Research progress on biochar-based material adsorption and removal of ibuprofen

Ibuprofen, commonly used for pain relief, inflammation, and to reduce high fever, etc., is a widely available over-the-counter drug. In recent years, due to the excessive use of ibuprofen, its presence in the aquatic environments has shown a significant increasing trend, raising concerns about potential risks to environmental safety, which attracted people’s close attention. Notably, biochar, known as an environmentally friendly functional material, had been widely studied and applied for the removal of ibuprofen in water environments. According to current reports, the adsorption capacity value of biochar for IBP is between 9.69–309 mg/g, and the adsorption mechanism mainly includes π-π stacking, hydrogen bonding, pore filling, etc. In response to this research hotspot, this study reviewed the most recent research progress on the adsorption of ibuprofen using biochar-based materials, including the modified preparation process of biochar and the adsorption mechanism of IBP on various modified biochar surfaces. Additionally, potential challenges and future development directions for the practical applications of biochar were discussed and proposed

Retrieval of crop biophysical parameters from Sentinel-2 remote sensing imagery

The red-edge bands place the recently available multispectral Sentinel-2 imagery at an advantage over other multispectral sensors, and hypothetically offer improved crop biophysical variable retrieval accuracy. In this study, Sentinel-2 data was tested for its ability to estimate winter wheat leaf area index (LAI), leaf chlorophyll content (LCC) and canopy chlorophyll content (CCC). Artificial neural network (ANN) and look-up table (LUT) (based on PROSAIL simulations) and vegetation index (VI) methods were applied to retrieve biophysical parameters, and compared with the biophysical processor module embedded in the Sentinel Application Platform (SNAP) software. Based on a set of in situ measurements (62 samples) and near-synchronous Sentinel-2 images, the inversion approaches were applied and validated. The results showed that: 1) Sentinel-2 red-edge bands improved the retrievals of chlorophyll / LAI compared to traditional VIs; 2) the red-edge VIs outperformed other approaches; and 3) the SNAP biophysical processor obtained comparable accuracies of LAI and CCC estimation compared to the ANN and LUT approaches, giving R2 values above 0.5 with relatively low RMSE (1.53 m2/m2 for LAI, and 148.58 μg/cm2 for CCC). We recommend VI retrieval approach for small region with ground measurements, whereas where ground data is not available, SNAP is applicable for versatile and rapid winter wheat parameter estimation (though results need to be evaluated alongside the provided quality indicators). Summarizing, the results demonstrate the suitability of Sentinel-2 data, especially its red-edge bands, for crop biophysical variables retrieval. Future studies will need to make comparisons across canopy types to better assess the capability of the SNAP biophysical processor