Removal of Some Heavy Metals by Electrocoagulation

2012 ◽  
Vol 468-471 ◽  
pp. 2882-2890 ◽  
Author(s):  
R. H. Al Anbari ◽  
S. M. Alfatlawi ◽  
J. H. Albaidhani

Heavy metal removal by electrocoagulation using iron electrodes material was investigated in this paper. Several working parameters, such as pH, current density and heavy metal ions concentration were studied in an attempt to achieve a higher removal capacity. A simple and efficient treatment process for removal of heavy metals is essentially necessary. The performance of continuous flow electrocoagulation system, with reactor consists of a ladder series of twelve electrolytic cells, each cell containing stainless steel cathode and iron anode. The treatment of synthetic solutions containing Zn 2+,Cu 2+,Ni 2+,Cr 3+,Cd 2+ and Co 2+ ,has been investigated. Results showed that iron is very effective as sacrificial electrode material for heavy metals removal efficiency and cost points. Also it was concluded that the chromium has lower efficient removal as compared to zinc, copper and nickel. At the same time cadmium and cobalt have minimum removal efficiency.

2018 ◽  
Vol 773 ◽  
pp. 373-378 ◽  
Author(s):  
Sujitra Onutai ◽  
Takaomi Kobayashi ◽  
Parjaree Thavorniti ◽  
Sirithan Jiemsirilers

This work aims to evaluate the effectiveness of fly ash based geopolymer powder as an adsorbent for heavy metals in aqueous solution. The structure of synthesized geopolymer was found to be highly amorphous due to the dissolution of fly ash phase. Moreover, the fly ash geopolymer powder has higher surface area compares to original fly ash with specific surface area of 85.01 m²/g and 0.83 m2/g, respectively. For this reason, the geopolymer powder has much higher removal efficiency compared to the original fly ash powder. The removal efficiency was affected by contact time, geopolymer amount, heavy metal initial concentration, pH, and temperature. The four heavy metals were chosen (Pb2+, Cu2+, Ni2+, Cd2+) for adsorption test. The highest heavy metal removal capacity was obtained at pH 5. The geopolymer powder adsorbed metal cations in the order of Pb2+>Cu2+>Cd2+>Ni2+. In addition, Langmuir model is more suitable for fly ash geopolymer powder adsorption of heavy metal ions in aqueous solution than Freundlich model. The results showed that the fly ash geopolymer powder has high efficiency for removal metal which could be employed excellent alternative for wastewater treatment.


2016 ◽  
Vol 7 (4) ◽  
pp. 387-419 ◽  
Author(s):  
Renu ◽  
Madhu Agarwal ◽  
K. Singh

Heavy metals are discharged into water from various industries. They can be toxic or carcinogenic in nature and can cause severe problems for humans and aquatic ecosystems. Thus, the removal of heavy metals from wastewater is a serious problem. The adsorption process is widely used for the removal of heavy metals from wastewater because of its low cost, availability and eco-friendly nature. Both commercial adsorbents and bioadsorbents are used for the removal of heavy metals from wastewater, with high removal capacity. This review article aims to compile scattered information on the different adsorbents that are used for heavy metal removal and to provide information on the commercially available and natural bioadsorbents used for removal of chromium, cadmium and copper, in particular.


2014 ◽  
Vol 25 (4) ◽  
pp. 51-54
Author(s):  
Anna Kwarciak-Kozłowska ◽  
Lucyna Sławik-Dembiczak ◽  
Bartłomiej Bańka

Abstract Phycoremediation is the use of algae for the removal or biotrans-formation of pollutants from wastewater. The study is a novel at-tempt to integrate nutrient (N and P) removal and some heavy met-als (iron, manganese and zinc) bioaccumulation from municipal wastewater using two microalgae species: Chlorella vulgaris and Scenedesmus armatus. The Chlorella vulgaris showed higher re-moval of total nitrogen (TN) both in influent and effluent waste water than Scenedesmus armatus. Nevertheless, more than 51% of total phosphorus (TP) in effluent and 36% in influent wastewaters were removed by Scenedesmus armatus. More efficient microalga in heavy metal removal in influent wastewater was Scenedesmus armatus. The results showed that Chlorella vulgaris was appropriate for TN removal and bioaccumulation of heavy metals from effluent wastewater. Nevertheless, Scenedesmus armatus was highly pref-erable for heavy metals removal from influent wastewater.


2020 ◽  
Vol 21 (1) ◽  
pp. 46
Author(s):  
Siti Wahidah Puasa ◽  
Kamariah Noor Ismail ◽  
Muhammad Amarul Aliff Bin Mahadi ◽  
Nur Ain Zainuddin ◽  
Mohd Nazmi Mohd Mukelas

Wastewater produced from the electroplating industry generally consists of heavy metals mixture and organic materials that need to be treated before it can be discharged to the environment. Thus, the present investigation was focused on the selectivity removal of heavy metal mixtures consists of Copper (Cu), Cadmium (Cd), and Zinc (Zn). Several operating conditions, including the effect of pH and coagulant (FeCl3) dosage, were varied to find the best performance of heavy metal removal. Results show the efficiency of heavy metals removal for both wastewater characteristics were approximately 99%. The experimental data on the treatment of synthetic wastewater was plotted using polynomial regression (PR) via Excel software. The value of adjusted R2 obtained for the final concentration of Cu, Zn, and Cd after treatment were 0.6884, 0.9676, and 0.9283, respectively, which shows data were acceptably fitted for Cu and very well fitted for Zn and Cd. The coagulation/flocculation process performed on actual wastewater shows that the lowest final concentration of Cu, Zn, and Cd after treatment were 0.487, 1.232, and 0 mg/L respectively at pH of 12.


NANO ◽  
2018 ◽  
Vol 13 (09) ◽  
pp. 1830006 ◽  
Author(s):  
Nader Ghaffari Khaligh ◽  
Mohd Rafie Johan

The pollution of water due to the release of heavy metals are particularly problematic and supplies of clean water have become a major problem worldwide. The heavy metal ions can cause toxicities and serious side effects toward human health; therefore, these metal ions should be removed from water and wastewater. A variety of strategies have been developed for efficient heavy metal removal from waters. Adsorption/ion exchange strategy play a great important role in removing heavy metal ions due to their advantages. Nanomaterials are excellent adsorbents and extensive studies have been performed to remove heavy metals from wastewater by developing and using various nanomaterials. Recent developments for the heavy metals removal by various nanomaterials, mainly including carbon-based nanomaterials, iron-based nanomaterials and photocatalytic nanomaterials in batch and flow systems are described in this review.


2020 ◽  
Vol 78 (3) ◽  
pp. 121-132
Author(s):  
Hadir A. Aly ◽  
Mohamed M. Abdel-Rahim ◽  
Ghada R. Sallam ◽  
Ayman M. Lotfy ◽  
Basem S. Abdelaty

AbstractA study was conducted to investigate the effects of natural zeolites as a water clarifier on the heavy metal removal efficiency from the underground saltwater used for rearing Dicentrarchus labrax fry. Five concentrations of zeolites were tested: 0 (Z0), 2.5‰ (Z2.5), 5‰ (Z5), 7.5‰ (Z7.5) and 10‰ (Z10). Fry with an initial body weight of 1.53±0.018 g/fish were stocked in 15 aquaria at a density of 10 fry/aquarium. The fish were fed a commercial diet (42% protein and 12.34% lipid) twice daily (09:30 and 14:00) at 5% of their body weight per day for 42 days. Growth, feed utilization, survival and heavy metal removal efficiency were evaluated. The growth performance and feed utilization indices gradually improved with increasing zeolite concentration, with the most significant (P≤0.05) values detected at Z10. The survival rate decreased significantly at Z10 compared with the control (Z0). Increasing the zeolite concentration significantly (P≤0.05) improved the removal efficiency of heavy metals in the rearing water with adsorption selectivity of Pb˃Cd˃Fe˃Cu˃Zn. Furthermore, an increase in the detoxification rate of heavy metals in fish flesh with increasing zeolite level was detected with the removal selectivity of Fe˃Cu˃Zn˃Pb˃Cd. In conclusion, it can be stated that natural zeolites can be used effectively to reduce heavy metals in polluted waters and subsequently in fish flesh in addition to improving fish performance.


2008 ◽  
Vol 58 (10) ◽  
pp. 1947-1954 ◽  
Author(s):  
S. Y. Chen ◽  
W. H. Chen ◽  
C. J. Shih

Because of having a high reduction potential, the zero-valent iron (ZVI) is often applied for the remediation of wastewater or groundwater with heavy metals. The purpose of this study was aimed to investigate the reaction behavior of heavy metals with ZVI nanoparticles in the wastewater. The affecting factors, such as initial pH, dosage of nanoscale ZVI and initial concentration of heavy metal, on the removal efficiency of heavy metals by ZVI in the wastewater were examined by the batch experiments in this study. It was found that the removal of heavy metals was affected by initial pH. The rate and efficiency of metal removal increased with decreasing initial pH. Greater than 90% of the heavy metals were removed when the initial pH was controlled at 2. In addition, the rate and efficiency of metal removal increased as the dosage of nanoscale ZVI increased. The removal efficiency of heavy metal was higher than 80% when 2.0 g/L of ZVI was added in the wastewater. On the other hand, the slow rate and low efficiency of metal removal from the wastewater treated by nanoscale ZVI was found in the wastewater with high concentration of heavy metal.


2012 ◽  
Vol 518-523 ◽  
pp. 361-368 ◽  
Author(s):  
Rong Bing Fu ◽  
Xin Xing Liu ◽  
Fang Liu ◽  
Jin Ma ◽  
Yu Mei Ma ◽  
...  

A new permeable reactive composite electrode (PRCE) attached with a permeable reactive layer (PRL) of Fe0 and zeolite has been developed for soil pH control and the improved removal efficiency of heavy metal ions (Cd, Ni, Pb, Cu) from soil in electrokinetic remediation process. The effects of different composite electrodes on pH control and heavy metal removal efficiency were studied, and changes in the forms of heavy metals moved onto the electrodes were analyzed. The results showed that with acidic/alkaline zeolite added and renewed in time, the composite electrodes could effectively neutralize and capture H+ and OH- produced from electrolysis of the anolyte and catholyte, avoiding or delaying the formation of acidic/alkaline front in tested soil, preventing premature precipitation of heavy metal ions and over-acidification of soil, and thus significantly improved the heavy metal removal efficiency. Fe0 in composite electrodes could deoxidize and stabilize the heavy metal ions. After that capture and immobilization of the pollutants were achieved. The results also showed that, using "Fe0 + zeolite" PRCE in the cathode with timely renewal, after 15-day remediation with a DC voltage of 1.5 V/cm, the total removal rates of Cd, Pb, Cu and Ni were 49.4%, 47.1%, 36.7% and 39.2%, respectively.


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