Phytoremediation Potential of <em>Chrysopogon zizanioides</em> for Toxic Elements in Contaminated Matrices

Many researchers have demonstrated the advantages of plants in the phytoremediation of soils and waters contaminated with heavy metals, herbicides, pesticides, leachates, etc. The unique morphological characteristics of Chrysopogon zizanioides, commonly known as vetiver, make it a hyperaccumulator of metals; its roots can store high concentrations of heavy metals such as As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn, and it has thus been successfully used in the field of environmental protection. This chapter presents the importance of vetiver, its characterization, and its potential use as phytoremediation potential for toxic elements in contaminated matrices

Synthesis of syn-γ-Amino-β-hydroxyphosphonates by Reduction of β-Ketophosphonates Derived from L-Proline and L-Serine

The reduction of γ-N-benzylamino-β-ketophosphonates 6 and 10, readily available from L-proline and L-serine, respectively, can be carried out in high diastereoselectivity with catecholborane (CB) in THF at -78 ºC to produce the syn-γ-N-benzylamino-β-hydroxyphosphonates 11 and 13 as a single detectable diastereoisomer, under non-chelation or Felkin-Anh model control

Evaluation of Hydraulic Retention Time on Treatment of Coffee Processing Wastewater (CPWW) in EGSB Bioreactor

The coffee processing agro-industry generates large quantities of wastewater requiring systematic treatment prior to disposal. For this reason, the aim of this study was to evaluate the hydraulic retention times (HRT) in treatment of coffee processing wastewater (CPWW) using a laboratory scale Expanded Granular Sludge Bed (EGSB) bioreactor at different HRT (3 to 9 days). The EGSB was evaluated in mesophilic condition (26 ± 2 °C) with an average pH of 7.5 ± 0.2 to determine the chemical oxygen demand (COD) removal efficiency. According to the results, the COD removal efficiency increases from 94 to 98% when the HRT increase from 3 to 9 days; the α factor remained stable (0.98) throughout the evolution of the bioreactor. The HRT´s between 7–9 days generated effluents capable to be dischargeable into water bodies with a permitted COD concentration according to World Health Organization (WHO) and Official Mexican Environmental Regulations permissible limits. Results evidenced that the HRT of 9 days was the one that greater COD removal generated, so the EGSB bioreactor can be a sustainable alternative to solve the environmental problems, compared to other conventional methods to CPWW treatment

Anaerobic treatment of agro-industrial wastewaters for COD removal in expanded granular sludge bed bioreactor

Untreated agro-industrial wastewaters are undesirable in the aquatic environment due to the presence of high organic matter contents. However, they may constitute a large potential for biogas production. The present investigation is focused on three laboratory-scale anaerobic expanded granular sludge bed (EGSB) bioreactors, continuously operated for 60 d under mesophilic condition with the aim of exploring the feasibility of treating three most significant agro-industrial wastewaters in Chiapas, Mexico (i.e., cheese whey, vinasse, and coffee-processing wastewater). The EGSB bioreactors were operated with a hydraulic retention time (HRT) of 6 d under stable conditions (i.e., buffer index (BI) of 0.31, 0.34, and 0.03), generating a maximum chemical oxygen demand (COD) removal efficiency of 91, 74, and 96% with an average methane production of 340, 245, and 300 mL/g COD∙d for cheese whey, vinasse, and coffee-processing wastewater, respectively. According to the obtained results, the EGSB bioreactors could be a sustainable alternative to simultaneously solve the environmental problems and to produce bioenergy

RHOEO DISCOLOR, A MEDICINAL PLANT WITH PHYTOREMEDIATION POTENTIAL.

<p>Rhoeo discolor is a plant used in traditional medicine mainly due to its anticancer properties. The present work studied, for the first time, its use as a phytoremediation plant. Samples of R. discolor were collected in the gardens of the Universidad Ju?rez Aut?noma de Tabasco. Chrysopogon zizanioides (vetiver), a phytoremediation plant, was used as positive control. Both plants were exposed for 144 h to leachates from a sanitary landfill for urban waste. Afterwards, they were washed, dried and pulverized. Specimens of each species were left unexposed to leachates to use as negative controls. Elements were identified and quantified by X-rays and by ICP. The elements identified in R. discolor exposed to leachates were quartz, CaCO3 and thiocyanate. Arsenic, lithium, Lead, and Thallium were identified at concentrations that were only 1.4 times lower than those found in vetiver, except for Tl (445.71 and 326.33 mg/kg in R. discolor and vetiver, respectively). In both evaluated species, exposure to leachates was associated with an increase in the concentration of Cu, K, Mn, Ni and S. In R. discolor and vetiver, the concentration of S increased 25 and 6 times, respectively. It was concluded that R. discolor has potential as a phytoremediation plant.</p

Alternative Use of Extracts of Chipilín Leaves (Crotalaria longirostrata Hook. &amp; Arn) as Antimicrobial

The genus Crotalaria comprises about 600 species that are distributed throughout the tropics and subtropical regions of the world; they are antagonistic to nematodes in sustainable crop production systems, and have also shown antimicrobial capacity. Chipilín (C. longirostrata), which belongs to this genus, is a wild plant that grows in the state of Chiapas (Mexico) and is traditionally is used as food. Its leaves also have medicinal properties and are used as hypnotics and narcotics; however, the plant has received little research attention to date. In the experimental part of this study, dried leaves were macerated by ethanol. The extract obtained was fractionated with ethyl ether, dichloromethane, ethyl acetate, 2-propanone, and water. The extracts were evaluated against three bacteria—namely, Escherichia coli (Ec), Citrobacter freundii (Cf), and Staphylococcus epidermidis (Se)—and three fungi—Fusarium oxysporum A. comiteca (FoC), Fusarium oxysporum A. tequilana (FoT), and Fusarium solani A. comiteca (FSC). During this preliminary study, a statistical analysis of the data showed that there is a significant difference between the control ciprofloxacin (antibacterial), the antifungal activity experiments (water was used as a negative control), and the fractions used. The aqueous fraction (WF) was the most active against FoC, FsC, and FoT (30.65, 20.61, and 27.36% at 96 h, respectively) and the ethyl ether fraction (EEF) was the most active against Se (26.62% at 48 h)