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1.
J Biosci Bioeng ; 126(1): 78-87, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29573983

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/pharmacokinetics
2.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-665036

ABSTRACT

Objective To select the optimum process of granule spray for Tangwang Mingmu Granules, To improve the yield and finished product quality. Methods The effects of the relative density, the type of excipients, the ratio of the extract and the excipient, the inlet temperature-the material temperature, the spray rate and the atomization pressure were selected by single factor and orthogonal test respectively to determine the optimum preparation process. Validation for three batch sample, particle flow, hygroscopicity and other related content of the preparation were studied. Results The optimum spray granulation process of Tangwang Mingmu Granules: the relative density of extract (60 ℃ determination) was 1.15–1.20; the excipient was selected as dextrin; the ratio of dry extract and excipient was 58:42; inlet temperature - material temperature was 90-75 ℃; atomization pressure was 0.12 mPa;spray rate was 10 Hz.Conclusion The preparation technology of Tangwang Mingmu Granules optimized in this study is with high preparation rate, good fluidity and hygroscopicity, which can be used for the preparation of Tangwang Mingmu Granules.

3.
J Biosci Bioeng ; 123(6): 714-721, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28319019

ABSTRACT

To seek a feasible technique for processing waste printed circuit boards (PCBs), pretreatment of PCBs by table separation and further bioleached by moderate thermophiles in a stirred tank reactor were investigated. The shaking table separation, conducted after grinding and sieving of PCBs, produced two fractions: metal-rich parts (RPCBs), which is more suitable for pyrometallurgy process than untreated PCBs, and metal-poor parts (PPCBs) with only 8.83% metals was then bioleached by a mixed culture of moderate thermophiles effectively. After adaptation, the mixed culture could tolerate 80 g/L PPCBs. The bioleaching results showed that metals recovery was 85.23% Zn, 76.59% Cu and 70.16% Al in only 7 days. Trace Pb and Sn were detected in the leachate because of precipitating. The microorganism community structure was analyzed by amplified ribosomal DNA restriction analysis. Two moderately thermophilic bacteria species were identified as Leptospirillum ferriphilum and Acidithiobacillus caldus. Furthermore, uncultured Thermoplasmatales archaeon was also detected in the leaching system. It was also shown that moderate thermophiles revealed best bioleaching ability when compared with mesophiles and the mixture of mesophiles and moderate thermophiles. Finally, we designed a two-stage process model according to the present study to achieve semi-industrial waste PCBs recycling and economic feasibility analysis indicated that the process was profitable.


Subject(s)
Acidithiobacillus/metabolism , Bioreactors/microbiology , Electronic Waste , Metals/metabolism , Recycling , Temperature , Metals/isolation & purification
4.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-667812

ABSTRACT

Objective To establish a simple and specific method for the determination of rhaponticin in Rhei Radix et Rhizoma. Methods A comparison of the methods of polyamide, silica gel TLC and HPLC in the determination of rhaponticin was studied to investigate the optimum way to identify authentic Rhei Radix et Rhizoma. Results The durability of polyamide and silica gel TLC method for the determination of rhaponticin in Rhei Radix et Rhizoma was poor. HPLC method was more suitable for the detection of rhaponticin. Conclusion HPLC method is accurate and reliable, and can be used for the quality control of Rhei Radix et Rhizoma and provide references for the authenticity of Rhei Radix et Rhizoma.

5.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-324212

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the associations of perception of safety atmosphere at workplace, occupational safety attitude and behaviors with occupational unintentional injury among manufacturing workers.</p><p><b>METHODS</b>A cross-sectional study was performed and a self-administered questionnaire was used to inquire socio-demographic characteristics, perceived safety atmosphere, occupational safety attitudes, occupational safety behaviors and occupational unintentional injuries among 10585 manufacturing workers selected from 46 enterprises in Guangdong. Structural equation modeling was applied to assess the relationship of the perception of safety atmosphere at workplace, occupational safety attitude, and occupational safety behaviors with occupational unintentional injury.</p><p><b>RESULTS</b>Among 24 pathways supposed in structural equation model, 20 pathways (except for the attitude toward occupational safety, the attitude toward managers' support, the work posture and individual protection) were significantly related to the occupational unintentional injuries. The further analysis indicated that the perceived safety atmosphere might impact the occupational unintentional injuries by the attitude toward occupational safety and occupational safety behaviors.</p><p><b>CONCLUSION</b>Workers' perception of safety atmosphere indirectly influenced on occupational unintentional injuries through occupational safety attitudes and occupational safety behaviors.</p>


Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Young Adult , Accidents, Occupational , Attitude , Cross-Sectional Studies , Occupational Health , Surveys and Questionnaires , Workplace
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