Absorption Spectrophotometry Analysis Research Articles

Immobilization of Cadmium Via Ureolytic Bacteria Isolated from Greywater Waste and Horse Faeces

With the constant growth of technology and pollution caused by urban expansion, heavy metal contamination has become an alarming concern. The performance of Microbial induced carbonate precipitation technology in immobilizing heavy metal has been demonstrated by several researchers. While various studies have successfully isolated ureolytic bacteria from a variety of sources, there are very limited studies that have focused on isolating them from local waste sources, specifically Greywater and Horse Faeces for MICP application, which benefits in terms of economical, sustainability, and efficiency for engineering purposes. The study aims to investigate the effect of urease-producing bacteria derived from Greywater and horse faeces on heavy metal immobilization. The methods include collecting waste samples, isolating and subculturing of ureolytic bacteria, testing the physiological characteristics of ureolytic bacteria, examining the tolerance test and evaluating heavy metal removal efficacy through Atomic Absorption Spectrophotometry (AAS) analysis, and last but not least, Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX) analyses of morphological and mineralogical properties of biominerals formed after heavy metal immobilization treatment. The study found that bacteria from Greywater were more effective at heavy metal immobilization than those from Horse Faeces. Additionally, AAS analysis indicates the greywater-derived bacteria from the residential area sample's exceptional competence in Cd2+ removal, with a significant 80.19% removal rate exceeding the horse faeces bacteria sample's removal rate of 65.26%. The morphological analysis confirmed the presence of heavy metal carbonate in treated heavy metal samples, as well as presenting insight into the effectiveness and application of local ureolytic bacteria's potential for heavy metal toxicity degradation.

Cd2+ Sequestration by Ureolytic Bacteria Isolated from Goat Faeces and Nursery Wastewater

As modern industrial production makes extensive use of heavy metals, a significant amount of sewage and solid wastes containing heavy metals are released into the environment. There is significant potential for bioremediation of multiple heavy metal contamination using biomineralization to immobilise the toxic metal. In this study, microbially induced carbonate precipitation (MICP) technology was used to treat Cd2+ contamination on plants, humans, and the environment. Ureolytic bacteria that collected from goat faeces and nursery wastewater were stimulated using enrichment technique. Next, physicochemical properties of the bacteria including urea agar base test, biomineralization test, conductivity & pH measurement test and optical density test were examined through enrichment subculturing of the bacteria. The morphological characterization of precipitate formed from both samples were analayzed by using scanning electron microscopy- energy dispersive x-ray diffraction method. Ureolytic bacteria of the goat faeces sample demonstrated greater tolerance to Cd2+ concentration compared to the nursery wastewater sample by obtaining a higher optical density values and larger amounts of precipitate produced by the goat faeces sample across all tested Cd2+ concentrations. As a result, from the atomic absorption spectrophotometry (AAS) analysis, the goat faeces sample showed higher efficiency in removing Cd2+ compared to the nursery wastewater sample, with a removal efficiency of 89.06% for the goat faeces sample and 77.75% for the nursery wastewater sample. Hence, this study confirmed that the interaction between ureolytic bacteria isolated from waste sources and heavy metal ions is vital for the overall effectiveness of heavy metal removal.

Three-dimensional bioprinted materials in alginate-hyaluronic acid complex based hydrogel based bio-ink as absorbents for heavy metal ions removal

Major environmental and health effects arise from the presence of heavy metals in water, including lead (Pb²⁺), mercury (Hg²⁺), chromium (Cr⁶⁺), cadmium (Cd²⁺), and arsenic (As³⁺), which contribute significantly to water pollution and pose severe risks to ecosystems and human health. This study demonstrates the fabrication of 3D printed self-regenerative functional living materials, a fungi, by using mixture of sodium alginate and hyaluronic acid hydrogel as absorbents to remove the heavy metals from the environment. Bioprinting has emerged as a transformative technology for fabricating complex biological constructs. The bioprinting experiments, conducted with optimized parameters, revealed the viscoelastic behavior of the hydrogel, suitable for 3D bioprinting applications. MicroCT analysis indicated that the hydrogel's porosity and structural properties support fungal growth in a controlled three-dimensional setting. Microscopic analyses, including phase contrast microscopy, FESEM, and HRTEM, provided insights into the cellular morphology of the bioprinted constructs. Cell viability was assessed using flow cytometry with FDA and PI staining, showing a significant population of live cells, affirming the biocompatibility of the hydrogel. Additionally, the study explored the hydrogel's potential for heavy metal removal from water samples. Multi-element standard solutions containing Copper (Cu²⁺), Cadmium (Cd²⁺), Nickel (Ni²⁺), Cobalt (Co²⁺), and Ferrous (Fe³⁺) ions at different concentrations were incubated with hydrogel patches embedded with Aspergillus flavus. Atomic absorption spectrophotometry analysis showed rapid initial removal rates of metal ions, with maximum removal efficiency achieved around the 12th hour. Comparisons with a control hydrogel without the fungal strain demonstrated significantly enhanced removal efficiency due to the presence of Aspergillus flavus. This study highlights the dual functionality of sodium alginate with hyaluronic acid -based hydrogels for bioprinting fungi and for environmental remediation of heavy metals, offering promising applications in environmental cleanup.

Assessment of heavy metal concentration in pelagic fish species and associated health risks along the Kanyakumari coast, India – a baseline study

ABSTRACT This research examines heavy metal concentration in fish from the Kanyakumari coast of India, emphasising its ecological consequences and possible health hazards for consumers. The study investigates the levels of several heavy metals such as zinc, manganese, iron, cadmium, copper, chromium, cobalt, lead, and nickel in different organs of multiple pelagic fish species obtained from the Kanyakumari fish landing site. Concentrations of heavy metals exhibit considerable variation among different fish organs and species, with distinct patterns identified for each metal. Muscle tissue often demonstrates reduced amounts of heavy metals in comparison to other organs. Except Zn and Fe, other heavy metals in fish muscle were above the acceptable limits set by health organisations. Cadmium was found to be 36-fold higher than the permissible limit, followed by nickel (30.4) and lead (7.6). Copper, nickel, and cadmium provide possible health hazards according to the Target Hazard Quotient (THQ). Lead and cadmium exhibit Excessive Lifetime Cancer Risk (ELCR) markedly above tolerable thresholds. Large predatory fish, such as Thunnus thynnus, exhibit elevated levels of contaminants such as cadmium. Environmental conditions, aquatic habitat, and dietary intake affect metal build-up in fish. The research employs multiple analytical methods and statistical methods, such as Atomic Absorption Spectrophotometry, correlation and Principal Component Analysis, to evaluate heavy metal concentrations and their interrelations. The study underscores the critical necessity for monitoring and mitigation techniques to combat heavy metal pollution in coastal waters and its possible effects on human health through fish intake.

Determination of Trace Elements Content of a Popular Traditional Herbal Medicine Used for Internal Hemorrhoids Treatment in Katsina State, Nigeria

Study’s Excerpt/Novelty Assessment of toxic metal concentrations of a widely used traditional herb in Katsina state, was carried out. Flame atomic absorption spectrophotometry and descriptive statistical analysis was employed in the research. Pb, Cr, and As were found to be beyond WHO/FAO thresholds. Full Abstract There has been an increase in the utilization of traditional herbal drugs for different medications and health care in Katsina state. This is possibly due to the growing need for complementary disease treatment, relative cheapness, availability, and wider distribution. Raw samples of a popularly used traditional herb (locally named - Dan Lambar Rimi) were purchased from local markets, prepared, and analyzed using a flame atomic absorption spectrophotometer for Pb, Cr, As, Co, Ni, and Cd concentrations. The obtained concentrations were then summarized using descriptive statistics in SPSS Version 27. The results for the elements analyzed were Ni (0.83 ± 0.15), Cd (0.20 ± 0.01), Pb (21.5 ± 6.63), As (2.10 ± 0.70), Cr (2.36 ± 0.37), and Co (1.15 ± 0.22) ppm. Cr, Pb and As concentrations were greater than the WHO/FAO threshold limits for herbal medicines, while that of Cd was within the recommended threshold. Furthermore, the concentrations of these metals (As, Cr, and Pb) were greater than the WHO/FAO acceptable threshold in 50% of the herbal samples analyzed. Therefore, these metals can pose a threat to public health, especially considering the conventional way in which this herbal medicine is used. With deliberate improvement in hygiene during its preparation prior to consumption, the risk will be brought to a minimal. Future studies should perform a detailed chemical risk assessment, especially when we look at the increase in the number of diseases of unknown etiology in the region.

Influence of Enriched Urease Producing Bacteria from Leachate and Restaurant Wastewater on Heavy Metal Removal

The escalation of heavy metal pollution in natural ecosystems due to industrialization presents a critical environmental concern, endangering the well-being of living organisms. Microbially Induced Carbonate Precipitation (MICP) technology, an emerging innovation, has gained attention from the scientific community for its potential in biocementation and bioremediation applications. However, a substantial gap in understanding exists regarding the utilization of ureolytic microbial strains from waste sources capable of effectively immobilizing high concentrations of heavy metals. This study endeavors to explore the latent potential of indigenous ureolytic bacteria derived from leachate and restaurant wastewater, possessing bioremediation capabilities for heavy metal immobilization. The investigation includes microbial screening, physiological characterization of ureolytic bacteria, assessment of their tolerance levels, and evaluation of heavy metal removal efficacy through Atomic Absorption Spectrophotometry (AAS) analysis. Notably, the results reveal that ureolytic bacteria from restaurant wastewater are more tolerant to Cd2+ concentrations compared to their leachate counterparts, manifesting optimum conductivity, pH, and optical density (OD). More so, AAS analysis demonstrates the restaurant wastewater-derived sample's remarkable proficiency in Cd2+ removal, achieving a substantial 95% removal rate, significantly outperforming the leachate wastewater sample's removal rate of 53%.

Isotherm and Kinetic Adsorption of Malachite Green Using Low-Cost Adsorbent of Coal Fly Ash

In this study, isotherm and kinetic adsorption of malachite green (MG) using coal fly ash (CFA) as the adsorbent was investigated. This study aimed to examine the character of CFA analyzed by Atomic Absorption Spectrophotometry (AAS), Fourier-Transformed Infra-Red (FTIR), and X-Ray Diffraction (XRD) analysis. In addition, the adsorption of MG on CFA was also studied, including the effect of solution pH, adsorbent mass, contact time, and concentration of malachite green on the adsorption process. From the experimental data, the kinetic parameters isotherms and energy of the adsorption were determined. Kinetic study showed that the kinetic adsorption of MG on CFA fit well the Ho and McKay's pseudo-second-order, with an adsorption rate constant (k2) of 0.0377 g mg-1 min-1. Furthermore, the Langmuir isotherm model was the most suitable model to describe adsorption. Changes in the standard Gibbs free energy calculated from equilibrium constant (KL) at room temperature (303 K) showed that the adsorption process occurred spontaneously through chemical interaction (chemisorption) and most probably formed a monolayer on the surface of the adsorbent.

Application Of The Sol-Gel Hydroxhapatite Synthesis Method From Green Clam Shell

Hydroxyapatite is the main mineral that makes up bones and teeth so that it has a level of similarity with the mineral parts of bones and can be used as an alternative bone substitute material. As an alternative material for bone substitution, hydroxyapatite has a fairly high economic value and is still dominated by imports from foreign countries. In an effort to reduce the level of imports of hydroxyapatite, research was carried out on green mussel shells as a source of calcium for the synthesis of hydroxyapatite. The synthesis of hydroxyapatite was carried out using the sol-gel method with raw materials for calcium precursors obtained from green mussel shells and varied concentrations of phosphoric acid (0.1 M, 0.5 M, 1 M; 1.5 M; and 2 M). Based on the analysis of the hydroxyapatite product produced using Atomic Absorption Spectrophotometry analysis, it was found that the ratio of Calcium-Phosphate (Ca/P) for H3PO4 concentrations was 0.1 M, 0.5 M, 1 M; 1.5M; and 2 M respectively by 1.73; 1.70; 1.67; 1.63; and 1.61. In addition, based on the results of the Fourier Transform Infra Red analysis, a random sample also found a Ca-O group; PO43; and OH- which is the main group of Hydroxyapatite and from SEM analysis the crystal morphology is known to be spherical, uneven and agglomerated so that in this study the synthesis of Hydroxyapatite using the sol-gel method was successfully carried out..

Вплив антропогенного навантаження на екологічний стан поверхневих вод в агроландшафтах західного регіону України

Goal. To analyze the state of open water bodies in the Western region of Ukraine and to identify factors that worsen their quality indicators. Methods. Route agroecological monitoring; methods of chemical and physicochemical analysis using atomic absorption spectrophotometry, flame photometry, and mathematical and statistical analysis. Results. In pond water samples taken in the village Pavlov of the Chervonograd district of the Lviv oblast, an excess of the maximum permissible concentration of nitrate and ammonium nitrogen was found — 11.8–13.2 and 4.6 mg/l, respectively. The content of manganese compounds here exceeded the normative indicators by 5–10 times. On the territory of home ownership in Zakarpattia region (vil. Sokyrnytsia, Khust district) the content of ammonium nitrogen in pond water samples exceeded the norm by 1.8 times, the content of copper by 20 times, and zinc by twice. Analysis of water from a pond located in the vil. Popeliv of the Ivano-Frankivsk district of the Ivano-Frankivsk oblast showed an excess of the norm according to the indicator of dry residue — 2120 mg/l. In water samples taken from the Prut River (vil. Sadzhavka, Nadvirniansk district, Ivano-Frankivsk oblast), the excess of normative indicators only for the iron content was 0.13 mg/l. In the water from the Sluch River (vil. Samchyky, Khmelnytskyi district, Khmelnytskyi oblast), the pH was 8.6, the phosphorus content exceeded the norm by almost two times, and copper by 10 times. In the water from the Dniester River near the vil. Nyzhniv of Ivano-Frankivsk district, Ivano-Frankivsk oblast the content of sulfates and manganese was 156.8 and 0.03 mg/l, respectively. In water samples taken from the Rika River (Khust district, Zakarpatska oblast) the iron content was 11.3 times higher than normal, and manganese was 5 times higher than normal. Conclusions. The results of the monitoring of water bodies in the specified regions proved that both natural and anthropogenic factors affect the water quality of open water bodies. The quality of pond water is largely influenced by anthropogenic factors related to the economic activities of people, and it is they that cause the accumulation of excessive amounts of nitrogen, ammonium, copper, and zinc compounds. The quality of water samples taken from the Prut, Stara, and Rika rivers was mostly determined by natural conditions. Pollution of the Sluch River with phosphorus and copper and the Dniester River with sulfates can be caused by the inflow of sewage with detergents, as well as animal waste, fertilizers, and pesticides from residential areas.

Analysis of Potassium Ion (K+), Sodium Ion (Na+), and Proteins from Coconut Water Variety of Coconut and Hybrid Coconut

Analysis of potassium ion (K+), sodium ion (Na+), and proteins of Dalam coconut varieties water and Hybrid coconut varieties water have been done. The sample is green coconut which was taken simple random from Deli Tua Barat village in the regency of Deli Tua. Analysis of potassium ion (K+) and sodium ion (Na+) was determined by Atomic Absorption Spectrophotometry method (AAS) and analysis of protein was determined by the Kjeldahl method. From the result analysis of Dalam coconut varieties water contain amount potassium ion 321.60 mg/100 mL + 0,77 mg/100 mL, sodium ion 33.17 mg/100 mL + 1.85 mg/100 mL, and protein 0,18 % + 0.05 %. Whereas Hybrid coconut varieties water contain amount potassium ion 278.67 mg/100 mL + 1.53 mg/100 mL, sodium ion 31.33 mg/100 mL + 0.83 mg/100 mL, and protein 0.48 % + 0.3 %.

Multivariate and health risks analysis of heavy metals in natural water sources around Enugu dumpsite, southeastern Nigeria

The concentrations of heavy metals and health risks associated with the consumption of domestic water sources around a dumpsite in Enugu (southeastern Nigeria) were assessed by atomic absorption spectrophotometry and multivariate analysis. The results showed the dumpsite leachate mean pH value of 4.1, Mn+ of 11.4 µg/l, Fe3+ 4.1 µg/l, Cd+ 0.3, As+ 6.03 µg/l, Pb+ 2.47 µg/l, Ni+ 14.13 µg/l, and Cr3+ 1.48. The groundwater and surface water samples had mean heavy metal values as follows: Mn+ 5.23 and 0.75 µg/l, Fe3+ 1.49 and 0.15 µg/l, Cd+ 0.08 and 0.10 µg/l, As+ 1.90 and 0.15 µg/l, Pb+ 1.01 and 0.35 µg/l, Ni+ 0.37 and 0.05 µg/l, and Cr3+ 0.03 and 0.05 µg/l, respectively. Comparison with maximum permissible limits indicated that the mean heavy metal concentrations of the tested samples were lower than the limits for drinking water, except for Mn+, As+, and Pb + , which were marginal above recommended limits. Principal component analysis results showed two principal components with the first principal component having high loadings of Mn+, Fe3+, As+, Pb+, Ni+, and Cr3+, which are statistically correlated. Probable sources of these contaminants include automobile parts and tools, batteries and electrical appliances and electronics heaped at the dumpsite. Analysis of variance results indicates a significant difference in datasets between and within each and both water sources. Human health risk assessment indices indicated that the water sources are moderate to highly polluted and could pose both non-carcinogenic and carcinogenic threats when consumed untreated, with children being more exposed than adults.

Sintesis dan Karakterisasi Arang Aktif Dari Kulit Salak Sebagai Adsorben Terhadap Kadar BOD, COD dan TSS Pada Limbah Cair Industri Tekstil

Textile liquid waste contains organic compounds and suspended solids such as BOD, COD, and TSS, which can cause environmental pollution. This study aims to determine the levels of BOD, COD, and TSS in textile wastewater using activated charcoal from the skin of salak before and after activation with phosphoric acid (H3PO4) at a concentration of 6%.The research results that have been carried out, on the making of activated charcoal from the skin of salak have been successfully carried out and meet the requirements of SNI 06-3730-1995, obtaining 2.4% water content, 2.3% ash content, and 476 mg/L iodine absorption. FT-IR spectrum analysis activated charcoal from the skin of salak has an O-H hydroxyl group at the peak of 3817 cm-1, C=O carbonyl group at 1713 cm-1, and C-O ether group at 1175 cm-1. FT-IR spectrum analysis activated charcoal from the skin of salak has O-H hydroxyl group at the peak of 3817 cm-1, C=O carbonyl group at 1713 cm-1, and C-O ether group at 1175 cm-1. Based on SEM analysis, activated charcoal from activated skin of salak has larger pores and surface area than before activation. Based on atomic absorption spectrophotometry analysis of textile wastewater without the addition of activated charcoal, the levels of BOD were 480 mg/L, COD 650 mg/L, and TSS 470 mg/L. After the addition of unactivated activated charcoal, the levels of BOD were 120 mg/L, COD 150 mg/L, and TSS 140 mg/L. After the addition of activated charcoal, BOD levels were 60 mg/L, COD 80 mg/L, and TSS 95 mg/L.This study concludes that activated charcoal from the skin of salak can reduce, levels of BOD, COD, and TSS in textile waste and has met the requirements set out in the Regulation of the Minister of the Environment of the Republic of Indonesia Number 5 of 2014.

Inulin Modulates Iron Metabolism in Piglets Fed a High‐Iron Milk Formula

ObjectiveIron‐fortified formula provides excessive amount of iron compared to breast milk, and there is a rising concern over the adverse effects of dietary iron overexposure at infancy. The study aimed to evaluate the effect of dietary prebiotics and synbiotics supplement on iron absorption and metabolism in a milk‐fed neonatal piglet model.MethodsOn postnatal day (PD) 2, piglets (n = 6/treatment) were blocked by sex and body weight (BW) and randomized to the following dietary treatments: 1) an iron‐adequate milk formula with 60 mg Fe/kg milk solid (AI), 2) a high‐iron milk formula with 480 mg Fe/kg milk solid (HI), 3) the HI formula supplemented with inulin (Orafti®IPS, Beneo) at 6% of milk solid (HIP), 4) the HIP formula with an oral supplement of 5 ml of Lactobacilus agilis YZ050 (L. agilis) at 1x109 CFU/ml once in every 3 days (HIS). Pigs were fed at 270 mL of milk/kg BW in 14 meals daily through an automatic programmable milk delivery system. Blood and fecal samples were collected on PD 1, 7, 14, 21, 28. On PD 28, piglets were euthanized, and tissue samples were collected. Tissue and fecal samples were analyzed for iron concentrations using flame atomic absorption spectrophotometry analysis. Blood samples were analyzed for hemoglobin (Hb) using Drabkin’s reagent and hematocrit (Hct) using Unico Micro‐hematocrit centrifuge. The mRNA expression of iron transporters and regulatory proteins in the intestinal tissues were determined by RT‐qPCR. Data were analyzed for one‐ or two‐way ANOVA with repeated measure for variables measured over time. Statistical significance was declared at P ≤0.05.ResultsOverall growth performance of piglets across the groups showed no statistical significance during the study. Both Hct and Hb were higher in HI, HIP, HIS than in AI during the study (P≤ 0.05). In comparison with AI, high‐iron formula markedly increased fecal iron concentration on PD7, 14, 21, 28 (P≤ 0.05) with exception of the comparison between AI and HIP on PD7. Use of inulin in HIP reduced fecal iron on PD21 and 28 in comparison with HI (P≤ 0.05). High‐iron formula significantly increased hepatic iron compared to AI (P≤ 0.05), while use of inulin alone or in combination with probiotics attenuated hepatic iron accumulation in comparison with HI (P≤ 0.05). The same response was also observed in analysis of iron concentration in colon content. Duodenal iron concentration was higher in HIP and HIS than in AI (P≤ 0.05), whereas ileal iron concentration was higher in HI than in AI (P≤ 0.05). The mRNA expression of divalent metal transporter 1 (DMT1) in colon was lower in HIP compared to AI (P ≤ 0.05); duodenal cytochrome b (DYCTB) in colon was lower in HI and HIP compared to AI (P ≤ 0.05).ConclusionHigh‐iron formula resulted in hepatic iron overload and increased iron flux in the large intestine and feces. Use of inulin alone or in combination with L. agilis diminished iron deposition in liver, colon, and feces caused by consumption of high‐iron formula in piglets.

Optical characterization of non-thermal plasma jet energy carriers for effective catalytic processing of industrial wastewaters

An argon plasma jet was sustained in open air and characterized for its chemical composition. The optically characterized plasma jet was used to treat industrial wastewater containing mixed textile dyes and heavy metals. Since plasma jet produces UV-radiations, the photocatalytic TiO2 was used to enhance plasma treatment efficiency especially for degradation of dyes. Mixed anatase and rutile phases of TiO2 (5.2–8.5 nm) were produced through surfactant assisted sol–gel approach. The emission spectrum confirmed the presence of excited argon, OH, excited nitrogen, excited oxygen, ozone and nitric oxide in the plasma jet. The spectral lines of excited Ar, NO, O3, OH−, N2, {mathrm{N}}_{2}^{+}, O, {mathrm{O}}_{2}^{+} and O+ species were observed at wavelength of 695–740 nm, 254.3 nm, 307.9 nm, 302–310 nm, 330–380 nm, 390–415 nm, 715.6 nm, 500–600 nm and 400–500 nm. These reactive species decompose the organic pollutants and separate the heavy metals from the water samples. The conductivity of plasma exposed water samples increased while pH and hardness decreased. The atomic absorption spectrophotometry analysis confirmed the presence of heavy metals in the samples, which were effectively removed through plasma treatment. Finally, the effect of plasma treatment on Staphylococcus aureus strains was more pronounced than Escherichia coli strains.

Ultrafine particle dispersion in the metropolitan area of Guadalajara, Mexico

Objectives: Dust, soil and leaf samples of Ficus benjamina were collected in the metropolitan area of Guadalajara (GMA) (Peña-García et al., 2017), allowing to identify the type of metallic particles, size, shape and spatial distribution. With the results obtained, the possible effects of metallic particles on human and plant health were discussed (Peña-García et al., 2019). Methodology: The sampling was in six municipalities of the GMA; Atomic absorption spectrophotometry analyses were carried out on leaves, which identified the presence of various elements that mostly exceeded the reference values. Through X-ray fluorescence, 23 elements were identified in soil, including Th and Ac in at least 14 sites. Using the scanning electron microscopy technique and elemental mapping analysis, coarse, fine and ultrafine metallic particles were identified in human bronchus and lung tissue, as well as fragments of cement, plastic, yeast and bacteria. The similarity between the metallic particles in the collected samples and those observed in lung tissue, warns of latent risks to the health of the GMA population. Contribution: The results obtained with the methodology used in this work allow us to glimpse the polluting potential in urban areas.

EFFECTS OF CALCIUM HYDROGEN PHOSPHATE ON LEAD UPTAKE BY COWPEA (VIGNA UNGUICULATA)

The effects of calcium hydrogen phosphate on lead (Pb) uptake by cowpea (Vigna unguiculata) were investigated in a growth chamber experiment coupled with atomic absorption spectrophotometry (AAS) and colorimetry analyses. Cowpea seeds were planted and harvested in soil samples treated with Pb+2 added as lead nitrate at the rates of 0, 1000 and 3000 mg/kg followed by calcium hydrogen phosphate (CaHPO4) at 0, 10, 50 and 250 mg/kg. Increases in shoot yield brought about by phosphate fertilization were observed to oppress the shoot lead concentration as a result of growth dilution, where the actual amount of lead in shoots was unaffected by phosphate treatment. This work revealed that there is no substantial effect on lead uptake by cowpea, as a result of phosphate fertilization. Therefore, phosphate fertilization is a good means of cowpea production with minimal lead uptake and hence safe for human consumption

Flame Atomic Absorption Spectrophotometry Analysis of Heavy Metals in Some Food Additives Available in Baghdad Markets, Iraq

Flame atomic absorption spectrophotometer (FAAS) was used in this study to determine the concentrations of heavy metals such as Ca, Fe, Mn, Cd, Co, Cr, Ni, Cu, Pb and Zn in some food additives of Iraq. The order of metal contents in food additives was found to be Ca ? Mn ? Fe ? Cu ? Zn ? Pb ? Cr ? Ni ? Co ? Cd. The concentration level of each metal was compared with that recommended by food agriculture organisation (FAO) and world health organisation (WHO). Calibration curves were linear for all standard solutions of heavy metals in the range starting from 0.02-0.4 mg/kg for Cd to 11-100 mg/kg for Ca. The correlation coefficients values (R2) of calibrations were investigated and ranged from 0.9971 for Cr to 0.9999 for Ca. The limit of detection (LOD) and limit of quantification (LOQ) were found to be in highest value for Ca (1.6569 mg/kg and 5.5232 mg/kg), while they were found to be in lowest values for Cd (0.0150 mg/kg and 0.0499 mg/kg).

One-step synthesis of zerovalent-iron-biochar composites to activate persulfate for phenol degradation.

A novel zerovalen-iron-biochar composite (nZVI/SBC) was synthesized by using FeCl3-laden sorghum straw biomass as the raw material via a facile one-step pyrolysis method without additional chemical reactions (e.g., by NaBH4 reduction or thermochemical reduction). The nZVI/SBC was successfully employed as an activator in phenol degradation by activated persulfate. XRD, SEM, N2 adsorption-desorption and atomic absorption spectrophotometry analysis showed that the nanosized Fe0 was the main component of the 4ZVI/SBC activator, which was a mesopore material with an optimal FeCl3·6H2O/biomass impregnation mass ratio of 2.7 g/g. The 4ZVI/SBC activator showed an efficient degradation of phenol (95.65% for 30 min at 25 °C) with a large specific surface area of 78.669 m2·g-1. The recovery of 4ZVI/SBC activator after the degradation reaction of phenol can be realized with the small amount of dissolved iron in the water. The 4ZVI/SBC activator facilitated the activation of persulfate to degrade phenol into non-toxic CO2 and H2O. The trend of Cl-, SO4 2- and NO3 - affected the removal efficiency of phenol by using the 4ZVI/SBC activator in the following order: NO3 - > SO4 2- > Cl-. The one-step synthesis of the nanosized zerovalent-iron-biochar composite was feasible and may be applied as an effective strategy for controlling organic waste (e.g. phenol) by waste biomass.

Adsorption and Desorption Efficiency of a Sugarcane Bagasse in the Removal of Fe2+ from a Galvanizing Industry

Disposal of industrial effluent is of health concern. Especially effluent from industries such as metal galvanizing, tannery, metallurgical, mining, chemical, battery and nuclear, agriculture, and others that generate heavy metals which deteriorate soil, groundwater quality and bio accumulate in food chains these are particularly harmful to both plants and animals. Removing Heavy Metals are mostly expensive, this necessitate researches on the efficient and effective use of agro based low cost adsorbent, which is also an efficient form of agricultural waste disposal. This study is to remove Fe2+ ions in industrial wastewater using raw Sugarcane Bagasse (SCB) adsorbent. The initial concentration of Fe2+ ions in the industrial (galvanizing) wastewater was first analyzed to determine the removal efficiency of SCB in adsorbing Fe2+ from wastewater and the optimum conditions (such as effect of phase contact time, rotating speed and concentration dosage) of the adsorbent was determined. The following characteristics of the agro waste material and wastewater were determined; Fourier Transform Infrared Spectroscopy FTIR analysis, digestion of wastewater samples and Atomic Absorption spectrophotometry (AAS) analysis. The results show that percentage removal of Fe2+ ions from aqueous solution was 95.11% with the raw sugarcane bagasse adsorbent. The sorption capacity decreases with increasing dosage concentration and phase contact time and the desorption studies demonstrated important data for the regeneration and recovery of both adsorbent and heavy metal ions.

Electrochemical reforming of ethanol in a membrane-less reactor configuration

As a result of the research of a more integrated process for hydrogen production, a new concept of membrane-less electrochemical reformer rises up for single-step hydrogen production in a single chamber reactor. In this system, the solid polymeric electrolyte is replaced by a low concentration liquid KOH solution electrolyte, simplifying its scale up and enhancing the stability of the cell. The viability of the system is studied for electrochemical reforming of ethanol and under an alkaline environment, which avoids the use of Pt-Ru or Pt-Sn high metal loading electrodes. Instead of these catalysts, commercial Pd/C Vulcan and Pt/C black are sprayed over Carbon Paper to be used as anode and cathode catalysts, respectively. In all the experiments carried out, a hydrogen stream with 100% of faradaic efficiency has been obtained. A temperature of 85 °C, a 3.5 mm electrodes distance and a fuel feeding solution of 1 mol·L−1 EtOH and 4 mol·L−1 KOH are the optimised conditions found in the studied range. These optimised conditions lead to current densities above 450 mA·cm−2 at lower cell potentials (1.4 V) than required for water electrolysis leading to lower energy consumption values. It is a remarkable result, as this electrocatalytic activity is higher than that obtained in previous studies based on membrane electrode assemblies systems. Finally, the stability of the system has been verified by mild term electrocatalyic experiments coupled with Atomic Absorption Spectrophotometry and X-ray diffraction analysis of fresh and used electrodes.