Achi news desk-
Scottish teams are exploring how biochar created from human waste that has been burned at high temperatures can be used as a water filter that can remove large amounts of phosphorus which, when present in excessive amounts, contribute to algal blooms.
As well as cleaning the water, the phosphorus the filter collects could then be reused to produce anything from cleaning products and matches, to fertiliser.
The innovative use of human waste would also provide a potential solution to another problem: currently around 130,000 tonnes of sewage waste in Scotland is disposed of either by being recycled to land or incinerated.
Apart from racking up a bill of £6 million a year for its disposal, expected changes to regulations mean that alternative treatment and processing methods must be explored.
The human waste biochar project is funded by the Industrial Biotechnology Innovation Center (IBioIC) and Scottish Water, which supplies the raw material used to create the charcoal-like substance for its sub- commercial company, Scottish Water Horizons.
It is testing the biochar at its wastewater development center in Bo’ness. As part of the project, experts at the Environmental Research Institute at UHI, North, West and Hebrides are also providing insight into biochar in filtration systems, supported by water treatment specialist AL-2 Teknik.
Bio-char derived from sewage sludge is safe and sanitary, with any residual toxins, pharmaceuticals or pesticides destroyed during the process which uses temperatures of up to 500°C.
Researchers involved in the project conducted tests using a variety of filter systems to determine which perform best. A biochar based filter was found to be able to remove large amounts of phosphorus from wastewater.
If used at scale as part of larger filtration systems, it could play an important role in treating water at the point of discharge to prevent algal plumes from forming.
Algal blooms can appear as a green, yellow-brown or red color and create a variety of problems including depleting water of oxygen which in turn affects aquatic life and releases toxins.
Often smelly and unsightly, it also poses a risk to other wildlife, people and pets.
The problem is more likely to appear when water is warm and slow moving, and thrives when nutrients such as phosphorus and nitrogen are present, sometimes as a result of fertilizer runoff.
Climate change with warmer temperatures and changes in rainfall patterns is exacerbating the problem.
Research by the UK Center for Ecology and Hydrology (UKCEH) showed in 2022 that the temperature of 97% of Scottish lakes and reservoirs monitored increased between 2015 and 2019. While most warmed by 0.25°C to 1.0°C per year over the period, 9% increased more than that, with some rising up to 1.3°C per year.
He has warned that a projected increase in air temperature of 2.5°C in Scotland between 2020 and 2080 would lead to an increase of 3°C in lakes and reservoirs over that period.
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That with changes in rainfall patterns increases the risk of algal blooms, potentially limiting the use of lakes and reservoirs for recreation and water supply as well as affecting wildlife.
Meanwhile, with natural reserves of phosphorus depleting at an alarming rate, the sewage-derived biochar filtration process could also open up new avenues for collecting the mineral.
Phosphorus is an essential element for life – rock phosphorus is spread on farmers’ fields in huge quantities, helping to underpin the world’s food supplies.
But it is a finite resource and the largest amounts are often mined in politically unstable places, raising concerns about future supplies and whether countries holding large natural reserves could control food production elsewhere in the world. eventually
Finding ways to recycle phosphate from animal and human waste, and exploring ways to recover it from other sources is a key challenge as new supplies become more uncertain.
Dr Szabolcs Pap, lead academic on the project, said: “While phosphorus poses challenges for the environment and sectors such as aquaculture due to its effect on algal blooms, it is also an element we all use in everyday products.
“Natural stores are depleting, so this cyclical bioprocess could lead to new opportunities to recover the nutrients from waste water and create new supply chains here in Scotland.
“At the same time, water companies are under increasing pressure to reduce waste and find alternatives for bioresources from sewage, so there is an added benefit in terms of sustainability.
“Biochar can be a valuable material with a range of potential applications, but the global market is in its infancy.
“The method of phosphorus recovery that we are exploring in this project is just one example of what it can be used for.”
The next phase of the research will involve on-site testing at some of Scottish Water’s smaller treatment plants, alongside ongoing conversations with regulators and development agencies about the emerging market for biochar commercialization in the Scotland.
AL-2 Teknik and its partner PyroDry have already supplied several systems in Europe and one in the United States, creating biochar from different bioresources. As a result of this project, it is hoped that the company could open its first facility in Scotland in the future.
The project has been supported by the IBioIC, which was established in 2014 to stimulate the growth of industrial biotechnology in Scotland. It has a target of £1.2 billion in related turnover and 4,000 direct employees for the sector by 2025.
To date, it has provided support to more than 200 companies across a range of collaborative innovation projects that have included academic-business partnerships and been co-funded by business.
Total investment to date of £6.8 million is said to have attracted an additional £35m from businesses, follow-on funding from other sources or partnering with other funding initiatives.
It says that as a direct result of the collaborative projects funded alone, 327 high value green jobs have been safeguarded or created by the businesses involved, leading to a further 3,000 jobs.
Dr Liz Fletcher, director of business engagement at the IBioIC, said: “This collaboration shows how one type of waste can be used to benefit the natural environment, tackling issues such as algal blooms which pose significant challenges as the climate change continues and water. temperature rises.
“Although the creation of biochar is in its infancy, we see huge potential for a growing market that could help many industries reduce waste and adopt more circular processes.”
