AquaPriori

Indispensable application for the treatment engineer

With AquaPriori every treatment engineer can determine whether a specific treatment process can remove a substance as well as the impact of the treatment process settings. No knowledge about the chemical substance properties nor time-consuming literature studies are needed. The application takes a user who has (some) knowledge of treatment technologies through a series of steps to arrive at an estimate of the removal efficiency. AquaPriori is therefore a welcome tool in both drinking water production and (municipal and industrial) wastewater treatment, as well as in surface water management.

Reverse osmosis and activated carbon filtration

The current version of AquaPriori can be used to assess the effectiveness of reverse osmosis and activated carbon filtration. In the coming years, oxidative processes (ozonisation and advanced oxidation) and soil aquifer treatment will be added.

Broader treatment vision

Besides predicting the treatment effects, AquaPriori also provides all kinds of information which is derived from scientific research and stored in a databank. Those working with AquaPriori have a broader treatment vision. With information on the properties and the occurrence of substances – the application has data on more than 100,000 substances – and the rate of removal and toxicological hazards, the user has effective and timely measures in easy reach.

QSAR process models

For the application, knowledge of treatment mechanisms has been translated into process models of treatment techniques. Once a substance has been identified, its properties can be determined using chemometric software. In the case of substances for which the treatment efficiency is unknown, process models and statistics (QSAR) can be used to predict the removal efficiency. Measurements from pilot-scale studies were used to train and validate these QSAR process models. The treatment efficiency of an unknown substance can also be estimated by comparing it in this regard to a corresponding substance. With models, statistical techniques and the design of a substance data bank, a prediction model has been developed which is as representative and reliable as possible (see figure).

Use of a QSAR process model to determine the removal of compounds for different treatment techniques.

Utility of AquaPriori for the water sector and public authorities

The rationale for the development of AquaPriori is to have available a direct, quantitative indication of the treatment performance for emerging substances, without there being a need to actually have this information. Experimental studies are not required, which keeps costs down.

The web application can be of utility to different parties:

• Drinking water utilities can, with the knowledge of the (possible) toxicity and the rate of removal of substances by different treatment processes and possible operational options, quickly assess whether an intake suspension is necessary, whether the operations can be optimised, or whether no measures are required for the time being. Appropriate measures and communication of information can contribute to maintaining a reliable image.
• Water Authorities and wastewater treatment processes can, with knowledge of the emission of substances into surface water and their removal in the WWTP, assess whether the operations should be adjusted, whether an additional treatment stage is needed, or whether no measures are required for the time being. Good quality surface water is needed for the aquatic environment, water reuse and the drinking water provision.
•  Public authorities can use AquaPriori in policy-making regarding emission requirements and in environmental policy (Water Framework Directive, licensing policy), because these rely on the knowledge available about substances. When the risks involved are not clearly defined, no specific environmental standard can exist. Statistical models such as QSARs can increase knowledge about the toxicity of substances and their removability. For the European chemical substance registration system (REACH), statistical models for toxicity are accessible in software, and their use is embedded in the risk assessment procedure. A priori knowledge about the removal efficiency for ‘new’ substances underscores the importance of accessible treatment models for the purpose of (reinforcing) risk assessment procedures.

Licence

Drinking-water utilities and laboratories that wish to use AquaPriori in the future will request a licence to do so. This licence gives them access to the most recent version of the application as well as support in its use. Licence holders will also have a user group where they can exchange their experiences. In this manner, a shared experience base will be built allowing for maximum possible effectiveness in the tool’s further development and application.