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In this study, N-doped straw biochar(N-BC) was prepared using urea for the removal of Pb2+, Cu2+, and Cr6+ from water. SEM, FT-IR, XRD, and XPS characterization analyses demonstrated the successful loading of N onto the biochar. The adsorption performance of the N-doped biochar was evaluated by orthogonal and single-factor experiments. The results showed that the magnitude of the effect on the adsorption of the three heavy metals was consistent with initial pH > dosing > pyrolysis temperature. In addition, the optimum initial pH for the adsorption of Pb2+, Cu2+, and Cr6+ was 5, 6, and 2, respectively. Compared to the single biochar, the adsorption of Pb2+, Cu2+, and Cr6+ by N-doped biochar increased from 6.33, 4.25, and 3.78 mg/g to 30.2, 16.28, and 14.53 mg/g. The adsorption of Pb2+, Cu2+, and Cr6+ followed quasi-secondary kinetics and the Langmuir model. Mechanistic studies showed that the adsorption mechanism of N-doped biochar for Cu2+ and Pb2+ involved surface adsorption, cation-π bonding, and complexation, while that for Cr6+ included electrostatic attraction and reduction. The reusability and excellent adsorption properties of the surface N-doped biochar from cycling experiments indicate that biochar is a good material for the removal of heavy metals from water. [ABSTRACT FROM AUTHOR]

[Objective] To meet the management standardization and market development needs and improve their testing technology and management capabilities, an increasing number of textile laboratories have passed the CNAS accreditation. CNAS-CL01-A010, Guidance on the application of testing and calibration laboratories competence accreditation criteria in the field of textile testing, is a document developed by CNAS based on textile testing characteristics and is a further clarification of the accreditation guideline CNAS-CL01. CNAS-CL01-A010 was revised through CNAS considering the problems in the textile laboratory accreditation and changes in the textile industry technology. The implementation of CNAS-CL01-A010: 2023 implies the continuous standardization and optimization of the management system activities of textile testing laboratories. By comparing and analyzing the changes between old and new versions, suggestions can be formulated for textile laboratories to improve the standardization of relevant testing activities and improve their own testing technology and management capabilities. [Methods] This study compares and analyzes the differences between old and new versions of CNAS-CL01-A010: in terms of the structural arrangement, the article numbers and chapter names of the new and old versions are compared, and the corresponding relationship with CNAS-CL01 is provided; in terms of article content, the new version has made 15 revisions, including 9 changes, 5 additions, and 1 deletion. Then, the changes concerning scope, organization, personnel, environmental facility and equipment, sample, testing methods, and monitoring methods are explained consecutively. Combined with the daily laboratory work, ideas for improvement and refinement of laboratory activities are introduced regarding documents, personnel, environmental facilities, standard substances, samples, and so on. [Results] According to the differences between old and new versions, combined with the background and reasons for the changes, the new version of the application note has a wider scope of application, stringent requirements regarding the competence of testing personnel and control of environmental facilities, and a directional and operable expression of requirements. In response to these changes, the laboratory can make the following improvements: 1 Revise and improve the system documents on time and check whether the existing documents meet the requirements of the new version of the application note; 2 Strengthen personnel management and ensure good personnel supervision/monitoring and training; 3 Construct a reasonable layout of the facility environment and monitor and control the environmental conditions affecting testing; 4 Pay attention to the period verification of standard substances to ensure the accuracy of test results; 5 Pay attention to sample management to protect the integrity of the test samples and meet the testing needs. [Conclusions] By comparing and analyzing the application notes of old and new versions, this study proposes an optimal reference for the improvement of laboratory activities, aiming to help textile testing laboratories correctly understand the latest accreditation requirements, promote the scientific and standardized management of laboratories, ensure that the testing capabilities continue being effective, and realize the efficient and healthy operation of laboratories. [ABSTRACT FROM AUTHOR]