scholarly journals Comparative Study on Electrochemical Treatment of Cyanide Wastewater

2021 ◽  
Vol 9 ◽  
Author(s):  
Siming Lei ◽  
Yonghui Song

The electrochemical treatment of wastewater is widely used for cleaning due to its efficiency. In this paper, two-dimensional (2D) and three-dimensional (3D) electrochemical systems were used to treat cyanide wastewater. The effect of the applied voltage and the material of the main electrode on the removal of various ions and the characteristics of chemical reactions were mainly studied. The results show that the applied voltage was the key effect of the electrochemical treatment process. The removal of ions from the wastewater at 2 V is mainly due to the effect of electro adsorption and enrichment precipitation, while at 4 V, it is mainly due to anodization and cathodic deposition. The treatment effect of the 3D electrode system was significantly better than the 2D system. The 3D electrode system by used granular activated carbon as the particle electrode, with the carbon filled stainless mesh (CM) and coal based electrode (CB) as the main electrode, the treatment effect were better than main electrode of stainless steel mesh (M). The 3D system with CB as the main electrode had an applied voltage of 4 V, a treatment time of 5 h, plate spacing of 10 mm, and the dosage of activated carbon particles was 2 g. The removal rates of CNT, Cu, Zn, CN−, and SCN− were 94.14, 94.53, 98.14, 98.55, and 93.13%, respectively. The main reaction in anode was the electroly oxidation of CN− and SCN−, while the electrolytic deposition of Cu, Zn, and other metal ions in the cathode surface. There were not only adsorption and electric adsorption of various ions, but also an electrolytic deposition reaction of Cu, Zn, and other metal ions on the surface of the activated carbon particle electrode. During the electrochemical reaction, the concentration of hydrogen ions near the anode increases locally, which produces the precipitation of CuSCN, Cu2Fe(CN)6, and Zn2Fe(CN)6, etc. in the solution, which are helpful for the removal of cyanide and heavy metal ions in cyanide wastewater.

2017 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
M.B. Nicodemus Ujih ◽  
Mohammad Isa Mohamadin ◽  
Milla-Armila Asli ◽  
Bebe Norlita Mohammed

Heavy metal ions contamination has become more serious which is caused by the releasing of toxic water from industrial area and landfill that are very harmful to all living organism especially human and can even cause death if contaminated in small amount of heavy metal concentration. Currently, peoples are using classic method namely electrochemical treatment, chemical oxidation/reduction, chemical precipitation and reverse osmosis to eliminate the metal ions from toxic water. Unfortunately, these methods are costly and not environmentally friendly as compared to bioadsorption method, where agricultural waste is used as biosorbent to remove heavy metals. Two types of agricultural waste used in this research namely oil palm mesocarp fiber (Elaesis guineensis sp.) (OPMF) and mangrove bark (Rhizophora apiculate sp.) (MB) biomass. Through chemical treatment, the removal efficiency was found to improve. The removal efficiency is examined based on four specification namely dosage, of biosorbent to adsorb four types of metals ion explicitly nickel, lead, copper, and chromium. The research has found that the removal efficiency of MB was lower than OPMF; whereas, the multiple metals ions removal efficiency decreased in the order of Pb2+ > Cu2+ > Ni2+ > Cr2+.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1907
Author(s):  
Fatma Hussain Emamy ◽  
Ali Bumajdad ◽  
Jerzy P. Lukaszewicz

Optimizing the physicochemical properties of the chitosan-based activated carbon (Ch-ACs) can greatly enhance its performance toward heavy metal removal from contaminated water. Herein, Ch was converted into a high surface area (1556 m2/g) and porous (0.69 cm3/g) ACs with large content of nitrogen (~16 wt%) using K2CO3 activator and urea as nitrogen-enrichment agents. The prepared Ch-ACs were tested for the removal of Cr(VI) and Pb(II) at different pH, initial metal ions concentration, time, activated carbon dosage, and temperature. For Cr(VI), the best removal was at pH = 2, while for Pb(II) the best pH for its removal was in the range of 4–6. At 25 °C, the Temkin model gives the best fit for the adsorption of Cr(VI), while the Langmuir model was found to be better for Pb(II) ions. The kinetics of adsorption of both heavy metal ions were found to be well-fitted by a pseudo-second-order model. The findings show that the efficiency and the green properties (availability, recyclability, and cost effectiveness) of the developed adsorbent made it a good candidate for wastewaters treatment. As preliminary work, the prepared sorbent was also tested regarding the removal of heavy metals and other contaminations from real wastewater and the obtained results were found to be promising.


RSC Advances ◽  
2014 ◽  
Vol 4 (64) ◽  
pp. 34144-34155 ◽  
Author(s):  
P. Saranya ◽  
S. Swarnalatha ◽  
G. Sekaran

Lipoprotein biosurfactant from extreme acidophile using fish oil and its immobilization in nanoporous activated carbon for removal of metal ions.


2021 ◽  
Vol 221 ◽  
pp. 239-251
Author(s):  
Syed Muhammad Salman ◽  
Fouzia Kamal ◽  
Muhammad Zahoor ◽  
Muhammad Wahab ◽  
Durr e Shahwar ◽  
...  

2021 ◽  
Vol 221 ◽  
pp. 139-151
Author(s):  
Omar S.A. Al-Khazrajy ◽  
Salam A. Mohammed ◽  
Omaimah Al-Musallami ◽  
Zahour Al-Rawahi ◽  
Emad Yousif

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Jun Wang ◽  
Xian Zhang

【Abstract】Objective: To investigate the clinical efficacy of carboprost tromethamine combined with mifepristone in the treatment of uterine fibroids. METHODS: A total of 66 patients with uterine fibroids admitted to our hospital between April 2018 and January 2019 were selected as subjects. According to the two different treatment methods, patients were divided equally. The observation group and the control group, each group of 33 people. The oxytocin drug treatment was medicated to the control group, and the prostaglandin tromethamine combined with mifepristone was medicated to the observation group. The treatment effect, adverse reaction, operation, and uterine muscle before and after surgery were observed in these two groups. Tumor tissue progesterone receptor and estrogen receptor levels. Results: The clinical treatment effect of the observation group was 93.94%, and the clinical treatment effect of the control group was 60.61%. The clinical treatment effect of the observation group was significantly higher than that of the control group; also the incidence of adverse reactions in the observation group in terms of rash, fatigue, nausea and vomiting was much lower than the control group, and could observe a significant difference. Finally in observation group, the amount of intraoperative blood loss, operation time and hospitalization time were better than those of the control group. The progesterone receptor and estrogen receptor levels in the uterine fibroid tissue after surgery should also be better than the control group, it is worth to make further comparison. Conclusion: Carprostol tromethamine combined with mifepristone is effective in the treatment of uterine fibroids and can be further developed.


2011 ◽  
Vol 233-235 ◽  
pp. 351-354 ◽  
Author(s):  
Hui Xia Lu ◽  
Jian You Wang ◽  
Shao Feng Bu

Applicable configuration alteration of the electrodeionization (EDI)process commonly for pure water production was carried out to treat dilute nickel wastewater in this paper. The effects of major operating parameters such as applied voltage, dilute and concentrate stream flow rates on the performance of EDI process were investigated systematically. The results showed that, with the feed water containing 50mg·L-1 Ni2+ and pH of 5.7, the dilute resistivity of the EDI could reach higher than 1.0MΩ·cm which gave a Ni2+ rejection more than 99.8% while the Ni2+ was concentrated as high as 1564mg·L-1 in the concentrate stream by optimizing the operating parameters. It was indicated that pure water production and concentrating of heavy metal ions could be simultaneously accomplished via EDI technology just in one process, valuable heavy metal and water resource could be recovered as well.


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