As AMP8 approaches, implementing or improving phosphorus removal capability is a pertinent issue for wastewater plants; but it is also a complex one. Here, Daniel Parry from Veolia Water Technologies highlights the importance of addressing long-term efficiency and OPEX alongside removal capability when it comes to identifying an effective solution.
Phosphorus removal dominated Asset Management Period (AMP) 7 and is likely to to be a big part of AMP8 when Ofwat publishes its final determinations for PR24 in December 2024. As such, many wastewater companies will already be working on a solution for each of their site’s current needs. However, it is important to consider not only how well a piece of water treatment technology can remove phosphorus, but also whether it is an energy-efficient solution with a low ongoing operational cost that will benefit the site in terms of both expenditure and environmental outlook.
So, how can phosphorus be treated with maximum efficiency and low OPEX? The following are some key areas to take into consideration:
Assess each site individually
It is important to specify a solution for each site on a case-by-case basis to ensure that no site is over or under-specified. Every wastewater treatment facility will have a unique set of requirements relating to the quantity of wastewater it is treating, the influent Total Phosphorus (TP), the impact of extreme weather events and the likely growth of the local population in the coming years. All these factors can impact the capacity of the water treatment solution required, its treatment capability and the level of inbuilt redundancy needed. At Veolia Water Technologies, we can assess your site to find the ideal water treatment solution for you – providing the required phosphorus removal capability and water treatment capacity with efficiency and cost always in mind.
Implement digital twin solutions
Digital twin solutions are crucial to optimise the efficiency of a wastewater treatment plant. While on-site staff can ensure a plant is working optimally throughout the day, digital monitoring solutions can deliver 24/7 optimisation, supporting operators and enabling water quality and consent levels to be prioritised at all times.
This can lead to significant OPEX savings from improved plant performance, reduced maintenance expenses and optimised resource utilisation. For example, with Veolia Water Technologies’ Hubgrade Wastewater Plant Performance digital twin solution, it is possible to increase biological and hydraulic capacity by up to 100%, optimise chemical consumption by up to 100% and postpone CAPEX heavy extension projects by more than 15 years.
In terms of efficiency, Hubgrade Wastewater Plant Performance is also capable of reducing the energy used during the treatment process by up to 30% and even halving a site’s operational carbon footprint.
Look for cutting-edge technology
At Veolia Water Technologies, we are constantly seeking to develop and improve our suite of wastewater treatment solutions to reduce energy and chemical usage. With references all around the globe, we have been able to hone our technologies to manage a range of effluent compositions and meet varying local water treatment requirements, learning from the results and applying the knowledge. In the UK, we have multiple proven tertiary treatment technologies, some examples include the Actiflo® and the Hydrotech™ Discfilter.
The patented Actiflo® high-performance sand ballasted flocculation system offers a very high flow rate and quick treatment. It is ideal for municipal and industrial applications including drinking water, wastewater and phosphorus removal. Despite its small footprint, it can comfortably achieve Total Phosphorus (TP) levels as low as 0.08mg/l, as evidenced on several UK projects. Notably, the Actiflo® can also accept a higher treatment volume over short periods of time, making it a useful solution when looking to reduce wastewater treatment plant bypasses and prevent costly Combined Sewer Overflow (CSO) specific installations being required.
Recent changes to our Actiflo® design have ensured that a lower OPEX can be achieved.
The Hydrotech™ Discfilter is a compact filtration system for the polishing of municipal effluent or industrial water reuse. Utilising woven cloth filters mounted on multiple discs, it boasts two to three times more filter area than other drum filters of the same dimensions. Crucially, it is capable of delivering output TP levels of 0.25mg/l. Plus, additional discs can be installed in the future to allow greater volumes of water to be treated as the plant’s catchment area population equivalent (PE) increases. Recent improvements to the discfilter have ensured that additional and replacement disc costs are minimal as the number of parts per disc has been reduced by 75%, simplifying the replacement process.
Veolia products in practice
During a trial period at two wastewater treatment plants in the South East of England, Actiflo® clarification units delivered phosphorus discharge levels as low as 0.03mg/l – exceeding the client’s requirements and providing significant OPEX savings.
The twin facilities required technology that could deliver incredibly low TP levels of <0.1mg/l and <0.08 mg/l respectively as they discharged into sensitive receiving waters and were in close proximity to a Site of Special Scientific Interest (SSSI), a Special Area of Conservation (SAC) and a National Nature Reserve.
An eight-week trial period with a mobile Actiflo® unit was able to successfully deliver TP discharge levels of 0.03mg/l, conclusively demonstrating the technology’s capabilities.
However, due to limited space the solution needed to be compact and craned into position. The Actiflo Turbo® range has the advantage of being 5 to 20 times smaller than other conventional clarification units of a comparable output thanks to its utilisation of microsand for ballasted flocculation, a method developed by Veolia Water Technologies.
As recommended, Veolia assessed each site individually to ensure that the most efficient solution was installed in each case. The final configuration at the first site, which required less stringent phosphorus removal, included two Actiflo Turbo® AS3 clarifiers with a flow to full treatment (FFT) of 123 litres per second. For the second site, four Actiflo Turbo® AS5 clarifiers were specified to treat an FFT of 489 litres per second.
The Veolia Water Technologies team made further recommendations to enable significant OPEX savings. In addition to the Actiflo Turbo® clarifiers, both sites also utilise Veolia’s ferric sludge reuse system. This was implemented after chemical analysis during the performance trials – enabled using Hubgrade Wastewater Plant Performance – showed that the sludge was still active enough to provide coagulation. The sludge at both sites is therefore recirculated, removing the need for a secondary dose of coagulant and cutting chemical expenditure significantly.
When looking to specify phosphorus removal technology, it is important to consider both treatment capability and operational impact. Specifying a solution that delivers the required output TP but significantly impacts a site’s energy usage and has high ongoing operational costs is not sustainable in terms of cost or environmental impact.
To futureproof a wastewater treatment plant against tightening phosphorus consent levels, expanding population and worsening
