11 research outputs found
Decentralized systems for the treatment of antimicrobial compounds released from hospital aquatic wastes
In many developing countries, untreated hospital effluents are discharged and treated simultaneously with municipal wastewater. However, if the hospital effluents are not treated separately, they pose concerning health risks due to the possible transport of the antimicrobial genes and microbes in the environment. Such effluent is considered as a point source for a number of potentially infectious microorganisms, waste antimicrobial compounds and other contaminants that could promote antimicrobial resistance development. The removal of these contaminants prior to discharge reduces the exposure of antimicrobials to the environment and this should lower the risk of superbug development. At an effluent discharge site, suitable pre-treatment of wastewater containing antimicrobials could maximise the ecological impact with potentially reduced risk to human health. In addressing these points, this paper reviews the applications of decentralized treatment systems toward reducing the concentration of antimicrobials in wastewater. The most commonly used techniques in decentralized wastewater treatment systems for onsite removal of antimicrobials were discussed and evidence suggests that hybrid techniques should be more useful for the efficient removal of antimicrobials. It is concluded that alongside the cooperation of administration departments, health industries, water treatment authorities and general public, decentralized treatment technology can efficiently enhance the removal of antimicrobial compounds, thereby decreasing the concentration of contaminants released to the environment that could pose risks to human and ecological health due to development of antimicrobial resistance in microbes.</p
<i>BjuB</i>.<i>CYP79F1</i> Regulates Synthesis of Propyl Fraction of Aliphatic Glucosinolates in Oilseed Mustard <i>Brassica juncea</i>: Functional Validation through Genetic and Transgenic Approaches - Fig 6
<p>(A) Gel picture showing amplification of <i>BjuB</i>.<i>CYP79F1</i> (PCR using forward primer GS1B-NS-FP and reverse primer GS1B-NS-RP) in five T<sub>0</sub> transgenics each of EH-2 and QTL-NIL <i>J16Gsl4</i>. (B) Expression analysis of <i>BjuB</i>.<i>CYP79F1</i> from leaves of T<sub>0</sub> transgenic lines by RT-PCR using the same primers as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150060#pone.0150060.g004" target="_blank">Fig 4</a>. V—Varuna, H—Heera, E—EH-2, QN—QTL-NIL <i>J16Gsl4</i>, gDNA—genomic DNA, cDNA—complementary DNA.</p
Phenotypic (for sinigrin) and genotypic (for <i>BjuB</i>.<i>CYP79F1</i>) co-segregation data of a F<sub>2</sub> population from a cross between QTL-NIL <i>J16Gsl4</i> line and Varuna.
<p>Phenotypic (for sinigrin) and genotypic (for <i>BjuB</i>.<i>CYP79F1</i>) co-segregation data of a F<sub>2</sub> population from a cross between QTL-NIL <i>J16Gsl4</i> line and Varuna.</p
Map of T-DNA construct of <i>BjuB</i>.<i>CYP79F1</i> used for genetic transformation of <i>B</i>. <i>juncea</i>.
<p>Map of T-DNA construct of <i>BjuB</i>.<i>CYP79F1</i> used for genetic transformation of <i>B</i>. <i>juncea</i>.</p
RT-PCR analysis from developing siliques showing expression of <i>BjuB</i>.<i>CYP79F1</i> in parents and F<sub>2</sub> segregants derived from a cross between Varuna and QTL-NIL <i>J16Gsl4</i>.
<p>RT-PCR reactions were performed using gene specific primers for <i>BjuB</i>.<i>CYP79F1</i> (forward primer GS1G-NS-FP and reverse primer GS1B-NS-RP) and Actin (forward primer Actin-FP and reverse primer Actin-RP). Amplification from genomic DNA was done by primer pair GS1G-NS-FP and GS1B-NS-RP (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150060#pone.0150060.s008" target="_blank">S2 Table</a>). No DNA lane was used as control. V—Varuna, QN—QTL-NIL <i>J16Gsl4</i> line, F<sub>1</sub> –F<sub>1</sub> between Varuna x QTL-NIL <i>J16Gsl4</i>, H—Heera, cDNA—complementary DNA, 1–8 –F<sub>2</sub> segregants where <i>BjuB</i>.<i>CYP79F1</i> is present (Varuna allele), 9–12 –F<sub>2</sub> segregants where <i>BjuB</i>.<i>CYP79F1</i> is absent (Heera allele).</p
Map of LG B4 showing positions of marker At1g16410 (named as <i>BjuB</i>.<i>CYP79F1</i>) and QTL <i>J16Gsl4</i> in <i>B</i>. <i>juncea</i>.
<p>Map of LG B4 showing positions of marker At1g16410 (named as <i>BjuB</i>.<i>CYP79F1</i>) and QTL <i>J16Gsl4</i> in <i>B</i>. <i>juncea</i>.</p
PCR amplification by three B genome specific primers (names of primers used have been given on top of the gel lanes) for <i>CYP79F1</i> from <i>B</i>. <i>juncea</i> lines Varuna (V) and Heera (H); <i>B</i>. <i>rapa</i> (R); <i>B</i>. <i>nigra</i> (N).
<p>PCR amplification by three B genome specific primers (names of primers used have been given on top of the gel lanes) for <i>CYP79F1</i> from <i>B</i>. <i>juncea</i> lines Varuna (V) and Heera (H); <i>B</i>. <i>rapa</i> (R); <i>B</i>. <i>nigra</i> (N).</p
High-Performance Recyclable Magnetic CuFe<sub>2–<i>x</i></sub>Cr<sub><i>x</i></sub>O<sub>4</sub> Nanocatalysts for Facile Reduction of Nitrophenols and Photooxidative Degradation of Organic Dyes
Remediating pollutants in water sources is essential
for preserving
and protecting our water resources. Water pollution can have severe
environmental, economic, and public health consequences. Water scarcity
for domestic purposes can eventually be addressed by improving wastewater
management. In the present study, highly active and magnetically separable
Cr-doped copper ferrites CuFe2–xCrxO4 (x =
0, 0.2, 0.4, 0.6, 0.8, and 1) were synthesized via a sol–gel
technique and employed for the conversion of nitrophenols to aminophenols
and photooxidative deterioration of various dyes such as methyl orange
(MO), rhodamine B (RhB), and methylene blue (MB), as well as their
ternary solution (RhB + MO + MB). Powder X-ray diffraction investigation
indicates that the prepared phases are well indexed in the Fd3̅ m space group except for CuFe2O4, which crystallizes in the I41/amd space group. The M–H hysteresis loop results support the ferromagnetic
behavior of the nanophases, which makes them magnetically separable.
The optical-band-gap energies of prepared nanostructures were found
to be in the range of 1.70–1.39 eV, which makes them appropriate
and reliable photocatalysts. CuFe2O4 was found
to be the most efficient nanocatalyst toward the conversion of nitrophenols
to aminophenols, while CuCrFeO4 showed a maximum degradation
efficiency for the deterioration of dyes. The kinetic models correctly
explain both reduction and photodegradation processes using pseudo-first-order
kinetics. Further, several recyclability runs demonstrated that the
nanocatalysts were extremely stable and reusable. This study reflects
the possibility of employing mesoporous nanocatalysts for practical
applications in the treatment of wastewater
Ultrathin, Flexible Organic–Inorganic Hybrid Solar Cells Based on Silicon Nanowires and PEDOT:PSS
Recently,
free-standing, ultrathin, single-crystal silicon (c-Si)
membranes have attracted considerable attention as a suitable material
for low-cost, mechanically flexible electronics. In this paper, we
report a promising ultrathin, flexible, hybrid solar cell based on
silicon nanowire (SiNW) arrays and polyÂ(3,4-ethylenedioxythiophene):polyÂ(styrenesulfonate)
(PEDOT:PSS). The free-standing, ultrathin c-Si membranes of different
thicknesses were produced by KOH etching of double-side-polished silicon
wafers for various etching times. The processed free-standing silicon
membranes were observed to be mechanically flexible, and in spite
of their relatively small thickness, the samples tolerated the different
steps of solar cell fabrication, including surface nanotexturization,
spin-casting, dielectric film deposition, and metallization. However,
in terms of the optical performance, ultrathin c-Si membranes suffer
from noticeable transmission losses, especially in the long-wavelength
region. We describe the experimental performance of a promising light-trapping
scheme in the aforementioned ultrathin c-Si membranes of thicknesses
as small as 5.7 μm employing front-surface random SiNW texturization
in combination with a back-surface distribution of silver (Ag) nanoparticles
(NPs). We report the enhancement of both the short-circuit current
density (<i>J</i><sub>SC</sub>) and the open-circuit voltage
(<i>V</i><sub>OC</sub>) that has been achieved in the described
devices. Such enhancement is attributable to the plasmonic backscattering
effect of the back-surface Ag NPs, which led to an overall 10% increase
in the power conversion efficiency (PCE) of the devices compared to
similar structures without Ag NPs. A PCE in excess of 6.62% has been
achieved in the described devices having a c-Si membrane of thickness
8.6 μm. The described device technology could prove crucial
in achieving an efficient, low-cost, mechanically flexible photovoltaic
device in the near future
Plasmonic Effects of Au/Ag Bimetallic Multispiked Nanoparticles for Photovoltaic Applications
In
recent years, there has been considerable interest in the use
of plasmons, that is, free electron oscillations in conductors, to
boost the performance of both organic and inorganic thin film solar
cells. This has been driven by the possibility of employing thin active
layers in solar cells in order to reduce materials costs, and is enabled
by significant advances in fabrication technology. The ability of
surface plasmons in metallic nanostructures to guide and confine light
in the nanometer scale has opened up new design possibilities for
solar cell devices. Here, we report the synthesis and characterization
of highly monodisperse, reasonably stable, multipode Au/Ag bimetallic
nanostructures using an inorganic additive as a ligand for photovoltaic
applications. A promising surface enhanced Raman scattering (SERS)
effect has been observed for the synthesized bimetallic Au/Ag multispiked
nanoparticles, which compare favorably well with their Au and Ag spherical
nanoparticle counterparts. The synthesized plasmonic nanostructures
were incorporated on the rear surface of an ultrathin planar c-silicon/organic
polymer hybrid solar cell, and the overall effect on photovoltaic
performance was investigated. A promising enhancement in solar cell
performance parameters, including both the open circuit voltage (<i>V</i><sub>OC</sub>) and short circuit current density (<i>J</i><sub>SC</sub>), has been observed by employing the aforementioned
bimetallic multispiked nanoparticles on the rear surface of solar
cell devices. A power conversion efficiency (PCE) value as high as
7.70% has been measured in a hybrid device with Au/Ag multispiked
nanoparticles on the rear surface of an ultrathin, crystalline silicon
(c-Si) membrane (∼12 μm). This value compares well to
the measured PCE value of 6.72% for a similar device without nanoparticles.
The experimental observations support the hope for a sizable PCE increase,
due to plasmon effects, in thin-film, c-Si solar cells in the near
future