Biochar produced from rice straw at 400 °C (RS400) was prepared to determine its alleviating effect on Cd phytotoxicity to wheat seedlings under different cultivation temperatures and pH. A hydroponic system (pH 4.3) and a loam soil slurry system were designed to respectively simulate acidic and neutral soil condition, and cultivation at increasing temperatures (20, 25, and 30 °C) were performed to evaluate the greenhouse effect. The root and shoot elongation and the Cd concentration in root and solution were measured; furthermore, batch experiments for Cd adsorption were undertaken. An increasing inhibition of the root by Cd addition was observed at increasing temperatures. The inhibition rate was 50.50 and 20.80% in hydroponic system and slurry system at 25 °C, respectively; however, the corresponding inhibition rates of root were significantly decreased to 25.5 and 3.5% with addition of RS400. This is mainly attributed to the reduction of Cd migration into the roots by RS400, which decreased Cd bioavailability. The mechanism behind the reduced Cd bioavailability is attributed to the Cd adsorption and the strong buffering capacity of acidity by RS400. Therefore, biochar could be a potential amendment for the remediation of Cd-contaminated soil even at increasing culturing temperatures.
The intent of this research is to investigate how the customers of a technological control laboratory for civil construction materials perceived the quality of the services delivered by the lab, specifically in regard to the service of concrete compression testing. The popular SERVQUAL scale, a multidimensional instrument used to capture customer expectations and perceptions, was used as a model for the application of a survey. Exploratory factor analyses were employed to evaluate customers’ perceptions and experiences of service quality in regard to the dimensions and accompanying attributes of the SERVQUAL scale. Twenty attributes, which were grouped within five dimensions (Reliability, Assurance, Tangibles, Responsiveness, and Empathy), were identified, explaining 80.417% of the variance between customer expectations and perceptions and characterizing these dimensions on a modified SERVQUAL scale. Analysis of the results allowed us to identify discrepancies in perceived service quality compared with customers’ expectations. Most of the identified gaps between expectations and perceptions resulted in negative values. 相似文献
Journal of Material Cycles and Waste Management - Waste classification is comprehensively carried out in China as an important national-level policy, and the large amount and the wide range of food... 相似文献