Electro-coagulation coupled Electro-floatation process: Feasible choice in Doxycycline removal from Pharmaceutical effluents

Article CC-BYInternational audienceElectrochemical treatment involving a coupled coagulation and floatation was performed in the removal of Doxycycline Hyclate (DCH) from aqueous solutions. All the experiments were carried out in an electrochemical reactor of 1.5 L which contained aluminium electrodes as cathode and anode. The removal of doxycycline hyclate (DCH) species by EC/EF was determined as a function of electrolysis time, pH, current intensity, flow rate and DCH concentration. From the observed results, it was corroborated that the DCH removal through the EC/EF process was excellent. The effective contribution from initial pH (7.03) and current intensity (5.39 mA cm-2) was very much remarkable and well apparent from flocs of good buoyancy. The removal of DCH was inversely proportional to spacing between electrodes (SBE) and circulating flow rate in the presence of the supporting NaCl electrolyte of 1 g L-1. It was also highly promoted by the addition of NaCl in comparison to NaNO3 and KCl to the electrolytic system. The compliance of four kinetic models was verified with DCH removal system. The free energy values from DKR model suggested the nature of bonding by chemical forces. Characterization by FTIR, SEM and XRD interpreted the assignments of various functional groups, surface morphology and crystalline incorporated amorphous nature, respectively of electro – generated flocs. The current efficiency and specific electrical energy consumption at optimized conditions of the EC/EF system were calculate

Activated carbon from lignocellulosic waste residues: effect of activating agent on porosity characteristics and use as adsorbents for organic species

This paper reports on the effect of activating agents such as the impregnation ratio of phosphoric acid (1:1–1:5) at constant activation temperature on the performance of porous activated carbon from waste residues (maize tassel). The variation in the impregnation ratio of the produced activated carbon (AC) from 1:1 to 1:5 enabled the preparation of a high surface area (1,263 m2/g) and a large pore volume (1.592 cm3/g) of AC produced from maize tassel (MT) using a convectional chemical activating agent (phosphoric acid). Impregnation ratios (IR) of the precursors were varied between 1:1 and 1:5 in which it was found that the ratio of 1:4 was optimal based on the high surface area, while 1:5 has the optimal pore volume value for the produced activated carbon

Osjetljiva spektrofotometrijska metoda za određivanje sulfonamida u farmaceutskim pripravcima

A new, simple and sensitive spectrophotometric method for the determination of some sulfonamide drugs has been developed. The method is based on the diazotisation of sulfacetamide, sulfadiazine, sulfaguanidine, sulfamerazine, sulfamethazine, sulfamethoxazole and coupling with 8-hydroxyquinoline in alkaline media to yield red coloured products, with absorption maximum at 500 nm. The Beer’s law is obeyed from 0.17.0 µg mL1. The limits of quantification and limits of detection were 0.110.18 and 0.030.5 µg mL1, respectively. Intraday precision (RSD 0.10.5%) and accuracy (recovery 97.3100.8) of the developed method were evaluated. No interference was observed from common adjuvants. The method has been successfully applied to the assay of sulpha drug in the pharmaceutical formulations.U radu je opisana nova, jednostavna i osjetljiva spektrofotometrijska metoda za određivanje sulfonamida. Metoda se temelji na prevođenju sulfacetamida, sulfadiazina, sulfagvanidina, sulfamerazina, sulfometazina i sulfametoksazola u diazoderivate koji kondenzacijom s 8-hidroksikinolinom u alkalnom mediju daju crveno obojene produkte s maksimumom apsorpcije pri 500 nm. Beerov zakon vrijedi u koncentracijskom rasponu 0,17,0 µg mL1. Granice kvantifikacije i granice detekcije su 0,11-0,18, odnosno 0,03-0,05 µg mL-1. Za predloženu metodu procijenjene su intermedirska preciznost (RSD 0.1-0,5%) i točnost (analitički povrat 97,3-100,8). Uobičanjene pomoćne tvari u tabletama ne interferiraju tijekom određivanja. Metoda je uspješno primijenjena za analizu sulfonamida u farmaceutskim pripravcima

One planet: one health. A call to support the initiative on a global science–policy body on chemicals and waste

The chemical pollution crisis severely threatens human and environmental health globally. To tackle this challenge the establishment of an overarching international science–policy body has recently been suggested. We strongly support this initiative based on the awareness that humanity has already likely left the safe operating space within planetary boundaries for novel entities including chemical pollution. Immediate action is essential and needs to be informed by sound scientific knowledge and data compiled and critically evaluated by an overarching science–policy interface body. Major challenges for such a body are (i) to foster global knowledge production on exposure, impacts and governance going beyond data-rich regions (e.g., Europe and North America), (ii) to cover the entirety of hazardous chemicals, mixtures and wastes, (iii) to follow a one-health perspective considering the risks posed by chemicals and waste on ecosystem and human health, and (iv) to strive for solution-oriented assessments based on systems thinking. Based on multiple evidence on urgent action on a global scale, we call scientists and practitioners to mobilize their scientific networks and to intensify science–policy interaction with national governments to support the negotiations on the establishment of an intergovernmental body based on scientific knowledge explaining the anticipated benefit for human and environmental health.Projekt DEA

Preparation and use of maize tassels’ activated carbon for the adsorption of phenolic compounds in environmental waste water samples

The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84–98.49 %, 80.75–97.11 %, and 78.27–97.08 % for BPA, o-NTP, and PCP, respectively) . The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes

Trends and Progress on Antibiotic-Resistant Mycobacterium tuberculosis and Genes in relation to Human Immunodeficiency Virus

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and tuberculosis (TB) are among the infectious diseases that cause high rates of mortality worldwide. The epidemiology of antibiotic resistance in correlation to people that live with TB and HIV has not been thoroughly investigated particularly in South Africa. Numerous cases of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) have been announced immensely worldwide. The spread and control of the MDR-TB pandemic due to unsuccessful treatment is one of the most serious public issues of concern, and this challenge is of international interest. Despite all measures that have been executed to overcome the challenge of MDR-TB in recent decades, the global MDR-TB trends have kept on accelerating with more and more people becoming victims. This is attributed to the abuse, misuse, and overuse of different antibacterial agents in human medicine, animal farms, and agricultural activities which serve as a wellspring for the evolution of antimicrobial resistance within the population. Over and above, the impetuous evolution, mutation, and the transfer of resistant genes via horizontal gene transfer are well-known contributive factors towards the antimicrobial resistance problem. Among the public health concerns in the world currently is the ever-increasing problem of antibiotic resistance which outpaces the progress of newly developed antimicrobials. The propagation of antimicrobial resistance (AMR) is even more amplified in areas where the pressure of antimicrobial resistant pathogens is elevated, and hence the population with ubiquitous HIV and AIDS is considered the hotspot. This review therefore aims to give in-depth coverage on the trends and the progress on the development of TB and HIV-resistant strains, highlight strategies to solve the problem, and accentuate the repercussions of the COVID-19 epidemic on the AMR

Low-cost fluoride adsorbents prepared from a renewable biowaste: Syntheses, Characterization and Modeling studies

International audienceThe preparation of composite adsorbents for fluoride anion was performed from natural cow dung and cow dung impregnated by a solution of calcium and iron salts. These starting materials were dried and carbonized at 300, 500 or 700°C for 2 h leading to Cow Dung Carbon (CDC) or Ca-Fe Impregnated Cow Dung Carbon ICDC. All these carbons were used as adsorbent in fluoride removal studies. Batch mode experiments using CDC and ICDC were conducted in which the fluoride removal varied linearly as a function of contact time, pH, adsorbent dose, initial fluoride concentration, temperature and interfering anionic species. Both kinetic and isotherm based models were checked for the applicability of the present fluoride sorption system onto CDC and ICDC. For carbonization at 300°C, the doping with Ca and Fe increased the defluoridation activity. The most efficient carbon was CDC which was prepared at 500°C. It showed a defluoridation activity of 15 mg g-1. This carbon was made from renewable cow dung without the need of a chemical activation. However, the recycling of F-loaded adsorbents may be carried out by washing in alkaline solution. CDC and ICDC were analyzed by scanning electron microscopy and X-ray diffraction in order to understand the reasons of their excellent defluoridation capacity. The growing of plants requires the consumption of essential inorganic nutrients such as Ca, Mg, and P which are known to be fluorophilic elements in fluoride adsorbents. After ingestion and digestion of plants by ruminants, some of these nutrients remained in cow dung and then in the corresponding carbonized materials where they acted as fluoride scavenger. This exceptional defluoridation capacity of CDC allows their use in rural countrie

Performance efficiency of electro-coagulation coupled electro-flotation process (EC–EF) versus adsorption process in Doxycycline removal from aqueous solutions

International audienceTwo treatment methodologies such as electro-coagulation coupled electro-flotation (EC–EF) and adsorption have been adopted to remove doxycycline hyclate (DCH) from the aqueous solution. An electro-coagulation (EC) coupled electro-flotation (EF) system has been designed in a closed reactor with a capacity of 1.5L on a laboratory scale. Electro-synthesis of alumina (electro-generated alumina, EGA) using aluminium electrodes with magnesium chloride as an electrolyte was achieved and used for the adsorption experiments. In both the treatment techniques, removal of DCH efficiency as a function of pH, initial DCH concentration and interfering electrolyte was studied. About 99% of DCH was removed at the end of 80 minutes in the range of pH 6–8 by EC–EF process whereas the adsorption technique achieved about 73% (73 mg g−1) of DCH removal in the pH range of 3–9 at the equilibrium time of 150 minutes. Current density of 5.39 mS cm−2 and EGA dose of 4 g L−1 was optimized respectively for the EC–EF and adsorption processes. The presence of accompanying electrolyte (NaCl) with DCH solution in the EC–EF process increased the electrical conductivity of 1.78 mS cm−1 and could achieve about 90% of DCH removal in the first 30 minutes. On the other hand, in the adsorption process, the participation of chloride (NaCl) as an interfering ion decreased the DCH removal to about 76%. Kinetic and isotherm models fitting the DCH removal dynamics in both the techniques have been checked for their validation. Characterization studies which include FTIR, SEM and XRD have also been done to explore the functional groups, surface morphology and crystalline nature of the solid material