The NUTREM process treats wastewater to exceptionally high standards using purely biological processes. It achieves very high levels of phosphorous (TP) and nitrogen (TN) removal by creating conditions within the process tanks which encourage the development of specific bacteria capable of absorbing and breaking down nutrients. TN is removed through a process of simultaneous nitrification and de-nitrification, whilst the TP is absorbed by PAOs (Phosphorous Accumulating Organisms).
Recent trials prove that NUTREM can achieve an exceptionally high level of phosphorous and nitrogen removal, even during the challenging winter months. There is also a much smaller footprint required for the process compared to traditional systems, enabling users to release land for other development.
It enjoys competitive operating costs making the process cost competitive on the TOTEX basis. To add to this, there is also the benefit of odour control, having no odour associated with the process.
The technology is ideal for use on sites where water re-use is an important consideration, due to its ability to produce very high quality effluent without requirement for significant additional tertiary treatment. When being installed for use with a new or growing development, the reactors can be installed in stages as and when they are required to treat additional flow. This makes the capital expenditure easier to manage and makes the solution more competitive for developers looking to spread the cost of their development.
One of the biggest problems being faced in the UK is the eutrophication of water bodies through overloading of nutrients such as Phosphorus and Nitrogen.
When eutrophication occurs, oxygen is stripped from the water body that is being affected, leading to a decline in the number of organisms that can be supported. The end result is that ‘dead zones’ (where no aquatic life can live at all) appear, and this phenomenon is occurring worldwide. Studies have shown that more than 50% of the lakes in Europe suffer from eutrophication. To help combat this issue, environmental departments are tightening the regulations on the quality of effluents discharged from wastewater treatment plants (WwTPs). WASCs are expecting new Total Nitrogen (TN) and Total Phosphorous (TP) consents at a number of WwTP sites and considerable tightening of existing consents.
The most common method for removal of phosphorous is chemical dosing with water treatment chemicals. Whilst up to 95% removal rates can be achieved using this technique, both CAPEX and OPEX are increased due to:
- On-going chemical costs
- Additional maintenance of the dosing equipment
- Increased sludge production by up to 40%
- The concentrated chemical (FeCl or Fe2(SO4)3) is very corrosive/dangerous
- Where iron is used as a dosing chemical, iron limits are set in the discharge permit conditions
NUTREM has been developed to significantly improve the biological removal rates of both TN and TP, thus saving the requirement for integration of chemical precipitation technologies with WwTPs.
NUTREM UK Prototype
The NUTREM prototype is located on the Southern Water site at Petersfield in Hampshire. The main Petersfield wastewater treatment plant is an old-fashioned filter bed works which treats 4,900m3 of sewage per day. The University of Portsmouth (UoP) leases an area of the works on which it conducts research projects and PWS has constructed its prototype on this area of the site. This gives PWS access to a fully equipped laboratory, as well as offices and conference facilities.
The prototype is set up to run as a fully operational plant and includes an automated sludge removal and thickening system. The latest in monitoring and control instrumentation has been built into the plant to enable continuous collection of water quality data from all stages of treatment.
Collaboration with our clients and in-house knowledge of operating WwTPs has optimised the plant design to keep operator intervention to a minimum. All equipment and instruments used in the plant construction and operation are ‘off the shelf’. Standard servicing and calibration tasks are all that is required. Static decanters and the absence of aeration diffusers on the tank floor means that NUTREM has a reduced level of maintenance requirement than standard SBR systems and many traditional STWs.
A combination of IP cameras (webcams) and remote connection allows PWS to monitor and control the prototype remotely. The cameras provide visibility on what is happening in the tank spaces which, when combined with the ability to operate pumps, compressors and drives from off site, gives a high degree of remote control.