Chulalongkorn University Theses and Dissertations (Chula ETD)

Removal of trace cadmium Ions using continuous multistage ion foam fractionation

Other Title (Parallel Title in Other Language of ETD)

การแยกไอออนแคดเมียมปริมาณน้อยมากโดยการแยกลำดับส่วนฟองไอออนแบบต่อเนื่อง

Year (A.D.)

2011

Document Type

Thesis

First Advisor

Sumaeth Chavadej

Second Advisor

O’Haver, John H

Third Advisor

Ratana Rujiravanit

Faculty/College

The Petroleum and Petrochemical College (วิทยาลัยปิโตรเลียมและปิโตรเคมี)

Degree Name

Doctor of Philosophy

Degree Level

Doctoral Degree

Degree Discipline

Petrochemical Technology

DOI

10.58837/CHULA.THE.2011.2370

Abstract

In this work, a continuous multistage ion foam fractionation column with bubble-cap trays was used to remove cadmium ions from water having a low cadmium concentration (10 m g/L) and sodium dodecyl sulphate (SDS) was used to generate the foam. To optimize the removal efficiency of cadmium ion s in terms of enrichment ratio, removal, separation factor and residual factor of cadmium | the system has to be operated to have the highest adsorptive transport with the lowest bulk liquid transport. An increase in feed SDS /Cd molar ratio enhanced significantly the removal of cadmium ions. The molar ratio of SDS /Cd in foam ate was found to be close to the theoretical adsorption molar ratio of 2/1 on the air-water interface of foam . Under the optimum operational conditions, the studied multistage ion foam fractionation system was able to remove cadmium ions greater than 99 %. The presence of added co-ions (SO42', NO3', and CI) was found to exhibit no effect on the removal efficiency of both SDS and cadmium ions. In contrast, the addition of counterions (N a+, K +, Ca2+, and M g2+) decreased the cadmium removal whereas it increased the SDS separation. The added divalent cations (Ca2+ and M g2+) gave the higher effect than the added monovalent cations (Na+ and K +) because the divalent cations can co-adsorb more preferentially than the monovalent ones with the SDS.

Other Abstract (Other language abstract of ETD)

In this work, a continuous multistage ion foam fractionation column with bubble-cap trays was used to remove cadmium ions from water having a low cadmium concentration (10 m g/L) and sodium dodecyl sulphate (SDS) was used to generate the foam. To optimize the removal efficiency of cadmium ion s in terms of enrichment ratio, removal, separation factor and residual factor of cadmium | the system has to be operated to have the highest adsorptive transport with the lowest bulk liquid transport. An increase in feed SDS /Cd molar ratio enhanced significantly the removal of cadmium ions. The molar ratio of SDS /Cd in foam ate was found to be close to the theoretical adsorption molar ratio of 2/1 on the air-water interface of foam . Under the optimum operational conditions, the studied multistage ion foam fractionation system was able to remove cadmium ions greater than 99 %. The presence of added co-ions (SO42', NO3', and CI) was found to exhibit no effect on the removal efficiency of both SDS and cadmium ions. In contrast, the addition of counterions (N a+, K +, Ca2+, and M g2+) decreased the cadmium removal whereas it increased the SDS separation. The added divalent cations (Ca2+ and M g2+) gave the higher effect than the added monovalent cations (Na+ and K +) because the divalent cations can co-adsorb more preferentially than the monovalent ones with the SDS.

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