Pharmaceuticals And Personal Care Products Adsorption Research Articles

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.

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.

In-situ active sites analysis of bifunctional metal-organic frameworks for coupled adsorption and electrochemical oxidation of PPCPs

Pharmaceuticals and personal care products (PPCPs) pose a significant wastewater pollution concern. While electrochemical oxidation is promising, it struggles with slow mass transfer. To address this, we propose a novel strategy utilizing bifunctional metal–organic frameworks (MOFs) that couple an adsorbent with an electrocatalyst. The real active sites within iron-based MOFs responsible for the adsorption of PPCPs are MIL-101(Fe) molecules, while the in-situ formed active sites, α-FeOOH, accelerate the charge transfer under bias, contributing to the electrooxidation of PPCPs. The rapid destruction of adsorbed organics on the dual-functional electrode surface enables to release adsorption sites. This, in turn, paves the way for fast and efficient re-adsorption of PPCPs molecules, consequently promoting mass transfer. Iron-based MOFs exhibit excellent adsorption capacity (∼60 mg g−1 for sulfosalicylic acid, ∼15 mg g−1 for acetaminophen) and electrooxidation ability (94 % removal in 2 h, 31.2 kWh kg−1 COD) with good stability in realistic pharmaceutical wastewater treatment. This study offers a novel strategy for removing PPCPs using molecular electrocatalysts and provides new insights for designing and constructing MOFs for refractory wastewater treatment.

The ability of biochars from cookstoves to remove pharmaceuticals and personal care products from hospital wastewater

Adequate treatment of wastewater to remove micropollutants constitutes a major concern globally. Despite this, large volumes of untreated wastewater are released into the environment, mainly due to the cost involved. Biochars have been suggested to have the potential to remove pharmaceuticals and personal care products (PPCP) from wastewater, but, adsorption potential needs to be investigated further. Production of biochars should also preferably be sustainable and based on low-cost materials. This study investigated the ability of nine biochars produced in three cookstoves and from three feedstocks. All biochars were characterized and then applied in adsorption experiments, based on authentic hospital effluent. Our analytical method included 32 pharmaceuticals and personal care products, and 28 of these were detected and quantified in hospital wastewater effluent samples. Some PPCP were present in relatively high concentrations (more than 24 µg/L). Adsorption experiments showed that the biochars used in the investigation had average removal rates (RR) ranging from 14.2% to 65.5%. Removal rates also varied between and within cookstoves and feedstock. Although cookstove biochars with a low surface area in this study generally showed lower removal rates, results from surface characterization were not detailed enough to correlate the physicochemical properties of the pollutants with the adsorption. Further characterizations are therefore needed to point out the most important parameters involved in PPCP adsorption on cookstove biochars.

Predicting adsorption capacity of pharmaceuticals and personal care products on long-term aged microplastics using machine learning

We investigated the adsorption mechanism of 66 coexisting pharmaceuticals and personal care products (PPCPs) on microplastics treated with potassium persulfate, potassium hydroxide, and Fenton reagent for 54, 110, and 500 days. The total adsorption capacity (qe) of 66 PPCPs on 15 original microplastics was 171.8 – 1043.7 μg/g, far below that of 177 long-term aged microplastics (7114.0 – 13,114.4 μg/g). Around 69.8% of qe was primarily influenced by the total energy, energy of the highest occupied molecular orbital, and energy gap of PPCPs, calculated using the B3LYP/6–31 G* level. Furthermore, 111 aged microplastics exhibited similar total qe values. Additionally, we developed predictive models based on attenuated total reflectance Fourier transform infrared spectroscopy to predict the individual and total qe on 192 microplastics. These models, including the maximal information coefficient and gradient boosting decision tree regression, exhibited high accuracy with Rtraining2 values of 0.9772 and 0.9661, respectively, and p-values below 0.001. Spectroscopic analysis and machine learning models highlighted surface functional group alterations and the importance of the 1528–1700 cm−1 spectral region and carbon skeleton in the adsorption process. In summary, our findings contribute to understanding the adsorption of PPCPs on microplastics, particularly in the context of long-term aging effects.

Removal of Typical PPCPs by Reverse Osmosis Membranes: Optimization of Treatment Process by Factorial Design

In this paper, the removal effect of reverse osmosis (RO) on three common pharmaceuticals and personal care products (PPCPs), including ibuprofen (IBU), carbamazepine (CBZ), and triclosan (TCS), were compared under different process conditions, and the removal rate of PPCPs, membrane flux, and PPCPs membrane adsorption capacity were analyzed. The removal rate increased with the increase of the influent concentration and pre-membrane pressure, while pH influenced the removal effect of different PPCPs by affecting the electrostatic interaction between pollutants and membranes. It was also found that the dynamic adsorption of PPCPs on RO membranes under different conditions complied with the pseudo-first-order reaction kinetic adsorption model. The maximum stable adsorption capacity and the adsorption rate of PPCPs on membranes under various conditions were simulated based on the model. Moreover, through factorial design, the removal rates of RO on IBU, CBZ, and TCS could reach 98.93%, 97.47%, and 99.01%, respectively, under the optimal conditions (with an influent concentration of 500 μg/L, pre-membrane pressure of 16 bar and pH = 10). By optimizing the process of removing PPCPs with the RO membrane method, the optimal process conditions of removing IBU, CBZ, and TCS with the RO membrane method were obtained, which provided reference conditions and data support for the practical application of removing PPCPs with the RO membrane method.

A multifunctional chitosan composite aerogel for PPCPs adsorption

Pharmaceuticals and personal care products (PPCPs) are gaining attention due to their persistence in the environment. Therefore, the development of novel adsorbents to remove them is strongly anticipated. In this study, an improved dual ice-template assembly method had been used for the preparation of ZIF-67/QGO/SB-CS aerogel through ZIF-67, benzoquinone-modified graphene oxide (QGO), and sulfobetaine-modified chitosan (SB-CS) for the adsorption and removal of PPCPs in water. We reported for the first time that the chitosan composite aerogel has antifouling, bacterial filtration and oil-water separation abilities with excellent PPCPs adsorption performance and reusable, which would be a viable option for long-lasting adsorbents for PPCPs in water.

Surface functional groups determine adsorption of pharmaceuticals and personal care products on polypropylene microplastics

The pervasiveness of microplastics (MPs), which can absorb pharmaceuticals and personal care products (PPCPs), has a certain impact on pollutant migration in natural waters. The adsorption behaviors of PPCPs on the aged polypropylene (PP) followed the pseudo-second-order kinetics and Langmuir isotherm, and the adsorption capacity (qe) on the aged PP was much higher than that on the fresh PP. The Weber-Morris and Boyd models confirmed that the liquid-film and intra-particle diffusion affected the adsorption of PPCPs on the aged PP while the surface diffusion was a rate-limiting step for the fresh PP. The analysis of SEM-EDS, BET, FT-IR, and XPS further showed that changes in the type and content of the surface functional groups of PP led to differences in adsorption capacity and adsorption interactions. The Dragon-descriptor-based LFER and the quantum-chemical-descriptor-based QSAR models reflected the difference in adsorption interaction mechanisms. The examined models showed that the adsorption of the fresh PP toward PPCPs relied on hydrophobic and hydrogen bonding interaction, while for the aged PP electrostatic interaction and hydrogen bonding controlled the adsorption. The findings clarified interactions between PPCPs and MPs and provided a theoretical basis for the assessment of environmental behavior and ecological risk when MPs and PPCPs coexist.

Insights into the adsorption of pharmaceuticals and personal care products (PPCPs) on biochar and activated carbon with the aid of machine learning

The science-informed design of ‘green’ carbonaceous materials (e.g., biochar and activated carbon) with high removal capacity of recalcitrant organic contaminants (e.g., pharmaceuticals and personal care products (PPCPs)) is indispensable for promoting sustainable wastewater treatment. In this study, machine learning (ML) incorporating PPCPs and biochar properties as well as adsorption conditions were applied to build adsorption prediction models and explore the contributions of various biochar’s inherent properties to their PPCPs adsorption capacity. The results demonstrated that the models developed by detailed biochar properties (e.g., surface functionality and hierarchical porous structure) from advanced microscopic and spectroscopic techniques were more accurate (i.e., the root-mean-square error decreased by 18−24%) than those by general information such as bulk elemental composition and total pore volume. The relative importance of surface carbon functionalities ranked in the order of C−O bond > CO bond > non-polar carbon for predicting the adsorption capacity. According to the partial dependence analysis, the average pore diameters of adsorbents that were larger than the maximum diameter of PPCPs molecules by 1.5-fold to 2.5-fold favored the PPCPs adsorption. This study reveals new insights into the adsorption of PPCPs and provides a comprehensive reference for the sustainable engineering of biochar adsorbents for PPCPs wastewater treatment.

Janus particles with pH switchable properties for high-efficiency adsorption of PPCPs in water

Pharmaceuticals and personal care products (PPCPs) are emerging pollutants and have received increasing attention in recent years. The regeneration of conventional adsorption materials used to remove PPCPs involves the desorption of secondary organic pollution, which is harmful and problematic. In this work, the impact of pH-responsive magnetic Janus particle catalysts on PPCPs’ performance of high-efficiency adsorption and degradation was studied. Magnetic core-shell Fe3O4@SiO2 nanoparticles were prepared via the STÖBER method. Polylactic acid (PLA) was grafted using a template method, and the polymerization of pH-responsive monomer 2-(diethylamino)ethyl methacrylate (DEAEMA) was initiated to obtain the pH-responsive magnetic Janus particles (Janus-Fe-P). SEM (scanning electron microscopy), particle size analysis, TEM (transmission electron microscopy), and N2 adsorption-desorption tests were used to characterize the morphology, magnetic property, and pH-responsive performance of the Janus-F-P. The Janus-F-P was used in the adsorptions of two kinds of representative PPCPs, i.e., hydrophilic (antipyrine) and hydrophobic (tiamulin), under neutral conditions. Commercially available NORIT CN activated carbon was used for comparison, and the adsorption results showed that the adsorption efficiency of Janus particles was higher than that of activated carbon. Therefore, Janus-F-P could be used to efficiently catalyze the degradation of adsorbed PPCPs in the Fenton/hydroxylamine system. The removal rate of PPCPs was above 85 % after repeated use (5 times).

Adsorption of pharmaceuticals and personal care products by deep eutectic solvents-regulated magnetic metal-organic framework adsorbents: Performance and mechanism

The ecological and human health threats brought by emerging pollutants are increasingly serious. Development of efficient removal methods is urgent. Herein, seven deep eutectic solvents (DESs) composed by quaternary ammonium salts and lactic acid or glycolic acid were synthesized and used to regulate magnetic (Fe3O4) metal organic framework (MUiO-66-NH2) composites. The obtained nanoparticles (named as DES-MUiO-66-NH2) were used as adsorbents to adsorb pharmaceuticals and personal care products (PPCPs). Langmuir isotherm model and pseudo-second-order kinetics model were suitable to analyze the adsorption process of DES-MUiO-66-NH2 to PPCPs, indicated that the adsorption of PPCPs was chemisorption on homogeneous surface of DES-MUiO-66-NH2 adsorbents. Under the optimal conditions, the adsorption capacity of DES-MUiO-66-NH2 toward ofloxacin and mefenamic acid reached up to 97.60 and 79.22 mg/g, respectively. Mechanism exploration indicated that DES-MUiO-66-NH2 selectively adsorbed PPCPs through electrostatic interaction, chelation, π-π stacking, hydrophobic interaction and hydrogen bonding. Density functional theory proved the chelation through theoretical calculation. Selective experiments manifested that the structures of DESs directly determined the specificity of DES-MUiO-66-NH2 for different PPCPs, and the investigation of structure–activity relationship provided new ideas for designing efficient tailor-made adsorbents for PPCPs. The proposed PPCPs removal approach focused on the guiding role of DESs in selective adsorption. And this green DESs regulation idea provided more options for the synthesis of high-efficiency and functional adsorbents for emerging pollutants.

Wrinkle structure on multifunctional MOFs to facilitate PPCPs adsorption in wastewater

A novel multifunctional metal-organic frameworks (MOFs) UiO-66@Fe3O4@UiO-66 (UiO = University of Oslo) was fabricated to adsorb pharmaceuticals and personal care products (PPCPs) under near neutral conditions. We designed a wrinkle structure on the surface of UiO-66@Fe3O4@UiO-66 by seeded growth strategy. These wrinkles were composed of Fe3O4 nanoparticles and outermost UiO-66. It made the specific surface area of the MOFs increases, and provided multiple active sites for a representative pollutant salicylic acid (SA) adsorption. Moreover, lattice defects formed during secondary growth facilitating the coordination interaction between SA and the secondary building unit of UiO-66@Fe3O4@UiO-66 under near neutral conditions. These advantages made the adsorption capacity of per unit mass UiO-66 in UiO-66@Fe3O4@UiO-66 about 42% higher than that of the pristine UiO-66, and the removal rate of 1 mg L−1 SA reach 64.5% in real wastewater. Furthermore, magnetic Fe3O4 particles in the wrinkles exhibited outstanding magnetic separation performance. So that UiO-66@Fe3O4@UiO-66 can be effectively separated from the liquid media and regenerated after adsorption. The results show that the wrinkled MOFs could be used as an excellent candidate for SA adsorption in real wastewater. More importantly, this strategy could guide the preparation of different kind of MOFs to adsorb PPCPs in wastewater.

Pharmaceuticals and personal care products removal from aqueous solution by nitrogen-functionalized carbon adsorbent derived from pomelo peel waste

The aim of this work is to investigate the feasibility of the preparation of nitrogen-functionalized adsorbent material from waste pomelo peel by using diammonium hydrogen orthophosphate (DAP) activation for the removal of Pharmaceuticals and personal care products (PPCPs) such as carbamazepine (CBZ), clofibric acid (CFA) and oxytetracycline (OTC). Our results showed that the adsorbent prepared by chemical activation in the presence of DAP lead to mesoporous material. The adsorbent exhibits acid and basic groups at its porous surface. The kinetic data are found to follow a pseudo-second order kinetic model. The Langmuir model provided a good description of the experimental isotherms for CBZ, whereas CFA and OTC adsorption behavior rather follow the Freundlich model. Moreover, the PPCPs adsorption was found to be strongly dependent on the pH of solution as well as the pKa of both adsorbents and PPCPs. The strong adsorptive interaction between PPCPs and P-DAP was mainly attributed to the combination interactions of electrostatic interaction, hydrogen bonding and π-π interactions.

Adsorptive removal of wide range of pharmaceuticals and personal care products from water using bio-MOF-1 derived porous carbon

Bio-MOF-1 was pyrolyzed at 1000 °C to obtain highly porous carbon containing oxygen and nitrogen. The bio-MOF-derived carbons (BMDCs) were firstly applied in the adsorptive removal of four pharmaceuticals and personal care products (PPCPs), with a wide range of acidities or basicities, from water. BMDC-12 h, obtained by pyrolysis for 12 h, was very competitive in the adsorption of PPCPs, in terms of both adsorption rate and adsorbed quantity. More importantly, carbon showed the highest adsorption capacities for both basic atenolol (ATNL; 552 mg/g) and acidic clofibric acid (CLFA; 540 mg/g) among all the adsorbents reported so far. The recyclability of BMDC-12 h in adsorption was also confirmed (after solvent washing) by both adsorption and characterization (by nitrogen adsorption and FTIR analyses). The plausible adsorption mechanism was also suggested based on the effect of solution pH on the adsorbed amounts of PPCPs. Electrostatic interaction was the primary mechanism for the adsorption of ATNL. However, CLFA adsorption could be explained mainly by H-bonding, where CLFA was the acceptor for hydrogen donated from BMDC-12 h. BMDC-12 h was suggested as a promising adsorbent for the removal of a wide range of PPCPs from water, based on the remarkably high adsorption capacity, rapid adsorption, and stable reusability.

Influence of CNT-rGO composite structures on their permeability and selectivity for membrane water treatment

In this study, flake-like reduced graphene oxide (rGO) was integrated with filamentous carbon nanotube (CNT) in different ways to prepare CNT-rGO composite membranes with three distinctive types of nanostructures. These membranes were further assessed at bench scale to determine the relationship between nanocomposite structure and membrane performance, including clean water permeability, removal efficiencies for pharmaceuticals and personal care products (PPCP), and resistance to organic fouling. Among the three types of prepared membranes, the membrane with CNT evenly distributed in the rGO layer outperformed other membranes in terms of PPCP removal efficiencies (76–100%), clean water permeability (4454Lm−2h−1bar−1), and antifouling property. Further membrane characterization using scanning electron microscopy and other analytical techniques revealed that the outstanding performance of this membrane resulted from the open CNT-rGO nanostructure that was beneficial for water permeation, PPCP adsorption, and membrane fouling reduction. Overall, these results demonstrated that, under the condition of similar compositions and surface properties, the nanostructures of CNT-rGO membranes significantly influenced membrane performance. Therefore, it is feasible to manipulate the nanostructures of CNT-rGO composite membranes to achieve high clean membrane permeability, outstanding antifouling property, and efficient contaminant removal.

Competitive adsorption of PPCP and humic substances by carbon nanotube membranes: Effects of coagulation and PPCP properties

Natural organic matter (NOM) and pharmaceuticals and personal care products (PPCP) are known to compete for adsorption sites on carbon nanotubes (CNT), resulting in decreasing PPCP adsorption onto CNT. In this study, four types of PPCP, as such acetaminophen (AAP), caffeine (CAF), triclosan (TCS), and carbendazim (CBD) were used to investigate the effects of PPCP properties and NOM coagulation on the competitive adsorption of PPCP and NOM. Coagulation preferentially removed HS from a natural surface water, thereby increasing adsorption of AAP, CAF, TCS and CBD by 19%, 13%, 17% and 11%, respectively. Similar trends were obtained with synthetic natural waters, for which the adsorption of AAP, CAF, TCS, and CBD increased by 29%, 7%, 44% and 69%, respectively, as humic acid (HA) concentration decreased from 10mgL−1 to 0mgL−1. Furthermore, PPCP properties also affected their competition with NOM for adsorption by CNT membranes Because CAF existed in cationic form at pH ranging from 7 to 8.3, its adsorption was less affected by the presence/coagulation of NOM than AAP, CBD, and TCS. Based upon these findings, coagulation has the potential to be integrated with CNT adsorption for the removal of PPCP compounds during advanced drinking water treatment.

Influence of wastewater precoagulation on adsorptive filtration of pharmaceutical and personal care products by carbon nanotube membranes

Multi-walled carbon nanotubes (MWCNT) have been widely studied for adsorption of pharmaceuticals and personal care products (PPCP). However, effluent organic matter (EfOM) is found to compete with PPCP for sorption sites on MWCNT, thereby markedly reducing the adsorptive capacities of MWCNT for PPCP in wastewater effluent. Herein, we report that precoagulation of secondary wastewater effluent effectively mitigated the competitive adsorption of EfOM and increased the adsorption capacities of MWCNT for acetaminophen, caffeine, triclosan, and carbendazim by up to 34%. Analyses of the coagulated waters using size exclusion chromatography and three-dimensional fluorescence spectrophotometry revealed that precoagulation primarily removed biopolymers and humic substances; the latter is known to suppress PPCP adsorption onto MWCNT. Moreover, the removal of EfOM by precoagulation reduced membrane permeability decrement and relieved membrane fouling. These results suggest that coagulation, a conventional technique widely used by water treatment plants, is a viable pretreatment approach for filtration of PPCP in wastewater by MWCNT. This finding also demonstrates the potential of integrating conventional technology and novel nanotechnology for cost-effective, advanced wastewater treatment.

Adsorption of pharmaceuticals and personal care products over metal-organic frameworks functionalized with hydroxyl groups: Quantitative analyses of H-bonding in adsorption

The removal of pharmaceuticals and personal care products (PPCPs) from water is important for ensuring a clean aquatic environment. In this work, the adsorptive removal of five PPCPs such as p-chloro-m-xylenol, bisphenol-A, triclosan, ketoprofen, and naproxen was carried out using metal-organic framework (MOF, here MIL-101) with or without modifications, i.e., introduction of hydroxyl groups. Quantitative investigations were conducted in order to understand the major mechanisms for adsorption. H-bonding is suggested as the principal mechanism for the adsorption of PPCPs over MOFs, where the PPCPs and MOFs can be H-acceptors and H-donors, respectively. This conclusion is drawn based on the fact that the quantity of adsorbed PPCPs increased monotonously with (i) increase in the number of H-acceptors (O in PPCPs) and (ii) increase in the number of –OH groups in the MOFs. The effect of solution pH on the amount of adsorbed triclosan also supports the suggested mechanism. Additionally, MIL-101-(OH)3 appears to be a useful adsorbent for PPCPs, especially for p-chloro-m-xylenol and ketoprofen.

Insight into the adsorption of PPCPs by porous adsorbents: Effect of the properties of adsorbents and adsorbates

Adsorption is an efficient method for removal of pharmaceuticals and personal care products (PPCPs). Magnetic resins are efficient adsorbents for water treatment and exhibit potential for PPCP removal. In this study, the magnetic hypercrosslinked resin Q100 was used for adsorption of PPCPs. The adsorption behavior of this resin was compared with those of two activated carbons, namely, Norit and F400D. Norit exhibited the fastest adsorption kinetics, followed by Q100. Norit featured a honeycomb shape and long-range ordered pore channels, which facilitated the diffusion of PPCPs. Moreover, the large average pore size of Q100 reduced diffusion resistance. The adsorbed amounts of 11 PPCPs on the three adsorbents increased with increasing adsorbate hydrophobicity. For Q100, a significant linear correlation was observed between the adsorption performance for PPCPs and hydrophobicity (logD value) of adsorbates (R2 = 0.8951); as such, PPCPs with high logD values (>1.69) could be efficiently removed. Compared with those of Norit and F400D, the adsorption performance of Q100 was less affected by humic acid because of the dominant hydrophobic interaction. Furthermore, Q100 showed improved regeneration performance, which renders it promising for PPCP removal in practical applications.

Multi-walled carbon nanotubes with selected properties for dynamic filtration of pharmaceuticals and personal care products

In this study, multi-walled carbon nanotubes (MWCNT) with selected properties, including pristine MWCNT, hydroxylated MWCNT (H-MWCNT), thin-walled MWCNT with large inner diameter (L-MWCNT), aminated MWCNT, and high-purity MWCNT were investigated for dynamic removal of eight pharmaceuticals and personal care products (PPCP). The removal ratios of different PPCP by the pristine MWCNT followed a decreasing order of triclosan (0.93) > prometryn (0.71) > 4-acetylamino-antipyrine (0.67) > carbendazim (0.65) > caffeine (0.42) > ibuprofen (0.34) > acetaminophen (0.29) at 100 min of filtration. Similar or even higher PPCP removals were obtained for all PPCP as the influent concentration decreased, suggesting potential consistent PPCP removals at environmental PPCP concentrations. The removal ratio of acetaminophen was increased to 0.74 by using H-MWCNT. SRFA (Suwannee River fulvic acid) suppressed PPCP adsorption to MWCNT, to greater extents with increasing SRFA concentrations. The L-MWCNT, despite a large inner diameter of 52 ± 3 nm, did not provide better resistance to the competitive adsorption of SRFA than MWCNT with a small inner diameter of 10 ± 2 nm. Future research will be conducted to minimize the effect of SRFA and facilitate application of MWCNT to the treatment of PPCP-contaminated water.