live on the natural material in the tanks and treat the gas hydrogen sulphide that causes the smells. The gas is sucked away by extractors before going through carbon filters back into the atmosphere.
Says Southern Water’s Principal Process Scientist Nigel Palmer: “By the time the gas passes through the layers of bark and seaweed, the bacteria and carbon have removed most smells.”
In the seashell tanks the system comprises an odour filter filled with cockle shells which
are constantly washed by a pumped system and develop a biological film on them.
This film neutralizes the gases further, helped by the calcium present in the seashells, and
an activated carbon filter later “polishes up” the air.
The shell filter holds 95,000 litres of seashells gathered from around the coast of the UK and Ireland but after a period of three to six years the shells will dissolve and have to be replaced. Some thirty cubic metres of seaweed comes from local beaches, Cornwall and the Irish Sea.
Local residents and councillors in the area had previously been so upset by the smells from the site that they had formed an Odour Forum to work together with Southern Water to identify problem areas and solutions. But in a recent visit to Peel Common the Forum found the results of the new green solution to be “fantastic.”
Southern Water Process Scientists are always looking to adopt and adapt appropriate technologies such as these to benefit the environment.
The Peel Common project is part of a Southern Water environmental scheme to improve water quality in the Solent area of southern England. The 30 million pounds sterling project is designed to remove nitrogen from the wastewater at the site.
Nitrogen in water can cause excessive plant growth or algal blooms which reduces the oxygen in the water available for other organisms. The end result will be an overall improvement in water quality in the Solent.
This project is part of a total 1.8 billion pounds Southern Water capital expenditure programme between 2005 and 2010 which aim to improve customer service, upgrade tap water quality, safeguard water resources and improve the quality of wastewater that is treated and recycled into rivers and the sea.
The seashell odour treatment system was originally developed by the Irish group Bord Na Mona, which now supplies shells to 10 Southern Water wastewater treatment works.
Bord na Móna Environmental Limited is a leading provider of solutions in waste management, including wastewater treatment and air pollution systems. The group employs approximately 1,800 people and operates out of 30 localities in Ireland, the United Kingdom and eastern United States. It has a turnover of nearly 296 million euros.