Selective adsorption of PHC and regeneration of washing effluents by modified diatomite.

Selective removal of petroleum hydrocarbons (PHCs) from soil washing effluents is the key to the surfactant-enhanced soil washing technology. In this study, the diatomite was modified by nonionic surfactant TX-100 and applied in the selective adsorption of PHCs in the soil washing effluents. The modified diatomites were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption/desorption and X-ray photoelectron spectroscopy respectively. The adsorption process followed the pseudo-second-order model and the adsorption isotherms indicated that the interaction between PHCs and modified diatomite was monolayer adsorption. The important operating factors such as TX-100 dosage, adsorbent dosage, time and temperature were optimized. With the participation of the low-cost adsorbent TX3-Db with high adsorption capacity, the recovery efficiency of the washing effluents was still up to 78.9% after three cycles. A selective adsorption mechanism, based on steric hindrance and electrostatic repulsion, was proposed to explain the removal of PHCs from washing effluents.

Effects of a Combined Motor Imagery and Action Observation Intervention on Vascular Cognitive Impairment: A Randomized Pilot Study.

OBJECTIVE: The aim of the study was to identify the effects of combined motor imagery and action observation therapy on vascular cognitive impairment. DESIGN: Thirty vascular cognitive impairment patients were randomly assigned into three groups. Cognitive training group was given conventional cognitive training, motor imagery + action observation group was treated with motor imagery and action observation therapy, and mixed therapy group was given conventional cognitive training and motor imagery + action observation therapy, for 8 wks continuously. The Montreal Cognitive Assessment Scale, Rivermead Behavioral Memory Test, and event-related potential were used to evaluate the cognitive function at baseline, 4- and 8-wk posttreatment, and 1-mo follow-up. RESULTS: There were significant time × group interactions in Montreal Cognitive Assessment Scale (F6,4.20 = 8.38, P < 0.001), event-related potential latent period (F6,294.24 = 5.10, P < 0.001), event-related potential amplitude (F6,1.68 = 23.08, P < 0.001), and Rivermead Behavioral Memory Test (F6,312.61 = 5.42, P < 0.001). Intragroup comparisons showed that Montreal Cognitive Assessment Scale and Rivermead Behavioral Memory Test scores and event-related potential amplitude increased significantly (P < 0.05), and event-related potential latency decreased significantly (P < 0.05) in all groups. Intergroup comparisons showed that the changes of all outcomes in mixed therapy group were greater than those in cognitive training and motor imagery + action observation group (P < 0.05) after treatment. CONCLUSIONS: These results suggest that the combination of cognitive training with motor imagery and action observation therapy is an effective treatment on cognitive function in people with vascular cognitive impairment.