EnviroChemie advanced oxidation processes for wastewater treatment

As drugs and medicines become more diverse and sophisticated, treating wastewater from the pharmaceutical industry becomes an increasingly demanding task. Alongside thorough analytical methods, EnviroChemie offers a range of technologies, including advanced oxidation processes (AOPs), that can reliably remove critical pharmaceutical substances from industrial wastewater.

AOPs typically use hydroxyl radicals as the most effective way of oxidating (breaking down) organic contaminants in wastewater, providing a highly effective advanced oxidation process for wastewater treatment, pre-treating the water to be fully cleaned by conventional methods.

The need for advanced oxidation processes

Pharmaceutical residues can be detected in water, including antibiotics, hormones and many other types of medication that people take or apply to their skin as an ointment. Wastewater is contaminated with residues of active pharmaceutical ingredients even during the production of those active pharmaceutical ingredients (APIs).

These substances can potentially harm people and animals, especially when a number of them accumulate in the environment over time. In particular, the range of medicines is steadily increasing, while at the same time more and more pharmaceuticals are being consumed due to demographic change. Therefore, the problem will inevitably be exacerbated in the future.

“A considerable portion of the medication is excreted and ends up in wastewater in unchanged form or as a degradation product,” comments Elmar Billenkamp, graduate engineer and department head at EnviroChemie.

Non- biodegradable active pharmaceuticals

APIs are generally not easily biodegradable, presenting the pharmaceutical industry with a major challenge in removing these residues from water effectively and cost-efficiently without harming the environment in the process.

“The tasks to be performed when treating wastewater from pharmaceutical production are becoming ever more diverse,” says Billenkamp, who adds that complex wastewaters are also subject to significant fluctuations: “We are also seeing ever more new active ingredients and applications.”

A current example is the surfactant octoxynol 9, used as a solution in COVID-19 rapid testing that may not be released into wastewater, even in small quantities, due to its toxicity.

Eliminating problematic ingredients at source

The extent to which the wastewater needs to be cleaned is determined by what is known as the Predicted No Effect Concentration (PNEC) value of a substance, which refers to the threshold value of a toxic substance in water at which it has been proven to have no effect on the environment.

Substances in water below the PNEC value are therefore deemed acceptable, and the wastewater can be discharged.

Therefore, it is unsafe to discharge high-PNEC wastewater into sewage treatment plants without pre-treatment to eliminate the problem at source.

While the requirements are becoming ever more stringent, analytical techniques are also continuously improving, as Billenkamp emphasises: “We have the wastewater examined ecotoxicologically in special laboratories. For this, our Research & Development department works together with universities and institutes.”

Pre-treating advanced oxidation process for wastewater treatment

Different methods can be considered for pretreating wastewater from pharmaceutical production. Multiple technologies can even be combined here.

Companies often have aqueous waste incinerated by external providers. This is highly cost-intensive, however, as the water must first evaporate before the solids can burn. Alongside the high energy consumption, a considerable amount of CO2 is emitted. “And the lorry transport also increases the carbon footprint,” explains Billenkamp.

Physical procedures are also expensive. Residues in wastewater are filtered out using membrane technology or absorbed by activated carbon. Following this, the company has to pay to have these residual materials disposed of. Depending on the type of wastewater, however, these methods can be suitable in combination with other technologies.

“The ingenious advanced oxidation processes are more common today,” explains Billenkamp. APIs or other substances that are not easily biodegradable are split into smaller organic fragments during these AOP advanced oxidization processes, which have become particularly important in the pharmaceutical industry, where many of the substances found in wastewater consist of long-chain molecules that cannot be broken up by bacteria in the sewage treatment plants.

During oxidation, for example, ozone or hydrogen peroxide (H₂O₂) combined with UV light result in the creation of hydroxyl (OH) radicals that react with nearly all oxidizable substances. As such, the complex molecules of the harmful substance are quickly and thoroughly broken down into smaller organic fragments, which are no longer critical and can subsequently be treated biologically.

Matching AOP technology to application

Which AOP process is the most effective depends on the type of wastewater and its components. “Most companies specialise in one procedure. However, we are not limited to a single procedure,” says Billenkamp. The wastewater experts from EnviroChemie test the various processes for the different pharmaceuticals in the company’s own labs and pilot plants in order to find a solution. “Together with our customers, we develop the right water treatment method for each individual case,” says Billenkamp.

For example, EnviroChemie has collaborated with Roche and the Duisburg-based Institute for Energy and Environmental Technology (IUTA) to develop a procedure for removing traces of pharmaceutical substances from the wastewater of a new production plant in Mexico. One of these substances was the API capecitabine from a cancer medication, which had been classified as ecotoxicologically critical following analyses. Here, the AOP ozone oxidation process (ozonation) scored ahead of UV/H₂O₂ and activated carbon in terms of its ecological and economic aspects in particular. It was first tested in the laboratory before being implemented on an industrial scale as ozonation wastewater treatment.

EnviroChemie wastewater treatment expertise

Advanced Oxidation Processes for Wastewater Treatment provide a powerful option for the removal of problematic organic compounds such as APIs.

While the value of advanced oxidation processes for wastewater treatment has been recognized for at least a decade, it has taken the engineering expertise of companies like EnviroChemie to allow AOPs to be applied at industrial scale as part of day-to-day operations.

Billenkamp describes how EnviroChemie needs to continuously analyse the composition of the wastewater for every project and adapt its treatment according to parameters such as hydrogen concentrations, quantities of peroxide needed, whether fillers have to be filtered out first, how long the wastewater needs to treated, and required capacity of UV lamps.

The full expertise of the specialists needs to be called upon during every project to individually tailor the right plant solution.

EnviroChemie employees collect experience on the optimum use of resources for many different wastewater types, while at the same time the Research & Development team enhances new technologies and existing processes.

Alongside the method adapted to the wastewater, the right dosage and the duration of treatment, the treatment of wastewater can also be optimised by fine-tuning process engineering aspects. EnviroChemie belongs to the EnviroWater Group, a specialist network of companies, which means it is well positioned when it comes to wastewater treatment. For example, up2e! has developed the Roturi® process for applications with ozone, which allows ozone to be used particularly efficiently for removing active pharmaceutical ingredients.

“The processes are designed in such a way that they can be flexibly adapted when the composition of the wastewater changes,” comments Billenkamp, “and they should pay for themselves over the long term.”

Resources

Click on Envochem AOP Advanced Oxidation Process to learn more.
Click on AOP Advanced Oxidation Process for Wastewater treatment for further information.
Click on Effectively removing medicine residues from wastewater for pharmaceutical applications.
Click on EnviroChemie water treatment technologies for other information.