- freely available
Materials 2017, 10(9), 1101; doi:10.3390/ma10091101
2. Materials and Methods
2.2. Preparation of CMS
2.3. Cd2+ Adsorption Experiments
2.4. Material Characterization
3. Results and Discussion
3.1. Effects of Different Modification Conditions on Cd2+ Removal
3.2. Material Characterization of MS and CMS
3.3. Effect of Different Physicochemical Conditions on Cd2+ Removal by CMS
- The optimal condition for the preparation of CMS was mixing 2% chitosan solution with MS for 2 h.
- SEM and XRD results showed no change in crystal morphology of MS after modification. However, the increase in C and N contents in EDS spectra, the increase in 2% of mass loss in TGA analysis, and the presence of 2850 and 2920 cm−1 bands in FTIR analyses confirmed chitosan uptake on MS after modification.
- The static single factor experiment results showed that under the condition of room temperature, pH of 7, vibration adsorption time of 90 min, and adsorbent dosage of 2 g/L, the Cd2+ removal from simulated wastewater with an initial concentration of 100 μg/L was over 96% when using CMS as the adsorbent, which meets the standard Cd2+ discharge prescribed in the Standards for Irrigation Water Quality (GB5084-2005) and the MCL and MCLG for groundwater and drinking water standards set by USEPA.
- The adsorption process of lower concentration of Cd2+ in water by CMS fitted with the Langmuir adsorption isotherm model well, with a saturated adsorption capacity of 1 mg/g.
Conflicts of Interest
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|Langmuir Constant||Freundlich Constant|
|Sm (μg/g)||KL (L/μg)||R2||logk||1/n||R2|
|Sample||CL (μg/L)||Removal (%)||CS (μg/g)|
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