Almost all the technologies we use in our daily lives contain sensors to facilitate their use and optimise their performance. Our mobile phones, cars, washing machines, TVs, etc. contain a range of sensors which make their use a seamless experience. In water technology, we see a similar trend:
- smart pumps contain sensors which measure pressure and provide protection against dry running
- smart treatment systems are equipped with sensors for a range of process parameters to optimise treatment efficiency
- smart pipes are fitted with sensors which detect pressure changes and breaches in a pipe’s integrity
A wide range of sensors can be used to monitor water treatment and transport processes, and thus contribute to further optimisation of these processes. Below, we present various examples of how sensor technologies can support process monitoring and optimisation.
Sensor-controlled process optimisation helps to reduce energy and chemicals consumption and, especially in light of the recent sharp rise in energy costs, such cost-savings can significantly reduce the Return on Investment of sensor implementation.
A wastewater utility can reduce energy consumption by more than 20% by optimising its active sludge process using sensors for dissolved oxygen, ammonia and nitrate.
The implementation of sensors for active sludge treatment optimisation leads to a 25% reduction in methane and laughing gas formation, both potent greenhouse gases.
Webinar
Wat-IF: decision-support tool for sensor scenarios at wastewater treatment plants
On 27 October 2020, Sensileau organised a webinar on our Decision-Support Tool called Wat-IF (Water Impact Forecast). The tool helps water managers to build a business case for innovative (sensor) technologies and new monitoring concepts at WWTPs with the objective of making them more sustainable, specifically in terms of reducing their carbon footprint and improving water quality.
In this webinar, Roozbeh Aminian, a student at the Technical University of Twente (NL), who is working on this tool, illustrates how Wat-IF can help wastewater utilities stabilise effluent quality, reduce their carbon footprint and, at the same time, minimise operational costs.
Additionally, Dr Leo Carswell (Technology Business Area leader at WRc, UK) explains the benefits and pitfalls of Advanced Process Control (APC) at wastewater treatment plants. At WRc, he is responsible for testing and evaluating a wide range of technologies, from pipeline rehabilitation through to advanced water quality monitoring systems. Leo specialises in instrumentation and, over the last twenty years, he has been involved in several projects regarding advanced process control systems in wastewater treatment plants.
Seven ways to save money and improve sustainability without making huge investments
During this webinar, various showcases are presented to illustrate how smart sensor technologies can help optimise wastewater processing to reduce energy and chemicals consumption, and facilitate the recovery of valuable resources such as water, phosphates and sustainable energy.
Future reality for municipal systems - Post-Covid 19 optimisation tools
During this webinar, Judith Herschell Cole shows how the Sensileau Sensor Platform supports water utilities in adjusting to the new normal in the aftermath of the coronavirus pandemic. This includes steps to automate processes using sensor technologies to enable remore control and adjusting monitoring programmes to minimise health risks for staff.
Showcase
Treatment of secondary effluent to drinking water standards at Beenyup Wastewater Treatment Plant
Western Australia Water Corporation describes how online monitoring plays a vital role in the treatment of secondary WWTP effluent to drinking water quality standards in order to replenish groundwater sources for water reuse purposes.
The key benefit obtained from online sensors is the capacity to provide the utility, regulators and government with confidence that the treatment process always performs to the required standards.
Use of a network of sensors to upgrade Eindhoven WWTP and improve ecological status of its receiving water
A Dutch WWTP has been upgraded to improve the water quality and ecological status of the surface water receiving the effluent discharge. De Dommel Water Management Board uses a network of online water quality and water quantity sensors in sewer networks and wastewater treatment plants in order to calibrate detailed models which describe the dynamics of the whole Eindhoven urban wastewater system. This showcase is an exemplary case of using monitoring results to calibrate detailed models which describe the dynamics of the whole Eindhoven urban wastewater system. These models have been used to evaluate the cost-effectiveness of different upgrade scenarios, addressing the need to improve water quality in order to comply with water quality regulations.
The results of the evaluation showed that a combination of relatively inexpensive sensor strategies could be used to address water quality issues in the whole urban wastewater system, allowing for the identification of effective solutions to achieve the defined receiving water quality objectives.
Drinking water in remote areas
Water Corporation Western Australia faces the challenge of collecting reliable water quality data in remote areas to check compliance with Drinking Water Guidelines. Access to communication is often very limited; on-site calibration of one sensor in a remote area costs around $1,500. Sensors thus need to be very robust and meet unusual technical requirements. This showcase describes their approach towards this challenge, where some sites are accessed by satellite to collect water quality data.
Benefits of the chosen approach include a significant reduction in risk due to better knowledge of water quality being delivered, quicker response to out-of-spec conditions and therefore a reduction in incident costs.
Development and implementation of QA/QC procedures for online sensors enabling their use in real-time control for drinking water
The Dutch utility Waternet uses two different treatment treatment plants to produce drinking water for the city of Amsterdam, NL. The raw water is continuously monitored using an array of sensors, including both physical-chemical technologies as well as effect-based biomonitors. The intake can be stopped when water quality is compromised. This showcase describes why and how all sensors used at the intake and during treatment were optimised. The utility's online sensors are now operated under certified ISO 17025 conditions, and support remote control of the various locations of their treatment plants and pumping stations.
The Dutch drinking water utility Waternet has optimised its QA/QC procedures for online water quality sensors, and has saved 30% on monitoring costs while significantly improving the operationality of their online instrumentation and the reliability of monitoring results.
Event detection in the distribution network and stakeholder involvement in action programmes
Drinking Water Utility A in the USA uses its online sensors for a wide variety of reasons, including the understanding of hydrodynamics and water quality and trouble shooting. Online sensors for e.g. conductivity are very effective at understanding water movements and mixing in a distribution system. When issues arise, online water quality data is useful in diagnosing the problems and in developing options for resolution.
The combination of grab samples and online monitoring helped identify areas of low usage/flow and oversized mains in the distribution system. DW-A was able to demonstrate significant detection of water quality issues with online sensor data.
NEWater wastewater reclamation to overcome water shortages
NEWater is a used water reclamation scheme, mainly for non-potable industrial or indirect potable reuse. This frees up potable water for domestic consumption. During dry periods, NEWater is added to PUB’s reservoirs to blend with raw water for the production of drinking water. This showcase describes how sophisticated online TOC monitoring is used to assess RO membrane integrity and ensure continuous high quality of the produced water.
Today, NEWater meets 40% of Singapore’s total water demand. By 2060, NEWater is projected to meet 55% of Singapore’s future water demand. Thus, NEWater forms a sustainable and renewable water source for Singapore, making it less susceptible to changing weather and rainfall patterns.
Wastewater process control – a UK case study
The drive within the water industry to save energy, reduce costs and minimise carbon footprint has led to a focus on the optimisation of wastewater treatment processes, specifically the activated sludge process (ASP), which can consume up to 70% of energy used at a wastewater treatment plant.
Advanced Process Control (APC) using sensors for dissolved oxygen (DO), ammonia and nitrate offers a reduction of up to 20% in energy costs, depending on plant loading characteristics, plant configuration and level of instrumentation.
Online THM analyser helps utility optimise operation and validate laboratory results
When the Brunswick & Topsham Water District (BTWD), Maine, US, observed increasing levels of trihalomethanes (THMs) which threatened to exceed regulatory standards, it was decided to implement an online THM monitor to obtain several daily snapshots of THM levels entering the distribution system. BTWD uses various wells which are swapped on a biweekly basis to supply a single station.
With the help of the high-frequency data obtained with the THM analyser, the fluctuating levels in THMs in the distribution network could be explained, and it became clear that the swapping of the wells played a major role in this process.