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Coagulation/Flocculation (C/F) process aims to efficiently eliminate turbidity, TSS, COD, BOD, toxic metals, phosphates, and UV254nm from wastewater. Both natural and synthetic coagulants, used alone or in conjunction with flocculants, play crucial roles in this treatment. This review summarizes recent trends in coagulants for wastewater treatment, highlighting a wide array of inorganic and organic coagulants that have demonstrated significant efficacy based on reviewed studies. Notably, Crab Shell Bio-Coagulant (CS) excels in turbidity remov5al, achieving a remarkable 98.91% removal rate, while oak leaves protein shows superior performance in TSS and COD removal. Synthetic inorganic coagulants like PALS, PSiFAC1.5:10:15, and PAPEFAC1.5-10-15 demonstrate outstanding turbidity removal rates, over 96%. POFC-2 coagulant stands out for efficiently removing TSS and COD from domestic wastewater, achieving up to 93% removal for TSS and 89% for COD. Moreover, the utilization of FeCl3 as an inorganic coagulant alongside chitosan as an organic flocculant shows promise in reducing turbidity, COD, and polyphenols in wastewater from vegetable oil refineries. PE-2, a novel organic coagulant, demonstrates exceptional efficacy in eliminating turbidity, TSS, COD, and BOD from sugar industry wastewater. Chitosan shows effectiveness in removing TOC and orthophosphates in brewery wastewater. Additionally, CTAB shows high efficiency in removing various toxic metal ions from wastewater. The hybrid coagulants: PAAP0.1,0.5 and PPAZF accomplish exceptional turbidity removal rates, approximately 98%.

The reuse and valorization of olive mill by-products, among others, is getting attention in the food and drugs-cosmetics sectors, due the recovery of their essential bioactive compounds in order to incorporate them as ingredients in functional foods, cosmetics, and pharmaceuticals. Olive pomace represents olive mill's main residue (by-product), and it is a sustainable and of low-cost renewable source of several bioactive compounds, while its valorization can reduce its environmental impact and make it an additional economic resource for food industries in a circular economy design. In this article, the natural bio-functional compounds of olive pomace with antioxidant and anti-inflammatory bioactivities are thoroughly reviewed. The incorporation of such bioactives as ingredients in functional foods and cosmetics is also discussed in detail. The limitations of such applications are also presented. Thus, promising techniques, such as encapsulation, and their applications for stabilizing and masking undesirable characteristics of such compounds, are also exhibited. The so far promising in vitro outcomes seem to support further in vivo assessment in trials-based setting.

Fermented alcoholic beverages and their by-products, including beer and breweries' bio-wastes like spent yeasts, grain, and hops, contain a plethora of natural bioactive compounds that have recently gained attention for their valorization as functional ingredients in several novel foods and nutraceuticals, as well as in drugs and cosmetics applications. Within this article, the natural bio-functional compounds of fermented beer product and breweries' by-products with anti-inflammatory, antithrombotic, and anti-oxidant bioactivities are thoroughly reviewed. The important roles of yeasts involved for such bioactives to be present in the fermented product and in the brewery bio-wastes are also outlined. The health promoting benefits of beer moderate consumption resulting from these bioactives, as part of a balanced diet, against inflammation-related chronic disorders is also discussed, along with the detrimental effects of beer consumption abuse and the potential benefits of alternative non-alcoholic beers. The mechanisms of action and synergism of the natural bioactives present in the fermented beer product and in breweries' by-products, with anti-inflammatory, anti-thrombotic, and antioxidant properties are also presented. Current research and future perspectives on valorizing bioactives of fermented beer and brewery by-products, such as spent yeasts, grain and hops in health-promoting functional foods, supplements, nutraceuticals cosmetics, cosmeceuticals, and pharmaceuticals are also thoroughly evaluated, while the limitations of their use are also discussed.

Pharmaceuticals are used to improve the lives of people across the globe. The high demand for their fabrication and use causes a very serious environmental threat since their presence is ubiquitous in aqueous matrices. For this reason, the synthesis, characterisation, and efficiency of three chitosan-based materials to eliminate pharmaceutical mixtures from aqueous solutions were examined in the present study. The target mixture comprised seven widely used drugs: carbamazepine, cyclophosphamide, adefovir, levofloxacin, metronidazole, glibenclamide, and trimethoprim. The grafting of poly(ethylene imine) and poly(acrylamide) on the chitosan structure allowed its physical characteristics to be controlled. An adsorption assessment was performed at different pH values, and it was concluded that pH = 4 was the optimum value. The adsorption kinetics revealed that the adsorption of a drug mixture involves a combination of physical and chemical adsorption. The adsorption process appeared to be finished after 1 h for all compounds of the studied mixture, with CS-AMI exhibiting the fastest kinetics. Mass adsorption experiments were also carried out to determine its effects. Overall, the grafting process significantly increased the adsorption capacity over the pristine material. Specifically, the highest capacity increase for CS-PEI was ~220% for carbamazepine, and for CS-AMI, it was 158% for trimethoprim. FT-IR, SEM, and XRD were used for the characterisation of the polymers. Based on the findings, the three materials are suggested as very effective adsorbents for the elimination of medicine residues from aqueous matrices.

Microplastics (MPs) have been detected in numerous ecosystems worldwide. To better understand their distribution and establish a foundation for risk assessment protocols, detailed information on MP concentrations and polymer compositions is essential. This study assessed the presence and chemical composition of MPs, ranging from 5 mm to 125 µm, in the effluents of a Greek wastewater treatment plant (WWTP) over a one-year period to understand the temporal variation in MP input into the receiving water fidentification and mass data were obtained through pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) analysis. The study found that fibers (50–78 %) were the predominant form of MPs compared to particles, with the most common size range being 125–200 μm for fibers and 200–2000 μm for particles. Py-GC/MS analysis indicated a clear dominance of polyolefins among the polymers analyzed, with MP mass concentrations ranging from 4.5 to 69.29 μg/L. Increased concentrations of MP items and mass were observed following rainfall events (due to elevated discharge and altered hydraulic parameters) and during windy conditions. This underscores the need for improved assessment of background parameters in future MP monitoring strategies. By providing data on MP input in WWTP effluents over a one-year period, this study enhances our understanding of seasonal MP dynamics and can serve as a crucial reference for future measurements.

The disposal of pharmaceutical compounds in wastewater is a significant environmental and health challenge. These drug residues can have adverse effects on aquatic ecosystems and human health. Chitosan, a natural polysaccharide derived from chitin, is promising as an effective material for adsorbing pharmaceutical waste due to its unique chemical structure containing amino and hydroxy functional groups that facilitate interactions with organic molecules in wastewater. Chitosan can adopt various structural forms, such as hydrogels, nanoparticles, beads, membranes, fibers, and aerogels, which offer opportunities to optimize its performance in adsorbing drug waste. In this review, which includes articles published in the last 5 years, the influence of chitosan's structural forms, particularly on the adsorption of pharmaceutical compounds in wastewater is explored. Furthermore, the different synthesis and fabrication methods for each chitosan form and highlight their characteristics, advantages, and specific applications, are discussed. Additionally, this review delves into the adsorption mechanisms involved in each form.

The chemical industry, a cornerstone of the global economy essential for modern life, has raised significant concerns due to its unique nature. Chemical technologies often require high energy inputs, involving ecotoxic reagents thus assessing risks from an economic standpoint becomes complex. While the economic aspects of chemical technologies have been discussed and economic tools have been used to inform investment decisions in this field, many fundamental issues remain unexplored, such as the clear definition of chemical technology economics and the reasons for its importance. The primary contribution of this article is to synthesize insights into these fundamental issues and propose pathways for future research in chemical technology economics. This review is divided into two sections: the first provides an overview of the significance of economic factors in chemical technologies, and the second explores the fundamentals of economics and their application to chemical technology considerations. Our research underscores that economic theories significantly influence the profile of chemical technologies, viewing the chemical sector as a dual asset. First, the sector has a unique opportunity to lead the way in promoting sustainable economic development, and second, it can adopt economic behaviors that align with environmental and societal needs.

The main goal of this study is the examination of polypropylene (PP) microplastics (MPs) as possible carriers of daily use pharmaceutical compounds. The selected compounds can be separated into three groups: (i) antibiotics (Trimethoprim, Metronidazole, Indomethacin, Isoniazid), (ii) anti-inflammatories (Ketoprofen, Diclofenac), and (iii) anti-hypertensive (Valsartan). Two types of PP MPs (virgin and UV-aged) were used in the experimental procedure, and the effect of time and the effect of the initial concentrations of the drugs were examined. The impact of various environmental factors such as pH, salinity, and natural organic matter were also explored. The last two factors were studied using real aqueous matrices such as wastewater and seawater. According to the obtained results, the highest uptake was observed in indomethacin (9.3 mg/g) and diclofenac (7.3 mg/g), owing to their physiochemical properties. Aged particles showed enhanced adsorption ability in accordance with the existing literature, as their adsorption capacity was between 0.5–1.5 times greater than that of the virgin ones. Regarding the desorption of compounds from the virgin and aged PP MPs at three different pH values, diclofenac and indomethacin exhibited the highest desorption capacity, while alkaline conditions favored the desorption ability of PP MPs for most of the target compounds.

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely utilized pharmaceuticals worldwide. Besides their recognized anti-inflammatory effects, these drugs exhibit various other pleiotropic effects in several cells, including platelets. Within this article, the multifaceted properties of NSAIDs on platelet functions, activation and viability, as well as their interaction(s) with established antiplatelet medications, by hindering several platelet agonists’ pathways and receptors, are thoroughly reviewed. The efficacy and safety of NSAIDs as adjunctive therapies for conditions involving inflammation and platelet activation are also discussed. Emphasis is given to the antiplatelet potential of commonly administered NSAIDs medications, such as ibuprofen, diclofenac, naproxen and ketoprofen, alongside non-opioid analgesic and antipyretic medications like paracetamol. This article delves into their mechanisms of action against different pathways of platelet activation, aggregation and overall platelet functions, highlighting additional health-promoting properties of these anti-inflammatory and analgesic agents, without neglecting the induced by these drugs’ side-effects on platelets’ functionality and thrombocytopenia. Environmental issues emerging from the ever-increased subscription of these drugs are also discussed, along with the need for novel water treatment methodologies for their appropriate elimination from water and wastewater samples. Despite being efficiently eliminated during wastewater treatment processes on occasion, NSAIDs remain prevalent and are found at significant concentrations in water bodies that receive effluents from wastewater treatment plants (WWTPs), since there is no one-size-fits-all solution for removing all contaminants from wastewater, depending on the specific characteristics of the wastewater. Several novel methods have been studied, with adsorption being proposed as a cost-effective and environmentally friendly method for wastewater purification from such drugs. This article also presents limitations and future prospects regarding the observed antiplatelet effects of NSAIDs, as well as the potential of novel derivatives of these compounds, with benefits in other important platelet functions.

PFAS, or per- and poly-fluoroalkyl substances, are a broad group of man-made organic compounds that are very persistent, mobile, and tend to bioaccumulate. Their removal from different environmental media is becoming increasingly important because they are associated with a multitude of (eco)toxicological effects on both humans and the environment. PFAS are detected in wastewater, groundwater, drinking water, and surface water, with the subcategories of PFOS and PFOA being the most detected. These organic compounds are divided into polymeric and non-polymeric groups. Non-polymeric PFAS are of great research interest due to their frequent detection in the environment. Numerous methods have been applied for the removal of PFAS and are divided into destructive and non-destructive (separation) techniques. Given the strength of the C–F bond, the destruction of PFAS is challenging, while for most of the separation techniques, the management of isolated PFAS requires further consideration. Most of the techniques have been applied to small-scale applications and show some limitations for larger applications, even though they are promising. Adsorption is an environmentally sustainable, economical, and high-performance technique that is applied to remove several classes of emerging pollutants from water. In this review, the use of various types of adsorbents for PFAS removal from water is reported, as well as the expected adsorption mechanisms. There are several technologies being considered and developed to manage PFAS; however, they are still in the experimental stage, with each showing its appeal for potential larger applications.

Wastewater treatment has attracted much attention in recent years as a potential source of water, and there are some concerns about its safety for human use. Eco-friendly and cost-effective adsorbent materials were successfully synthesized from several peels, such as orange, banana, pomegranate, avocado, kiwi, etc., and were used as natural adsorbents or as activated carbons derived from these peels for water and wastewater treatment. In this review, the latest research focusing on the effective modification of these peels for the removal of several pollutants found in wastewaters are summarized and compared, such as pharmaceuticals, dyes, heavy metals, and anions that are released in waste and have a negative impact on human and animal health. In this review, focus is given to activated carbon produced from fruit peels. Moreover, fruit peels as adsorbent materials, without previously being converted to activated carbon, are of limited use in the recent literature.

Nanoparticles have gained considerable attention during the present millennium due to its unique properties and usage of same in all the scientific fields. The present study was aimed to phyto-fabricate zinc oxide nanoparticles (ZnO NPs) from Sida acuta and evaluate its antioxidant and photocatalytic activity against the dye victoria blue (VB). The phyto-fabricated ZnO NPs when subjected for physico-chemical characterization showed an absorbance peak at 373 nm and was spherical in nature. Strong and well-distinguished sharp peaks were noticed in X-ray diffraction analysis with an average size of ∼32.82 nm calculated through Scherrer’s formula. The size was also authenticated through dynamic light scattering analysis and transmission electron microscopy. The Fourier transform-infrared spectroscopy confirmed that the phyto-constituents of the plant extract served as capping/stabilizing agents during the synthesis of ZnO NPs. The atomic force microscopy studies on morphology and geometrics of the synthesized particles indicated that particles were monodispersed with colour difference. In addition, the surface area of ZnO NPs measured by Braunauer–Emmett–Teller experimental studies for adsorption isotherms was found to be 7.364 m2·g−1. The antioxidant efficacy of the phyto-fabricated ZnO NPs offered concentration-dependent antioxidant activity with an IC50 value of 0.74 mg·mL−1. Further, the VB (9 mM) dye degradation studies using the phyto-fabricated ZnO NPs (0.75 g·L−1) resulted in dye degradation of 93% at 40 min in natural sunlight. Further, the reuse and recycling of the photocatalyst for dye degradation offered 70.25% dye degradation ability within 40 min exposure to sunlight at the fifth cycle of reusability thereby indicating effective dye degradation ability of the phyto-fabricated ZnO NPs from the aqueous leaf extract of S. acuta.

Through epistemic efforts in water remediation, numerous sorbents have emerged as either low-cost or more expensive. This review article describes the properties, functions and modifications of cost-effective sorbents based on chitosan and poly(vinyl alcohol) blends for aqueous solutions treatment from heavy metals. Interesting synthesis routes have been reported for the production of membranes, beads, foams and mats, while the kinetic and thermodynamic studies provide spherical knowledge of the system. Tables with the adsorbent’s capacity and enthalpy change are included, while indicative images from the synthesis and characterization techniques of the adsorbents are presented.

Over the past 30 years, the global consumption of pharmaceuticals has risen by almost 3 times. Despite being fundamental to the protection of human life, pharmaceuticals have been implicated as a considerable source of environmental pollution, owing to the various ways that they and their components end up into water bodies, resulting in the gradual contamination of their surrounding environment. Technological approaches are required to address such a challenge should be both competent and cost-effective. A wide variety of treatments has been assessed, concluding that the adsorption method is an appealing, simple but powerful tool for the extraction of pollutants. More specifically, the use of Chitosan and its modifications through physicochemical methods have received the spotlight as an emerging solution for the elimination of organic pollutants from aqueous media. The presence of amino and hydroxyl groups provides modification sites that allow for various potential interactions between chitosan and pollutants, such as pharmaceuticals. This work examines the trends in chitosan modifications and their effectiveness in eliminating pharmaceuticals through adsorption treatments. The adsorption mechanisms have also been studied. This review classifies the pharmaceuticals studied in subcategories, while determining the characteristics of the adsorbents used during the removal effort. The importance of this work lies in the assembly of published works related to chitosan and its modifications (2018–2021), and the summarization of the key findings with regard to their capacity to eliminate pharmaceuticals from aqueous solutions.

Solving the problem of atmospheric air pollution has been one of the most pressing topics on the modern agenda of sustainable development for more than a decade. Every day mankind emits significant amounts of greenhouse gases and toxic substances such as SO2, particulate matters, benzene, lead, etc. The low quality of atmospheric air caused by high degree of contamination entails significant negative consequences for the environment and human health in the long term. A steady increase in greenhouse gas emissions into the atmosphere provokes an increase in average temperature and, consequently, serious climate changes. Governments of different countries are developing a wide range of state programs to protect the environment and are implementing various initiatives to eco-modernize industrial enterprises that are the largest emitters of emissions. However, despite the measures taken, the situation with atmospheric air pollution remains acute in most countries of the world. The purpose of this study is to review and analyse the most common economic and administrative-legal instruments used to reduce the negative impact on atmospheric air. Based on the results of the study, the most effective tools were identified and recommendations for their further improvement were proposed.

In this study, activated carbon was suitably modified with Mg/Si/La and its effectiveness in removing As(III) was investigated. The structure of Magnesium/Silica/Lanthamum@Activated Carbon (Mg-Si-La@AC) was fully characterized and several parameters, such the dosage, pH, contact time, and initial As(III) concentration, were studied. Thus, the BET surface area, total pore volume, and micropore volume of Mg-Si-La@AC were measured to be 271.46 m2/g, 0.006 cm3/g and 0.52 cm3/g, respectively. The results showed that the optimal condition for the reduction in As(III) from the initial concentration of 100 μg/L to below 10 μg/L was the addition of 1.5 g/L of adsorbent at pH 7.0. Furthermore, 4 h of contact time showed >90% removal. The Langmuir isotherm model was best fitted to the experimental results, exhibiting a maximum adsorption capacity of 322 μg/g, and the PSO kinetic model was found to be the most applicable according to kinetics. Consecutive regeneration studies were carried out and the results showed that the adsorbent was effectively used up to four cycles.

In the present work, a new method for dermal delivery using nanobubbles (NBs) is investigated. Oxygen NBs are generated in deionized water and used to produce cosmetic formulations with hyaluronic acid as an active ingredient. Nanobubbles result in the improvement of the effect and penetration of the active ingredient through Strat-M, a synthetic membrane that resembles human skin. Experiments conducted with the Franz Cell device confirm the greater penetration of the active ingredient into Strat-M due to NBs, compared to cosmetic formulations that do not contain NBs. The effect of NBs was further examined by measuring UV-Vis and FTIR spectra. A possible mechanism was outlined, too. It was also found that NBs do not change the pH or the FTIR spectrum of the cosmetic serum indicating non-toxicity.

The global concern about the fate of plastic particles, including microplastics (MPs) and nanoplastics (NPs), in aquatic ecosystems has undoubtedly grown as million tons of polymeric fragments are released in oceans in an annual basis. The ability of these plastic items being transferred into the several aquatic ecosystems in combination with their ability to absorb organic or inorganic pollutants onto their surface, raises the need for a sufficient monitoring of MPs/NPs in complex aquatic environmental matrices. In the frame of these, microscopic techniques are considered as ideal tools to critically assist other analytical techniques due to their fast-screening character or even complete a detailed analysis of plastic particles in some cases. In the light of the above, the present review discusses a group of microscopic techniques used in the analysis of plastic particles isolated from aquatic samples most likely to be important in future monitoring actions, emphasizing on their operating fundamentals, merits and limitations. Moreover, the microscopic techniques are highlighted as green tools in the analysis of plastic particles/fragments due to their minimum need of reagents, solvents, and energy required for the implementation of such a kind of analysis. Finally, the effective combination of microscopic techniques with spectroscopic ones are also presented.

Highlights Tribenuron-methyl-loaded zein nanoparticles synthesized. TM-loaded zein nanoparticles characterized by DLS, FTIR, SEM. The TM’s drug encapsulation efficiency (EE%) within the nanoparticles was ca. 81% ± 3. F127/VPA and lignin/VPA microemulsions were tested for their cytotoxic activity. Use of nanoparticles containing tribenuron-methyl (TMZNP-5) herbicides had a significant effect on weed control. After 5 weeks, TMZNP-5 was able to completely suppress the C. arvensis.

Many industries use huge amounts of synthetic dyes which may release into the wastewater in dyeing processes causing serious damage to aquatic life as they are recalcitrant, nonbiodegradable, stable to oxidizing agents, and toxic. Adsorption on activated carbon has been found to be a very efficient treatment method. In this work, a new adsorbent material composed of activated carbon and aluminum chloride (AC-Al) was prepared for the removal of a commercial anionic and anthraquinonic reactive dye, i.e., Reactive Black 5 (RB5) under various experimental conditions. Several parameters, such as the adsorbent’s dosage, initial RB5 concentration, pH, and contact time, were studied in order to determine the feasibility of AC-Al. According to the results, it was found that there was an increase in RB5 removal as the adsorbent’s dosage increased, especially, in pH 2 ± 0.1, where the removal rate increased, and reaching 100% by 1.0 g/L of AC-Al. Freundlich isotherm and pseudo-second-order kinetic models adequately fit the experimental data, indicating that favorable and heterogeneous adsorption occurred, closer to chemisorption. According to thermodynamics, it was found that the adsorption procedure was endothermic in nature (∆H0 = 62.621 kJ/mol) and spontaneous (∆G0 < 0), and according to the positive value of ∆S0 0.0293 (kJ/mol∙K), there is an increase in random interaction between solid and liquid interfaces. Finally, the AC-Al adsorbent was successfully regenerated and reused for four cycles.

Chitin is mentioned as the second most abundant and important natural biopolymer in worldwide scale. The main sources for the extraction and exploitation of this natural polysaccharide polymer are crabs and shrimps. Chitosan (poly-β-(1 → 4)-2-amino-2-deoxy-d-glucose) is the most important derivative of chitin and can be used in a wide variety of applications including cosmetics, pharmaceutical and biomedical applications, food, etc., giving this substance high value-added applications. Moreover, chitosan has applications in adsorption because it contains amino and hydroxyl groups in its molecules, and can thus contribute to many possible adsorption interactions between chitosan and pollutants (pharmaceuticals/drugs, metals, phenols, pesticides, etc.). However, it must be noted that one of the most important techniques of decontamination is considered to be adsorption because it is simple, low-cost, and fast. This review emphasizes on recently published research papers (2013–2021) and briefly describes the chemical modifications of chitosan (grafting, cross-linking, etc.), for the adsorption of a variety of emerging contaminants from aqueous solutions, and characterization results. Finally, tables are depicted from selected chitosan synthetic routes and the pH effects are discussed, along with the best-fitting isotherm and kinetic models.

This study explores the photocatalytic transformation of the antiviral drug abacavir employing different advanced oxidation processes (AOPs) such as UV/TiO2, UV/MOF/H2O2, UV/MOF/S2O82−, UV/Fe2+/H2O2, and UV/Fe2+/S2O82−. All processes appear to be effective in eliminating abacavir within a few minutes, while the evolution profile of the basic transformation product, descyclopropyl-abacavir (TP-247) was also monitored. Moreover, the implementation of the most efficient technologies towards the removal of abacavir in different matrices such as wastewater effluent and leachate was also assessed, revealing that the organic matter present or the inorganic constituents can retard the whole process. Four major transformation products were detected, and their time-evolution profiles were recorded in all studied matrices, revealing that different transformation pathways dominate in each matrix. Finally, the prediction of the toxicity of the major TPs employing ECOSAR software was conducted and showed that only hydroxylation can play a detoxification role in the treated solution.

The occurrence of arsenic in water is a global problem for public health. Several removal technologies have been developed for arsenic removal from water, and adsorption onto iron oxy-hydroxides is the most widely used technique. Granular ferric hydroxide (GFH) has been used mainly for As(V) removal, but it has the disadvantage that it can create a problem with the residual concentration of iron in the water. Moreover, graphene oxide (GO), which contains a large amount of reactive oxygen, exhibits high adsorbing capacity. In this study, the combined use of GO and GFH as adsorbent materials in different molar ratios was investigated in order to achieve the maximum As(III) removal from aqueous solutions. The effect of the adsorbent’s dosage, pH value, contact time, initial As(III), and different molar ratios of GO/GFH was examined. As depicted, the presence of GFH enhances the use of GO. In particular, the molar ratio of GO/GFH 2:1 (i.e., 0.2 g/L GO and 0.1 g/L GFH) is chosen as optimal at pH value 7.0 ± 0.1, while the removal percentage increased from 10 % (absence of GFH) to 90% with the simultaneous addition of GFH. Freundlich isotherm and pseudo-second-order kinetic models described the experimental data adequately and the highest adsorption capacity that was achieved was 22.62 μg/g.

Graphene is a popular material with outstanding properties due to its single layer. Graphene and its oxide have been put to the test as nano-sized building components for separation membranes with distinctive structures and adjustable physicochemical attributes. Graphene-based membranes have exhibited excellent water and gas purification abilities, which have garnered the spotlight over the past decade. This work aims to examine the most recent science and engineering cutting-edge advances of graphene-based membranes in regard to design, production and use. Additional effort will be directed towards the breakthroughs in synthesizing graphene and its composites to create various forms of membranes, such as nanoporous layers, laminates and graphene-based compounds. Their efficiency in separating and decontaminating water via different techniques such as cross-linking, layer by layer and coating will also be explored. This review intends to offer comprehensive, up-to-date information that will be useful to scientists of multiple disciplines interested in graphene-based membranes.

Currently, sulfate-radical-based advanced oxidation processes are promising candidates to become viable post-treatment processes for wastewater purification. In this work, a continuous flow UV light/persulfate (PS)/zero-valent iron (ZVI) system has been applied for wastewater treatment for the first time. The influence of certain photo-Fenton-like process parameters, such as space time, PS concentration, and PS to ZVI molar ratio, on the removal of total organic carbon (TOC), was examined using the Box–Behnken design. First, synthetic municipal wastewater was used for the experiments, and the polynomial regression model was constructed utilizing the real data by using the response surface methodology (RSM). The adequacy of the RSM model was assessed by analysis of variance, which showed that the model was reliable and could be applied to improve the process parameters for TOC removal. Moreover, both synthetic and real municipal wastewater were spiked with carbamazepine (CBZ), which is commonly prescribed as an antiepileptic drug, to investigate its fate in the UV/PS/ZVI system. With a space time of 60 min, PS concentration of 60 mM, and PS to ZVI molar ratio of 15, it was possible to remove 71% of TOC and completely remove CBZ from the synthetic municipal wastewater, whereas a 60% TOC removal and complete removal of CBZ were achieved at a space time of 50 min, PS concentration of 50 mM, and PS/ZVI molar ratio of 15 for the real municipal wastewater. This difference in TOC removal could possibly be linked to the complex matrix of the real wastewater and the presence of radical scavenging agents.

Fossil fuels are the main sources of human energy, but their combustion releases toxic compounds of sulfur oxide. In the oil industry, using the optimal methods to eliminate sulfur compounds from fossil fuels is a very important issue. In this study, the performance of montmorillonite/graphitic carbon nitride (a new hybrid nanostructure) in increasing the biodesulfurization activity of Rhodococcus erythropolis IGTS8 was investigated. X-ray diffraction, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy and transmission electron microscopy were used for the characterization of the nanoparticles. The effective factors in this process were determined. Optimum conditions for microorganisms were designed using the Design Expert software. Experiments were performed in a flask. The results indicated that the biodesulfurization activity of a microorganism in the presence of the nanostructure increases by 52%. In addition, in the presence of the nanostructure, the effective factors are: 1. concentration of the nanostructure; 2. concentration of sulfur; 3. cell concentration. In the absence of the nanostructure, the only effective factor is the concentration of sulfur. Through analysis of variance, the proposed models were presented to determine the concentration of the 2-hydroxy biphenyl produced by the microorganisms (biodesulfurization activity) in the presence and absence of the nanostructure. The proposed models were highly acceptable and consistent with experimental data. The results of a Gibbs assay showed that the biodesulfurization efficiency of in the presence of the nanostructure was increased by about 52%, which is a very satisfactory result. The biodesulfurization activity of decorated cells in a bioreactor showed a significant increase compared with nondecorated cells. Almost a two-fold improvement in biodesulfurization activity was obtained for decorated cells compared with free cells.