In the current era of digital transformation, the uptake of new technologies has already revolutionized several industries, and the wastewater treatment sector is no exception. As environmental concerns increase, wastewater treatment plants have evolved so they can address the challenges associated with wastewater management more efficiently and sustainably.
We are at a critical juncture. The decisions and actions taken today regarding a scarce commodity such as water will shape its availability in the years to come. Therefore, harnessing new technologies as a lever for change is particularly important. These technologies are destined to transform the wastewater treatment process and are spearheaded by digital transformation to improve the efficiency and quality of treated water.
1. Automation and control
In the age of science and technology, automation and control have played a pivotal role in industrial optimization and safety. This revolution has been driven by the convergence of operational technology (OT) and information technology (IT), creating a perfect match between technological innovation and efficiency in the wastewater treatment sector.
The integration of OT and IT in supervision systems has enabled real-time process monitoring and control, raising operational productivity to new heights. The increased variety and standard of sensors on the market has led to the generation of large volumes of data that measure water quality and the efficiency of the processes involved in its treatment. This data includes detailed measurements of contaminant concentrations and physical, chemical and biological parameters. However, the real value of this information lies in the ability and knowledge to handle and exploit it. The increasing number of monitored variables and the growth in processing capacity, either in the cloud or through edge-computing, has brought the creation of robust, cutting-edge solutions based on complex algorithms.
2. Internet of Things (IoT)
The Internet of Things (IoT) has played an essential role in revolutionizing the digital transformation of wastewater treatment plants (WWTPs). IoT devices, such as smart meters, are strategically located at key points in the plant, enabling them to collect relevant data in real time and on an ongoing basis. The information generated by the sensors is transmitted to a central platform, where it is processed and transformed into high-value data, providing a detailed, real-time picture of the state of the system.
IoT technology enables wireless transmission of monitoring signals, providing greater control and supervision beyond the plant site. Firstly, where the discharges take place, controlling their quality and detecting any illegal dumping. However, one of the most valuable advances has been real-time monitoring of the sewer network in the WWTP’s catchment basin, pinpointing early detection of illegal discharges into the network and taking preventive measures to mitigate the impact that this discharge will have when it enters the WWTP. Additionally, this technology means more effective investigations can be carried out to detect pollutant sources in the network.
In addition to upgrading the quality of the purification process, IoT technology has also driven more efficient management of the resources used in plants, such as energy and reagents, by optimizing consumption and reducing waste, thus leading to lower operating costs.
3. Big Data and advanced analytics
The vast amounts of information generated by wastewater treatment plants can be leveraged through the use of advanced analytics and big data analysis techniques. Patterns, trends and correlations can be identified by collecting and studying historical and real-time data to optimize treatment processes.
Advanced analytics can be used to predict and anticipate any potential issues. This makes it easier to make proactive decisions and implement corrective measures before serious incidents occur. Another example of the implementation of big data in wastewater treatment plants is in the use of the energy required to start up the purification system. This aims to save costs through maximum optimization and energy efficiency. Likewise, big data can also be deployed for the next step in wastewater treatment: the reuse of treated water.
4. Advanced treatment and innovative technologies
Some of the technologies that are making inroads in the urban wastewater treatment sector include:
- Advanced oxidation. Advanced oxidation is a process in which chemical reagents or free radicals are used to break down persistent organic contaminants in wastewater. This technology is especially effective for managing chemical compounds that are difficult to treat with conventional methods.
- Ultrafiltration and reverse osmosis. Water is forced through membranes under high pressure, leaving contaminants behind and producing purified water that can be reused in a variety of applications.
- Photocatalytic oxidation. This is based on the use of a catalyst (titanium dioxide) that is activated by ultraviolet (UV) light to break down organic contaminants and microorganisms in wastewater. The UV light triggers the catalyst, generating free radicals that oxidize and degrade the pollutants.
- Ultrasonic reactors. These use high-frequency ultrasonic waves to treat wastewater. These waves create microbubbles that collapse violently, generating high temperatures and pressures that disintegrate contaminants and microorganisms, and effectively decontaminate water.
- Naturally or genetically enhanced microorganisms. This technique is based on the use of naturally enhanced microorganisms to treat wastewater with refractory TOC/COD or specific contaminants. It consists of selecting microorganisms, generating improved variants and then feeding them into the treatment process.
- Electrocoagulation and electrooxidation. This method applies an electric current to eliminate pollutants through coagulation and oxidation processes.
5. Renewable energies
Reducing its carbon footprint as well as operational costs are two key factors for any utility and wastewater treatment plant operator. Therefore, one of the main objectives of WWTPs must be to improve energy efficiency.
There are four strategies in WWTP operations that complement each other to enhance energy efficiency.
- Real-time consumption monitoring and control. This enables the development of new strategies to reduce energy consumption, as well as to detect faults effectively and in real time.
- Optimization of the biological reactor’s aeration system. This involves adjusting the quantity and distribution of air in the biological reactors to maximize treatment process efficiency.
- Optimization of biogas production, volume generated and use strategy. The volume of biogas produced in the anaerobic digestion process can be increased and strategies can be applied to manage its storage and use.
- Installation of photovoltaic panels. Solar energy can be used to generate electricity and cover part of the WWTP’s energy needs.
6. Digital Twin
A digital twin is a real-time virtual replica of a physical plant. It is created by sensors and monitoring systems that collect data on WWTP operations. This data is sent to software that processes and simulates the plant’s behavior, generating a constantly updated digital model. The digital twin enables the performance of the WWTP to be monitored and analyzed. Potential problems can be anticipated, and processes can be optimized. It also serves as a platform to test and simulate changes or improvements before physically implementing them, therefore reducing costs and operational risks.
These virtual replicas in WWTPs can include biokinetic mathematical models and self-calibration algorithms with machine learning, simulating the behavior of biological and physicochemical processes in real time, and thus optimizing the plant’s performance and efficiency.
