ABSTRACT
Biohydrometallurgy is generally considered as a green technology for the recycling of industrial solid waste. In this study, an indigenous fungal strain named Y5 with the ability of high-yielding organic acids was isolated and applied in bioleaching of waste printed circuit boards (PCBs). The strain Y5 was identified as Penicillium chrysogenum by morphological and molecular identification. Meanwhile, we investigated that an optimal set of culturing conditions for the fungal growth and acids secretion was 15 g/L glucose with initial pH 5.0, temperature 25°C and shaking speed 120 rpm in shaken flasks culture. Moreover, three bioleaching processes such as one-step, two-step and spent medium processes were conducted to extract copper from waste PCBs. Spent medium bioleaching showed higher copper extraction percentage and it was 47% under 5%(w/v) pulp density. Transmission electron microscope (TEM) observation combining with energy dispersive analysis of X-rays (EDAX) showed that the leached metal ions did not obviously damage the hypha cells. All above results indicated that P.chrysogenum strain Y5 has the tolerance to metal ions, suggesting its potential in recycling of metals from waste PCBs in industry.
Subject(s)
Copper/pharmacokinetics , Electronic Waste , Industrial Waste , Penicillium chrysogenum/isolation & purification , Penicillium chrysogenum/metabolism , Recycling/methods , Biodegradation, Environmental , Copper/analysis , Copper/isolation & purification , Green Chemistry Technology/methods , Metallurgy/methods , Metals, Heavy/chemistry , Metals, Heavy/isolation & purification , Metals, Heavy/pharmacokinetics , Microscopy, Electron, Transmission , Penicillium chrysogenum/cytology , Soil Pollutants/chemistry , Soil Pollutants/isolation & purification , Soil Pollutants/pharmacokineticsABSTRACT
<p><b>OBJECTIVE</b>To study the clinical effect of segmental resection of the liver using Glissonean pedicle transection for primary liver cancer.</p><p><b>METHODS</b>The clinical data of 55 primary liver cancer patients admitted from January 2006 to October 2008 were analyzed retrospectively. Twenty-five of the patients underwent segmental resection of the liver by Glissonean pedicle transection (group A), and 30 underwent routine hepatectomy (group B). The positivity rate of the resection margin, micrometastasis in the hepatic parenchyma surrounding the lesions and postoperative recurrence rates were investigated.</p><p><b>RESULTS</b>The positivity rate of the resection margin was 4.0% in group A, significantly lower than that of group B. The number of histological micrometastasis was significantly higher in group A than in group B (16 vs 8). The median distance of histological micrometastasis was 6.8 mm (2.7-25.6 mm) in group A and 4.2 mm (2.4-9.0 mm) in group B. The one-year recurrence rate was significantly lower in group A than in group B (16% vs 26.7%).</p><p><b>CONCLUSION</b>Glissonean pedicle transection for segmental liver resection is a simpler procedure than routine hepatectomy for primary liver cancer and can reduce the number of histological micrometastasis and recurrence rate.</p>
