Adsorption of diclofenac on mesoporous activated carbons: Physical and chemical activation, modeling with genetic programming and molecular dynamic simulation

LED-light-driven over ZnO/biochar nanocomposite for activation of peroxymonosulfate to enhanced photocatalytic removal of methyl orange dye in aqueous solutions

ABSTRACTOrganic dyes are stable and persistent toxic compounds in the aquatic environment that are refractory to decompose by removal methods such as physico-chemical, optical and biological. Their presence in the aquatic media threatens human and wildlife. Herein, ZnO nanoparticles (NPs) due to good chemical durability, low cost and good photocatalytic performance was anchored on biochar (ZnO@biochar) nanocomposites were synthesized towards activation of peroxymonosulfate (PMS) for the photocatalytic removal of methyl orange (MO) dye. Several methods were used to characterization of the nanocomposites including FESEM, XRD, PL, EDS, FT-IR spectroscopy, and N2 adsorption/desorption. The results of the techniques demonstrated that the well-dispersed ZnO NPs were loaded onto the biochar surface. According to the particle size distribution graph, the average particle size of 64 nm was obtained for the ZnO NPs. BET analyzes showed that pore volume, the specific surface area (SSA) and average pore size of the synthesized nanocomposite increased. The survey of effective operational parameters indicated that the highest photocatalytic activity for MO removal was in the pH 3 of solution, 5 ppm initial dye concentration, 30 mg ZnO/biochar nanocomposite, and 20 mg PMS dose under LED-50W lamp irradiation (97.03% in the reaction time of 80 min). During the process, the reduction of the total organic carbon (TOC) contents and chemical oxygen demand (COD) were observed. Moreover, the MO degradation kinetics under optimal operating conditions were determined. It is concluded that the ZnO@biochar nanocomposite/PMS process was an efficient degradation method for the decomposition of the dye pollutant.

Diclofenac sodium adsorption on activated carbon: experimental, modeling and bayesian statistics

The present study modeled the adsorption process of the drug diclofenac sodium on activated charcoal. For this purpose, a mass balance-based model was used considering a fixed bed column. The mass transfer rate in the solid phase was represented by a driving force model proposed in this study, and a gamma exponent with a range of 0 > γ ≤ 2 was assigned to the model. Different isotherms were adopted to represent the equilibrium at the solid/liquid interface: the Langmuir, Freundlich, Sips and Redlich-Peterson isotherms. The modeling was approached from the perspective of Bayesian statistics, and the Markov chain Monte Carlo method was used for parameter estimation. Model validation was performed with experimental data obtained under different operating conditions of initial concentration ($C_{0.

Highly efficient removal of diclofenac sodium with polystyrene supported ionic liquid

ABSTRACTDiclofenac sodium (DS) is now recognized as an emerging pollutant, and is one of the most commonly discovered pharmaceuticals in water due to its extensive application in the clinic. This study examined the adsorption performance of a polystyrene-supported ionic liquid material (PS-[Nim][Cl]) for the removal of diclofenac sodium (DS) from water. The data from this study showed that maximum removal of DS can be achieved even in conditions with significant pH and temperature fluctuations. The adsorption process was rapid, more than 90% of DS could be removed within the first 10 min and adsorption equilibrium could be reached in just 30 min with a high removal efficiency (>99.9%). Adsorption reached saturation with a maximum adsorption capacity of approximately 785.2 mg/g. Moreover, the presence of K+, Na+, Ca2+, Mg2+, Cl-, and H2PO4- ions had little influence on DS adsorption, even when concentrations of these ions were 10,000 times higher than that of DS in water samples. The adsorbent also showed promising performance for the treatment of environmental water samples and groundwater containing DS.

Porous activated carbons derived from waste Moroccan pine cones for high-performance adsorption of bisphenol A from water

Porous-activated carbons (ACs) derived from Moroccan pine cones (PC) were synthesised by a two step-chemical activation/carbonisation method using phosphoric acid (PC-H) and zinc chloride (PC-Z) as activating agents and used for the adsorption of bisphenol A (BPA) from water. Several techniques (TGA/DTA, FT-IR, XRD, SEM and BET) were used to determine the surface area and pore characterisation and variations during the preparation of the adsorbents. The modification significantly increased the surface area of both ACs, resulting in values of 1369.03 m2 g-1 and 1018.86 m2 g-1 for PC-H and PC-Z, respectively. Subsequent adsorption tests were carried out, varying parameters including adsorbent dosage, pH, initial BPA concentration, and contact time. Therefore, the highest adsorption capacity was observed when the BPA molecules were in their neutral form. High pH values were found to be unfavourable for the removal of bisphenol A from water. The results showed that BPA adsorption kinetics and isotherms followed pseudo-second-order and Langmuir models. Thermodynamic studies indicated that the adsorption was spontaneous and endothermic. Besides, the regeneration of spent adsorbents demonstrated their reusability. The adsorption mechanisms can be attributed to physical adsorption, hydrogen bonds, electrostatic forces, hydrophobic interactions, and π-π intermolecular forces.

Removal of diclofenac sodium from aqueous solution using different ionic liquids functionalized tragacanth gum hydrogel prepared by radiation technique

Diclofenac sodium (DCF) was reported as an important emerging environmental pollutant and its removal from wastewater is very urgent. In this study, different alkyl substituted ionic liquids (1-alkyl -3-vinyl- imidazolium bromide [CnVIm]Br, n = 4, 6, 8, 10, 12) functionalized tragacanth gum (TG-CnBr) are prepared by radiation induced grafting and crosslinking polymerization. The adsorption behaviors of ionic liquids functionalized tragacanth gum for diclofenac sodium from aqueous solutions are examined. The adsorption capacity of TG-CnBr for diclofenac sodium increases with the increasing of alkyl chain length of the imidazolium cation and the hydrophobicity of the hydrogels. The maximum adsorption capacity by TG-C12Br for diclofenac sodium at 30, 40 and 50 °C were 327.87, 310.56 and 283.29 mg/g, respectively. The adsorption of TG-C12Br towards diclofenac sodium was little decreased with NaCl increasing. The removal efficiency was still remained 94.55 % within 5 adsorption-desorption cycles by 1 M HCl. Also, the adsorption mechanism including electrostatic attraction, hydrophobic interaction, hydrogen bonding, and π - π interaction was proposed.

Dual valorization of coastal biowastes for tetracycline remediation and biomethane production: A composite assisted anaerobic digestion

Harnessing coastal biowaste for dual valorization in water treatment and biofuel production holds paramount importance for sustainability and resource challenges. This study investigated the potential of engineered composite (CABC) derived from coastal biowaste-based materials for tetracycline (TC) removal and biomethane production. High-yield calcium carbonate (CaCO3; 95.65%; bivalve shells) and biochar (GA-BC; 41.50%; green macroalgae) were produced and used as precursors for CABC. The characterization results revealed presence of β-CaCO3 and ν2-CO3 aragonite in CaCO3, and composite homogeneity was achieved. The CABC exhibited a maximum TC sorption capacity of 342.26 mg/g via synergistic sorption mechanisms (i.e., surface/pore filling, electrostatic attraction, calcium ion exchange, and chelation). Supplementation of anaerobic digestion process with GA-BC, CaCO3, and CABC was investigated via three consecutive cycles. Biochemical methane potential of glucose as a sole substrate was increased from 157.50 to 217.00, 187.00, and 259.00 mL-CH4, while dual substrate (glucose+TC) treatment was increased from 94.5 to 146.5, 129.0, and 153.00 mL-CH4 for GA-BC, CaCO3, and CABC, respectively. Moreover, system stability and TC removal were increased with the addition of GA-BC (40.90%), CaCO3 (16.30%), and CABC (53.70%). Therefore, this study exemplifies the circular bioeconomy approach, demonstrating the sustainable use of biowaste-derived composite for water treatment and biofuel production.

Occurrence, toxicity, impact and removal of selected non-steroidal anti-inflammatory drugs (NSAIDs): A review

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used pharmaceuticals for human therapy, pet therapeutics, and veterinary feeds, enabling them to enter into water sources such as wastewater, soil and sediment, and seawater. The control of NSAIDs has led to the advent of the novel materials for treatment techniques. Herein, we review the occurrence, impact and toxicity of NSAIDs against aquatic microorganisms, plants and humans. Typical NSAIDs, e.g., ibuprofen, ketoprofen, diclofenac, naproxen and aspirin were detected at high concentrations in wastewater up to 2,747,000 ng L-1. NSAIDs in water could cause genotoxicity, endocrine disruption, locomotive disorders, body deformations, organs damage, and photosynthetic corruption. Considering treatment methods, among adsorbents for removal of NSAIDs from water, metal-organic frameworks (10.7-638 mg g-1) and advanced porous carbons (7.4-400 mg g-1) were the most robust. Therefore, these carbon-based adsorbents showed promise in efficiency for the treatment of NSAIDs.

Enhanced adsorption of diclofenac onto activated carbon derived from PET plastic by one-step pyrolysis with KOH

Plastic pollution is a severe threat to the health of ecosystems, and recycling plastics is recognized as a key control strategy. This study used the one-step pyrolysis assisted with KOH activation to recycle the widely used polyethylene terephthalate (PET) plastic as activated carbon (PET-AC) which was subsequently applied to adsorb diclofenac (DCF), a frequently detected emerging contaminant in water, for the first time. It was found that both the pyrolysis temperature and the addition of KOH can effectively regulate the pore sizes and volumes of PET-AC. PET-AC obtained at 700 °C demonstrated a high adsorption capacity of DCF up to 179.42 mg g-1 at 45 °C. The adsorption kinetics was conducted with both static jar and dynamic column tests and analyzed with various models. Thermodynamic results demonstrated that the adsorption of DCF was spontaneous and endothermic. The material also presented an excellent potential to adsorb other pharmaceuticals and personal care products in water. XPS and FTIR analysis indicated that the adsorption might be mainly driven by the physical forces, especially π-π interaction and hydrogen bonding. This study provided a reference for recycling waste plastic as an efficient adsorbent to eliminate organic contaminants from water.

Efficient sonocatalytic degradation of orange II dye and real textile wastewater using peroxymonosulfate activated with a novel heterogeneous TiO2–FeZn bimetallic nanocatalyst

TiO₂–FeZn nanocatalyst combined with sonolysis were used to activate peroxymonosulfate (PMS) as a highly efficient advanced oxidation process (US/TiO₂–FeZn/PMS) for the decoloration of orange II dye (OII) and real textile wastewater. The characterization of the as-synthesized NPs was performed by SEM, FTIR, EDX and XRD analyses. Optimal experimental conditions of operational parameters were obtained: pH = 3, 15 mg/L initial OII concentration, 0.2 g/L PMS, 0.7 g/L nanocatalyst dosing, and 300 W ultrasonic power. The decolorization was observed to increase with increasing the dose of nanocatalyst and the ultrasonic power, and with decreasing pH (under acidic conditions). Under optimal experimental conditions, decolorization and COD removal of textile wastewater were 99.9% and 74.6%, respectively, at 40 min. The TiO₂–FeZn/PMS/US as a novel process exhibited a higher removal of OII (95%) than TiO₂ NPs/PMS/US process (54%). The OII removal efficiency by the different processes decreased in the following order: TiO₂–FeZn/US/PMS > TiO₂–FeZn/PMS > TiO₂–FeZn/US > TiO₂ /US/PMS > US/PMS > TiO₂–FeZn > PMS > US. The recyclability study revealed that the process could be reused up to three consecutive cycles. The current US/nanocatalyst/PMS system was concluded to be an efficient, reusable and stable nanocatalyst for the oxidation of textile dyes.

The role of polybrominated diphenyl ethers in the induction of cancer: a systematic review of insight into their mechanisms

Environmental pollution caused by persistent organic pollutants (POPs) has increased the challenge for the scientific communities. Polybrominated diphenyl ethers (PBDEs), classified as POPs, are widely applied in various materials as brominated flame retardants (BFRs). Because of the nature of these chemical compounds including toxicity, stability, and capability to bioaccumulate and biomagnify, PBDEs have posed a great challenge and risk to human health and wildlife. Therefore, the side effects of exposure to PBDEs as ubiquitous pollutants in the environment on cancer progression were investigated using a systematic review (SR) survey. To achieve this goal, forty studies were considered after defining the search terms and inclusion criteria, and/or exclusion criteria; the eligible records were collected from the international bibliographic databases. Based on the findings of the reviewed records, environmental exposure to the BFRs including PBDEs has a positive association with different mechanisms that induce cancer progression. However, the findings of the reviewed studies were not totally consistent with the mode of action and side effects are yet to be fully elucidated. Several articles have reported that BFRs can be carcinogenic and induce epithelial to mesenchymal transition via different mechanisms. The main mode of action involved in the environmental exposure to BFRs and the risk of cancer progression is endoplasmic reticulum and oxidative stress (OS). Generally, the imbalance of antioxidant mechanisms, reactive nitrogen species (RNSs) and reactive oxygen species (ROSs), during damage in cells, and stress caused OS, which increases tumorigenesis via multiple mechanisms, such as DNA damage, inflammation, and angiogenesis.

Porous Biomass Carbon Derived from Clivia miniata Leaves via NaOH Activation for Removal of Dye

Clivia miniata (CM), is an important ornamental plant and has been widely cultivated all over the world. However, there are no reports on Clivia miniata-based porous biomass carbon (CMBC). In this study, for the first time, CM leaves were used to generate porous biomass carbon via NaOH activation. The structures and surface characteristics were determined using scanning electron microscopy, N2 adsorption/desorption, TGA, FT-IR, X-ray diffraction, Raman and X-ray photoelectron spectra tests. CMBC has a large SSA (2716 m2/g) and a total pore volume of 1.95 cm3/g. To test the adsorption performance via adsorption experiments, the cationic and synthetic dye, malachite green (MG), was utilized as the adsorption model. The CMBC had a greatest adsorption capacity of 2622.9 mg/g at a pH value of 8 and had a fastest adsorption capacity of 1161.7 mg/g in the first 5 min. To explain MG adsorption into CMBC, the Freundlich isotherm and the pseudo-second-order kinetic model were used. The adsorption mechanism of MG was also investigated. After 10 cycles, the adsorption efficiency of CMBC to MG could still reach 85.3%. In summary, CMBC has excellent potential in dyeing wastewater pollution treatment.

Removal of anti-inflammatory drugs using activated carbon from agro-industrial origin: current advances in kinetics, isotherms, and thermodynamic studies

Nonsteroidal anti-inflammatory drugs (NSAIDs) are highly consumed around the world and consequently found as emerging pollutants in water; they are found in concentrations up to µg L−1 making their removal a priority. In this matter, adsorption is an efficient alternative for drug removal, so using activated carbon (AC) as an adsorbent is a highly explored subject. The current interest is to obtain AC from waste, for example, those of agro-industrial origin, reducing this way the overall costs of the process. Although information regarding the use of AC from agro-industrial origin in the removal of NSAIDs is limited, an exclusive compilation is required to understand the state of the art to date. This work aims to update information related to the adsorption of ibuprofen, diclofenac, and naproxen on agro-industrial AC, and it is focused on the period 2016–2021. It highlights the characteristics of agro-industrial AC responsible for efficient adsorption. Recent adsorption studies, including kinetics, isotherms, and thermodynamics, are analyzed and compared. Progress on removing NSAIDs from real wastewater is also presented and finally proposed adsorption mechanisms and costs related to these removal processes.

A graphene oxide modified cellulose nanocrystal/PNIPAAm IPN hydrogel for the adsorption of Congo red and methylene blue

A simple strategy is developed to fabricate a graphene oxide modified cellulose nanocrystal/PNIPAAm IPN (GO-CNC/PNIPAAm IPN) hydrogel. It is a high-efficiency and low-cost adsorbent for the removal the anionic dye CR and cationic dye MB.