Modeling surface water-groundwater interaction in arid and semi-arid regions with intensive agriculture

In semi-arid and arid areas with intensive agriculture, surface water-groundwater (SW-GW) interaction and agricultural water use are two critical and closely interrelated hydrological processes. However, the impact of agricultural water use on the hydrologic cycle has been rarely explored by integrated SW-GW modeling, especially in large basins. This study coupled the Storm Water Management Model (SWMM), which is able to simulate highly engineered flow systems, with the Coupled Ground-Water and Surface-Water Flow Model (GSFLOW). The new model was applied to study the hydrologic cycle of the Zhangye Basin, northwest China, a typical arid to semi-arid area with significant irrigation. After the successful calibration, the model produced a holistic view of the hydrological cycle impact by the agricultural water use, and generated insights into the spatial and temporal patterns of the SW-GW interaction in the study area. Different water resources management scenarios were also evaluated via the modeling. The results showed that if the irrigation demand continuous to increase, the current management strategy would lead to acceleration of the groundwater depletion, and therefore introduce ecological problems to this basin. Overall, this study demonstrated the applicability of the new model and its value to the water resources management in arid and semi-arid areas.     

Recent developments in the enhancement of some postharvest biocontrol agents with unconventional chemicals compounds

BackgroundProduce are susceptible to microbial attack from diverse sources and the use of novel BCAs has gained recognition as alternative and sustainable applications to lessen the current emerging problems with synthetic fungicide use. Most researchers recommend the combination of two or more biocontrol agents in postharvest diseases control. To this end, the enhancement of biocontrol agents and the mechanisms of action in biocontrol systems have attracted many research interests. In this regard, there have been remarkable efforts to develop a multifaceted system approach for disease control.Scope and approachIt has been recognized that the various methods of biological control act together additively or synergistically to achieve significant commercial level of 97–99% disease control. The integration of microbial agents with a wide range of unconventional chemicals and their corresponding mechanisms of action to controlling postharvest fungal pathogens of fruits has been proven be successful.Key findings and conclusionsIn this review, the combined strategy of unconventional chemical compounds and other BCAs have contributed to varied degree of postharvest diseases control. The beneficial effects of these methods depend on the appropriate combination of the agents based on adequate knowledge of their mechanisms of action in the biocontrol system. Lastly, efforts to upscale these methods to commercial implementation level must be given the necessary consideration.     

Heteroatom embedded graphene-like structure anchored on porous biochar as efficient metal-free catalyst for ORR

Efficient biomass-derived carbon have large potential as alternative to metal-based catalysts for oxygen reduction reaction (ORR). This study demonstrates a feasible strategy to largely prepare enteromorpha (EP) derived biochar with N, S embedded graphene-like structure anchored, which is firstly used as efficient metal-free electrocatalyst for ORR. Omitting the selection and classification of raw material as well as further additional activation and/or modification by dopants, the preparation process was merely adjusted via pyrolysis and acid etching. The obtained catalyst with low content of N (3.80 at%), S (1.00 at%) and large surface area (778.2 m² g⁻¹) exhibited an onset potential of 0.95 V vs RHE in a four electron pathway, which showed superior stability and durability compared to that of commercial Pt/C catalyst. The outstanding performance of the catalyst is expected to be a potential candidate for sustainable and large-scale industrial energy conversion and storage processes in the near future.