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

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.

2009 ◽  
Vol 163 (2-3) ◽  
pp. 1157-1164 ◽  
Author(s):  
Muhammad K. Jamali ◽  
Tasneem G. Kazi ◽  
Muhammad B. Arain ◽  
Hassan I. Afridi ◽  
Nusrat Jalbani ◽  
...  

2014 ◽  
Vol 894 ◽  
pp. 266-270
Author(s):  
Quan Bi Huang ◽  
Hui Li Liu ◽  
Yi Nian Zhu ◽  
He Hua Zheng

Two carbonate tailing samples were collected from Dachang mine tailing reservoirs, Guangxi Province, China. The chemical speciation of Zn, As, Cd and Sb contained in tailing samples were determined by Dold seven-stage sequential extraction procedure, as well as mineralogical and chemical analysis. Then the potential migration abilities of these heavy metals were evaluated. The tailing analysis results showed that the main minerals were calcite, quartz, sphalerite and pyrite, the major elements were Si, S, Ca, Fe and Al, and the trace heavy metals included Zn, As, Cd and Sb. Zn mainly existed in secondary sulfide, primary sulfides and residual fraction, and As was in primary sulfide and residue, but Sb and Cd was residual fraction. The mobility of heavy metals followed the order: Zn > Sb > Cd > As.


1985 ◽  
Vol 17 (4-5) ◽  
pp. 587-598 ◽  
Author(s):  
R. J. Oake ◽  
C. S. Booker ◽  
R. D. Davis

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.


2019 ◽  
Vol 24 (1) ◽  
pp. 23
Author(s):  
Lestari Lestari ◽  
Fitri Budiyanto

The assessment of the biological availability of metals is rarely used only by knowing the total concentration of the metal. Therefore, six sediment samples from Muara Angke, Teluk Jakarta were assessed the chemical speciation of heavy metals. This study aims to determine metal speciation using the BCR sequential extraction procedure and to determine metal speciation to evaluate bioavailability in the sediments of Muara Angke, Jakarta Bay. In sediment from Muara Angke, the ability to move sequence of heavy metals studied was Pb>Zn>Cu>Ni. The mostly accumulated in the non-residual fraction of the total concentrations are Cu, Ni, Pb and Zn which indicated that the mobility and anthropogenic inputs of these metals in Muara Angke were quite high. The Risk Assessment Code (RAC) reveal that Zn and Ni at almost station exist in exchangeable and a fraction of carbonate-bound and therefore high-risk category. Most of the Cu at most of the station is in the oxidizable fraction, except a small portion found at all station is in the exchangeable fraction and fraction of carbonate-bound thus posing a low risk for the waters environment. The patterns of Pb speciation show no to low risk to the waters environment. However, metal observations in the waters are necessary because they are persistent and can accumulate which threatening the water environment.


2009 ◽  
Vol 57 (2) ◽  
pp. 215-230 ◽  
Author(s):  
M. Jamali ◽  
T. Kazi ◽  
M. Arain ◽  
H. Afridi ◽  
J. Baig ◽  
...  

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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