Treatment of anticancer drugs in a real wastewater effluent using nanofiltration: A pilot scale study

Nanofiltration combined with ozone-based processes for the removal of antineoplastic drugs from wastewater effluents

Over the past years, there has been an increasing concern about the occurrence of antineoplastic drugs in water bodies. The incomplete removal of these pharmaceuticals from wastewaters has been confirmed by several scientists, making it urgent to find a reliable technique or a combination of techniques capable to produce clean and safe water. In this work, the combination of nanofiltration and ozone (O3)-based processes (NF + O3, NF + O3/H2O2 and NF + O3/H2O2/UVA) was studied aiming to produce clean water from wastewater treatment plant (WWTP) secondary effluents to be safely discharged into water bodies, reused in daily practices such as aquaculture activities or for recharging aquifers used as abstraction sources for drinking water production. Nanofiltration was performed in a pilot-scale unit and O3-based processes in a continuous-flow column. The peroxone process (O3/H2O2) was considered the most promising technology to be coupled to nanofiltration, all the target pharmaceuticals being removed at an extent higher than 98% from WWTP secondary effluents, with a DOC reduction up to 92%. The applicability of the clean water stream for recharging aquifers used as abstraction sources for drinking water production was supported by a risk assessment approach, regarding the final concentrations of the target pharmaceuticals. Moreover, the toxicity of the nanofiltration retentate, a polluted stream generated from the nanofiltration system, was greatly decreased after the application of the peroxone process, which evidences the positive impact on the environment of implementing a NF + O3/H2O2 process.

Theoretical rejection of fifty-four antineoplastic drugs by different nanofiltration membranes

The rise of nanofiltration technologies holds great promise for creating more effective and affordable techniques aiming to remove undesirable pollutants from wastewaters. Despite nanofiltration's promising potential in removing antineoplastic drugs from liquid matrices, the limited information on this topic makes it important to estimate the rejection rates for a larger number of compounds, particularly the emerging ones, in order to preview the nanofiltration performance. Aiming to have preliminary estimations of the rejection rates of antineoplastic drugs by nanofiltration, 54 antineoplastic drugs were studied in 5 nanofiltration membranes (Desal 5DK, Desal HL, Trisep TS-80, NF270, and NF50), using a quantitative structure-activity relationship (QSAR) model. While this methodology provides useful and reliable predictions of the rejections of compounds by nanofiltration, particularly for hydrophilic and neutral compounds, it is important to note that QSAR results should always be corroborated by experimental assays, as predictions were confirmed to have their limitations (especially for hydrophobic and charged compounds). Out of the 54 studied antineoplastic drugs, 29 were predicted to have a rejection that could go up to 100%, independent of the membrane used. Nonetheless, there were 2 antineoplastic drugs, fluorouracil and thiotepa, for which negligible removals were obtained (<21%). This study's findings may contribute (i) to the selection of the most appropriate nanofiltration membranes for removing antineoplastic drugs from wastewaters and (ii) to assist in the design of effective treatment approaches for their removal.

Efficient mitigation of emerging antibiotics residues from water matrix: Integrated approaches and sustainable technologies

The prevalence of antibiotic traces in the aquatic matrices is a concern due to the emanation of antibiotic resistance which requires a multifaceted approach. One of the potential sources is the wastewater treatment plants with a lack of advance infrastructure leading to the dissemination of contaminants. Continuous advancements in economic globalization have facilitated the application of several conventional, advanced, and hybrid techniques for the mitigation of rising antibiotic traces in the aquatic matrices that have been thoroughly scrutinized in the current paper. Although the implementation of existing mitigation techniques is associated with several limiting factors and barriers which require further research to enhance their removal efficiency. The review further summarizes the application of the microbial processes to combat antibiotic persistence in wastewater establishing a sustainable approach. However, hybrid technologies are considered as most efficient and environmental-benign due to their higher removal efficacy, energy-efficiency, and cost-effectiveness. A brief elucidation has been provided for the mechanism responsible for lowering antibiotic concentration in wastewater through biodegradation and biotransformation. Overall, the current review presents a comprehensive approach for antibiotic mitigation using existing methods however, policies and measures should be implemented for continuous monitoring and surveillance of antibiotic persistence in aquatic matrices to reduce their potential risk to humans and the environment.

Competitive adsorptive removal of promazine and promethazine from wastewater using olive tree pruning biochar: operational parameters, kinetics, and equilibrium investigations

This research aims to remove two phenothiazines, promazine (PRO) and promethazine (PMT), from their individual and binary mixtures using olive tree pruning biochar (BC-OTPR). The impact of individual and combinatory effects of operational variables was evaluated for the first time using central composite design (CCD). Simultaneous removal of both drugs was maximized utilizing the composite desirability function. At low concentrations, the uptake of PRO and PMT from their individual solutions was achieved with high efficiency of 98.64%, 47.20 mg/g and 95.87%, 38.16 mg/g, respectively. No major differences in the removal capacity were observed for the binary mixtures. Characterization of BC-OTPR confirmed successful adsorption and showed that the OTPR surface was predominantly mesoporous. Equilibrium investigations revealed that the Langmuir isotherm model best describes the sorption of PRO/PMT from their individual solutions with maximum adsorption capacities of 640.7 and 346.95 mg/g, respectively. The sorption of PRO/PMT conforms to the pseudo-second-order kinetic model. Regeneration of the adsorbent surface was successfully done with desorption efficiencies of 94.06% and 98.54% for PRO and PMT, respectively, for six cycles.

Antineoplastic drugs in urban wastewater: Occurrence, nanofiltration treatment and toxicity screening

Antineoplastic drugs are pharmaceuticals that have been raising concerns among the scientific community due to: (i) their increasing prescription in the fight against the disease of the twentieth century (cancer); (ii) their recalcitrance to conventional wastewater treatments; (iii) their poor environmental biodegradability; and (iv) their potential risk to any eukaryotic organism. This emerges the urgency in finding solutions to mitigate the entrance and accumulation of these hazardous chemicals in the environment. Advanced oxidation processes (AOPs) have been taken into consideration to improve the degradation of antineoplastic drugs in wastewater treatment plants (WWTPs), but the formation of by-products that are more toxic or exhibit a different toxicity profile than the parent drug is frequently reported. This work evaluates the performance of a nanofiltration pilot unit, equipped with a Desal 5DK membrane, in the treatment of real WWTP effluents contaminated (without spiking) with eleven pharmaceuticals, five of which were never studied before. Average removals of 68 ± 23% were achieved for the eleven compounds, with decreasing risks from feed to permeate for aquatic organisms from receiving waterbodies (with the exception of cyclophosphamide, for which a high risk was estimated in the permeate). Aditionally, no significative impact on the growth and germination of three different seeds (Lepidium sativum, Sinapis alba, and Sorghum saccharatum) were determined for permeate matrix in comparison to the control.

Ozonation and UV photolysis for removing anticancer drug residues from hospital wastewater

The present study investigates the use of UV light and the ozone process for doxorubicin, daunorubicin, epirubicin, and irinotecan degradation. The process was carried out using different pH values in hospital wastewater. The use of UV radiation reduces the concentration of anticancer drugs, but in all cases, this technology was not able enough to remove on the whole these contaminants from hospital wastewater. The best condition was achieved when using pH 9 for most of the analytes. Doxorubicin, daunorubicin, and epirubicin were degraded at 97.3%, 88.3%, and 99.0%, respectively. Irinotecan showed the lowest degradation, just 55.6%; a slightly higher degradation (63.8%) was obtained when pH 5 was used. Complete removal of doxorubicin, daunorubicin, epirubicin, and irinotecan was achieved when ozone treatment was used for all the pH studied. The results indicated that UV light and the ozone process can be used as a tertiary treatment to reduce the concentration of anticancer drugs in the effluents. Ozonation, therefore, proved to be more efficient than the photolysis process, when considering the percentual degradation of the original compounds in shorter timespans.