جستجوی مقالات مرتبط با کلیدواژه « Decontamination » در نشریات گروه « علوم پایه »

Extensive utilization of pesticides in the agricultural sector is acknowledged for their potent insecticidal properties, effectively safeguarding crops and consequently enhancing both yield and quality. However, the organophosphate compounds (OPs) predominantly found in these pesticides are highly toxic and known for their rapid skin absorption, leading to acute poisoning and posing public health challenges. Early exposure requires immediate and efficient decontamination to prevent further skin absorption of OPs. The current cleaning agents, such as soap and bleach, are often associated with harsh chemicals that can be corrosive to the skin. Furthermore, these conventional options tend to merely wash away chemicals, potentially leaving effluent that still carries toxic compounds, causing pollution to the environment. Thus, there is a need for approaches that not only clean effectively but also degrade the harmful substances. This paper proposes a method to synthesize solid soap from palm oil incorporating 2-PAM as an active agent for effective decontamination. The resulting yellowish solid soaps exhibit pH values in the 9-10 range, lathering capabilities, and controlled moisture content (4.19 % for S1, 2.42 % for S2, 2.1 % for S3). FTIR analysis confirms successful 2-PAM integration in soaps S2 and S3, as evidenced by specific bands at 3016 cm-1 to 3015 cm-1, 1736 cm-1 to 1735 cm-1, 1368 cm-1 to 1364 cm-1, and 1217 cm-1 to 1215 cm-1. These characteristics set the stage for further research into the efficacy of these soaps in organophosphate decontamination and their role in environmental pollution control.

Tuberculosis (TB) is the common cause of death due to a single infectious agent. MTB culture is still the gold standard for TB diagnosis. For optimal care of pulmonary TB, effective decontamination methods are required to isolate and identify MTB. The simpler Kudoh decontamination/culture method swab was compared with modified Petroff to isolate mycobacteria from sputum specimens. A total of 15 sputum samples were collected from patients with Xpert MTB/RIF assay-confirmed pulmonary TB. The samples were processed with both decontamination methods. Each sample group was inoculated directly on the Lowenstein-Jensen (LJ) and the Middlebrook 7H10 agar medium. The growth of contamination, recovery rate, and detection time were observed in both media. Out of 15 samples, the contamination rate on the LJ by both methods was 2 (13%), respectively, whereas the Middlebrook 7H10 by both methods showed 1 (6.6%). The recovery rate on the LJ was 13 (86.6%) by the Kudoh method and 14 (93.3%) by the modified Petroff method, while 13 (86.6%) showed positive culture on the Middlebrook 7H10 by both. In this study, positive culture results using the modified Petroff technique showed more colony growth than the Kudoh technique, indicating more viable MTB colonies than the Kudoh technique. Petroff modification technique shows the growth of the number of colonies more than Kudoh technique, but the Kudoh technique shows the results of positive culture that is no different to the recovery level even though the number of colonies that grow in less Kudoh technique.

Several heavy metals are found naturally in the earth’s crust and are exploited for various industrial and economic purposes. Among these heavy metals, a few have direct or indirect impact in the human body. Some of these heavy metals such as copper, cobalt, iron, nickel, magnesium, molybdenum, chromium, selenium, manganese, and zinc have functional roles which are essential for various diverse physiological and biochemical activities in the body. However, some of these heavy metals in high doses can be harmful to the body and in minute quantities have delirious effects on the body causing acute and chronic toxicities in humans. The process of removal of heavy metals is important due to their toxic effects on living organisms. Conventional methods possess many irreconcilable disadvantages pertaining to cost and efficiency. As a result, an in vitro laboratory-scale batch technique was employed to examine the removal efficacy of a novel unmodified natural biosorbent, Opuntia fragalis leaf (OFL) for detoxification of Cu(II) ions from human blood plasma. The outcome of detoxification of Cu(II) ions from human blood plasma using an unmodified biosorbent was accomplished by optimizing biosorption parameters such as biosorbent dosage, initial Cu(II) ions concentration, pH, and agitation time. The percentage of detoxification increases as the biosorption factors were increased with an optimum biosorbent dose of 2 g, initial Cu(II) ions concentration of 40 mg/L, pH of 6 and contact time of 60 minutes. The unmodified natural biosorbent was characterized to investigate the functional groups responsible for binding the Cu(II) ions from the blood plasma onto the biosorbent using Fourier Transform Infrared Spectroscopy. It was revealed that -N-O, -N-H, -C-C-, and -OH were accountable for Cu(II) ions detoxification from human blood plasma. Scanning electron microscopy (SEM) identified pores present on the biosorbent and revealed the biosorbent's outstanding surface chemistry. The experimental values were subjected to the Langmuir, Freundlich, and Temkin isotherms. The correlation of fitness, R2 (0.8231) value of the Langmuir isotherm model correlates best among the biosorption isotherms; thus, it best explains the detoxification process. Q0 for Langmuir monolayer coverage is 1.8103 mg/g which infers the maximum amount of Cu(II) ions biosorbed per pore site. The dimensionless factor RL= 0.0234 implies that the biosorption process is favourable. The Freundlich isotherm biosorption intensity, n is 1.9912 connotes the extent of binding affinity between the Cu (II) ions and the untreated biosorbent. The Temkin isotherm model yielded a biosorption heat of 6.4237 j/mol. In addition, the experimental data were subjected to multiple kinetic models to determine the rate of Cu(II) ions detoxification from human blood plasma. The pseudo-second order model fits best among the examined models, with the highest R2 value of 1.

Mycotoxins are harmful toxic metabolites of fungi that are present as contaminants in many foods, dairy, and agricultural products and constitute a potential health hazard. Therefore, novel decontamination approaches for decreasing its bioavailability are of huge interest to improve human safety. In recent years, biological methods have been developed to control mycotoxin contamination. The degradation of mycotoxins (especially aflatoxins (AFs), which are created by the genus Aspergilla species, mainly A. parasiticus, A. flavus, and A. nomius) using microorganisms is an important bio-based method to reduce mycotoxin levels in foodstuffs without the production of harmful intermediates and by-products. Many studies have reported that detoxification occurs by binding the mycotoxin to the cell wall structure of microorganisms. Several factors, including the microorganism strain, the type of toxin, microorganism concentration, the viability of the microorganism, and the contact period, are involved in the detoxification processes. This review discusses the available literature on the biological decontamination of mycotoxins by probiotic microorganisms (mainly), describes the detoxification mechanisms involved in such processes, and the factors influencing the stability of interactions. Future perspectives on this area are also reported. Based on the current data, one should be able to select the most efficient microorganisms to degrade mycotoxins over a wide range of concentrations.

During the operation of Graphite -fuel HTGR (High-Temperature Gas-cooled Reactor) nuclear reactors, Graphite  used as a neutron moderator, is irradiated and has a variety of contaminants (such as Cs-137, Co-60, and Sr-90) and due to industrial and environmental considerations, decontamination of irradiated Graphite  is very important. In this study, the decontamination of Cs-137 trapped in Graphite  pores of Graphite -fuel (HTGR) nuclear reactors has been analyzed. The proposed method for decontamination of irradiated Graphite  surfaces is the thermal plasma-sputtering method with noble feed gases, which are used to reduce the risk of radioactive Graphite  waste and in this regard, a mathematical model was developed to describe the process of decontamination of irradiated Graphite, which is prone to release Wigner energy due to defects and torsion caused by radiation. The results show that the decrease in radiation pollution of irradiated Graphite  waste and various parameters of its decontamination process depend on the release of Wigner energy. The results obtained are in good agreement with the other researchers results.

The most important component for living beings on the earth is access to clean and safe drinking water. Globally, water scarcity is pervasive even in water rich areas as immense pressure has been created by the burgeoning human population, industrialization, civilization, environmental changes and agricultural activities. The problem of access to safe water is inevitable and requires tremendous research. Nanotechnology has many successful applications in different fields but recently its application for water and wastewater treatment has emerged as a fast developing, promising area. This chapter highlights the recent advances on the development of nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater that are contaminated by toxic metals, organic and inorganic compounds, bacteria and viruses. In addition, the toxic potential of engineered nanomaterials for human health and the environment will also be discussed. This chapter also deals with the fate and transport of engineered nanomaterials in water and wastewater treatment systems along with the risks associated with nanomaterials.

This study investigated single-step extraction of heavy metals from contaminated sediments collected in the port of Cádiz. Experimental tests of washing with an aqueous solution of a chelating agent were performed at selected solid/liquid (S/L) ratios. Two chelating agents were chosen: 0.3 M EDTA(pH 3.8 and 8) and sodium citrate (1 M). The objective of the tests was to investigate extractive decontamination by the washing treatment. The study was focused on the extraction of Pb, Cu, Zn, and Cd. The experiments showed that the decontamination efficiencies of the extractants were of the order: EDTA (pH 3.8) > EDTA (pH 8) ~ sodium citrate. EDTAsolution with slightly acid pH was optimal for the extraction of Pb, Cu, Zn and Cd. The data obtained from the thermal analysis of sediments after the decontamination process indicated the success of the extraction procedurewhich is proposed as a technique for controlling the behaviour of the decontamination process.

Nanocrystalline magnesium oxides were prepared by sol–gel method and were characterized by X-ray diffraction, N2-BET, SEM and infrared spectroscopy techniques. The results confirmed the formation of Nano- MgO materials with crystallite size in range of 5-20 nm and surface areas of 336-556m2/g. The product has been tested as destructive adsorbent for the decontamination of (2-chloroethyl) ethyl sulfide (2-CEES), a mimic of bis(2-chloroethyl) sulfide(“HD” or Mustard Gas). Destructive adsorbent reaction has been carried out in heptanes and methanol media. The reaction was investigated by GC-FID and GC–MS techniques. Reaction rate in heptane has been observed to be higher than methanol. It seems a nonpolar media aided material transfer to the reactive surface sites without blocking them.

Ab initio calculations at the density functional theory (DFT) and the second-order Møller−Plessetperturbation theory levels with 6-31+G(d), 6-31G(d) basis sets for non-metal atoms and LANL2DZfor metal have been performed for the adsorption of dimethyl methylphosphonate (DMMP) on ZnOby Gaussisn 98 program. The calculated rotational constants by B3LYP/6-31G(d) are in moreagreement with the experimental values. The type of interaction between the Zn from ZnO andphosphoryl group from DMMP is estimated by AIM analysis. The molecular adsorption occurs byvan der waals interaction of Zn⋯O=With one Hydrogen bonding, between CH3 groups andoxygen of zinc oxide.

Catalytic and photocatalytic reactions of (2-chloroethyl) phenyl sulfide (2-CEPS), a mimic of bis (2-chloroethyl) sulfide (i.e. Sulfur mustard) were studied on the surfaces of titanium oxide. TiO2 nanoparticles (anatase, rutile and mixture of 80% anatase/20% rutile) along with bulk TiO2 were tested as reactive sorbents for reaction of 2-CEPS at room temperature (25±0.5°C). Reactions were monitored by GC-FID technique and reaction products were characterized by GC-MS. Data explores the role of hydrolysis and elimination reactions in the reaction of 2-CEPS on titanium oxide. In these reactions, 2-CEPS undergo photocatalytic reactions to yield (2-hydroxyethyl) phenyl sulfide, (2-ethoxyethyl) phenyl sulfide and vinyl phenyl sulfide. Also data reveals that the maximum decontamination of 2-CEPS was related to nano-TiO2 (80% anatase/ 20% rutile)/ UV.