scholarly journals THE STUDY ON OPTIMIZATION OF COPPER LEACHING FROM WASTE PCBs BY USING RESPONSE SURFACE METHODOLOGY

2018 ◽  
Vol 56 (2C) ◽  
pp. 16-22
Author(s):  
Tran Thi Ngoc Mai
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Electrochemical Technology ◽  
Copper Leaching ◽  
Waste Pcbs ◽  
Important Solution ◽  
Leaching Efficiency ◽  
H2o2 Addition

Recycling printed circuit boards (PCBs) is an important solution not only to treat hazardous waste but also to recover valuable materials. This research focus on optimizing the leaching copper process from waste PCBs to recycle. This process was performed in Fe2(SO4)3 solution at room temperature and using H2O2 as an oxidant. For optimization, response surface methodology was used to investigate the different parameters, including Fe2(SO4)3 concentration, volume of H2O2 addition and leaching time. Design Expert 10.0 software was applied to design the experiments and calculate the regression equation of the response function. As a result, a model was established which is compatible with the experimental data at the correlation coefficient (R2) of 0.99. The optimal conditions were identified as Fe2(SO4)3 concentration of 0.35 M, volume of H2O2 addition at 10 mL and leaching time of 10 h. Under this condition, leaching efficiency of 90.5 percent was achieved. After leaching, copper was recovered from extract solution by electrochemical technology with the efficiency of 85 percent. The results from this study hence proposed a very promising method for recycling copper in PCBs. 

scholarly journals Removal of organic compounds from wastewater originating from the production of printed circuit boards by UV-Fenton method

2017 ◽  
Vol 43 (4) ◽  
pp. 39-49 ◽  
Author(s):  
Maciej Thomas ◽  
Barbara Białecka ◽  
Dariusz Zdebik
Keyword(s):  
Response Surface Methodology ◽  
Wastewater Treatment ◽  
Response Surface ◽  
Organic Compounds ◽  
Printed Circuit Boards ◽  
Advanced Oxidation ◽  
Circuit Boards ◽  
Initial Value ◽  
Printed Circuit ◽  
Second Stage

AbstractThe possibility of removing organic compounds from wastewater originating from the photochemical production of printed circuit boards by use of waste acidification and disposal of precipitated photopolymer in the first stage and the UV-Fenton method in a second stage has been presented. To optimize the process of advanced oxidation, the RSM (Response Surface Methodology) for three independent factors was applied, i.e. pH, the concentration of Fe(II) and H2O2concentration. The use of optimized values of individual parameters in the process of wastewater treatment caused a decrease in the concentration of the organic compounds denoted as COD by approx. 87% in the first stage and approx. 98% after application of both processes. Precipitation and the decomposition of organic compounds was associated with a decrease of wastewater COD to below 100 mg O2/L whereas the initial value was 5550 mg O2/L. Decomposition of organic compounds and verification of the developed model of photopolymers removal was also carried out with use of alternative H2O2sources i.e. CaO2, MgO2, and Na2CO3·1,5H2O2.

scholarly journals Effect of Graphite on Copper Bioleaching from Waste Printed Circuit Boards

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 79 ◽  
Author(s):  
Linlin Tong ◽  
Qianfei Zhao ◽  
Ali Kamali ◽  
Wolfgang Sand ◽  
Hongying Yang
Keyword(s):  
Printed Circuit Boards ◽  
Acid Leaching ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Copper Leaching ◽  
Initial Ph ◽  
Efficient Extraction ◽  
Bacteria Culture ◽  
The Impact

The efficient extraction of copper as a valuable metal from waste printed circuit boards (WPCBs) is currently attracting growing interest. Here, we systematically investigated the impact of bacteria on the efficiency of copper leaching from WPCBs, and evaluated the effect of graphite on bioleaching performance. The HQ0211 bacteria culture containing Acidithiobacillus ferrooxidans, Ferroplasma acidiphilum, and Leptospirillum ferriphilum enhanced Cu-leaching performance in either ferric sulfate and sulfuric acid leaching, so a final leaching of up to 76.2% was recorded after 5 days. With the addition of graphite, the percentage of copper leaching could be increased to 80.5%. Single-factor experiments confirmed the compatibility of graphite with the HQ0211 culture, and identified the optimal pulp density of WPCBs, the initial pH, and the graphite content to be 2% (w/v), 1.6, and 2.5 g/L, respectively.

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