Metal removal efficiency of novel LD-slag-incorporated ceramic membrane from steel plant wastewater

Author(s):  
M. Changmai ◽  
P. Mondal ◽  
A. Sinha ◽  
P. Biswas ◽  
S. Sarkar ◽  
...  
2010 ◽  
Vol 62 (6) ◽  
pp. 1274-1280 ◽  
Author(s):  
Chi-Wang Li ◽  
Chun-Hao Chiu ◽  
Yu-Cheng Lee ◽  
Chia-Hao Chang ◽  
Yu-Hsun Lee ◽  
...  

In our previous publications, compressed air-assisted solvent extraction process (CASX) was developed and proved to be kinetically efficient process for metal removal. In the current study, CASX with a ceramic MF membrane integrated for separation of spent solvent was employed to remove and recover metal from wastewater. MF was operated either in crossflow mode or dead-end with intermittent flushing mode. Under crossflow mode, three distinct stages of flux vs. TMP (trans-membrane pressure) relationship were observed. In the first stage, flux increases with increasing TMP which is followed by the stage of stable flux with increasing TMP. After reaching a threshold TMP which is dependent of crossflow velocity, flux increases again with increasing TMP. At the last stage, solvent was pushed through membrane pores as indicated by increasing permeate COD. In dead-end with intermittent flushing mode, an intermittent flushing flow (2 min after a 10-min or a 30-min dead-end filtration) was incorporated to reduce membrane fouling by flush out MSAB accumulated on membrane surface. Effects of solvent concentration and composition were also investigated. Solvent concentrations ranging from 0.1 to 1% (w/w) have no adverse effect in terms of membrane fouling. However, solvent composition, i.e. D2EHPA/kerosene ratio, shows impact on membrane fouling. The type of metal extractants employed in CASX has significant impact on both membrane fouling and the quality of filtrate due to the differences in their viscosity and water solubility. Separation of MSAB was the limiting process controlling metal removal efficiency, and the removal efficiency of Cd(II) and Cr(VI) followed the same trend as that for COD.


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.


2020 ◽  
Vol 58 (5A) ◽  
pp. 22
Author(s):  
Dao Thanh Son ◽  
Van Tai Nguyen ◽  
Thuy Nhu Quynh Vo ◽  
Vinh Quang Tran ◽  
Thi My Chi Vo ◽  
...  

Heavy metal contamination is among the globally environmental and ecological concerns. In this study we assessed the development of the two green algae Schroederia setigera and Selenastrum bibraianum under exposures to 5 – 200 µg/L of Ni, Zn, and Cd in the laboratory conditions. Heavy metal removal efficiency of S. setigera was also tested in 537 µg Ni/L, 734 µg Zn/L, and 858 µg Cd/L. We found that the exposures with these heavy metals caused inhibitory on the growth of S. bibraianum. The S. bibraianum cell size in the 200 µg Zn/L treatment was around two times smaller than the control. However, Zn and Cd at the concentration of 200 µg/L did not inhibit the growth of S. setigera over 18 days of exposure. The S. setigera also grew well during 8 days exposed to Ni at the same concentration. Besides, the alga S. setigera could remove 66% of Zn, 18% of Cd and 12% of Ni out of the test medium after 16 days of incubation. The Vietnam Technical Regulation related to metals should be considered for ecological protection. We recommend to test the metal removal by the alga S. setigera at pilot scale prior to apply it in situ


Author(s):  
Angelo R. F. Pipi ◽  
Aroldo G. Magdalena ◽  
Giselda P. Giafferis ◽  
Gustavo H. R. da Silva ◽  
Marina Piacenti-Silva

2018 ◽  
Vol 932 ◽  
pp. 124-128
Author(s):  
Wei Feng Liu ◽  
Xue Wei Li ◽  
Wen Bo Dong ◽  
Le Bo ◽  
Yi Min Zhu ◽  
...  

Poly-γ-glutamic acid (γ-PGA) produced by Bacillus pumilus C2 was employed to remove heavy metals from sewage of magnesium - based exhaust gas cleaning system (Mg-EGCS). The components of heavy metals in the sewage were detailed analyzed. On the base of the analytical results, the effects of addition amount of γ-PGA, adsorption time, temperature and NaCl concentration on the removal efficiency of typical heavy metals were further investigated. The optimal removal rates of heavy metals were obtained at the γ-PGA dosage of 9 g/L and adsorption duration of 30 min. The γ-PGA had excellent tolerance for high temperatures up to 80°C and exhibited steady heavy metal removal efficiency in NaCl concentrations of 0 – 24%. Under the optimal conditions, the removal rates of Zn, Cr, V, Cd, Pb and Ni by γ-PGA in a real sewage of Mg-EGCS achieved 53.6%, 100%, 49.2%, 72.7%, 33.7% and 39.9% respectively.


2014 ◽  
Vol 70 (2) ◽  
pp. 307-314 ◽  
Author(s):  
Paula Cecilia Soto-Rios ◽  
Kazunori Nakano ◽  
Megumu Fujibayashi ◽  
Marco Leon-Romero ◽  
Osamu Nishimura

As alternative materials for heavy metal removal, this study investigated biosorbents to determine their suitability for permeable reactive barriers. The lead removal efficiencies of brown seaweed (Undaria pinnatifida) and reed (Phragmites australis) were determined under different conditions (batch and column system). The experimental results for these biomaterials fitted the Langmuir isotherm with high correlation values. It was verified that the influence of temperature on affinity was higher than that on adsorption capacity. While the lead removal efficiency of U. pinnatifida was higher than of P. australis in the batch experiments, lead removal efficiency decreased for both materials at approximately the same time in the column experiments. This indicates that the dominance of the chemical and physical adsorption mechanisms could result in differences in these systems.


2007 ◽  
Vol 41 (9) ◽  
pp. 2028-2038 ◽  
Author(s):  
Isabel Beauchesne ◽  
Ridha Ben Cheikh ◽  
Guy Mercier ◽  
Jean-François Blais ◽  
Taha Ouarda

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