Removal of pharmaceutical compounds using bentonite clay

Removal of pharmaceutical compounds in tropical constructed wetlands

SummaryPharmaceuticals are often not fully removed in wastewater treatment plants (WWTPs) and are thus being detected at trace levels in water bodies all over the world posing a risk to numerous organisms. These organic micropollutants (OMPs) reach WWTPs at concentrations sometimes too low to serve as growth substrate for microorganisms; thus, co‐metabolism is thought to be the main conversion mechanism. In this study, the microbial removal of six pharmaceuticals was investigated in a membrane bioreactor at increasing concentrations (4–800 nM) of the compounds and using three different hydraulic retention times (HRT; 1, 3.5 and 5 days). The bioreactor was inoculated with activated sludge from a municipal WWTP and fed with ammonium, acetate and methanol as main growth substrates to mimic co‐metabolism. Each pharmaceutical had a different average removal efficiency: acetaminophen (100%) > fluoxetine (50%) > metoprolol (25%) > diclofenac (20%) > metformin (15%) > carbamazepine (10%). Higher pharmaceutical influent concentrations proportionally increased the removal rate of each compound, but surprisingly not the removal percentage. Furthermore, only metformin removal improved to 80–100% when HRT or biomass concentration was increased. Microbial community changes were followed with 16S rRNA gene amplicon sequencing in response to the increment of pharmaceutical concentration: Nitrospirae and Planctomycetes 16S rRNA relative gene abundance decreased, whereas Acidobacteria and Bacteroidetes increased. Remarkably, the Dokdonella genus, previously implicated in acetaminophen metabolism, showed a 30‐fold increase in abundance at the highest concentration of pharmaceuticals applied. Taken together, these results suggest that the incomplete removal of most pharmaceutical compounds in WWTPs is dependent on neither concentration nor reaction time. Accordingly, we propose a chemical equilibrium or a growth substrate limitation as the responsible mechanisms of the incomplete removal. Finally, Dokdonella could be the main acetaminophen degrader under activated sludge conditions, and non‐antibiotic pharmaceuticals might still be toxic to relevant WWTP bacteria.

Sequential high-recovery nanofiltration and electrochemical degradation for the treatment of pharmaceutical wastewater

Pharmaceutical compounds removal by adsorption with commercial and reused carbon coming from a drinking water treatment plant

Enhancement of ozonation of seawater-based wastewater containing pharmaceutical compounds by total residual oxidants: Salinity, ammonia, and organic matter

Adsorption of pharmaceutical products from aqueous solutions on functionalized carbon nanotubes by conventional and green methods: A critical review

Fungi have been shown to be promising candidates to be used in removal of pharmaceutical compounds during wastewater treatment processes. However, fungal growth, including removal efficiency, can be affected by several factors, such as temperature and the pH. The ability of fungal isolates to grow in the presence of carbamazepine, diclofenac, ibuprofen, and sulfamethoxazole was tested. Removal efficiency results indicated that a fungal isolate of Aspergillus luchuensis can completely (>99.9%) remove diclofenac from a synthetic wastewater media without a pH correction within 10 days of incubation. Furthermore, the results of the biosorption test for A. luchuensis indicate that this isolate uses the biosorption mechanism as a strategy to remove diclofenac. Finally, the results demonstrate that A. luchuensis can remove >98% of diclofenac in non-sterile wastewater without a pH correction immediately after biomass inoculation on biofilm carriers while Trametes versicolor requires an incubation period of at least 24 h to completely remove diclofenac. Therefore, this isolate is a promising candidate for use in removal of pharmaceutical compounds from wastewater with typical pH 7.8, minimizing a requirement of the pH correction.

Chapter 12 - Removal of Pharmaceutical Compounds from Wastewater and Surface Water by Natural Treatments

Hospitals are one of the key contributors of pharmaceutical contaminants of emerging concern to the sewer systems. Hospitals wastewaters contain concentrations of pharmaceutical compounds between 3 and 150, which are higher than urban wastewater streams. However, dedicated treatments of the hospital effluents before discharge to the sewer system are not compulsory. Besides, conventional wastewater treatment plants have not been designed to remove pharmaceutical compounds effectively, and consequently, these micropollutants can reach the aquatic ecosystems. The removal of pharmaceutical compounds in real hospital wastewater was gaged using three different microbial cultures (white rot-fungus <italic>Trametes versicolor</italic>, microalga <italic>Isochrysis galbana</italic>, and a mixed culture of non-sulfur purple phototrophic bacteria). Before and after bioassays of the hospital wastewater, environmental hazard quotients were used to evaluate the biological treatment efficiency. Up to 45 out of the 79 compounds included in the analytical method were noticed in the hospital wastewater, with a predominance of analgesics/anti-inflammatories (acetaminophen, ibuprofen, ketoprofen, and naproxen). It was followed by antibiotics (azithromycin, ciprofloxacin, and ofloxacin, out of which the first two are included in the watch list of substances for monitoring in water in 2020) and anti-hypertensive drugs. <italic>Isochrysis galbana</italic> reached a reduction of 45% of the total concentration of pharmaceuticals, whereas <italic>Trametes versicolor</italic> and mixed culture of purple phototrophic bacteria improved the reductions up to 69% and 76%, respectively. Moreover, potential environmental risk compounds (antibiotics, particularly ciprofloxacin and ofloxacin) were removed by <italic>Trametes </italic>v<italic>ersicolor</italic> in higher extension, obtaining a total hazard quotient reduction higher than the other two cultures. Removal efficiency and environmental risk assessment of remaining PhACs were used to evaluate the performance of the new biological systems for the treatment of emerging pollutants. According to both criteria, <italic>T. versicolor</italic> seems the most capable alternative for removing pharmaceutical compounds in hospital wastewater effluents.

Occurrence and removal of pharmaceutical compounds and steroids at four wastewater treatment plants in Hawai'i and their environmental fate

Removal of pharmaceutical compounds from urine via chemical coagulation by green synthesized ZnO-nanoparticles followed by microfiltration for safe reuse

Presence of pharmaceutical compounds in wastewater streams is a matter of great concern as the persistence nature of these chemicals affects the terrestrial and aquatic organisms. Conventional effluent treatment plants from pharmaceutical industries are not efficient enough to remove the pharmaceutical compounds released along with the waste products. Therefore, more effective and cost-effective waste treatments procedures are required for removal of these chemicals. Nowadays, microalgal-based waste treatment systems are drawing huge attention due to their potential advantages like efficient, low-cost removal of hazardous chemicals, generation of valuable products, sequestering of greenhouse gases, etc. This chapter discusses various microalgal-based systems for removal of pharmaceutical compounds and their challenges and future prospects.

Microalgal-based carbon encapsulated iron nanoparticles for the removal of pharmaceutical compounds from wastewater

Photo-Fenton and Electro-Fenton performance for the removal of pharmaceutical compounds in real urban wastewater

The potential of microorganisms for the treatment of municipal biosolids is continuously growing. The present studies evaluated the potency of Trametes hirsuta for the reduction in biosolid mass, production of extracellular enzymes, and removal of pharmaceutical compounds (PhACs) in biosolid slurry in the presence and absence of spiked PhACs [5 non-steroidal anti-inflammatories (NSAIs) and 2 psychoactive compounds (PACs)]. Toxicity after 35 days of fungal treatment was also assessed. Results showed that the growth of T. hirsuta is limited above 25% and wholly inhibited above 50% of biosolids in the slurry. At 12% of biosolid concentration, biosolid mass was reduced by 90%, NSAIs were entirely removed, but PACs' removal was only ~20%. Increasing biosolid content to 25% did not markedly affect biosolid reduction but significantly enhanced the removal of PACs (>50%). Results also showed that both PhACs and biosolids induced the production of oxidative enzymes. In 12% biosolids in the slurry, the oxidative potential measured by the ABTS assay (OABTS) reached 5,000 mM of OABTS in the presence of PhACs, and 2,500 mM of OABTS without PhACs, as compared to 1,200 mM of OABTS in control culture. Finally, we report that white rot fungi (WRF) treatment significantly decreased the toxicity of the biosolids.