Adsorption of crystal violet on rice husk activated carbon

The need to develop effective technology for the treatment of liquid effluent of dye-intensive industries such as textile, rubber, paint, and printing is synonymous with the need to save the life-threatening risks posed by these carcinogenic and mutagenic pollutants on human and aquatic lives. Isotherms of adsorption of crystal violet (CV) on activated carbon (AC) synthesized from rice husk are presented herewith to elucidate the mechanism of the adsorption process of crystal violet dye contaminated water on rice husk activated carbon. AC was synthesized from rice husk via a phosphoric acid activating agent at low temperatures. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (DR) isotherm studies were employed. The mean square values for Langmuir, Freundlich, Temkin and D-R models were 0.98, 0.91, 0.94, and 0.63, respectively. Analysis of the isotherms of the adsorption of crystal violet sorbate on the synthesized rice husk sorbent suggested that the adsorption process proceeded via a homogeneous monolayer mechanism. Langmuir isotherm gave the best fit of the adsorption process. Langmuir isotherm constant was –1.40 l/mg, and the equilibrium adsorption capacity was 13.53 mg/g

Isotherm study of crystal violet on activated carbon synthesized from millet stover

Continuous release of synthetic dyes from industrial effluent into surface water poses a huge environmental threat and health hazard to humans and aquatic life. The need to right the wrong occasioned by the inimical industrial practice of uncontrolled release of carcinogenic dyes into the surface water calls for research into effective treatment technologies for the treatment of dye-contaminated industrial effluent. The isotherm of Crystal Violet (CV) solution on activated carbon (AC) synthesized from millet stover was investigated and presented herein. Samples of AC were synthesized from millet stover at 120⁰C using phosphoric acid as the activating agent. Employing varying mix ratios of stover-to-phosphoric acid (1:0, 1:1, 1:2, 1:3, and 1:4), respective samples of AC were synthesized. The batch adsorption process of the various samples of the AC in 15 mg/l initial concentration of an aqueous solution of CV was carried out at varying times. The CV’s change in the sorbate’s concentration was monitored using a UV spectrophotometer. The optimum adsorption time was 240 min. The optimally synthesized activated carbon was the 1:2 sample having an equilibrium sorbent concentration of 0.74 mg/L and sorbate uptake of 95.1%. Langmuir, Freundlich and Temkin isotherm models were employed for the isotherm analysis. The R^2 values of the Langmuir, Freundlich and Temkin models were 0.99, 0.90, and 0.94, respectively. The isotherm constants for the Langmuir, Freundlich and Temkin models were –1.52 l/mg, –4.08, and 0.005 l/min, respectively. The Langmuir isotherm model best fitted the adsorption mechanism with a maximum equilibrium adsorption capacity of 14.0 mg/g

Chemical and Physical Comparative Study of the Effect of Wet and Dry Beneficiation of Kankara Kaolin

Chemical and physical comparative effect of wet and dry beneficiation processes for purification of kaolin was studied. X-ray flourescence XRF and particle size analysis of kaolin clay before and after beneficiation were carried out. The Si/Al ratio of the raw kaolin which was 1.90 decreased by 1.6 and 17.9% after the wet and dry beneficiation processes respectively. The clay content of the raw clay which was 48 wt% was improved to 73 wt% after the dry beneficiation while the impurity content was reduced from 52 to 27wt%.http://dx.doi.org/10.4314/njt.v34i2.1

Microwave-Assisted Adsorptive Desulfurization of Model Diesel Fuel Using Synthesized Microporous Rare Earth Metal-Doped Zeolite Y

The microwave-assisted adsorptive desulfurization of model fuel (thiophene in n-heptane) was investigated using a synthesized rare earth metal-doped zeolite Y (RE Y). Crystallinity of the synthesized zeolite was 89.5%, the silicon/aluminium (Si/Al) molar ratio was 5.2, the Brunauer–Emmett–Teller (BET) surface area was 980.9 m2/g, and the pore volume and diameter was 0.3494 cm3/g and 1.425 nm, respectively. The results showed that the microwave reactor could be used to enhance the adsorptive desulfurization process with best efficiency of 75% at reaction conditions of 100 °C and 15 minutes. The high desulfurization effect was likely due to the higher efficiency impact of microwave energy in the interaction between sulfur in thiophene and HO-La(OSiAl)

Association Between the Epigenetic Lifespan Predictor GrimAge and History of Suicide Attempt in Bipolar Disorder

Bipolar disorder (BD) has been previously associated with premature mortality and aging, including acceleration of epigenetic aging. Suicide attempts (SA) are greatly elevated in BD and are associated with decreased lifespan, biological aging, and poorer clinical outcomes. We investigated the relationship between GrimAge, an epigenetic clock trained on time-to-death and associated with mortality and lifespan, and SA in two independent cohorts of BD individuals (discovery cohort - controls (n = 50), BD individuals with (n = 77, BD/SA) and without (n = 67, BD/non-SA) lifetime history of SA; replication cohort - BD/SA (n = 48) and BD/non-SA (n = 47)). An acceleration index for the GrimAge clock (GrimAgeAccel) was computed from blood DNA methylation (DNAm) and compared between groups with multiple general linear models. Differences in epigenetic aging from the discovery cohort were validated in the independent replication cohort. In the discovery cohort, controls, BD/non-SA, and BD/SA significantly differed on GrimAgeAccel (F = 5.424, p = 0.005), with the highest GrimAgeAccel in BD/SA (p = 0.004, BD/SA vs. controls). Within the BD individuals, BD/non-SA and BD/SA differed on GrimAgeAccel in both cohorts (p = 0.008) after covariate adjustment. Finally, DNAm-based surrogates revealed possible involvement of plasminogen activator inhibitor 1, leptin, and smoking pack-years in driving accelerated epigenetic aging. These findings pair with existing evidence that not only BD, but also SA, may be associated with an accelerated biological aging and provide putative biological mechanisms for morbidity and premature mortality in this population

Impact of Normothermic Preservation with Extracellular Type Solution Containing Trehalose on Rat Kidney Grafting from a Cardiac Death Donor

BACKGROUND: The aim of this study was to investigate factors that may improve the condition of a marginal kidney preserved with a normothermic solution following cardiac death (CD) in a model of rat kidney transplantation (RTx). METHODS: Post-euthanasia, Lewis (LEW) donor rats were left for 1 h in a 23°C room. These critical kidney grafts were preserved in University of Wisconsin (UW), lactate Ringer's (LR), or extracellular-trehalose-Kyoto (ETK) solution, followed by intracellular-trehalose-Kyoto (ITK) solution at 4, 23, or 37°C for another 1 h, and finally transplanted into bilaterally nephrectomized LEW recipient rats (n = 4-6). Grafts of rats surviving to day 14 after RTx were evaluated by histopathological examination. The energy activity of these marginal rat kidneys was measured by high-performance liquid chromatography (HPLC; n = 4 per group) and fluorescence intensity assay (n = 6 per group) after preservation with UW or ETK solutions at each temperature. Finally, the transplanted kidney was assessed by an in vivo luciferase imaging system (n = 2). RESULTS: Using the 1-h normothermic preservation of post-CD kidneys, five out of six recipients in the ETK group survived until 14 days, in contrast to zero out of six in the UW group (p<0.01). Preservation with ITK rather than ETK at 23°C tended to have an inferior effect on recipient survival (p = 0.12). Energy activities of the fresh donor kidneys decreased in a temperature-dependent manner, while those of post-CD kidneys remained at the lower level. ETK was superior to UW in protecting against edema of the post-CD kidneys at the higher temperature. Luminescence intensity of successful grafts recovered within 1 h, while the intensity of grafts of deceased recipients did not change at 1 h post-reperfusion. CONCLUSIONS: Normothermic storage with extracellular-type solution containing trehalose might prevent reperfusion injury due to temperature-dependent tissue edema

Blood Epigenome-Wide Association Studies of Suicide Attempt in Adults With Bipolar Disorder

Suicide attempt (SA) risk is elevated in individuals with bipolar disorder (BD), and DNA methylation patterns may serve as possible biomarkers of SA. We conducted epigenome-wide association studies (EWAS) of blood DNA methylation associated with BD and SA. DNA methylation was measured at \u3e700,000 positions in a discovery cohort of n = 84 adults with BD with a history of SA (BD/SA), n = 79 adults with BD without history of SA (BD/non-SA), and n = 76 non-psychiatric controls (CON). EWAS revealed six differentially methylated positions (DMPs) and seven differentially methylated regions (DMRs) between BD/SA and BD/non-SA, with multiple immune-related genes implicated. There were no epigenome-wide significant differences when BD/SA and BD/non-SA were each compared to CON, and patterns suggested that epigenetics differentiating BD/SA from BD/non-SA do not differentiate BD/non-SA from CON. Weighted gene co-methylation network analysis and trait enrichment analysis of the BD/SA vs. BD/non-SA contrast further corroborated immune system involvement, while gene ontology analysis implicated calcium signalling. In an independent replication cohort of n = 48 BD/SA and n = 47 BD/non-SA, fold changes at the discovery cohort\u27s significant sites showed moderate correlation across cohorts and agreement on direction. In both cohorts, classification accuracy for SA history among individuals with BD was highest when methylation at the significant CpG sites as well as information from clinical interviews were combined, with an AUC of 88.8% (CI = 83.8-93.8%) and 82.1% (CI = 73.6-90.5%) for the combined epigenetic-clinical classifier in the discovery and replication cohorts, respectively. Our results provide novel insight to the role of immune system functioning in SA and BD and also suggest that integrating information from multiple levels of analysis holds promise to improve risk assessment for SA in adults with BD

Poly[ADP-Ribose] Polymerase-1 Expression Is Related To Cold Ischemia, Acute Tubular Necrosis, and Delayed Renal Function In Kidney Transplantation

Cold ischemia time especially impacts on outcomes of expanded-criteria donor (ECD) transplantation. Ischemia-reperfusion (IR) injury produces excessive poly[ADP-Ribose] Polymerase-1 (PARP-1) activation. The present study explored the hypothesis that increased tubular expression of PARP-1 contributes to delayed renal function in suboptimal ECD kidney allografts and in non-ECD allografts that develop posttransplant acute tubular necrosis (ATN)