Abstract
In this work, a novel alginate/citrate composite aerogel (CA–SC) was synthesized by chemical grafting technology combined with vacuum freeze-drying method, and CA–SC was used for removing calcium (Ca2+) and magnesium (Mg2+) ions from water. The experimental results indicate that the as-prepared CA–SC has a high affinity for Ca2+ and Mg2+ and can remove 96.5% of Ca2+ (or 96.8% of Mg2+) from the corresponding solution. The maximum adsorption capacities of CA–SC for Ca2+ and Mg2+ are 62.38 and 36.23 mg/g, respectively. These values are higher than those of the most reported Ca2+-sorbents and Mg2+-sorbents. The CA–SC adsorbent can be regenerated through a simple pickling step, and its adsorption performance keeps stable after repeated use. Analysis of the adsorption mechanism shows that the CA–SC combines Ca2+ and Mg2+ in water mainly through coordination effect.
Highlights
The functional groups in the adsorbent were verified via spectroscopic characterization of sodium citrate, sodium alginate, and CA–SC
The absorption peak around 1020 cm−1 in sodium alginate and CA–SC can be assigned to C–O–C vibration
Compared with the infrared spectra of sodium alginate and sodium citrate, the new absorption peak at 1536 cm−1 in CA–SC is an N–H bond derived from the modified ethylenediamine [17]
Summary
The methods for Ca2+ and Mg2+ removal from water mainly include precipitation [3], boiling [4], use of lime–soda ash [5], ion exchange [6], electrodialysis [7], and adsorption [8,9]. Among such treatment methods, the adsorption method has attracted much attention in recent years because of its advantages of simple operation, recyclability, and low cost [10,11]
Sign-in/Register to view highlights & summary 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.
