Effective solid acid catalysts play a key role to produce high-quality biodiesel through triglyceride transesterification.

No abstract

Yin (2016) Efficient culture protocol for plant regeneration from cotyledonary petiole explants of Jatrophacurcas L., Biotechnology & Biotechnological Equipment, 30:5, 907-914, DOI: 10.1080/13102818.2016 A high-frequency and reproducible protocol for induction of adventitious shoot buds and plant regeneration from cotyledonary petiole explants of Jatropha curcas L. has been developed. The cotyledonary petiole explants of J. curcas cultured directly on medium supplemented with thidiazuron (TDZ) induce regeneration of poor quality shoot buds that have a low regeneration frequency. However, treating the explants with high concentrations (10À60 mg/L) of TDZ solution for certain time periods (5À80 min) significantly increased the regeneration frequency and improved the quality of the regenerated shoot buds. The best shoot buds induction (88.42%) and number of shoot buds (12.67) per explant were observed when in vitro explants were treated with 20 mg/L TDZ solution for 20 min before being transferred on hormone-free medium after 30 days. Regeneration was also influenced by the orientation (horizontal or vertical) of the explants on the medium, and by the origin of the cotyledonary petioles (in vitro or in vivo) used for the preparation of explants. We performed subsequent experiments for elongation and rooting of the regenerated shoot buds. Addition of L-arginine to the medium was conducive to the elongation of the shoot buds. A concentration of 7.5 mg/L L-arginine yielded the best results. The elongated shoots could initiate roots to become intact plantlets in half-strength Murashige and Skoog medium containing 0.1 mg/L indole-3-butyric acid. After acclimatization, these plantlets could be transplanted to the soil and the growth was normal. Therefore, application of the methods described here helped to increase plant regeneration efficiency.

Concentrations of eight heavy metals (i.e., Fe, Mn, Cr, Ni, Cu, Zn, Cd and Pb) in the seawater, suspended particulate matter (SPM) and sediments of the Zhanjiang Bay were investigated in 2014. The concentrations of metals were generally low in the seawater and sediments of the Zhanjiang Bay in winter and summer, indicating good environmental quality in the bay. The distribution patterns of Fe and Mn in three phases indicated the influence of terrestrial inputs. The partition coefficients log(Kd) between the dissolved and particulate phases showed a general decrease in the order of Pb≈Cd>Fe≈Mn>Ni≈Cr>Zn>Cu. The concentrations of some metals in the dissolved and particulate phases showed seasonal variations. Phytoplankton production and complexation reactions may contribute to this phenomenon. The relationships among metals in different phases were different, and there were few close relationships among metals in the dissolved phase, many close relationships in the particulate phase, and more close relationships in the sedimentary phase. This finding may be related to the different mobility levels of metals in different phases.

The efficiency of a novel microalgal culture system (an airlift loop bioreactor [ALB] engaged with a fluidic oscillator to produce microbubbles) is compared with both a conventional ALB (producing fine bubbles without the fluidic oscillator) and non-aerated flask culture. The impact of CO 2 mass transfer on Dunaliella salina growth is assessed, through varying the gas (5% CO 2 , 95% N 2 ) dosing flow rate. The results showed that approximately 6 -8 times higher chlorophyll content was achieved in the aerated ALB cultures than in the non-aerated flasks, and there was a 20% -40% increase in specific growth rate of D. salina in the novel ALB with microbubbles when compared with the conventional ALB cultures. The increase in chlorophyll content was found to be proportional to the total amount of CO 2 mass transfer. For the same dosing time and flow rate, higher CO 2 mass transfer rate (microbubble dosing) resulted in a greater growth rate.

In marine environments, urea is an important component of the biogeochemical cycle of nitrogen. The autochthonous and allochthonous sources (rivers, aquaculture, waste water input, etc.) of urea play a key role in urea cycles in adjacent coastal waters. Because urea is a specific marker to trace the sewage fluxes in coastal waters, we investigated urea associated with terrestrial source input and coastal water in Zhanjiang Bay (ZJB) during the time from November 2018 to July 2019, and the spatiotemporal urea distribution and the bioavailability of dissolved organic nitrogen (DON) based on urea concentration in the ZJB were explored. The results showed that the urea enrichment in coastal water was mainly due to discharge from urban sewage systems, rivers, and coastal aquaculture. The concentration of urea ranged from 1.14 to 5.53 μmol·L−1, and its mean value was 3.13 ± 1.02 μmol·L−1 in the ZJB. The urea concentration showed a significantly different seasonal variation in the ZJB (p < 0.05), and the highest and lowest concentrations were found in November 2018 and April 2019, respectively. Its high value appeared in the north and northeast of the ZJB, which were polluted by coastal aquaculture and agriculture fertilizer utilization. The range of urea concentration of terrestrial source inputs in the ZJB was 1.31–10.29 μmol·L−1, and the average urea concentration reached 3.22 ± 0.82 μmol·L−1. Moreover, the total urea flux surrounding the ZJB was 2905 tons·year−1. The seasonal terrestrial source of urea flux contributions had significant seasonal variation in wet, normal, and dry seasons (p < 0.05). The ZJB was subjected to a large flux of urea by estuaries and sewage outlet discharges. The seasonal urea concentration in all stations (>1 μmol·L−1) indicated that urea in the ZJB may have a bioavailable DON source. As a bioavailable nitrogen source, the ability of terrestrial source-derived urea to increase eutrophication should not be ignored in ZJB.

The adsorption mechanism of carbon dioxide (CO2) on Li/UiO-66 was studied by an in situ DRIFTS study.

Solid sorbents are considered to be promising materials for carbon dioxide capture. In recent years, many studies have focused on the use of solid waste as carbon dioxide sorbents. The use of waste resources as carbon dioxide sorbents not only leads to the development of relatively low‐cost materials, but also eliminates waste simultaneously. Different types of waste materials from biomass, industrial waste, household waste, and so forth were used as carbon dioxide sorbents with sufficient carbon dioxide capture capacities. Herein, progress on the development of carbon dioxide sorbents produced from waste materials is reviewed and covers key factors, such as the type of waste, preparation method, further modification method, carbon dioxide sorption performance, and kinetics studies. In addition, a new research direction for further study is proposed. It is hoped that this critical review will not merely sum up the major research directions in this field, but also provide significant suggestions for future work.