31 research outputs found
Use of rhamnolipid to remove heavy metals from aqueous streams via micellar enhanced ultrafiltration
In this research, the rhamnolipid biosurfactant was utilized in micellar-enhanced ultrafiltration (MEUF) of heavy metals from contaminated waters. The effects of different major operating conditions on the (MEUF) system performance were investigated for copper, zinc, nickel and cadmium using two membranes. The optimal conditions were successfully applied to treat six contaminated wastewaters from metal refining industries and three contaminated groundwaters using the two membranes (> 99% rejection ratio). To efficiently choose the most influential factors to the MEUF system, optimization by the response surface methodology approach was utilized and data quality was examined. Three studies were performed in order to investigate the mechanism and the interactions between the heavy metal ions and the rhamnolipid micelles in the rhamnolipid-based UF system. The first study successfully investigated the applicability of Gouy-Chapman approach for binding of heavy metal ions to rhamnolipid biosurfactant in the MEUF system and the mechanism via electrostatic attraction was suggested. The second study efficiently evaluated binding behavior of the four heavy metal ions individually and collectively onto the rhamnolipid. The order was Cu 2+ > Cd 2+ > Zn 2+ > Ni 2+ .The third study analyzed the equilibrium data using Langmuir, Freundlich, and linear adsorption models. The Freundlich model fitted the data better and the K F values were from 1.3 to 6.1. In addition, solidification/stabilization (S/S) technology was successfully used to stabilize solid wastes contaminated with heavy metal. Furthermore, preliminary trials were performed to examine the recovery of the rhamnolipid from the retentates for possible reuse. The amounts recovered ranged from 12 ± 1% to 18 ± 1% of the rhamnolipid concentration initially present in the retentate. Similarly, preliminary trials to reuse water from the retentates were investigated. The total portions recovered ranged from about 81.0 ± 0.34% to 82.3 ± 0.46$% of the total feed water. This work may be used as preliminary investigations for further detailed pilot and/or large-scale studies to treat contaminated groundwater and industrial wastewater
Surfactants-based remediation as an effective approach for removal of environmental pollutants—A review
Deterioration of environmental quality and equilibrium by rampant industrial expansion, accelerated urbanization and unchecked population growth has become a high-priority concern. The release of an alarming number of toxic polluting agents such as volatile organic compounds, dyes, heavy metals, pharmaceuticals, pesticides, industrial wastes, and personal care products due to natural or anthropogenic activities pose direct adverse effects on human health and living entities. This issue is inescapably increased because of the lack of efficient technologies for the proper disposal, management, and recycling of waste. It is of paramount importance to track alternative solutions to address these pollution problems for an eco-sustainable environment. Conventional remediation techniques are either inefficient, cumbersome or restricted due to certain techno-economic limitations. Environmental compatibility and high pollutant-removal efficacy make surfactants valuable for removal of organic pollutants and toxic heavy metal ions from different mediums. In this review, we present recent and up-to-date information on micelles/surfactants-assisted abatement of a vast number of toxic agents of emerging concern from water/wastewater including volatile organic compounds, personal care products, pharmaceutically active residues, toxic metals, dye pollutants, pesticides, and petroleum hydrocarbons. Based on the literature survey, it can be concluded that micelles-assisted water and soil treatment technology can have a better future on large-scale decontamination of wastewater. Though bio-surfactants are environmentally friendlier matrices and have successfully been employed for environmental decontamination; their large-scale applicability is challenging owing to high costs. Additional research efforts on the development and employment of novel bio-surfactants might render wastewater treatment technology greener, smarter and economical
Pharmacological bioactivity of Ceratonia siliqua pulp extract: in vitro screening and molecular docking analysis, implication of Keap-1/Nrf2/NF-ĸB pathway
Abstract Inflammation is interfaced with various metabolic disorders. Ceratonia siliqua (CS) has a higher pharmaceutical purpose. The research aimed to investigate the biofunction of CS pulp aqueous extract (CS-PAE) with an emphasis on its integrated computational approaches as opposed to different specific receptors contributing to inflammation. The extract was assessed for its chemical and phenolic components via GC–MS, LC–MS, HPLC, and total phenolic and flavonoid content. In vitro, bioactivities and molecular docking were analyzed. Findings indicate that CS-PAE demonstrated higher scavenging activities of nitric oxide, 1,1-diphenyl-2-picrylhydrazyl radical, superoxide anion, hydrogen peroxide, and anti-lipid peroxidation (IC50 values were 5.29, 3.04, 0.63, 7.35 and 9.6 mg/dl, respectively). The extract revealed potent inhibition of RBCs hemolysis, acetylcholine esterase, monoamine oxidase-B, and α-glucosidase enzymes (IC50 was 13.44, 9.31, 2.45, and 1.5 mg/dl, respectively). The extract exhibited a cytotoxic effect against prostate cancer Pc3, liver cancer HepG2, colon cancer Caco2, and lung cancer A549 cell lines. Moreover, CS-PAE owned higher antiviral activity against virus A and some bacteria. When contrasting data from molecular docking, it was reported that both apigenin-7-glucoside and rutin in CS-PAE have a good affinity toward the Keap-1/Nrf2/ NF-ĸB pathway. In conclusion, CS-PAE showed promise in therapeutic activity in metabolic conditions
Therapeutic Screening of Herbal Remedies for the Management of Diabetes
The study of diabetes mellitus (DM) patterns illustrates increasingly important facts. Most importantly, they include oxidative stress, inflammation, and cellular death. Up to now, there is a shortage of drug therapies for DM, and the discovery and the development of novel therapeutics for this disease are crucial. Medicinal plants are being used more and more as an alternative and natural cure for the disease. Consequently, the objective of this review was to examine the latest results on the effectiveness and protection of natural plants in the management of DM as adjuvant drugs for diabetes and its complex concomitant diseases
Therapeutic Screening of Herbal Remedies for the Management of Diabetes
The study of diabetes mellitus (DM) patterns illustrates increasingly important facts. Most importantly, they include oxidative stress, inflammation, and cellular death. Up to now, there is a shortage of drug therapies for DM, and the discovery and the development of novel therapeutics for this disease are crucial. Medicinal plants are being used more and more as an alternative and natural cure for the disease. Consequently, the objective of this review was to examine the latest results on the effectiveness and protection of natural plants in the management of DM as adjuvant drugs for diabetes and its complex concomitant diseases
Does the recognition of transient post-ischemic stunning in gated SPECT myocardial perfusion imaging have a diagnostic value in patients with CAD?
An iterative technique to segment PET lesions using a Monte Carlo based mathematical model
The need for an accurate lesion segmentation tool in 18FDG PET is a prerequisite for the estimation of lesion response to therapy, for radionuclide dosimetry, and for the application of 18FDG PET to radiotherapy planning. In this work, the authors have developed an iterative method based on a mathematical fit deduced from Monte Carlo simulations to estimate tumor segmentation thresholds.
METHODS:
The GATE software, a GEANT4 based Monte Carlo tool, was used to model the GE Advance PET scanner geometry. Spheres ranging between 1 and 6 cm in diameters were simulated in a 10 cm high and 11 cm in diameter cylinder. The spheres were filled with water-equivalent density and simulated in both water and lung equivalent background. The simulations were performed with an infinite, 8/1, and 4/1 target-to-background ratio (T/B). A mathematical fit describing the correlation between the lesion volume and the corresponding optimum threshold value was then deduced through analysis of the reconstructed images. An iterative method, based on this mathematical fit, was developed to determine the optimum threshold value. The effects of the lesion volume and T/B on the threshold value were investigated. This method was evaluated experimentally using the NEMA NU2-2001 IEC phantom, the ACNP cardiac phantom, a randomly deformed aluminum can, and a spheroidal shape phantom implemented artificially in the lung, liver, and brain of patient PET images. Clinically, the algorithm was evaluated in six lesions from five patients. Clinical results were compared to CT volumes.
RESULTS:
This mathematical fit predicts an existing relationship between the PET lesion size and the percent of maximum activity concentration within the target volume (or threshold). It also showed a dependence of the threshold value on the T/B, which could be eliminated by background subtraction. In the phantom studies, the volumes of the segmented PET targets in the PET images were within 10% of the nominal ones. Clinically, the PET target volumes were also within 10% of those measured from CT images.
CONCLUSIONS:
This iterative algorithm enabled accurately segment PET lesions, independently of their contrast value