20 research outputs found
Remediation of contaminated soil in copper mining areas using plant-based surfactants
This research brings to knowledge the effectiveness of a novel plant-based saponin from
Acacia concinna (shikakai) for the remediation of heavy metal contaminated soils.
Shikakai has long been used for traditional hair treatment in India and other parts of the
world but has not been used for soil remediation. The effectiveness of this saponin was
compared with rhamnolipid (a class of microbial cleaning agent which has been studied
widely and applied in soil remediation), EDTA (a chemical chelate known to be soluble
and having many commercial applications including soil remediation), Sapindus
mukorossi, commonly known as soapnut (a known plant-based biosurfactant that has
been proved to enhance soil washing). The feasibility of soil washing for the removal of
Pb and Cu, from soil collected from contaminated sites polluted by copper mining and
industrial activities, as well as sandy loam soil spiked with Cd, Cu, Pb, and Zn were
investigated in laboratory-scale batch and column experiments. Influencing parameters
including the concentration of washing solutions and the pH of the washing solutions,
soil-solution ratio and washing time were studied. These parameters were found to
influence the removal efficiencies of the washing agents. The removal efficiency
increased with an increase in surfactant concentration, washing time, and soil-solution
ratio but decreased with an increase in solution pH. The results of washing contaminated
soil from copper mining and industrial pollution, show that soapnut removed a cumulative
of 66.98% and 72.98% of Cu from soil with low Cu contamination (C1) and high Cu
contamination (C2) after triple wash cycles while shikakai removed 71.08% and 78.08%
at the same conditions. While soapnut removed a cumulative of 78.98% and 77.98% of
Cu, shikakai removed 82.91% and 83.90% of Pb from soil C1 and C2 after triples wash
cycles. The batch washing experiments of the spiked soils show that the maximum
removal efficiency of 92.82% was obtained when 6% of EDTA was used to wash Cu
contaminated soil. At the same condition, soapnut, shikakai, and rhamnolipids achieved
the removal efficiency of 77.07%, 76.92% and 56.31 respectively. The cumulative
removal of heavy metals from column experiments ranged from 37.95 to 74.05% after
washing with 10 pore volumes. The performance of column experiments demonstrates
that the application of these cleaning agents in in-situ soil remediation can be an effective
alternative to ex-situ remediation. The optimization of washing parameters, using
response surface methodology (RSM) based on Box– Behnken Design shows that the
optimal conditions of process parameters for Pb and Cu removal using shikakai were:
(Conc. 3.3% and 3.7), (SSR 28.79 and 30.30), and (pH 3 and 3) respectively. The results
proved the effectiveness of shikakai as a surfactant and as well as substitute for EDTA
and rhamnolipid which have been known and applied for soil washing in several
laboratory and field experimental projects
Effect of Vernonia amygdalina Ethanolic Root Extract on the Hepato- and Nephro-Protective Properties of Albino Rats (Rattus novergicus)
The hepato- and nephro-protective potentials of Vernonia amygdalina ethanolic root extract was evaluated for 14 days using standard bioassay in 45 normal male albino rats. The rats were divided into four treatment groups I – IV and a control group V. Groups I – IV were given 100mg.kg-1, 200mg.kg-1, 400mg.kg-1 and 600mg.kg-1 body weight, respectively while the control (group V) was given equal volume of feed and water. The extracts were administered orally to the animals for 14 days. Blood samples were collected using the ocular puncture method before and weekly after administration to evaluate the extracts’ effects on aspartate transaminase (AST), acid phosphatase (ACP), alanine transaminase (ALT), alkaline phosphatase (ALP), bilirubin, creatinine and blood urea nitrogen (BUN) levels. The mean serum levels of the liver marker enzymes AST, ACP, ALT, ALP, total bilirubin and direct bilirubin ranged from 10.00±0.53 to 11.44±0.44, 31.29±0.64 to 33.14±0.56, 27.22±0.94 to 29.67±0.37 and 37.83±0.59 to 40.57±1.02, 3.42±0.08 to 3.61±0.07 and 2.06±0.11 to 2.51±0.05 respectively. The mean levels of the nephrotic enzymes, creatinine and BUN also ranged from 39.87±1.79 to 43.04±1.57 and 6.62±0.21 to 15.98±0.17 accordingly. Although no significant difference (p>0.05) was observed in the serum levels of the liver marker enzymes and creatinine when compared with the control, a dose and duration dependent significant increase (p<0.05) occurred in the BUN level. This tends to suggest that the ethanolic root extract of Vernonia amygdalina on a short term basis has some hepato-protective property while its nephro-protective ability is still doubtful. Keywords: Vernonia amygdalina, Ethanolic root extract, Liver maker enzymes, Nephrotic enzymes, Albino rat