In general, China National Accreditation Service for Comformity Assesment (CNAS) is responsible for organizing proficiency testing activities in China?
Coking residuary water contains phenol and cyanogens, which contaminate water source badly. Therefore, the coking residuary water has to be dealt with and discharged.
Test result shown that accuracy of testing result is incresaed after the improvement compared to the previous result.This did decrease the misjudgement for qualified product.