SYNTHESIS OF MACROPOROUS HUMIC ACID RESINS AND THEIR CHELATING PROPERTIES FOR HEAVY METAL IONS

Macroporous HA resins (HAR) can be prepared in pearl form by grafting HA onto crosslinked PS through azo or through ester and / or ether linkages. At pH 13 and the HA / PSNH_2 weight ratio 0.7—1.0, PSN_2~+-Cl~-couples with HA and results in the formation of a7o-type HA resin (HAR-A), which shows good adsorbility towards heavy metal ions. The Cu~(2+) sorption capacity of ester / ether type humic acid resin (HAR-E) is increased by lengthening the reaction time of HA and PSCH_2Cl. The structure of HAR is discussed on the basis of the IR spectra. The sorption capacity of HAR-A is 1.01 mmol / g for Cd~(2+) and 0.6—0.53 mmol/g for Ni~(2+), Mn~(2+), Cu~(2+), Co~(3+) and Zn~(2+). respectively. The calculated distribution coefficients of heavy metal ions on HAR-A can be arranged in the following order: Cu~(2+)(8.7×10~3)>Cd~(2+) (3.8×10~2)>Zn~(2+)(2.4×10~2)>Ni~(2+)(1.8×10~2)>Mn~(2+)(4.9×10). At pH 6.5, Cu~(2+), Cd~(2+), Ni~(2+), Mn~(2+) can be quantitatively adsorbed by HAR-A and completely eluted with 1N HNO_3. HAR-A can be regenerated and reused. Trace quantities of the above-mentioned heavy metal ions in four samples of the natural occurring water and one sample of the tap water were analyzed by using HAR-A.

SYNTHESIS OF MACROPOROUS HUMIC ACID RESINS AND THEIR CHELATING PROPERTIES FOR HEAVY METAL IONS*

 Macroporous HA resins (HAR) can be prepared in pearl form by grafting HA onto crosslinked PS through azo or through ester and / or ether linkages. At pH 13 and the HA / PSNH₂ weight ratio 0.7—1.0, PSN₂⁺Cl^-couples with HA and results in the formation of a7o-type HA resin (HAR-A), which shows good adsorbility towards heavy metal ions. The Cu²⁺ sorption capacity of ester / ether type humic acid resin (HAR-E) is increased by lengthening the reaction time of HA and PSCH₂Cl. The structure of HAR is discussed on the basis of the IR spectra.The sorption capacity of HAR-A is 1.01mmol/g for Cd²⁺,Mn²⁺,Cu²⁺,Co²⁺and Zn²⁺,respectively.The calculated distribution coefficents of heavy metal ions on HAR-A can be arranged in the following order;Cu²⁺(8.7×10³)>Cd²(3.8×10²)>Zn²⁺(2.4×10²)>Ni²⁺(1.8×10²)>Mn²⁺(4.9×10).At pH 6.5,Cu²⁺,Cd²⁺,Ni²⁺,Mn²⁺ can be quantitatively asdorbed by HAR-A and completely eluted with 1N HNO₃.HAR-A can be regenerated and reused.Trace quantities of the above-mentioned heavy metal ions in four samples of the natural occurring water and one sample of the tap water were analyzed by using HAR-A.