Kinetic, Equilibrium and ThermodynamicStudies of the Adsorption of Methylene Bluefrom Synthetic WastewaterUsing Cow Hooves

Aims:To investigate the feasibility and thekinetic of using cow hooves (CH) as a low-costadsorbent for the removal of methylene blue (MB) from synthetic wastewater.Place and Duration of Study:Chemistry Laboratory, Afe Babalola University, Ado-Ekiti,Nigeria, from October 2012 to January 2013.Methodology:This study was conducted through batch process. The influence of initialpH, contact time, CH dosage and temperature on the adsorption property of CH wasinvestigated using pH ranging from 2.0–11.0, contact time of 5-180 minutes, CH dosage of0.15–1.0 g and temperature of 298–318 K. All experiments were carried out using 0.25 g ofCH per 100 mL of MB solution except for effect of CH dosage. The equilibrium studieswere carried out using MB concentration ranging from 10–100 mgL-1at 298, 308 and318K and the experimental data obtained were analysed and modelled using Langmuir,Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models.Results:Our results indicated that a time of 90 minutes was required for equilibrium to beattained for25 mgL-1MB. The percentage removal of MB was found to increase withincrease in pH.The isotherm data were best fitted by Temkin isotherm model. The kineticsmodelling of the experimental data agreed with the pseudo-second-order model suggesting that chemisorption was the rate determining step. The values of thethermodynamic parameters (∆G0,∆H0and∆S0) revealed that the adsorption process wasspontaneous at very low temperature, feasible and exothermic.Conclusion:Cow hoof could be a promising low-cost adsorbent for the removal ofmethylene blue from wastewater and this could be bestachieved at high MB pH and withina period of one and half hours

Kinetic, Equilibrium and Thermodynamic Studies of the Adsorption of Methylene Blue from Synthetic Wastewater Using Cow Hooves

Aims: To investigate the feasibility and the kinetic of using cow hooves (CH) as a low-cost adsorbent for the removal of methylene blue (MB) from synthetic wastewater. Place and Duration of Study: Chemistry Laboratory, Afe Babalola University, Ado-Ekiti, Nigeria, from October 2012 to January 2013. Methodology: This study was conducted through batch process. The influence of initial pH, contact time, CH dosage and temperature on the adsorption property of CH was investigated using pH ranging from 2.0–11.0, contact time of 5-180 minutes, CH dosage of 0.15–1.0 g and temperature of 298–318 K. All experiments were carried out using 0.25 g of CH per 100 mL of MB solution except for effect of CH dosage. The equilibrium studies were carried out using MB concentration ranging from 10–100 mgL-1 at 298, 308 and 318 K and the experimental data obtained were analysed and modelled using Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models. Results: Our results indicated that a time of 90 minutes was required for equilibrium to be attained for 25 mgL-1 MB. The percentage removal of MB was found to increase with increase in pH. The isotherm data were best fitted by Temkin isotherm model. The kinetics modelling of the experimental data agreed with the pseudo-second-order model suggesting that chemisorption was the rate determining step. The values of the thermodynamic parameters (ΔG0, ΔH0 and ΔS0) revealed that the adsorption process was spontaneous at very low temperature, feasible and exothermic. Conclusion: Cow hoof could be a promising low-cost adsorbent for the removal of methylene blue from wastewater and this could be best achieved at high MB pH and within a period of one and half hours

Activated Carbon from Spent Brewery Barley Husks for Cadmium Ion Adsorption from Aqueous Solution

This study investigated the feasibility of using acid activated carbon prepared from brewery spent barley husks for the adsorption of cadmium from aqueous solution. The effects of operation parameters such as pH, contact time, adsorbent dosage, concentration and temperature were verified. The amount of cadmium adsorbed increased with increase in solution pH, initial solution concentration and with the amount of adsorbent dosed. A time of 5 minutes was required for attainment of equilibrium. The equilibrium data obtained were analysed using both Langmuir and Freundlich isotherm models and the data were better described by Langmuir model with correlation coefficient of 0.9183. The thermodynamic parameters revealed that the removal of cadmium by the activated carbon was exothermic and spontaneous. Thus, activated carbon obtained from brewery spent barley husk can be employed as an economically viable low-cost adsorbent for removing cadmium from aqueous solution

Assessing anthropogenic contribution to PM2.5 from an urban residential area of Lagos, Nigeria using aliphatic hydrocarbon compounds as indicators

Aliphatic hydrocarbons in PM2.5 samples from a residential area of Lagos, Nigeria, were quantified using a Curie-point pyrolysis–gas chromatography–mass spectroscopy (CPPGC/MS). The total concentrations of ∑n-alkanes (C20-C34), hopanes (∑4Hopanes), and steranes (∑3Steranes) ranged from 1.8 to 146.6 ng m-3 (avg. 43.6 ± 35.1 ng m-3), 0.0 to 89.9 ng m-3 (avg. 18.7 ± 25.9 ng m-3), and 0.0 to 26.0 ng m-3 (avg. 3.3 ± 6.7 ng m-3), accounting for 0.2%, 0.1%, and 0.01% of the total PM2.5 mass concentrations, respectively. They also accounted for, 1%, 0.4% and 0.1% of the organic matter content, respectively, making them non-negligible component of the organic matter in this region. An evaluation of the n-alkanes source diagnostic indices revealed that engines powered by gasoline and diesel were the main sources of particulate matter aliphatic hydrocarbons in this area of Lagos, consistent with the results obtained from steranes and hopanes profiles. Based on the air mass trajectories, both local and regional air mass transports showed a significant influence on the amounts of carbonaceous materials and aliphatic hydrocarbon compounds arriving at the study site. The results from this study established the occurrence of anthropogenic air pollution in Lagos residential area with a major contribution from petrogenic sources

Nephroprotective Effect of Essential Oils from Ginger (Zingiber officinale) and Turmeric (Curcuma longa) Rhizomes against Cadmium-induced Nephrotoxicity in Rats

Several studies have shown that cadmium (Cd) induces nephrotoxicity and many plant foods phytochemicals have been found useful but their possible mechanism of action still remains unexplored. Hence, this study aimed to investigate the nephroprotective effect of essential oils from Nigeria ginger and turmeric rhizomes in cadmium-treated rats by examining their effect on renal function biomarkers (creatinine, urea and BUN), inflammatory cytokines (IL-6, IL-10 and TNF-Alpha) and renal adenosine deaminase (ADA) activity. The result revealed that essential oils from ginger and turmeric rhizomes exert anti-inflammatory effect by preventing alterations of renal function markers and cytokines (IL-6, IL-10 and TNF-Alpha) levels in Cd-treated rats. In addition, the essential oils inhibited renal ADA activity in Cdtreated rats. In conclusion, inhibition of ADA activity and modulation of inflammatory cytokines could be suggested as the possible mechanism of action by which essential oils from ginger and turmeric rhizomes exert their nephroprotective activitie

Organic Matter Accumulation Mechanism in the Lower Cambrian Strata from Well Luntan 1 in the Tarim Basin, NW China

A large amount of light crude oils have been found within 4000 to 7000 m deep strata of Cambrian, Ordovician, and Silurian reservoirs in the Tarim Basin, NW China. To enhance the understanding of parental materials of deep oils, a set of high-quality source rocks from the Yuertusi Formation in well Luntan 1 (maximum drilling depth of 8882 m) was studied in terms of their sedimentary condition and mechanism of organic matter enrichment. Total organic carbon (TOC) content, carbon isotope of kerogen (δ13Cker), and major and trace elements of the rocks from the Sinian Qigebulake, Cambrian Yuertusi, and Xiaoerbulake Formations in well Luntan 1 were analysed. The results showed that the δ13Cker value of the Yuertusi Formation barely changed with an average of -31.19‰. High TOC contents accompanied by enrichments of the bioessential trace elements, such as cadmium, chromium, copper, nickel, and zinc, occurred in the lower part of the Yuertusi Formation. Excess barium (Baxs) and phosphorus concentrations revealed high primary productivity during the deposition of the Yuertusi Formation. Moreover, variations in the enrichment factors of molybdenum, uranium, and vanadium and molybdenum-uranium covariation pattern indicated suboxic-anoxic conditions in the Qigebulake Formation, anoxic-euxinic conditions in the Yuertusi Formation, and suboxic-oxic conditions in the Xiaoerbulake Formation. The TOC contents were significantly correlated with the paleoproductivity and paleoredox parameters, indicating that high productivity and reducing conditions jointly controlled the organic matter accumulation and preservation in well Luntan 1