Migration and transformation rule of heavy metals in sludge during hydrolysis for protein extraction
- 296 Downloads
The content and speciation of heavy metals can fundamentally affect the hydrolysis of sludge. This research study investigates the migration and transformation rule of heavy metals during the hydrolysis process by measuring the content of exchangeables (F1), bound to carbonates (F2), bound to Fe-Mn oxides (F3), bound to organic matter (F4), and residuals (F5) under different periods of time undergoing hydrolysis. The results show that the hydrolysis process generally stabilized Cu, Zn, Mn, Ni, Pb, Cr, and As by transforming the unstable states into structurally stable states. Such transformations and stabilization were primarily caused by the changes in local metal ion environment and bonding structure, oxidation of sulfides, pyrolyzation of organic matter, and evaporation of resulting volatile materials. An X-ray diffractometry (XRD) of the residuals conducted after hydrolysis indicated that hydrolysis did have a significant influence on the transportation and transformation of heavy metals.
KeywordsMigration and transformation Heavy metals Sludge Hydrolysis
This work was financially supported by Specialized Research Fund for the Doctoral Program of Higher Education of China (20130075110006) and “Textile light” application basic research of China (J201503) and the Fundamental Research Funds for the Central Universities (15D111321).
- American Public Health Association (1998) Standard methods for the examination of water and wastwater, 20th edn. American Public Health Association, Washington, D.CGoogle Scholar
- Aydilek A, Edil T (2008) Solidification/Stabilization of PCB-Contaminated Wastewater Treatment Sludges. GeoCongress 2008:724-731. doi: 10.1061/40970(309)91
- Chen F, Zhu X, Yu W (2012) The transformation of heavy metal be in activated sludge process. In: Chu MJ, Xu HH, Jia Z, Fan Y, Xu JP, (eds) Sustainable Environment And Transportation, Pts 1–4. 178–181, 633–636Google Scholar
- Ddaniali D (1990) Stabilization/solidification of heavy metals in latex modified Portland cement matrices. J Hazard Mater 24:113–134Google Scholar
- Gao DX, Hao JC, Jin JH et al (2008) Effects of single stress and combined stress of Hg and Cd on soil enzyme activities. J Agro-Environ Sci 27(3):903–908Google Scholar
- Jakubus M, Czekala J (2001) Heavy metal speciation in sewage sludge. Pol J Environ Stud 10:245–250Google Scholar
- Jiang J, Yang XD, Wang K (2007) Inhibition of cysteine protease papain by metal ions and polysulfide complexes, especially mercuric ion. J Chin Pharm Sci 16(1):1–8Google Scholar
- Lu S, Hu Y, Su B et al (2007) Effect of metal ions on activity and conformation of acid phosphatase from wheat germ. Chem Res Appl 19(4):386–389Google Scholar
- Zhang W-f, R-j S, D-x L, Yang M (2013) Extraction of amino acids from excess activated sludge by enzymatic hydrolysis. J Donghua Univ (English Edition) 30:44–48Google Scholar