Abstract
A central composite design (CCD) was employed to evaluate the combined effects of pH, hardness and dissolved organic carbon (DOC) on the toxicity of Cu (II) and Cr(VI) towardDaphnia magna. Surface response design (SRD) analysis showed that pH and DOC were found to be most significant for the Cu(II) toxicity (p<0.05), while pH and hardness for the Cr(VI) toxicity. According to the results of chemical speciation using the Visual MINTEQ program, increases in pH and DOC concentration led to decreased toxicity of Cu(II) by reducing the concentration of toxic Cu2+ species. For the Cr(VI) toxicity, increases in pH and hardness led to decreased toxicity towardD. magna by reducing the concentrations of toxic HCrO4− and CrO42− species. Based on the SRD analysis, surface response models were developed for prediction of the 24-h and 48-h mortalities ofD. magna in the presence of Cu(II) and Cr(VI) under different pH, hardness and DOC conditions.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
