• Title/Summary/Keyword: DOWEX G-26

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Ion Exchange of Copper from Sulphate Effluent using DOWEX G-26 (황산용액(黃酸溶液)으로부터 DOWEX G-26에 의한 구리의 회수(回收))

  • Nguyen, Nghiem Van;Lee, Jae-Chun;Jha, Manis Kumar;Kim, Min-Seuk;Jeong, Jin-Ki;Hwang, Taek-Sung
    • Resources Recycling
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    • v.17 no.4
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    • pp.37-46
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    • 2008
  • In view of the increasing importance of the waste recycling to meet the strict environmental regulations, the present investigation reports an adsorption process using cationic exchanger DOWEX G-26 for the recovery of copper from the synthetic sulphate solutions containing copper 0.3 to 0.5 mg/ml, similar to the CMP waste effluent of electronic industry. Various process parameters viz. contact time, solution pH, resin dose, and A/R ratio for elution were investigated to recover copper from the effluents. Complete adsorption of copper from the solution was achieved at equilibrium pH 2.5 and aqueous I resin (A/R) ratio of 100 ml/g in 14 minutes contact time. The adsorption of copper on DOWEX G-26 resin was found to follow the Langmuir isotherm and second order reaction. The copper was eluted from loaded resin with dilute sulphuric acid to produce copper-enriched solution.

Effects of Extraction Methods on Histidine-containing Low-molecular Weight Peptides and Pro-oxidants Contents in Tuna Thunnus Extracts (다랑어(Thunnus) 추출물 중의 Histidine 함유 저분자 펩타이드 및 산화촉진물질 함량에 미치는 추출방법의 영향)

  • Kim, Hong-Kil;Song, Ho-Su
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.6
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    • pp.684-693
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    • 2017
  • We investigated methods for extracting histidine-containing low-molecular-weight (LMW) peptides such as anserine, carnosine and histidine from the edible meat of tuna byproducts. Extracts were treated by several methods including heat treatment ($80^{\circ}C$, 10 min), DOWEX ion exchange (IEC), ultrafiltration (UF), and carboxymethyl (CM)-cellulose column chromatography (IEC+CMC); then the levels of protein, total iron, histidine, carnosine, and anserine were measured. Extracts treated with IEC+CMC using CM-cellulose were analyzed for total iron, protein, histidine, and anserine content, which were $6.27{\pm}0.26mg/mL$, $5.20{\pm}0.21{\mu}g/mL$, 0.80 mg/mL, 0.208 mg/mL, and 4.40 mg/mL, respectively, in yellowfin tuna; and $9.05{\pm}0.82mg/mL$, $4.06{\pm}0.20{\mu}g/mL$, 1.62 mg/mL, 0.012 mg/mL, and 7.28 mg/mL in bigeye tuna. By comparison in IEC-UF treated extracts, protein, total iron, and histidine content decreased by 43%, 73%, and 27% in yellowfin and 0.4%, 54%, and 23% in bigeye tuna, wheres carnosine and anserine content increased by 22% and 17%, respectively. Freeze-dried (FD) extracts exhibited similar trends as non-dried extracts, i.e., dipeptide content increased with purification steps, whereas pro-oxidant (total iron and protein) content decreased. IEC+CMC treated FD extracts had the highest anserine, content, and the greatest reductuion in pro-oxidants.