At a time when operating margins in water and wastewater are under growing pressure, the need to control cost is paramount, reports Susan Fearn Ringsell.
Cost is – and has always been – a key consideration for the water sector. This can manifest itself in several different ways, explains Nick Simpson, marketing and communications director at Suez Water UK.
“In recent years, for example, the focus has been on improving the efficiency with which a process plant operates, normally by a combination of reducing energy consumption and improvements to condition monitoring systems, to optimise operational and maintenance processes,” he says.
In many respects, this approach has reached the point where only minimal gains can be achieved.
Now, the focus has switched towards methods of reducing water consumption, water reuse and better use of analytical services, as a means of enhancing both product quality and process efficiencies.
While the number of AD facilities treating sewage sludge may be growing steadily – rising just 12% from 2010-2015 – these 159 plants actually generated over 25% more power over the same period
Matt Hale, international sales manager, HRS Heat Exchangers
This can be achieved through a better understanding of the way in which changes in one section of the plant or process can affect the operation of downstream equipment.
“In part, this change has been driven by the success of many industrial process companies,” explains Simpson.
“They now need to upscale their production, but are often limited by water abstraction and discharge licences. This effectively restricts the potential for expansion, unless ways can be found to make better use – or reuse – of existing resources.”
Growing trends
Similarly, the cost of wastewater disposal has grown significantly over recent years, as discharge consents have become increasingly more stringent. This has coincided with a growing level of corporate social and environmental responsibility.
Over the years, wastewater companies have adopted different approaches to sludge treatment, but there is now a trend towards anaerobic digestion (AD) and away from incineration.
“While the number of AD facilities treating sewage sludge may be growing steadily – rising just 12% from 2010-2015 – these 159 plants actually generated over 25% more power over the same period,” says Matt Hale, international sales manager at HRS Heat Exchangers.
Hale explains: “This can be largely attributed to efficiency improvements within the wastewater sector, which is renowned for its approach to innovation, often setting the standard for operational efficiency within the entire AD industry.”
In addition, Ofwat’s recent Water 2020 report is set to kickstart a market for treated sewage sludge.
“The regulator hopes to encourage markets between operators and also develop synergies with the wider organic waste market,” adds Hale.
Anaerobic digestion technology has moved on considerably over the last 15 years, he states: “As a result, many of the original wastewater AD facilities are now looking to upgrade, switching from producing electricity to biomethane This is in order to take advantage of the Renewable Heat Incentive instead, particularly given the positive outcome of last year’s consultation on the RHI scheme.”
Jonathan Penn, global product manager, continuous water analysers at ABB, anticipates the demand for analysis being driven by legislation, environmental performance, energy reduction, the ongoing need to control price of water to consumers, water conservation, asset protection and achieving consistent water quality.
“The drive towards TOTEX in the water utilities sector is also putting an increased emphasis on total life costs, as well as driving the need for users to gather a greater range of operational data in order to maximise the overall efficiency of their networks and treatment plants,” adds Penn.
“Water companies are tasked with meeting the highest water standards whilst operating in the toughest of circumstances,” says Paul Hough, treatment rental expert at Xylem.
“With strict legislation and the potential of large financial penalties for failure, it’s imperative that [they] meet the latest treatment standards.”
Challenging expertise
A major issue is a lack of skilled and experienced staff. “For many companies, water and wastewater management is not a core skill – their business is for example in brewing or refining,” says Simpson.
As a result, water purification and wastewater treatment systems often function below optimal levels of efficiency and reliability, and are operated and maintained by engineers whose primary role lies elsewhere in the business.
“Working with a supplier such as Suez which specialises in the development, operation and maintenance of water and wastewater technologies, can therefore introduce the required expertise and skillsets into a process business, but on a contractual basis with agreed KPIs, targets and penalty clauses,” explains Simpson.
“This has the added benefits of reducing the overall cost of operations and maintenance, while improving plant efficiency.”
Working with a supplier which specialises in the development, operation and maintenance of water and wastewater technologies, can introduce the required expertise and skillsets into a process business
Nick Simpson, marketing and communications director, Suez Water UK
There is a tendency to keep using outdated equipment in order to save costs and reduce the hassle of switching rather than opting for the best available techniques, suggests Penn.
“Very often, this behaviour will only be changed when something goes wrong and penalties are incurred.
“It can be a long process convincing users of the benefits of new technologies, especially where they use a technique that is radically different from what has gone before,” he adds.
A focus on the cheapest short-term solution for users, as well as the need to comply with standards, plus decisions around Big Data and the skills gap, all present challenges.
Future improvements
However, the ability to monitor, interrogate and control plant and equipment remotely, and to gather and analyse data from a host of process systems – from a simple bearing upwards – creates new opportunities to reduce cost and improve efficiency.
Similarly, although not necessarily a new trend, the issue of climate change is beginning to be taken more seriously by process managers and is yielding benefits.
By improving the efficiency of their wastewater AD plants, many of the UK’s water companies are enjoying increased ROI, helping to make their service more affordable and sustainable
“For example, the growing incidence of localised flooding has the potential to disrupt the operation of many process sites; addressing this issue can often be as simple as raising assets such as motors and fans off the ground and above anticipated flood levels,” says Simpson.
“By improving the efficiency of their wastewater AD plants, many of the UK’s water companies are enjoying increased ROI, helping to make their service more affordable and sustainable; particularly important as the water industry uses around 3% of all the electricity generated in the UK,” concludes Hale.
Developments in sensing technologies are also helping to reduce the cost and time of resolving issues incurred with traditional measurement techniques.
“An example is optical sensing, which is helping to overcome many of the issues associated with traditional membrane-based electrochemical techniques,” explains Penn.
He cites ABB’s optical dissolved oxygen (DO) sensor as one example and explains how it features a design capable of withstanding the problems that can affect conventional membranebased sensors.
“The sensor is also immune to the effects of sulfides, sulfates, hydrogen sulfide, carbon dioxide, ammonia, pH, chloride and other interferences. This enables it to provide consistent readings over long periods of time without suffering from sensor drift,” explains Penn.
The ongoing move towards digitisation – and the latter’s ability to deliver a better understanding of what is happening within a process through near and real-time detailed data – could help to drive take up of new technologies. Not least when that data needs to be used for environmental reporting purposes.
