Sections
- Introduction
- Wastewater from pharmaceutical industries
- Treatment of discharges with emerging contaminants
- Advanced Oxidation Processes (AOP) + Biological Treatments
- Biological Processes
- Vacuum Evaporation
- Advanced Oxidation (AOP) + Evaporation
- Recovery of active principles from discharges (API)
- Conclusion
Introduction
Each year, over 100,000 tons of pharmaceutical products are consumed worldwide. Active Pharmaceutical Ingredients (APIs), during their manufacture, as well as later during their use and disposal, are the source of environmental pollution that must be properly managed by both companies and administrations.
Wastewater treatment in the pharmaceutical industry is a crucial issue to ensure the protection of the environment and public health. The wastewater generated in this sector is very variable in terms of flow and composition, which makes treatment complex.
Various purification technologies are commonly adopted for the treatment of these discharges such as: biological treatment by activated sludge, MBBR biological process (fixed biomass on a moving bed), anaerobic treatments, selective treatments of micro-contaminants, etc., but often drawbacks appear, which in many cases are caused by inhibitory and toxic contaminants, as well as by organic compounds resistant to oxidation.
For this reason, many industries turn to an outsourced solution, entrusting the management of their effluents to specialized companies. Among the most effective treatments for this type of discharge, evaporation stands out. Condorchem Enviro Solutions offers a wide variety of evaporation systems suitable for these effluents.
Wastewater from Pharmaceutical Industries
The pharmaceutical industry requires purified water for the production of its specific products, in addition to consuming tap water for the sanitation of equipment, containers, and primary packaging. As a result, effluents characterized by containing chemical residues, such as leftover drugs and/or detergents used in cleaning, are obtained.
Wastewater from the pharmaceutical industry shows great variability in its quantity and components, due to different modes of production and composition of medicines.
Although the amount of pharmaceutical waste discharged may be low, its continuous entry into the ecosystem can increase the concentration of pollutants in nature, posing a long-term risk to aquatic and terrestrial organisms.
In the processes of manufacturing pharmaceutical products, substances containing chemicals, cleaning products, and so-called APIs or active ingredients, which are the basis of the medicines marketed for the prevention and treatment of diseases, are used. These pollutants, abnormal for the environment, are known as “emerging contaminants” (EC), and are compounds that are discharged into the water and are not regulated. Emerging contaminants, also called micro-contaminants, are chemical compounds resulting from human activities performed in daily life, such as personal hygiene or health care. They are substances of different origin and chemical composition about which relatively little is known regarding their impact on the environment and on human health.
Treatment of Discharges with Emerging Contaminants
In general, biological treatment processes are considered the most economical for wastewater treatment, but the lack of knowledge and the complexity of the components present in the wastewater from pharmaceutical industries make the application of a specific treatment difficult. Likewise, the presence of certain compounds such as antibiotics and disinfectants prevents the complete elimination of pollutants through conventional biological treatments.
Advanced Oxidation Processes (AOP) + Biological Treatments
There are various technologies applicable to achieve proper treatment of wastewater from pharmaceutical industries, specifically effluents that contain micro-contaminants or emerging contaminants.
The treatments that have shown the greatest effectiveness are provided by advanced oxidation processes (AOP). These technologies use chemical oxidants to reduce the levels of chemical oxygen demand (COD), which are also used to break the bonds of these polluting organic compounds and facilitate their biodegradability, thus saving reagents and their operational cost is less high than if it were intended to oxidize all the organic matter with reagents.
These treatments are based on physicochemical processes capable of producing profound changes in the chemical structure of contaminants, involving the generation and use of powerful transient species, mainly the hydroxyl radical (OH-), which is the strongest oxidant after F-. Additionally, the generation of radicals is carried out using oxygen, hydrogen peroxide, and supported catalysts, so the reaction by-products are only water and carbon dioxide.
Among the main technologies of advanced oxidation processes, the Fenton processes and their variants stand out, which consist of the addition of iron salts as catalysts, in the presence of hydrogen peroxide (H2O2), in an acidic medium, and under certain pressure and temperature conditions, for the formation of OH- radicals.
After the AOP, an appropriate biological treatment can be carried out on the effluent, with which, in many cases, the limits of tolerated discharges can be reached, or even reductions of the pollutants that allow the reuse of these treated waters in services of the industry itself, or for irrigation.
Biological Processes for Pharmaceutical Wastewater
Regarding biological processes, these are the most commonly used:
Activated Sludge Biological Process: Although it is the most competitive process when dealing with wastewater containing easily biodegradable organic matter, due to the possible presence of inhibitory and toxic compounds for the biomass, as well as the low biodegradability of some effluents produced, it is not the most recommended process. However, if the pollution is biodegradable, it is a simple and efficient process.
Moving Bed Biofilm Reactor (MBBR) Process: When the wastewater is compatible with a biological treatment and the content of organic matter is high, MBBR is undoubtedly the most efficient option. This technology involves the growth of biomass in the form of a biofilm on plastic supports that are continuously moving within the biological reactor.
These supports have a high specific surface area per unit of volume, a factor that makes it possible to grow a greater amount of biomass per unit of volume than in the case of conventional reactors. MBBR, on one hand, does not present the problems of bed clogging due to excessive biomass growth that fixed bed systems do, and compared to the conventional system, it is considerably more efficient because the biofilm that forms on the walls of the support is characterized by greater effectiveness than biological flocs.
Furthermore, considering that the support particles have a high specific surface area, MBBR reactors are much smaller in volume than activated sludge reactors. Another additional advantage is that the process can be divided into different stages, and in each of these, a specific biomass adapted to the pollutant load of the feed stream will grow. This flexibility allows for the degradation of more persistent compounds. This technique is only viable when the pollution is biodegradable.
Anaerobic Digestion Process: In cases where the wastewater has a high concentration of biodegradable organic matter and there are no toxic or inhibitory substances, treating the wastewater through an anaerobic digestion process can be efficient and economical. Being anaerobic not only saves on the aeration of the process, but it also generates biogas, which can be relatively easily converted into thermal and electrical energy.
Vacuum Evaporation
Vacuum evaporation is a process that involves the removal of water or other solvents from a solution by applying heat under vacuum conditions. By reducing the atmospheric pressure over the solution, the boiling point of the liquid is lowered, allowing it to evaporate at lower temperatures.
Contributions of the process:
Evaporation is a technology widely used in wastewater treatment, including those generated by the pharmaceutical industry. Here we summarize how this process contributes to effluent treatment:
- Concentration of contaminants: During evaporation, the water is heated and turns into vapor. The organic and inorganic contaminants present in the water do not evaporate and remain concentrated in the residual solution. This allows for a reduction in the total volume of wastewater that needs to be treated later, and separates a significant portion of the contaminants.
- Recovery of valuable products: The concentrated products can be valuable for the industries that generate them, such as APIs for pharmaceutical industries. Their recovery requires a controlled evaporation process under certain operating conditions to prevent deterioration or loss of qualities.
- Elimination of micro-contaminants: Although evaporation does not completely remove micro-contaminants, it can concentrate them. Subsequently, additional techniques (such as adsorption or filtration) can be applied to remove these concentrated contaminants.
- Energy efficiency: Vacuum evaporators have improved various technical aspects with the goal of reducing energy consumption, as is the case with heat pump evaporators, or those that operate with steam thermocompression.
Limitations of the process:
Evaporation is an efficient technique for the treatment of wastewater from the pharmaceutical industry, but it also has its limitations. Here we explore some of them:
- Complexity of effluents: Pharmaceutical wastewater can contain a variety of compounds, including active pharmaceutical ingredients (APIs), chemicals, and micro-contaminants. Evaporation may not always efficiently remove all these components due to their complexity.
- Energy costs: Although evaporation is effective, it requires energy to heat the water and turn it into vapor. This can increase operational costs.
- Concentration of contaminants: While evaporation concentrates the contaminants in the reject (the non-evaporated fraction), this can be a problem if the reject is discharged without additional treatment. The concentrated compounds may still be harmful to the environment.
- Limitations in the removal of micro-contaminants: Although evaporation can concentrate micro-contaminants, it does not always completely eliminate them. Additional steps may be required to address these specific compounds.
- Need for complementary technologies: To address the mentioned limitations, they are often combined with other treatment techniques, such as adsorption, biodegradation. The choice of the right technology depends on the specific composition of the wastewater.
Advanced Oxidation (AOP) + Evaporation
The combination of advanced oxidation and evaporation is a high-performance solution for treating wastewater generated by the pharmaceutical industry.
Advanced Oxidation Processes (AOP) are methods that use highly reactive hydroxyl radicals (OH-) to oxidize and degrade organic contaminants. These processes have advantages such as the ability to mineralize organic compounds and reactivity with a wide range of contaminants. However, AOP also have drawbacks, such as high costs due to the addition of reagents and energy requirements. It is for this reason that they are often combined with other treatments.
Vacuum evaporation is a technique that concentrates contaminants by converting water into vapor, while reducing the total volume of wastewater and allowing the recovery of valuable products.
The combination of AOP and evaporation can be beneficial, as AOP can degrade hard-to-treat organic compounds, and evaporation can concentrate contaminants before applying other treatments. This combination of processes is especially suitable for low flows and high contaminant loads.
Recovery of Active Pharmaceutical Ingredients (APIs) from Discharges
What are APIs?
APIs are chemical substances that must be handled with extreme caution due to their potential impact on public health. Inadequate treatment of APIs can lead to cross-contamination, loss of drug potency, or the emergence of impurities, which could endanger patient health and compromise the reputation of the pharmaceutical company.
The production processes for APIs follow this basic outline:
- Reception and Storage. APIs typically arrive at the pharmaceutical company’s facilities in the form of powder, granules, or liquids. It is crucial to have rigorous procedures for the reception and storage of these materials, ensuring their correct identification, integrity, and traceability.
- Handling and Processing. During drug manufacturing, APIs are handled and processed to formulate the final products. This process includes operations such as mixing, granulation, compression, and encapsulation, which must be carried out following strict Good Manufacturing Practice (GMP) protocols.
- Analysis and Quality Control. Comprehensive analyses are performed to verify the identity, purity, and potency of the APIs, as well as to detect the presence of impurities. These quality controls are essential to ensure that the drugs meet regulatory standards and are safe for use.
- Storage and Distribution. Finished APIs must be stored under appropriate conditions to preserve their stability and prevent contamination. In addition, safe procedures must be established for the distribution of APIs to other manufacturing facilities or to end customers.
API manufacturing is subject to strict controls by various regulatory agencies, and it is crucial that companies comply with these regulations and apply good manufacturing practices to ensure the quality and safety of pharmaceutical products.
However, these compounds, along with other chemical ingredients, are released into the environment due to their presence in wastewater, creating a problem that needs to be addressed at the source, i.e., during the production process. This is achieved through the use of efficient technologies for treating effluents, such as wastewater evaporators and crystallizers.
Treatment and Recovery of Active Ingredients Using Vacuum Evaporators
Conventional wastewater treatments do not always manage to eliminate all residues of active pharmaceutical ingredients (APIs), as these are very complex residues to treat and municipal wastewater treatment plants (WWTPs) usually do not include the appropriate technology for this purpose.
In the pharmaceutical industry, some compounds are valuable and/or reusable, such as APIs. The evaporation process can help concentrate these compounds for their subsequent recovery. For example, solvents or chemicals used in the synthesis of medications can be recovered.
The removal of active pharmaceutical ingredients (APIs) by evaporation is a method used in the pharmaceutical industry to purify or concentrate chemicals. This process involves the controlled evaporation of the solvent in which the active ingredient is dissolved, separating the desired compound in a solid or concentrated form.
Evaporation removal is an effective technique for the separation and concentration of active ingredients in pharmaceutical production, but it is important to carry it out carefully to avoid degradation or loss of the compound of interest. Therefore, factors such as temperature, pressure, and exposure time during the evaporation process must be considered to ensure the quality and purity of the final product.
The evaporation of active pharmaceutical ingredients (APIs) can be carried out under a variety of pressure and temperature conditions, depending on several factors, such as the physical and chemical properties of the active ingredient and the solvent, as well as the specific requirements of the process. However, there are some general conditions that are considered common:
- Temperature. The evaporation temperature varies according to the active ingredient and the solvent used. Generally, a temperature high enough to efficiently evaporate the solvent but low enough to avoid degradation or volatilization of the active ingredient is selected. Therefore, temperatures are usually in the range from ambient to moderately elevated, depending on the needs of the process and the stability of the compound.
- Pressure. The pressure can also vary depending on the specific conditions of the process. In many cases, reduced or vacuum pressure is used to facilitate evaporation at lower temperatures, which helps prevent thermal degradation of the active ingredient and solvent. Reduced pressure lowers the boiling point of the solvent, facilitating its evaporation at lower temperatures.
- Exposure Time. The time during which the active ingredient is maintained under evaporation conditions is also important. A balance is sought between efficient removal of the solvent and minimization of the exposure of the active ingredient to conditions that may cause its degradation.
In summary, the evaporation of active pharmaceutical ingredients is typically performed at moderate temperatures, with reduced or vacuum pressures to facilitate evaporation and minimize degradation, and with controlled exposure times to ensure the quality of the final product.
For the evaporation of active pharmaceutical ingredients (APIs) under vacuum, various types of evaporators can be used, which are designed according to the specific needs of the application.
- Falling Film Vacuum Evaporators (Envidest MVR FF). These evaporators use a falling film design to maximize mass and heat transfer efficiency. They are suitable for concentrating viscous and heat-sensitive solutions, as they allow a short residence time and gentle evaporation.
- Multiple Effect Evaporators (Envidest MFE and Envidest DPM). These allow achieving high concentrations in the products to be dehydrated because they operate with multiple effects.
- Heat Pump Evaporators (Envidest LT VS). These allow the evaporation of the discharge containing the product to be dehydrated at low temperature and under controlled pressure conditions in a moderate exposure time. They are suitable for concentrating high viscosity solutions and APIs prone to degradation at high temperatures.
- Vacuum Crystallizers with Heat Pump (Desalt LT – DRY). With these devices, high concentration values of the product to be separated and dried are achieved, with low consumption and high performance, respecting the stability of the API compounds.
As we have discussed, it is important to select an evaporator that offers precise control of the temperature and pressure of evaporation, as well as high mass transfer efficiency, to ensure efficient evaporation and high quality of the final product.
Conclusion
Proper management of pharmaceutical discharges is crucial for protecting the environment and public health. Among the various technologies available, vacuum evaporation emerges as an effective and sustainable solution for treating discharges from the pharmaceutical industry, although it is important to consider its limitations and combine it with other strategies to achieve comprehensive and responsible management of these complex wastewaters.
The combination of advanced oxidation and evaporation may be the most suitable solution, especially when seeking a comprehensive and sustainable approach for treating effluents containing micro-contaminants.
In a context of increasing environmental awareness and stricter regulations, vacuum evaporation is expected to continue being an attractive option for the treatment of discharges from the pharmaceutical industry.
Bibliography and inquiries:
Wastewater treatment of the pharmaceutical industry through the ozone technique
Tratamiento de aguas residuales industriales | Condorchem Enviro Solutions
