Removal of Pharmaceuticals from Wastewater: Analysis of the Past and Present Global Research Activities

Potassium permanganate-modified eggshell biosorbent for the removal of diclofenac from liquid environment: adsorption performance, isotherm, kinetic, and thermodynamic analyses

This study assess how well diclofenac (DCF) can be separated from aqueous solution using potassium permanganate-modified eggshell biosorbent (MEB). The MEB produced was characterised using XRD, FTIR, and SEM. Batch experiments were conducted to examine and assess the impact of contact time, adsorbent dosage, initial concentration, and temperature on the adsorption capacity of the MEB in the DCF sequestration. The best parameters to obtained 95.64% DCF removal from liquid environment were 0.05 g MEB weight, 50 mg/L initial concentration, and 60 min contact time at room temperature. The maximum DCF sequestration capacity was found to be 159.57 mg/g with 0.05 g of MEB at 298 K. The adsorption isotherm data were more accurately predicted by the Freundlich model, indicating a process of heterogeneous multilayer adsorption. The results of the kinetic study indicated that the pseudo-second-order kinetic models best matched the experimental data. The findings revealed that the dynamic of DCF entrapment is largely chemisorption and diffusion controlled. Based on the values of thermodynamic parameters, the process is both spontaneous and endothermic. The primary processes of DCF sorption mechanism onto the MEB were chemical surface complexation, hydrogen bonding, π-π stacking, and electrostatic interactions. The produced MEB showed effective DCF separation from the aqueous solution and continued to have maximal adsorption capability even after five regeneration cycles. These findings suggest that MEB could be highly efficient adsorbent for the removal of DCF from pharmaceutical wastewater.

Searching for pharmaceutically active products and metabolites in environmental waters of Peru by HRMS-based screening: Proposal for future monitoring and environmental risk assessment

The presence of pharmaceutical active products (PhACs) in the aquatic environment is a matter of current concern, and there is an increasing trend to include these compounds in water quality monitoring programs and environmental risk assessments. Several studies have reported the presence of PhACs in environmental waters worldwide, but only a few studies have focused on Latin American countries. Thus, available information on the occurrence of parent pharmaceuticals, especially their metabolites, is very scarce. Peru is one of the less monitored countries in terms of contaminants of emerging concern (CECs) in waters, and only one study has been found, which was focused on the quantification of selected PhACs in urban wastewater and surface water. The aim of this work is to complement the previous data reported on PhACs in the aquatic environment by application of a wide-scope high-resolution (HRMS)-based screening, making use of target and suspect approaches. In the present work, 30 pharmaceuticals, drugs or other compounds (sweeteners, UV filters, etc.) and 21 metabolites have been identified, with antibiotics (and metabolites) being the most prevalent compounds. The use of liquid chromatography (LC) coupled to ion mobility-HRMS allowed the tentative identification of parent compounds and metabolites, for which the analytical reference standard was not available, with a high level of confidence in their identification. Based on the results obtained, a strategy for the monitoring of PhACs and relevant metabolites in environmental waters from Peru and for subsequent risk assessment is proposed. Our data will also help to focus future studies to evaluate the removal efficiency of wastewater treatment plants and the impact of treated water in receiving water bodies.

Analytical Determination of Cephalosporin Antibiotics Using Coordination Polymer Based on Cobalt Terephthalate as a Sorbent

In this work, a coordination polymer based on cobalt terephthalate was obtained and characterized by elemental analysis, infrared spectroscopy, X-ray diffraction analysis, and scanning electron microscopy. The coordination polymer was tested as a sorbent for the solid-phase extraction of cephalosporin antibiotics, including ceftriaxone, cefotaxime, and cefazolin, from aqueous solutions. The coordination polymer had a high adsorption capacity (520.0 mg/g). Antibiotics adsorption followed pseudo-second order kinetic model and the Freundlich isotherm model. The calculated thermodynamic parameters indicate a spontaneous process. The resulting coordination polymer has good stability and reusability. The possibility of separating the studied cephalosporins on a chromatographic column filled with a coordination polymer was shown. This work opens great prospects for the development and application of a coordination polymer based on cobalt terephthalate for the removal of cephalosporins from ambient water.

Scale-up of photoreactor with TiO2 thin layer for wastewater treatment

This study is devoted to the scale-up potential of TiO₂/UV photocatalyst for real wastewater treatment including its durability tests. The activity of the prepared TiO₂ layers was first tested in a laboratory reactor on key representative pollutants diclofenac, chloramphenicol and triclosan. A special pilot plant reactor of a two-tube system with 21 stainless steel annulets covered by TiO₂ thin layers and the inner volume of 3.5 L was constructed. Pilot tests were performed with wastewater from the pharmaceutical industry containing danazol and norethisterone with the concentration varying between 4 and 7 mg L^-1 at the flow 18 L h^-1 and municipal wastewater at the output sewage plant for 67,000 inhabitants containing bisphenol A, 4-nonyphenol, estron, ethinylestradiol and triclosan in the concentrations of the individual contaminants varying between 50 and 600 ng L^-1 at the flow 200 L h^-1. After the treatment during the pilot photocatalytic test, the concentration of individual contaminants decreased by 82-100%, while no decrease in the efficiency of the photocatalytic process was recorded during the long-term tests lasting for 3-6 months.

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.