Speciation of heavy metals in untreated sewage sludge by using microwave assisted sequential extraction procedure

2009 ◽  
Vol 163 (2-3) ◽  
pp. 1157-1164 ◽  
Author(s):  
Muhammad K. Jamali ◽  
Tasneem G. Kazi ◽  
Muhammad B. Arain ◽  
Hassan I. Afridi ◽  
Nusrat Jalbani ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Sequential Extraction ◽  
Extraction Procedure ◽  
Sequential Extraction Procedure ◽  
Microwave Assisted ◽  
Untreated Sewage

Fractionation of Heavy Metals in Sewage Sludges

1985 ◽  
Vol 17 (4-5) ◽  
pp. 587-598 ◽  
Author(s):  
R. J. Oake ◽  
C. S. Booker ◽  
R. D. Davis
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Sequential Extraction ◽  
Extraction Procedure ◽  
Sequential Extraction Procedure ◽  
Organic Fraction ◽  
Sewage Sludges ◽  
Exchangeable Fraction ◽  
Complete Extraction

Metals (Cd, Cr, Cu, Ni, Pb and Zn) have been fractionated in representative sewage sludges (primary, secondary, digested) by a sequential extraction procedure using KNO3 1M (removes the ‘exchangeable' fraction), KF 0.5M (‘sorbed'), Na4P2O7 0.1M (‘organic'), Na2EDTA 0.1M (‘carbonate') and HNO3 6M (‘sulphide'). Major differences according to sludge type were not seen. Cd occurred mainly in the ‘carbonate' fraction and 38–62% of Cr was in the ‘organic' fraction. 43–70% Cu was in the sulphide fraction whilst >40% of Ni was extracted in the ‘exchangeable/sorbed' fractions. Pb was found predominantly in the ‘organic' and ‘carbonate' fractions and Zn in the ‘organic' fraction. The complete extraction procedure removed 54–100% of the total metals content of the sludges. Changes in fractionation caused by drying, storage and time of extraction are reported. The results form the first part of a detailed investigation into the chemistry of metals in sewage sludge.

Fraction Distribution Changes of Heavy Metals in Co-Pyrolysis of Sewage Sludge and Corn Straw

2011 ◽  
Vol 236-238 ◽  
pp. 187-191 ◽  
Author(s):  
Qiu Rong Zhang ◽  
Shuang Quan Zhang ◽  
Ting Ting Pan
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Sequential Extraction ◽  
Pyrolysis Temperature ◽  
Extraction Procedure ◽  
Sequential Extraction Procedure ◽  
Residual Fraction ◽  
Corn Straw ◽  
Icp Ms ◽  
Fraction Distribution

Maiz’s short sequential extraction procedure was used to extract the heavy metals in the carbon residues made from sewage sludge by co-pyrolysis with corn straw. The content of heavy metals in the residues was determined by ICP-MS to study the fraction distribution changes of heavy metals. It is concluded that the content of mobile and mobilization heavy metals exsisted in the residue decrease and the content of residual heavy metals increase due to the co-pyrolysis. The co-pyrolysis temperature has great effect on the fraction distribution changes of heavy metals. The content of residual fraction for Cr, Ni, Pb is up to the top at 700°C and for Cd、Cu、Zn is at 500°C. The carbon residues are unhazardous and safe.

Evolution of Heavy Metals Leachability and Speciation in Residues of Sewage Sludge Treated by Microwave assisted Pyrolysis

2012 ◽  
Vol 178-181 ◽  
pp. 833-837 ◽  
Author(s):  
Lin Fang ◽  
Na Na Yuan ◽  
Yi Guang Wu ◽  
Xu Xin Zhao ◽  
Hong Yuan Sun
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Sequential Extraction ◽  
Extraction Procedure ◽  
Stable Phase ◽  
Toxicity Characteristic Leaching Procedure ◽  
Microwave Assisted ◽  
Novel Approach ◽  
Conventional Pyrolysis ◽  
Leaching Procedure

In this study the sewage sludge are treated by microwave assisted pyrolysis (MAP) with different microwave receptors, and then, the immobilization of heavy metals in the residues are evaluated through the toxicity characteristic leaching procedure (TCLP) and sequential extraction procedure. The volatilization of Cd, Pb and Zn could be decreased by MAPs more efficiently than the conventional pyrolysis (CP). The average leaching percentages of Cu, Zn and Pb in residues produced by MAPs are decreased 90%, 88% and 81% more than the CP process respectively, and no leaching Cd is detected. Moreover, more than 67% of Cu, Pb, Zn and 55% of Cd in residues of MAP speciated into stable phase, which is higher than the metals in the residues of CP. The effect of heavy metals stabilized in residues of MAP was determined in the order as Cd > Cu > Pb > Zn. The results suggest the immobilization of heavy metals in the residues are enhanced in the process of MAP. This novel approach should be of significance in immobilizing heavy metals in residues of sewage sludge.

Time-saving application for sequential extraction of heavy metals by optimized BCR method and lixiviation from untreated sewage sludge

2009 ◽  
Vol 57 (2) ◽  
pp. 215-230 ◽  
Author(s):  
M. Jamali ◽  
T. Kazi ◽  
M. Arain ◽  
H. Afridi ◽  
J. Baig ◽  
...  
Keyword(s):  
Waste Water ◽  
Heavy Metals ◽  
Reference Material ◽  
Sewage Sludge ◽  
Sequential Extraction ◽  
Certified Reference Material ◽  
Extraction Procedure ◽  
Domestic Waste ◽  
Bcr Sequential Extraction ◽  
Optimum Recovery

This article describes an improvement in the modified BCR three-step sequential extraction procedure employed for heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in untreated domestic waste-water sewage sludge collected from different cities in Pakistan.The BCR sequential extraction protocol requires 16 h for each step, whereas in the present work optimum recoveries of all heavy metals were attained in 10 h/step. The validity of the proposed BCR sequential extraction procedure was checked using certified reference material (BCR 483). Various parameters such as time interval (2–16 h) and sample mass (0.2–1.0 g) were studied to achieve optimum recovery of the heavy metals studied. The extracted analytes were determined by atomic absorption spectrometry. The optimum recovery of heavy metals from the certified reference material and from experimental samples was achieved at a sample mass of 0.4 g, while the time required for extraction on a mechanical shaker at 30 rpm was found to be 26–32 h. The sequence of easily available (acid-exchangeable) heavy metals was determined as Cd<Zn<Ni<Cr<Pb<Cu. With the exception of Cd the dominant fractions of the heavy metals were associated with organic matter, while 31.0 and 47.8% of Cd was present in acid-soluble and reducible forms, respectively. A lixiviation test (DIN 38414-S4) was used to evaluate the leaching of heavy metals from the domestic waste-water sewage sludge used for agricultural purposes.

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