Tetracycline removal from soil by phosphate-modified biochar: Performance and bacterial community evolution.

Since the remediation performance of soil tetracycline pollution by original biochar is not ideal, many modified methods have been proposed to improve its performance. Considering the cost, complex modification process and environmental friendliness, many modified biochar are difficult to be used in soil environments. In this work, biochar derived from corn stover was modified using phosphate to increase the adsorption ability of soil tetracycline and alleviate the negative effects caused by tetracycline. The results showed that pyrolysis temperatures and anion types of phosphate (PO43-, HPO42-, H2PO4-) played important roles in the performance of modified biochar. Compared with original biochar, phosphate modified biochar not only improved the adsorption capacity, but also changed the adsorption behavior of tetracycline. Via SEM, BET and FTIR techniques, the intrinsic reasons for the increase of adsorption capacity were explained by the change of morphological structures as well as functional groups of the modified biochar. K3PO4 and high temperature (800 °C) maximally improved the surface morphology, increased the pore structure, changed the surface functional groups of biochar, and then increased the adsorption capacity of tetracycline (124.51 mg/g). Subsequently, the optimal material (K3PO4-800) was selected and applied for tetracycline contaminated soil remediation. Compared to the soil without remediation, K3PO4-800 modified biochar effectively reduced the effective concentration of tetracycline in soil, and improved soil K and P nutrition, and reshaped microbial communities. Our study showed that K3PO4-800 modified biochar was not only a good tetracycline resistant material, but also a good soil amendment.

Using a Service Ontology to Understand What Influences Older Adults' Outdoor Physical Activities in Nanjing.

Older adults are not actively participating in outdoor physical activities. An understanding of what factors influence older adults' outdoor physical activities is important for informing interventions. This study aims to examine the potential effect of service ontology on the intention of outdoor physical activities in older adults. Face-to-face surveys were conducted with 421 older adults from eight districts in Nanjing, China. One-way analysis of variance and ordinal logistic regression analysis revealed that seven of the 20 factors have a positive effect on intention of outdoor physical activities, including gender, health self-assessment, family structure, accessibility, exercise instructors, emergency service, and staff in outdoor space. To further improve the intention of outdoor physical activities, governments and service designers should focus on providing age-friendly community infrastructures. Moreover, specific attention should be paid toward older females and people with low-income/poor health conditions, and strategies should also be adopted to significantly improve the quantity and instruction efficiency of exercise instructors.