Influence of Suspended Clay Minerals and Humic Matter on the Solid Phase Extraction Efficiency of Selected Pesticides from Water

The purpose of this investigation was to determine the influence of humic acids (HA) and Ca-montmorillonite (CaM) on the solid-phase extraction (SPE) efficiency of atrazine, alachlor and α-cypermethrin from water samples at various pH-values. The nature and intensity of binding of the studied pesticides to CaM were determined by X-ray diffraction analysis and termogravimetric analysis (TGA) test. The studied pesticides eluted from discs were analysed by thin-layer chromatography (TLC). The effects of CaM and humic acid were generally pH-dependent and acted independently in extraction efficiency influence. Lower recovery of pesticides was observed at higher pH values when CaM was ≥0.1 g and was attributed to greater dispersion of clay, increased surface area and subsequent adsorption. Concentrations of dissolved organic carbon (DOC) in humic acid had less effect on the extraction efficiency when water was at pH 8 compared to water at pH 2, which was probably due to greater nonpolar interactions of the pesticides to the charge-neutralized humic acid molecule.     

An updated review on advancement in fermentative production strategies for biobutanol using Clostridium spp.

A significant concern of our fuel-dependent era is the unceasing exhaustion of petroleum fuel supplies. In parallel to this, environmental issues such as the greenhouse effect, change in global climate, and increasing global temperature must be addressed on a priority basis. Biobutanol, which has fuel characteristics comparable to gasoline, has attracted global attention as a viable green fuel alternative among the many biofuel alternatives. Renewable biomass could be used for the sustainable production of biobutanol by the acetone-butanol-ethanol (ABE) pathway. Non-extinguishable resources, such as algal and lignocellulosic biomass, and starch are some of the most commonly used feedstock for fermentative production of biobutanol, and each has its particular set of advantages. Clostridium, a gram-positive endospore-forming bacterium that can produce a range of compounds, along with n-butanol is traditionally known for its biobutanol production capabilities. Clostridium fermentation produces biobased n-butanol through ABE fermentation. However, low butanol titer, a lack of suitable feedstock, and product inhibition are the primary difficulties in biobutanol synthesis. Critical issues that are essential for sustainable production of biobutanol include (i) developing high butanol titer producing strains utilizing genetic and metabolic engineering approaches, (ii) renewable biomass that could be used for biobutanol production at a larger scale, and (iii) addressing the limits of traditional batch fermentation by integrated bioprocessing technologies with effective product recovery procedures that have increased the efficiency of biobutanol synthesis. Our paper reviews the current progress in all three aspects of butanol production and presents recent data on current practices in fermentative biobutanol production technology.

     

Microbial decolorization of synthetic dyes and reactive dyes of industrial effluents by using a novel fungus Aspergillus proliferans

A decolorizing fungal strain was isolated and identified by the morphology and genotypic characterization as Aspergillus proliferans. The effect of A. proliferans on decolorization of synthetic dyes (70 mg ml(-1)) and colored effluent was evaluated in liquid culture medium. A. proliferans expressed their effective decolorization activity in effectual decolorization of synthetic dyes and industrial effluent. Synthetic dyes were decolorized by 76 to 89% within 6 days of treatment and 73.5% of color was removed in industrial effluent within 8 days. The addition of optimum carbon and nitrogen sources were effectively stimulated the decolorization activity. The high concentration of glucose repressed the decolorization activity and supplementation of yeast extract has significantly enhanced the effluent decolorization at p < 0.05. Laccase enzyme was isolated from liquid state fermentation, which showed significant enzyme activity (10,200 Uml(-1)) at p < 0.005. The crude enzyme decolorizes the dyes aniline blue and congo red in 14 hours (40.9 to 70%) and the effluent in 14 hours (88.6%). Moreover, the culture free supernatant without the fungal biomass has also effectively decolorized the effluent and synthetic dyes. The fungi Aspergillus proliferans was used not only for decolorization but also for better bioremediation of industrial effluent.