2007, Vol.8, No.4

Carbon Letters 2023 KCI Impact Factor : 1.35 KCI-WoS Impact Factor : 4.82

pISSN : 1976-4251 / eISSN : 2233-4998
https://journal.kci.go.kr/carbon

During a 4-year period (2001-2005) 09 animals were surgically treated because of abdominal wall defects (hernia). Out of 9animals 8 were bovines and one caprine. In each case the defect was repaired with carbon fibre mesh. All the cases weresuccessfully treated and no complication was observed up to six months postoperatively.

CTC grade, 12×30 BSS particle size and 104 m2/g surface area, was impregnated with metal salts such Cu, Cr, Ag, Mo andZn, and an organic compound Triethylene diamine (TEDA) to prepare different carbon systems such as whetlerite, whetlerite/TEDA, whetlerite/KI/KOH and ASZMT. The prepared adsorbents along with active carbon were characterized for surfacearea and pore volume by N2 adsorption at liquid nitrogen temperature. These carbon systems were compared for their CT(concentration X time) values at 12.73 to 53.05 cm/sec space velocities and 2 to 5 cm carbon column bed heights. The carbon3.712 mg/L iodine vapour concentration and 12.73 cm/sec space velocity. The study clearly indicated the adsorption capacitiesof carbon systems to be directly proportional to their surface area values. Dead layer with all the prepared carbon systems wasfound to be less than 2.0 cm indicating it to be minimum bed height to have protection against I2 vapours. Effect of carbon bedheight and flow rate was also studied. The active carbon showed maximum protection at all bed heights and flow rates incomparison to all other impregnated carbon systems, showing that only physical adsorption is responsible for the removal ofiodine vapours.

Samples of active carbon of 1150 m2/g surface area were impregnated with ammoniacal salts of copper, chromium and silver,with and without triethylenediamine. The samples of impregnated carbon were aged at 50oC, with and without 90% RH(relative humidity), for a little more than one year and chemically evaluated periodically. Initially copper (II) and chromium(VI) reduced very fast in the samples in humid atmosphere to the extent of 30% and 60% respectively in four months. Thesevalues were found to be unaffected by the presence of triethylenediamine (TEDA) indicating that the chemical did not retardwas significantly less (10-12%, w/w) in four months. It was quite evident; therefore, that the moisture was mainly responsiblefor the reduction of chromium (VI) and coper (II) species in impregnated carbons. The prolonged ageing of the samples withand without triethylenediamme after four months with and without humid atmosphere showed that the extent of reduction ofchromium (VI) was very low, i.e. 5-10% and of coper (II) was 2-25%. Silver is not reduced due to carbon, as it remainedunchanged in concentration on storage. The impregnated carbon samples (100 g) without triethylenediamine, which were agedconcentration of 4 mg/L and airflow rate of 30 lpm showed a high degree of protection (80- 110 minutes).