Construction of efficient bismuth/boron-based flexible electrode in organic media toward neutral hydrogen evolution

Preparing high-efficient, low-cost and stable catalysts to produce hydrogen in neutral electrolyte is a major challenge due to the sluggish kinetics, low conductivity and complex hydrogen adsorption-desorption process. Here, series...

Reactivity of a Carene-Derived Hydroxynitrate in Mixed Organic/Aqueous Matrices: Applying Synthetic Chemistry to Product Identification and Mechanistic Implications

β-hydroxynitrates (HN) are a major class of products formed during OH and NO3 initiated oxidation of terpenes. Their production contributes significantly to secondary organic aerosol (SOA) formation and NOx sequestration. However, studying the condensed phase reactions of this important class of molecules has been hindered by the lack of commercially available authentic standards. The goal of this work was to examine the influence of water concentration and solvent identity on product yields of a tertiary HN derived from 3-carene prepared in house. To assess the role of water on conversion chemistry, bulk-phase reactions were conducted in DMSO-d6, a non-nucleophilic solvent, with a gradient of water concentrations, and analyzed with 1H NMR. Product identifications were made by comparison with authentic standards prepared in house. Four major products were identified, including an unexpected diol produced from carbocation rearrangement, diol diastereomers, and trans-3-carene oxide, with varying yields as a function of water concentration. Product yields were also measured in two protic, nucleophilic solvents, MeOD-d4 and EtOD-d6. Finally, reactions with added chloride formed alkyl chloride products in yields approaching 30%. These results are among the first to highlight the complexities of nucleophilic reactions of hydroxynitrates in bulk, mixed aqueous/organic media and to identify new, unexpected products.

Effect of drainage layers on water retention of potting media in containers.

Excess water retention in the potting medium is a significant problem for plants grown in containers due to the volume of saturated medium which forms above the drainage hole. Adding a layer of coarse material like gravel or sand at the bottom is a common practice among gardeners with the aim of improving drainage, but some researchers have argued that such layers will raise the saturated area and in fact worsen drainage. Two different depths and four different materials of drainage layer were tested with three different potting media to determine the water retention in the container after saturating and draining freely. For loamless organic media, almost all types of drainage layer reduced overall water retention in the container compared to controls. For loam-based media, most drainage layers had no effect on the overall water retention. Two simple models were also used to estimate the water retention in the media alone, excluding the drainage layer itself. All drainage layers reduced water retention of loamless organic media, according to both models. There was disagreement between the two models applied to loam-based media, and further study is required to determine the most accurate. Both models showed that some drainage layers with smaller particle sizes reduced water retention in loam-based media, but disagreed on the effect of drainage layers with larger particle sizes. Overall, any drainage layer was likely to reduce water retention of any medium, and almost never increased it. Thicker drainage layers were more effective than thinner layers, with the most effective substrate depending on the potting media used. A 60 mm layer of coarse sand was the most universally-effective drainage layer with all potting media tested.

Alternative medium for the growth of endophytic fungi

Medium for the growth of endophytic fungi generally uses Potato Dextrose Agar media, but because the price is expensive, it is necessary to find materials for alternative media from organic materials that are easy to obtain and inexpensive. The legume group was one of the alternative ingredients as the source of protein, corn, and rice as the source of carbohydrates for the growth medium. This study aimed to determine the potential of organic matter such as rice, corn, and legumes as a medium for the growth of endophytic fungi. The research methods included: rejuvenation of endophytic fungus isolation, preparation of organic medium from rice, corn, legumes, and potatoes, growth test of endophytic fungus on 4 types of organic media.

Zinc removal from highly acidic and sulfate-rich wastewater in horizontal sub-surface constructed wetland

This study demonstrated the successful utilization of a lab-scale baffled horizontal constructed wetland substituted with mixed organic media for zinc removal from high acidity (∼610 mg L−1 as CaCO3) sulfate-rich (∼1,300 mg L−1) wastewater. The wetland was planted with Typha latifolia. The mean zinc concentration in the influent was gradually increased from 0.56 ± 0.02 mg L−1 to 5.3 ± 0.42 mg L−1. The mean zinc concentration in the outflow was 0.22 ± 0.19 mg L−1, accounting 95% zinc removal throughout the study. However, total zinc uptake by plants was 533 mg kg−1, accounting for only 1.2% of total zinc removal and therefore, major zinc retention occurred within wetland media (83%). The overall activity and specific sulfidogenic activity decreased at the end of the study to 1.43 mg COD removed mg TVS−1 d−1 and 0.60 mg sulfate reduced mg TVS−1 d−1, respectively. Additionally, 16S rRNA sequencing revealed major dominant phyla present: Firmicutes (36%), Proteobacteria (16%), Actinobacteria (8.8%), Planctomycetes (7.8%), Chloroflexi (3.5%), Acidobacteria (1.9%) and Fibrobacteres (1.5%).