Pharmaceuticals And Personal Care Products Research Articles

Ultraviolet activation of monochloramine to treat contaminants of emerging concern: reactions, operating parameters, byproducts, and opportunities.

The presence of CECs in aquatic systems has raised significant concern since they are potentially harmful to the environment and human health. Eliminating CECs has led to the development of alternativesto treat wastewater, such as advanced oxidation processes (AOPs). The ultraviolet-mediated activation of monochloramine (UV/NH2Cl) is a novel and relatively unexplored AOPs for treating pollutants in wastewater systems. This process involves the production of amino radicals (•NH2) and chlorine radicals (Cl•) from the UV irradiation of NH2Cl. Studies have demonstrated its effectiveness in mitigating various CECs, exhibiting advantages, such as the potential to control the amount of toxic disinfection byproducts (TDBPs) formed, low costs of reagents, and low energy consumption. However, the strong influence of operating parameters in the degradation efficiency and existence of NH2Cl, the lack of studies of its use in real matrices and techno-economic assessments, low selectivity, and prolonged treatment periods must be overcome to make this technology more competitive with more mature AOPs. This review article revisitsthe state-of-the-art of the UV/NH2Cl technology toeliminate pharmaceutical and personal care products (PPCPs), micropollutants from the food industry, pesticides, and industrial products in aqueous media. The reactions involved in the production ofradicals and the influence of operating parameters are covered to understand the formation of TDBPs and the main challenges and limitations of the UV/NH2Cl to degrade CECs. This review article generates critical knowledge about the UV/NH2Cl process, expanding the horizon for a better application of this technology in treating water contaminated with CECs.

Exploring the synergistic role of electron-rich Pd and electron-deficient Ni in promoting electrocatalytic hydrodechlorination

Pd has been widely used in electrocatalytic hydrodechlorination (EHDC) due to its excellent catalytic properties, but the expensive price limits its large-scale application. To address the above issues, Pd/NiFeP-Ti3C2Tx/NF electrodes with excellent EHDC capability are prepared by introducing the electron-rich Pd and the electron-deficient Ni. The synergistic role of electron-rich Pd and electron-deficient Ni lowers the energy barrier for active hydrogen (H*) generation by water splitting, thus endowing Pd/NiFeP-Ti3C2Tx/NF electrodes excellent ability to generate H*. H* has the lowest migration barrier between Pd and Ni, thus Pd and Ni produce large amounts of H* that can freely migrate to attack adsorbed chlorinated pollutants. Compared to other catalysts, Pd/NiFeP-Ti3C2Tx/NF electrode has the highest mass activity and can remove various emerging chlorinated pharmaceuticals and personal care products (PPCPs). This is a novel strategy to prepare low-cost electrodes with excellent performance to facilitate the practical application of EHDC technology.

Human exposure characteristics of pharmaceutical and personal care product chemicals and associations with dietary habits

Considering the widespread presence of pharmaceutical and personal care products (PPCPs) in the environment and their adverse health effects, human exposure to PPCPs has caused worldwide concern. However, there remains insufficient information on the exposure assessment of the Chinese population. Based on this, the exposure levels of 13 PPCPs in the urine samples of 986 Chinese adults were measured, aiming to provide information on the prevalence of PPCP occurrence and investigate potential correlations between PPCP exposure and obesity. Results showed that the detection rates of these compounds in urine ranged from 28.12 % to 98.58 %, with median concentrations ranging below the limit of detection to 10.58 ng mL−1. Methyl-paraben (MeP) was the most dominant paraben and had the highest urinary concentration (median = 10.12 ng mL−1), while 4-hydroxy-benzophenone (4-OH-BP) was the dominant benzophenone derivative (median = 0.22 ng mL−1). In antibacterials, the urinary concentration of triclosan (mean = 42.00 ng mL−1) was much higher than that of triclocarban (mean = 0.63 ng mL−1). PPCP concentrations were significantly associated with sex, age, body mass index, education level, and annual household income (p < 0.050). Regression analysis of dietary habits showed that seafood and tea consumption may be significant exposure sources of PPCP exposure (p < 0.050). Furthermore, individual exposure to MeP (odds ratio (OR) < 1, p = 0.002) and 4-OH-BP (OR < 1, p = 0.009) exhibited a significantly negative association with obesity in females. Also, analysis results from quantile g-computation and Bayesian kernel machine regression models demonstrated that an inverse correlation between PPCP mixture exposure and obesity was significant in females. This study reports the extensive prevalence of PPCP exposure among adults from China, and may provide crucial insights into PPCP exposure dynamics. More epidemiological studies are need in the future, with a thorough knowledge of PPCP exposure.

Nitrogen-doped carbon nanotube catalytic membrane with peroxymonosulfate activation for the degradation of metronidazole and bisphenol A: Performance and mechanism comparison

As typical pharmaceuticals and personal care products (PPCPs), metronidazole (MNZ) and bisphenol A (BPA) normally presented in sewage effluent and surface water. The nitrogen-doped multi-walled carbon nanotube (NCNT) membrane was prepared and utilized as a peroxymonosulphate (PMS) catalyst to degrade MNZ and BPA. Within the NCNT membrane/PMS catalytic system, MNZ and BPA can be efficiently degraded, while different catalytic degradation mechanism exists related with their structure, adsorption properties and even PMS dosage. The optimal conditions for the degradation of MNZ and BPA were investigated. Quenching tests and electron paramagnetic resonance examination demonstrated that •OH radicals and 1O2 played roles in MNZ degradation, while surface-bound radicals and 1O2 dominated BPA degradation within the NCNT membrane catalytic PMS system. Electrochemical tests proved that an electron-transfer process between NCNT membrane and PMS during MNZ degradation, and the electron-transfer process was further verified with the degradation experiment in the binary-solute system (BPA and MNZ). PMS dosage had little influence on the degradation mechanism of MNZ and BPA.

Ecological risk assessment of commonly used antibiotics in aquatic ecosystems along the coast of China

The consistent input of antibiotics into aquatic environments may pose risks to various creatures and ecosystems. However, risk assessment of pharmaceuticals and personal care products (PPCPs) in aquatic environments is frequently limited by the lack of toxicity data. To investigate the risk of commonly used antibiotics to various aquatic creatures, we focused on the distribution patterns and temporal dynamics of antibiotics in the coastal estuary area of China and performed a comprehensive ecological risk assessment for four antibiotics: erythromycin (ERY), tetracycline (TCN), norfloxacin (NOR) and sulfamethoxazole (SMX). An interspecies correlation estimation (ICE)-species sensitivity distribution (SSD) combined model was applied to predict the toxicity data of untested aquatic species, and an accurate ecological risk assessment procedure was developed to evaluate the risk level of PPCPs. The results of risk quotient assessments and probabilistic risk assessments (PRAs) suggested that four objective antibiotics in the Chinese coastal estuary area were at a low risk level. These antibiotics posed a high risk in antibiotic-related global hot spots, with probabilistic risk values for ERY, NOR, SMX, and TCN of 81.33 %, 27.08 %, 21.13 %, and 15.44 %, respectively. We applied an extrapolation method to overcome the lack of toxicity data in ecological risk assessment, enhanced the ecological reality of water quality criteria derivation and reduced the uncertainty of risk assessment for antibiotics.

Ferromanganese oxide-functionalized TiO2 for rapid catalytic ozonation of PPCPs through a coordinated oxidation process with adjusted composition and strengthened generation of reactive oxygen species

Ferromanganese oxide (MFOx) was first utilized to functionalize TiO2 and an MFOx@TiO2 catalyst was developed for catalytic ozonation for rapid attack of pharmaceutical and personal care products (PPCPs) with adjusted reactive oxygen species (ROSs) composition and strengthened ROSs generation. Unlike Al2O3, which strongly relied on adsorption and was significantly influenced by MFOx loading, synergistic catalytical effects of MFOx and TiO2 were observed, and optimal MFOx doping of 2 wt% and MFOx@TiO2 dosage of 500 ppm were obtained for catalyzing ozonation. In ibuprofen (IBP) degradation, MFOx@TiO2-catalyzed ozonation (MFOx@TiO2/O3) obtained 2.0-, 4.7- and 6.9-folds the kobs of TiO2/O3, MFOx/O3 and bare ozonation (B/O3). Stronger O3 decomposition was observed by MFOx@TiO2 over bare TiO2 with the participation of redox pairs Fe(II)/Fe(III) and Mn(II)/Mn(III)/Mn(IV) and increased surface oxygen vacancies (SOVs) from 9.8 % to 33.7 % was detected. The results revealed that Fe(II), Mn(II) and Mn(III) with low valance accelerated Ti(III) generation from Ti(VI), obtaining an unprecedented high Ti(III) composition occupying 35.3 % of the total Ti atoms. Ti(III) catalyzed the direct reduction of SOVs-O2 to •O2–, and it accelerated the formation of Ti(VI)-OH and Ti(VI)-O which catalyzed O3 decomposition into •O2–. •O2– was found to primarily initiate IBP degradation with nucleophilic addition and dominated over 66 % IBP removal. The enhanced •O2– generation further strengthened •OH and 1O2 production. MFOx@TiO2/O3 obtained 17 %, 21 % and 30 % higher TOC removal over TiO2/O3, MFOx/O3 and B/O3, respectively. Acute toxicity tests confirmed the effective toxicity control of organics by MFOx@TiO2/O3 process (inhibition rate: 10.9 %). Degradation test of atenolol and sulfamethoxazole confirmed the catalytic effects of MFOx@TiO2. MFOx@TiO2 performed strong resistance to water matrix in application test and showed good stability and reusability. The study proposed an effective catalyst for strengthening the ozonation process on PPCPs degradation and provided an in-depth understanding of the mechanisms and characteristics of the MFOx@TiO2 catalyst and MFOx@TiO2/O3 process.

Management of caffeine in wastewater using MOF and perovskite materials: optimization, kinetics, and adsorption isotherm modelling

Pharmaceuticals and personal care products (PPCPs) have been increasingly used all over the world and they have been reported on water cycle and cause contamination. Among these pharmaceuticals is caffeine (CAF). In this work, CAF removal from aqueous samples by metal–organic framework (UIO-66) and perovskite (La0.7Sr0.3FeO3) was achieved. Detailed studies on the preparation of MOFs and perovskite oxides compounds have been presented. Extensive characterizations such as X-Ray diffraction (XRD), field emission scanning electron microscope (FESEM), Fourier transform infrared spectra (FT-IR), N2 adsorption–desorption isotherms were also carried out to assure proper formation and to better understand the physico-chemical behavior of the synthesized samples before and after adsorption. Batch experiments of CAF adsorption onto both MOFs and perovskite were performed to compare the effectiveness of both materials on the removal competence of the CAF residue at different conditions including the effect of pH, initial concentration, and contact time. It was observed that the adsorption capacity of CAF by MOF increased with increasing acidity. On the other hand, the adsorption capacity of perovskite is stable in pH 4–10. The maximum adsorption capacities of UiO-66 and perovskite toward CAF are high as 62.5 mg g−1 and 35.25 mg g−1, respectively. Equilibrium isotherms were investigated by numerous models: Langmuir, Freundlich, Temkin, Redlich-Peterson, Sips, Langmuir-Freundlich, Toth, Kahn, Baudu, and Fritz Schlunder. Moreover, the kinetics of the CAF@MOF and CAF@Perovskite systems have been studied by five kinetic models (Pseudo-1st -order (PFO), Pseudo-2nd -order (PSO), Mixed 1st, 2nd-order, Intraparticle diffusion and Avrami). The best model described the adsorption of CAF onto both of MOF and perovskite was the mixed 1st, 2nd-order model. The metal–organic framework and perovskite were applied to quickly extract CAF from water samples successfully. The maximum removal percentage obtained for MOF and perovskite was 0.89% and 0.94% respectively within 30 min contact time which suggests that these materials are considered as promising adsorbents for CAF.

Comprehensive viewpoint on ionic liquids applications in sustainable pharmaceutical technology (experiments, simulations, and managerial insights)

Ionic liquids (ILs) have many applications, one of which is their use in the pharmaceutical and medical industries. In the pharmaceutical industry, there are many obstacles and challenges to the synthesis of solid crystal active pharmaceutical ingredients (APIs), and ILs can be used to solve these obstacles. Combining APIs with ILs (API-ILs) improves some of their properties, such as solubility, permeability, biological activity, and drug delivery, and how to improve these properties has been examined in this review. Also, ILs are used as catalysts in synthesizing drugs due to their unique properties, which are directly in some reactions and indirectly in others. In the last part, the removal of pharmaceuticals and personal care products (PPCPs) from sewage and underground water, which threatens the health of humans and animals, is investigated. This removal is done using ILs, and it is very important. Molecular Dynamic modeling demonstrated that the behavior of the ILs with different applications can be predicted. Likewise, by applying thermodynamic and Monte Carlo simulations, IL production programming can be done with the highest efficiency. Finally, the development of Monod modeling can be useful due to designing a sustainable system for recycling IL-based pharmaceutical wastewater as a sample of the circular economy.

Parabens and triclosan in red swamp crayfish (Procambarus clarkii) from China: Concentrations, tissue distribution and related human dietary intake risk

Parabens (PBs) and triclosan (TCS) are commonly found in pharmaceuticals and personal care products (PPCPs). As a result, they have been extensively found in the environment, particularly in aquaculture operations. Red swamp crayfish (Procambarus clarkii) consumption has significantly risen in China. Nevertheless, the levels of PBs and TCS in this species and the associated risk to human dietary intake remain undisclosed. This study assessed the amounts of five PBs, i.e., methyl-paraben (MeP), ethyl-paraben (EtP), propyl-paraben (PrP), butyl-paraben (BuP) and benzyl-paraben (BzP), as well as TCS in crayfish taken from five provinces of the middle-lower Yangtze River. MeP, PrP and TCS showed the highest detection rates (hepatopancreas: 46–86 %; muscle: 63–77 %) since they are commonly used in PPCPs. Significantly higher levels of ∑5PBs (median: 3.69 ng/g) and TCS (median: 7.27 ng/g) were significantly found in the hepatopancreas compared to the muscle (median: 0.39 ng/g for ∑5PBs and 0.16 ng/g for TCS) (p < 0.05), indicating bioaccumulation of these chemicals in the hepatopancreas. The estimated daily intake values of ∑5PBs and TCS calculated from the median concentrations of crayfish were 6.44–7.94 ng/kg bw/day and 11.4–14.0 ng/kg bw/day, respectively. Although no health risk was predicted from consuming crayfish (HQ <1), consumption of the hepatopancreas is not recommended.

Edge state engineering of nitrogen/phosphorus co-doped graphene nanoribbons towards electron-transfer-based peroxydisulfate activation

The electron transfer-based nonradical advanced oxidation processes (AOPs) exhibit great potential for degrading organic pollutants. However, achieving efficient electron transfer-based nonradical AOPs remains challenging. In this study, we developed the edge-rich and nitrogen/phosphorus (N/P) co-doped graphene nanoribbons by unfolding the multi-walled carbon nanotubes (MWCNTs). The catalysts with the edge-rich structure are capable of efficiently activating the peroxydisulfate (PDS) towards the degradation of carbamazepine (CBZ), a representative pharmaceutical and personal care products (PPCPs). Through adjusting the N/P ratio, the N/P co-doped graphene nanoribbons presented the optimal degradation kinetic constant of 0.452 min−1, compared with 0.0611 min−1 for the intact MWCNTs. Electrochemical characterizations, in situ Raman, galvanic oxidation tests, and quenching experiments confirmed that the N/P co-doped graphene nanoribbons followed an electron transfer-dominated nonradical pathway for pollutant degradation. Density functional theory (DFT) demonstrated that the exposed N/P co-doped edges at the boundary of graphene nanoribbons could elongated OO bond of PDS in facilitating PDS activation. This study provides a new approach to develop the nonradical AOPs-based techniques.

Azadirachta indica leaf extract based green-synthesized ZnO nanoparticles coated on spent tea waste activated carbon for pharmaceuticals and personal care products removal

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in aqueous systems, posing threat to both human health and environment. In prior research, predominant focus has been on examining various adsorbents for removing PPCPs from single-pollutant systems. However, no study has delved into simultaneous adsorption of PPCPs multi-pollutant mixture. This study evaluates performance of Azadirachta indica leaf extract-based green-synthesized ZnO nanoparticles coated on spent tea waste activated carbon (ZTAC) for removing sulfadiazine (SZN) and acetaminophen (ACN). Adsorption investigations were conducted in single-component (ACN/SZN) and binary-component (ACN + SZN) systems. The synthesized ZTAC was characterized using SEM, XRD, FTIR, EDX, porosimetry and pHpzc analysis. The study examines impact of time (1–60 min), dose (0.2–4 g/L), pH (2–12) and PPCPs concentration (1–100 mg/L) on ACN and SZN removal. Various kinetic and isotherm models were employed to elucidate mechanisms involved in sorption of PPCPs. Furthermore, synergistic and antagonistic aspects of sorption process in multi-component system were investigated. ZTAC, characterized by its crystalline nature and surface area of 980.85 m2/g, exhibited maximum adsorption capacity of 47.39 mg/g for ACN and 34.01 mg/g for SZN under optimal conditions of 15 min, 3 g/L and pH 7. Langmuir isotherm and pseudo-second-order kinetic model best-fitted the experimental data indicating chemisorption mechanism. Removal of ACN and SZN on ZTAC demonstrated synergistic nature, signifying cooperative adsorption. Overall, valorization of ZTAC offers effective and efficient adsorbent for elimination of PPCPs from wastewater.

For the occurrence of PPCPs from source to tap: A novel approach modified in terms of sample preservation and SPE cartridge to monitor PPCPs in our water supply

BackgroundThe ongoing infusion of pharmaceutical and personal care products (PPCPs) into ecosystems sustains a perpetual life cycle and leads to multi-generational exposures. Limited understanding of their environmental impact and their intrinsic ability to induce physiological effect in humans, even at low doses, pose great risks to human health. Few scholarly works have conducted systematic research into the occurrence of PPCPs within potable water systems. Concurrently, the associated monitoring techniques have not been comprehensively examined with regards to the specific nature of drinking water, namely whether the significant presence of disinfectants may influence the detection of PPCPs. ResultsA modified approach in terms of detailed investigation of sample preservation and optimization of an in-lab fabricated solid phase extraction (SPE) cartridge filled with DVB-VP and PS-DVB sorbent was proposed. Favorable methodological parameters were achieved, with correlation coefficients spanning from 0.9866 to 0.9998. The LODs of the PPCPs fluctuated from 0.001 to 2 μg L−1, while the LOQs varied from 0.002 to 5 μg L−1. The analysis of spiked samples disclosed a methodological precision of 2.31–9.86 % and a recovery of 52.4–119 %. We utilized the established method for analyzing 14 water samples of three categories (source water, finished water and tap water) from five centralized water supply plants. A total of 24 categories encompassing 72 PPCPs were detected, with the concentrations of PPCPs manifested a marked decrease from source water to finished water and finally to tap water. SignificanceOur research meticulously examined the enhancement and purification effects of widely used commercial SPE cartridges and suggested the use of in-lab fabricated SPE cartridges packed with DVB-VP and PS-DVB adsorbents. We also conducted a systematic evaluation of the need to incorporate ascorbic acid and sodium thiosulfate as preservatives for PPCP measurement, in consideration of the unique characteristics of drinking water matrices, specifically, the significant concentration levels of disinfectants. Furthermore, the proposed method was effectively employed to study the presence of PPCPs in source water, finished water, and tap water collected from centralized water supply plants.

A QSAR prediction model for adsorption of organic contaminants on microplastics: Dubinin-Astakhov plus linear solvation energy relationships

Numerous pharmaceuticals and personal care products (PPCPs) co-exist with various types of microplastics (MPs) in the environment, making it extremely hard to experimentally measure all their adsorption interactions. Thus, a precise prediction model is on demand. In this study, we combined the commonly used Dubinin-Astakhov (DA) model and the linear solvation energy relationships (LSERs) model to predict the adsorption capacity (Q0) and adsorption affinity (E) of MPs for PPCPs, including the key parameters of MP (specific surface area, oxygen-containing functional groups), and the Kamlet-Taft solvation parameters of organic contaminants. The model was validated with the experimental data of 8 PPCPs and 8 MPs (i.e. pristine and aged PE, PET, PS, PVC) plus some published adsorption data. This new model also indicated that the adsorption of PPCPs on those MPs was primarily governed by hydrophobic interaction and hydrogen bonding. The developed model can predict the adsorption of PPCPs onto MPs with a high accuracy and can also provide insights into the understanding of interaction forces in the adsorption process.

Combined effects of pH and dissolved organic matter on the availability of pharmaceuticals and personal care products in aqueous environment

The interaction between pharmaceuticals and personal care products (PPCPs) with dissolved organic matter (DOM) can alter their bioavailability and toxicity. Nevertheless, little is known about how pH and DOM work together to affect the availability of PPCPs. This study investigated the impact of pH and DOM on the availability of seven PPCPs, namely Carbamazepine, Estrone, Bisphenol A, Testosterone Propionate, Triclocarban, 4-tert-Octylphenol and 4-n-Nonylphenol, using negligible depletion solid-phase microextraction (nd-SPME). The uptake kinetics of PPCPs by the nd-SPME fibers increased proportionally with DOM concentrations, likely due to enhanced diffusive conductivity in the unstirred water layer. At neutral pH, the partitioning coefficients of PPCPs for Humic Acid (log KDOC 3.87–5.25) were marginally higher than those for Fulvic Acid (log KDOC 3.64–5.11). Also, the log KDOC values correlated linearly with the log DOW (pH 7.0) values of PPCPs, indicating a predominant role for hydrophobic interactions in the binding of DOM and PPCPs. Additionally, specific interactions like hydrogen bonding, π-π, and electrostatic interactions occur for certain compounds, influenced by the polarity and spatial conformation of the compounds. For these ionizable PPCPs, the log DDOC values exhibit a strong dependence on pH due to the dual influence of pH on both DOM and PPCPs. The log DDOC values rose from pH 1.0 to 3.0, peaked at pH 5.0 to 9.0, and then (sharply) declined from 11.0 to 13.0. The reasons are that in strong acidic circumstances, the coiled and compressed shape of DOM inhibits the hydrophobic interaction, whereas in strong alkaline conditions, significant electrostatic repulsion reduces the sorption. This study reveals that the effects of DOM on the bioavailability of PPCPs are dependent on both pH and the specific compound involved.

One-step solvent thermal synthesis of 3D networked MOF composites for preparation of anultrasensitive chemosensor for hydroquinone and catechol.

Pharmaceuticals and personal care products (PPCPs) have a significant impact on the environment and human health, due to their sometimestoxic and carcinogenic characteristics. Therefore, an innovative chemosensor was constructed for ultrasensitive determinationof two typical PCCPs (hydroquinone (HQ) and catechol (CC)) in several minutes. The homemade chemosensor (UiO-67@GO/MWCNTs) consisted of MOF(UiO-67), graphene oxide (GO), and multi-walled carbon nanotubes (MWCNTs) composites; it was a networked, structurally sparse, porosity-rich, homogeneous octahedral composite, and had ultra-high electrical conductivity, which provided lots of active adsorption sites, promote charge transfer, and enrich lots of molecules to be measured in a few minutes. The prepared electrochemical sensor showed good long-term stability, applicability, reproducibility, and immunity to interference for the determination of HQ and CC, with a wide linear range of response of 5.0 ~ 940µM for both HQ and CC, and a low limit of detection with satisfactory recoveries. In addition, a new strategy of using MOF composites as the basis for electrochemical determination of organic small molecules was established, and a new platform was constructed for the quantitative determination of organic small molecules in various environmental samples.

Occurrence, distribution, and ecological risk assessment of pharmaceuticals and personal care products in the surface water of Lipu River, China

Pharmaceuticals and Personal Care Products (PPCPs) are inadvertently released into the aquatic environment, causing detrimental effects on aquatic ecosystem. There is an urgent need of an in-deep investigation on contamination information of PPCPs in aquatic environment as well as the ecological risks to the aquatic ecosystem. This study was carried out in Lipu River basin, China, to investigate the distribution pattern and ecological risks of PPCPs. Results showed that PPCPs pollution is ubiquitous, 29 out of 30 targeted PPCPs were detected in Lipu River. Fourteen PPCPs were detected with a frequency of 100% in all water samples, and ten PPCPs were detected with a frequency of more than 80%. The cumulated PPCPs concentrations ranged from 33.30 ng/L to 99.60 ng/L, with a median value of 47.20 ng/L in Lipu River. Caffeine, flumequine, nifedipine, and lomefloxacin were the predominant PPCPs in study area. Caffeine showed high ecological risk, five and seven individual PPCP showed medium and low ecological risk to algae.

Anaerobic co-metabolic biodegradation of pharmaceuticals and personal care products driven by glycerol fermentation

Anaerobic digestion in two sequential phases, acidogenesis and methanogenesis, has been shown to be beneficial for enhancing the biomethane generation from wastewater. In this work, the application of glycerol (GOH) as a fermentation co-substrate during the wastewater treatment was evaluated on the biodegradation of different pharmaceuticals and personal care products (PPCPs). GOH co-digestion during acidogenesis led to a significant increase in the biodegradation of acetaminophen (from 78 to 89%), ciprofloxacin (from 25 to 46%), naproxen (from 73 to 86%), diclofenac (from 36 to 48%), ibuprofen (from 65 to 88%), metoprolol (from 45 to 59%), methylparaben (from 64 to 78%) and propylparaben (from 68 to 74%). The heterotrophic co-metabolism of PPCPs driven by glycerol was confirmed by the biodegradation kinetics, in which kbio (biodegradation kinetics constant) values increased from 0.18 to 2.11 to 0.27–3.60 L g−1-VSS d−1, for the operational phases without and with GOH, respectively. The assessment of metabolic pathways in each phase revealed that the prevalence of aromatic compounds degradation, metabolism of xenobiotics by cytochrome P450, and benzoate degradation routes during acidogenesis are key factors for the enzymatic mechanisms linked to the PPCPs co-metabolism. The phase separation of anaerobic digestion was effective in the PPCPs biodegradation, and the co-fermentation of glycerol provided an increase in the generation potential of biomethane in the system (energetic potential of 5.0 and 6.3 kJ g−1-CODremoved, without and with GOH, respectively). This study showed evidence that glycerol co-fermentation can exert a synergistic effect on the PPCPs removal during anaerobic digestion mediated by heterotrophic co-metabolism.

Peroxydisulfate degradation of diclofenac sodium activated by nZVI@MoS2: Key roles of superoxide radicals in the free radical pathway and electron transfer in the nonradical pathway

Diclofenac sodium (DCF) has potential biological toxicity and is difficult to degrade through conventional methods; therefore, there is a pressing imperative to develop an approach to address this environmental predicament. In this work, nZVI@MoS2 was synthesized via liquid-phase reduction to activate peroxydisulfate (PDS) for the degradation of DCF. The results demonstrated efficient degradation of DCF within 30 min with the nZVI@MoS2/PDS system. Quenching experiments, electron paramagnetic resonance (EPR) spectroscopy, steady-state concentration calculations, and electrochemical experiments demonstrated that DCF predominantly underwent degradation through an O2−-dominated free radical pathway and an electron transfer-dominated nonradical pathway. The nZVI@MoS2 composite promoted the Fe2+/Fe3+ cycle, generated O2− and showed exceptional electrochemical performance in enhancing electron transfer. The paths for DCF degradation were revealed via HPLC–MS analyses. Toxicological assessment software revealed reduced toxicity of DCF. This study presents a novel approach for the degradation of wastewater containing pharmaceuticals and personal care products (PPCPs).

Pollution levels and ecological risks of PPCPs in water and sediment samples of Danjiangkou Reservoir.

The concentrations and distribution patterns of three typical pharmaceuticals and personal care products (PPCPs) in water and sediment samples obtained from Danjiangkou Reservoir during two seasonal sampling periods were studied to determine their impact on water quality. The temporal and spatial variations in concentrations measured were analyzed and related to ecological risks with data obtained during the mean-flow period (in June) and the dry period (in November). We found a high detection rate of ketoprofen (KTP) in water samples from Danjiangkou Reservoir; the concentrations ranged from not detected (ND) to 46.80ng/L with the highest values measured in the Hanku tributary samples followed by the samples collected in the main body of Danjiangkou Reservoir. The KTP concentrations in the Danku tributary samples were the lowest measured in this study. In addition, the concentrations of KTP in the Shending River, Sihe River, Jianghe River, Guanshan River, and Jianhe River water samples were relatively high in the mean-flow period. The water sample detection rates and concentrations of triclosan (TCS) and triclocarban (TCC) were low in both the mean-flow period and the dry period. All three kinds of PPCPs were detected in the sediment samples with the concentrations of KTP, TCS, and TCC ranging from 0.76 to 7.89μg/kg, 0.01 to 0.59μg/kg, and 0.01 to 11.36μg/kg, respectively. Overall, the concentrations of the three measured PPCPs in the water and sediment samples were all relatively low compared to results reported in the recent literature. The dry period concentrations of PPCPs in the water samples were lower than the concentrations measured in the mean-flow period. However, dry period concentrations were higher in the sediment samples compared to those in the mean-flow period samples. Our interpretation of the spatial and temporal patterns of PPCPs in Danjiangkou Reservoir suggests that these compounds were likely mainly derived from wastewater discharge in the upper reaches of the reservoir. The risk quotient (RQ) method was used for an ecological risk assessment of the detected PPCPs in this study. We found that TCS in water and sediment posed medium ecological risks to algae at different times of the year. In view of the extreme importance of water safety in Danjiangkou Reservoir, the ecological risks of PPCPs require additional attention.

The fate of pharmaceuticals and personal care products (PPCPs) in sewer sediments:Adsorption triggering resistance gene proliferation

In recent years, large quantities of pharmaceuticals and personal care products (PPCPs) have been discharged into sewers, while the mechanisms of PPCPs enrichment in sewer sediments have rarely been revealed. In this study, three PPCPs (tetracycline, sulfamethoxazole, and triclocarban) were added consecutively over a 90-day experimental period to reveal the mechanisms of PPCPs enrichment and the transmission of resistance genes in sewer sediments. The results showed that tetracycline (TC) and triclocarban (TCC) have higher adsorption concentration in sediments compared to sulfamethoxazole (SMX). The absolute abundance of Tets and suls genes increased in sediments under PPCPs pressure. The increase in secretion of extracellular polymeric substances (EPS) and the loosening of the structure exposed a large number of hydrophobic functional groups, which promoted the adsorption of PPCPs. The absolute abundance of antibiotic resistance genes (ARGs), EPS and the content of PPCPs in sediments exhibited significant correlations. The enrichment of PPCPs in sediments was attributed to the accumulation of EPS, which led to the proliferation of ARGs. These findings contributed to further understanding of the fate of PPCPs in sewer sediments and opened a new perspective for consideration of controlling the proliferation of resistance genes.