Textile wastewater purification using an elaborated biosorbent hybrid material (Luffa-Cylindrica-Zinc Oxide) assisted by alternating current

This paper aims to synthesize hybrid materials with high pollutant-uptake capacity and low costbased based on Luffa cylindrica (L.C) and different percentage of Zn in the presence and absence of alternating current (AC). Physico-chemical, morphological and structural characterizations of the hybrid materials were performed by Boehm method, point zero charge (H), infrared characterizations (IR), scanning electron microscopy (SEM), energy-dispersive spectroscopyand and X-ray photoelectron spectroscopy. The efficiency of the designed hybrid materials was optimized based on their performance in water depollution. Methylene blue (MB) and industrial textile wastewater were the investigated pollutants models. IR characterizations confirmed the fixation of Zn onto the L.C by the creation of Zn-OH, Zn-O and Zn-O-C bonds. Boehm titration showed that the fixation of Zn onto L.C is accompanied by an increase of the basic functions of its surface and subsequently an increase in the H. SEM results confirmed the fixation of Zn onto the L.C coupling AC with biosorption showed an increase in the adsorbed amount of MB and speed when adding the 4% of Zn compared to the pure L.C the Q shifted from 3.22 to 9.84 and 8.81 mg/g, respectively, for hybrid materials synthesized under AC, in absence of AC and pure L.C

Tetracycline removal from aqueous solution by electrooxidation using ruthenium-coated graphite anode

This paper reports the electrochemical oxidation treatment of 80 mL of acidic aqueous solutions with 0.2 mM of the drug tetracycline in 25 mM Na2SO4&nbsp;using a lab-scale electrochemical cell. The performance of tetracycline removal with Ru-coated graphite by the chemical bath deposition (CBD) and raw graphite anode has been demonstrated. The effects of operating parameters were tested such as pH, applied current, supporting electrolyte concentration, and initial tetracycline concentration. The best tetracycline degradation was obtained with Ru-coated graphite anode due to its higher oxidation power, which allowed the complete degradation of refractory compounds. The modified surface structure of the Ru-coated graphite anode was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy-dispersive X-ray (EDX). The EO process with Ru-coated graphite anode allowed 93.8% tetracycline abatement after 100 min of electrolysis at an applied current of 100 mA. In all cases, tetracycline decay obeyed pseudo-first-order kinetics. The tetracycline removal performance of graphite electrodes with nano coating on graphite has offered a performing alternative. A Comparative study revealed that electrolysis with Ru-coated graphite acted as a better electrode material than raw graphite for the catalytic reaction.</p

Textile wastewater purification using an elaborated biosorbent hybrid material (Luffa-Cylindrica-Zinc Oxide) assisted by alternating current

This paper aims to synthesize hybrid materials with high pollutant-uptake capacity and low costbased based on Luffa cylindrica (L.C) and different percentage of Zn in the presence and absence of alternating current (AC). Physico-chemical, morphological and structural characterizations of the hybrid materials were performed by Boehm method, point zero charge (H), infrared characterizations (IR), scanning electron microscopy (SEM), energy-dispersive spectroscopyand and X-ray photoelectron spectroscopy. The efficiency of the designed hybrid materials was optimized based on their performance in water depollution. Methylene blue (MB) and industrial textile wastewater were the investigated pollutants models. IR characterizations confirmed the fixation of Zn onto the L.C by the creation of Zn-OH, Zn-O and Zn-O-C bonds. Boehm titration showed that the fixation of Zn onto L.C is accompanied by an increase of the basic functions of its surface and subsequently an increase in the H. SEM results confirmed the fixation of Zn onto the L.C coupling AC with biosorption showed an increase in the adsorbed amount of MB and speed when adding the 4% of Zn compared to the pure L.C the Q shifted from 3.22 to 9.84 and 8.81 mg/g, respectively, for hybrid materials synthesized under AC, in absence of AC and pure L.C

Agricultural waste materials for adsorptive removal of phenols, chromium (VI) and cadmium (II) from wastewater: A review

Management of basic natural resources and the spent industrial and domestic streams to provide a sustainable safe environment for healthy living is a magnum challenge to scientists and environmentalists. The present remedial approach to the wastewater focuses on recovering pure water for reuse and converting the contaminants into a solid matrix for permanent land disposal. However, the ground water aquifers, over a long period slowly leach the contaminants consequently polluting the ground water. Synthetic adsorbents, mainly consisting of polymeric resins, chelating agents, etc. are efficient and have high specificity, but ultimate disposal is a challenge as most of these materials are non-biodegradable. In this context, it is felt appropriate to review the utility of adsorbents based on natural green materials such as agricultural waste and restricted to few model contaminants: phenols, and heavy metals chromium(VI), and cadmium(II) in view of the vast amount of literature available. The article discusses the features of the agricultural waste material-based adsorbents including the mechanism. It is inferred that agricultural waste materials are some of the common renewable sources available across the globe and can be used as sustainable adsorbents. A discussion on challenges for industrial scale implementation and integration with advanced technologies like magnetic-based approaches and nanotechnology to improve the removal efficiency is included for future prospects

Modern designs of electrochemical sensor platforms for environmental analyses: principles, nanofabrication opportunities, and challenges

In recent decades, much attention has been paid to using nanomaterials in the development of highly-sensitive sensors for environmental monitoring. This review describes how nanomaterials are being used to develop electrochemical sensing platforms for environmental analysis (air pollution, water quality, soil nutrients, and soil pathogens). In particular, we discuss the use of nanofabrication techniques (e.g., monolayer self-assembly, dropcasting, molecular imprinting, electrodeposition, in situ polymerization, hydrogenation, and 3D printing) in the fabrication of high-sensitive electrodes is addressed. The potential use of carbon, organic, inorganic, and hybrid nanomaterials in electrochemical sensing platforms and to enable automation, real-time detection, and multiplexed test development are also addressed. Recent applications of mobile, disposable, wearable, implantable, and self-powered electrochemical sensors for monitoring ions, particles, compounds, nutrients, microorganisms, and contaminants in real environmental samples are covered. Finally, the opportunities and challenges in nanofabrication high-performance electrochemical sensors and optimizing their performance in testing real samples are highlighted

New generation adsorbents for the removal of fluoride from water and wastewater: A review

© 2021 Elsevier B.V.Water is essential for life and is threatened by the pollution and contamination generated by human activity and industries. Fluoride contamination of water is a serious problem in the world. The review article highlights on new generation adsorbents including carbon-based adsorbents, nano-adsorbents, bio-sorbents, inorganic materials, modified and composite adsorbents for purification of fluoride from water. It was indicated from the review that a Zinc oxide nanoparticles is the best adsorbents for the removal of fluoride from aqueous media, with a capacity adsorption (qmax) of 100 mg/g. The fluoride uptake best-fit both the Langmuir and Freundlich isotherm models as well as a pseudo second order kinetic model. A wide range of values for the thermodynamic parameters (both negative and positive) were reported for fluoride across different studies. Kinetic and thermodynamic, molecular modelling and simulations, knowledge gaps and future prospects are also presented

Use of hypoglycemic plants by Tunisian diabetic patients

AbstractIntroductionThe recourse to the herbal medicines in treating diabetes is frequent in Africa and especially in Tunisia. Its practice is transmitted orally and ritually from generation to generation. The objectives of this study are to determine the plants used, their methods of preparation, consumption and profile of patients who use them (habitat, profession, gender, age …).Patients and methodsA questionnaire concerning the use of herbal medicines has been proposed to diabetic patients consulting in the National Institute of Nutrition of Tunis, on the output of the medical consultation of diabetes.ResultsTwo hundred patients responded. 23% of patients were using herbal medicine. The main plants used are gum arabic (71.7%) fenugreek (28.3%) of white artemisia (21.7%) and marrube (10.9%). 28.3% of them have type 1 diabetes. The average duration of diabetes was 10.5 ± 6.9 years, 72.4% of patients reduced their dosages of drug treatment because of the onset of hypoglycemia.ConclusionsThe use of herbal medicines is frequent in the therapeutic arsenal of type 2 diabetes in Tunisia. This practice must however be based on the findings of scientific studies which are still scarce. The conditions of their utilization must be defined and users should be warned against potential side effects

A comprehensive review on green perspectives of electrocoagulation integrated with advanced processes for effective pollutants removal from water environment

The rapidly expanding global energy demand is forcing a release of regulated pollutants into water that is threatening human health. Among various wastewater remediating processes, electrocoagulation (EC) has scored a monumental success over conventional processes because it combines coagulation, sedimentation, floatation and electrochemical oxidation processes that can effectively decimate numerous stubborn pollutants. The EC processes have gained some attention through various academic and industrial publications, however critical evaluation of EC processes, choices of EC processes for various pollutants, process parameters, mechanisms, commercial EC technologies and performance enhancement via other degradation processes (DPs) integration have not been comprehensively covered to date. Therefore, the major objective of this paper is to provide a comprehensive review of 20 years of literature covering EC fundamentals, key process factors for a reactor design, process implementation, current challenges and performance enhancement by coupling EC with pivotal pollutant DPs including, electro/photo-Fenton (E/P-F), photocatalysis, sono-chemical treatment, ozonation, indirect electrochemical/advanced oxidation (AO), and biosorption that have substantially reduced metals, pathogens, toxic compound BOD, COD, colors in wastewater. The results suggest that the optimum treatment time, current density, pulse frequency, shaking speed and spaced electrode improve the pollutants removal efficiency. An elegant process design can prevent electrode passivation which is a critical limitation of EC technology. EC coupling (up or downstream) with other DPs has resulted in the removal of organic pollutants and heavy metals with a 20% improved efficiency by EC-EF, removal of 85.5% suspended solid, 76.2% turbidity, 88.9% BOD, 79.7% COD and 93% color by EC-electroflotation, 100% decolorization by EC-electrochemical-AO, reduction of 78% COD, 81% BOD, 97% color by EC-ozonation and removal of 94% ammonia, 94% BOD, 95% turbidity, >98% phosphorus by aerated EC and peroxicoagulation. The major wastewater purification achievements, future potential and challenges are described to model the future EC integrated systems