Competitive adsorption of Cd(II) and Pb(II) in aqueous solution onto humic acid derived from sewage sludge

This paper presents the adsorption behaviors of humic acid (HA) on coal ashes and powdered activated carbons (PACs). A bituminous coal, with or without calcium-loading, was used as a feedstock for coal ash preparation. The working solution of HA with a concentration of 20 mg/L was used in all adsorption tests. The results showed that calcium-enriched coal ash (CECA) gave rise to the removal rate of HA as high as 84.05%, much higher than those of raw coal ash (RCA) and PACs. The impacts of solution pH and adsorbent dosage on HA adsorption capacity were also investigated. It was found that lower pH facilitated to the removal of HA from aqueous solution by means of CECA, and the optimal CECA dosage was about 1.0g/L at pH 7.00. The data obtained in this study suggested that calcium-enriched coal ash could be useful and cost-effective in the treatment of wastewaters containing HA-like organic macro-molecules.

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TiO2 BEADS FOR PHOTOCATALYTIC DEGRADATION OF HUMIC ACID IN PEAT WATER

Indonesian Journal of Chemistry ◽

10.22146/ijc.21389 ◽

2011 ◽

Vol 11 (3) ◽

pp. 253-257 ◽

Cited By ~ 1

Author(s):

Winarti Andayani ◽

Agustin N M Bagyo

Keyword(s):

Aqueous Solution ◽

Humic Acid ◽

Oxalic Acid ◽

Chemical Oxygen Demand ◽

Photocatalytic Degradation ◽

Uv Light ◽

Batch Reactor ◽

Oxygen Demand ◽

Color Intensity ◽

Before And After

Degradation of humic acid in aqueous solution containing TiO2 coated on ceramics beads under irradiation of 254 nm UV light has been conducted in batch reactor. The aim of this experiment was to study photocatalytic degradation of humic acid in peat water. The irradiation of the humic acid in aqueous solution was conducted in various conditions i.e solely uv, in the presence of TiO2-slurry and TiO2 beads. The color intensity, humic acid residue, conductivity and COD (chemical oxygen demand) of the solution were analyzed before and after irradiation. The compounds produced during photodegradation were identified using HPLC. The results showed that after photocatalytic degradation, the color intensity and the COD value of the solution decreased, while the conductivity of water increased indicating mineralization of the peat water occurred. In addition, oxalic acid as the product of degradation was observed.

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The Role of Carboxyl and Hydroxyl Groups of Humic Acid in Removing AuCl4- from Aqueous Solution

Indonesian Journal of Chemistry ◽

10.22146/ijc.23620 ◽

2017 ◽

Vol 17 (1) ◽

pp. 95 ◽

Cited By ~ 5

Author(s):

Sri Sudiono ◽

Mustika Yuniarti ◽

Dwi Siswanta ◽

Eko Sri Kunarti ◽

Triyono Triyono ◽

...

Keyword(s):

Aqueous Solution ◽

Humic Acid ◽

Peat Soil ◽

Sharp Decrease ◽

Hydroxyl Groups ◽

Mixed Solution ◽

Oh Groups ◽

Characterization Result ◽

Ft Ir

Humic acid (HA) extracted from peat soil according to the recommended procedure of the International Humic Substances Society (IHSS) has been tested to remove AuCl4- from aqueous solution. The removal was optimum at pH 2.0 and it was mainly dictated by attachment through hydrogen bonding to unionized carboxyl (–COOH) groups and reduction by the action of the hydroxyl (–OH) groups to gold (Au) metal. The removal of AuCl4- improved after HA was purified through repeated immersion and shaking in a mixed solution containing 0.1 M HCl and 0.3 M HF. When the purification led to the sharp decrease in ash content from 39.34 to 0.85% (w/w) and significant increase in both the –COOH and –OH contents from 3240 to 3487 mmol/kg and from 4260 to 4620 mmol/kg, respectively; the removal of AuCl4- improved from 0.105 to 0.133 mmol/g. This improvement of AuCl4- removal by the purified HA was accompanied by higher ability in reduction to Au metal. The attached AuCl4- on –COOH groups of both crude and purified HAs was qualitatively observed by the characterization result of FT-IR spectroscopy, while the presence of Au metal on the surface of those HAs was verified by the characterization result of XRD.

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