Volume 3 Issue 3

Authors: Md. Abul Kashem; S M Imamul Huq; Shigenao Kawai; Bal Ram Singh

Abstract: A pot experiment was conducted to investigate the cadmium tolerance and phytoextraction efficiency of arum (Colocasia antiqourum) grown in soil spiked with cadmium (Cd) levels of 0, 5, 10, 25, 50, and 100 mg kg-1. Arum plants were grown for 105 days in the Cd contaminated soil. After harvest, the plants were separated into leaves, stems, bulbs and roots and dry mass of those were recorded. Dry matter yield was not affected by the application of Cd but Cd concentration in plant parts increased linearly with Cd application rates in soil. Without growth retardation, Cd concentrations in arum increased from 8.3 to 75 mg kg-1 in the leaves, 40 to 262 mg kg-1 in the stems, 4.3 to 55 mg kg-1 in the bulbs and 166 to 912 mg kg-1 in the roots, when Cd levels increased from 5 to 100 mg kg-1 in the soil. In the shoots (leaves and stems) of arum, Cd concentration was 137 and 168 mg kg-1 at the 50 and 100 mg kg-1 Cd supply levels in soils respectively. Those values were above the accepted threshold level of Cd hyper accumulator plants. Similar to Cd concentration, Cd accumulation (concentration × dry weight of plant) increased in different parts of arum with Cd application rates in the soil.Cadmium accumulation in the whole plant increased from 2.2 to 16.2 mg plant-1 when Cd levels in the soil increased from 5 to 100 mg kg-1 Cadmium accumulation in different parts of arum decreased in the order: root > stems > bulbs > leaves. Cadmium translocation from root to shoot was about 50% of the total Cd, showing a moderate mobility of Cd in arum, however, this plant is easy to harvest with roots. The outcomes of this study confirm that this plant is a suitable candidate for the phytoremediation of Cd contaminated soil.

Keywords: Cadmium; Hyperaccumulator; Contaminated Soil; Phytoremediation


Authors: Ishwerdas L. Muthreja; Chandrashekhar P. Pandhurnekar; Mahendra S. Kadu; Ajay K. Agarwal

Abstract: The objective of this study was to investigate removal characteristics of Nickel (Ni+2) ions from aqueous solution using exhausted thermal power plant coal fly ash. The effects of various experimental conditions such as amount of adsorbent, contact time both in mixing condition and steady state condition; and initial metal concentration on the efficiency of Ni+2 ions removal from the aqueous solution were studied at room temperature. In this study, it was found that fly ash effectively adsorb Ni+2 ions from aqueous solution. When lime used as an admixture along with the fly ash, the removal tendency of Ni+2 ions from the solution was found to be increased. In the batch kinetics study, it was observed that adsorption process is pseudo-second order reaction. From the adsorption isotherm study, it reveals that the equilibrium adsorption data fit well in to the Freundlich adsorption isotherms model than Langmuir adsorption isotherms. The test results indicated that fly ash could be used as a cheap adsorbent for effective removal of Ni+2 ions in aqueous solutions.

Keywords: Removal of Ni+2 Ions Using Fly Ash; Low Cost Adsorbent; Admixture; Adsorption Isotherm; Reaction Kinetics


Authors: R. L. Crawford; E. R. Coats; C. K. Brinkman; T. L. Green; M. M. Ederer; F. S. Alhamlan

Abstract: Microbial populations are present in high concentrations in dairy wastewater treatment lagoons and thus pose a potential public health risk. A broad and robust detection assay is needed to monitor the presence of human pathogens in such systems. The objective of this study was to develop and corroborate a microarray-based assay for screening and monitoring of agriculturally-impacted waters for immediate detection of > 1,500 specific viruses and bacteria. Water samples from two dairy lagoons (Lagoons I and II) were screened using molecular assays (such as ElectroChemical Detection (ECD) 12K microarray) in conjunction with traditional analytical chemical methods. Bacterial signature DNA sequences and viral signature DNA/RNA sequences that are associated with human diseases were detected in higher numbers in both lagoons. The presence of some of these microbial signatures in the lagoons was confirmed using PCR and qPCR techniques. Based on microscopic analyses, most probable number (MPN) counts, total viable counts (CFU), 16S rRNA gene analysis, microarray signal intensity analyses, and qPCR assays, the microbial community density was found to trend higher in Lagoon I than Lagoon II; however, microbial diversity in Lagoon I trended lower. Results from this research confirm the usefulness of ECD-based microarray technology as a pathogen screening method for agriculturally-impacted waters.

Keywords: Electrochemical Detection Microarray, Pathogen Detection, Monitoring, Dairy Lagoons


Authors: Saidatul Akmar Aziz; Mohd Armi Abu Samah; Afiza Abdullah Suhaimi

Abstract: Biosorption of Lead (II) ions from aqueous solution by treated corn (Z. Mays) leaves biomass was studied. The biosorption percent of Lead (II) ions onto treated Z. Maysleaves biomass was evaluated as a function of pH, amount of dose and contact time. The treatment of biosorbent using alkali resulted in an increase in the biosorption. The maximum percentage uptakes values were found as 97.6% at pH 3, 94.1% with the amount of 3.0 g of biosorbent and 93.3% at 180 minutes of contact time with initial Lead (II) concentration of 10 mgL-1. Metal uptake of Lead (II) ions was 0.4833 mg/g at pH 3, 1.74 mg/g with 3.0 g amount of biosorbent and 0.31 mg/g at 180 minutes contact time. The treated Z. Mays biomass was found to be suitable and potential for removal of Lead from aqueous solution.

Keywords: Z. Mays; Biosorption; Biosorbent; Lead; Biomass


Authors: A. Lawal; A.O. Atoyebi; G.O. Olutona; J.A.O. Oyekunle; A.O. Ogunfowokan

Abstract: A nine-step sequential extraction protocol of Zn, Mn, Cd, Cu, Ni, Co and Pb in sediments from Asunle River that receives effluents from the waste dumpsite of the Obafemi Awolowo University, Ile Ife Nigeria was carried out. Total and dissolved levels of the heavy metals in water samples were also determined using Flame Atomic Absorption Spectrophotometer (FAAS). The results of total metal concentration (μg/mL) in water ranged from 0.04 ± 0.01 Cd to 2.25 ± 0.57 Zn while the mean levels of dissolved metal in water ranged between 0.004 ± 0.000 μg/mL and 0.87 ± 0.17 μg/mL. Mean levels of total heavy metal (μg/g) in the sediment samples ranged between 10.99 ± 2.18 – 74.62 ± 11.96 in Pb and 645.10 ± 62.15 – 3753.03 ± 176.29 in Mn. The apparent mobility and potential bioavailability for each metal in the sediment was >70%. The study showed that both the water and sediment samples were contaminated with heavy metals to varying degrees primarily as a result of effluents discharging into the river from the dumpsite within the vicinity of the river.

Keywords: Heavy Metals; Speciation Studies; Water; Sediment; Asunle River