Dissertation > Excellent graduate degree dissertation topics show

Feasible Leaching Procedure of Toxicity Characteristic of MSWI Fly Ash and Its Melting Residures

Author: ZhangXiaoZuo
Tutor: WangJingGang；XiBeiDou
School: Beijing University of Chemical Technology
Course: Environmental Engineering
Keywords: MSWI Fly ash Melting Heavy metal leaching toxicity Horizontal vibration extraction procedure TCLP
CLC: X701
Type: Master's thesis
Year: 2005
Downloads: 210
Quote: 6
Read: Download Dissertation

Abstract


Fly ash is second pollutant produced from incineration of Municipal Solid Waste (MSW), Vitrification is effective technology for the solidification of fly ash. We studied the characteristic of fly ash and its melting residue, identified their hazardous characteristic, evaluated environmental risk during the course of utilization of melting residue, studied the transference law of heavy metals such as lead, chromium, zinc, copper during melting. The results showed that according to Extraction Procedure Toxicity of our country and Toxicity Characteristic Leaching Procedure of US EPA, fly ash belonged to hazardous waste, but its melting residue was not hazardous waste and didn’t show current and potential threats to human health during the course of utilization. The transference law of heavy metals was represented by solidification ratio.Leaching toxicity is important hazardous characteristic of fly ash and its melting residue. From discussing the influence of pH, Liquid-to-Solid Ratio (L/S Ratio) and leaching time on leaching characteristic of heavymetals in fly ash, we understand leaching characteristic of fly ash better, and provided experimentation basis for standards of management, disposal and utilization of fly ash. The results showed that pH was a major controlling factor in metal leaching ability. The metals exhibited a marked increase in leaching ability at low and sometimes high pH values, while relatively low leaching ability of the metals was observed at neutral pH values. Total extractable metal concentration (mg/g fly ash ) increased as the L/S Ratio increased until it got the maximal leaching concentration, after that it was changeless, but concentration of heavy metals in leachate decreased because lower mass of waste in the leaching solution. The longer fly ash was in contact with the extraction solution, the more metal will leach. When use mixture of sulfuric and nitric acids as a leaching solution, heavy metals in fly ash achieved equilibrium concentration in less than 8h.On the basis of studying advanced experiences of developed countries and analyzing the results of examination, leaching procedure that was used to identify toxicity characteristic of fly ash should combine disposition means that fly ash was chosen and aim of environmental protection that was pay attention to when considered possible pollution of fly ash in disposition site. When we evaluate whether MSW fly ash can be disposed in safe landfill, leaching procedure of our country is feasible. To determine whether melting residues of fly ash can be utilized as resources, the leaching procedure that use mixture of sulfuric and nitric acids as a

Related Dissertations

  1. Preparation and Properties of Highly Active Dietary Fiber and Carboxymethylcellulose from Gracilaria Residue,TS254.9
  2. The Comprehensive Evaluation of Flue-cured Tobacco Origin Place Environment and Tobacco Leaf of Fangxian,S572
  3. Theanalysis of Harmfulness Factors about Heavy Metals in the Course of Beef Cattle Feeding,S823
  4. Influence of Biochar Amendments on Decomposition of Soil Organic Carbon and Morphology of Heavy Metal in Red Paddy Soil,S153.6
  5. Study on Monitoring and Early Warning for Heavy Metal in Textiles,TS107
  6. Field In-Situ Remediation of Cu-Cd Polluted Soil by Amendments,X53
  7. Experimental Study on Heavy Metals Adsorption or Release from Sediments of East Dongting Lake,X524
  8. Preparationandapplication of the Strong Alkali Anion Exchange Fiber Based the Polyethylene,TQ342.84
  9. Cloning, Identification and Eukaryotic Expression of Variable Region of Monoclonal Antibodies Against Chelated Mercury, Copper and Zinc and Three Dimentional Modeling of Recombinant Antibody,X171.5
  10. The Removal of Heavy Metal Ions from Wastewater by Graphene/MnO2 Adsorbent,X703
  11. The Heavy Metals Distribution Characteristics and Risky Evaluations of Farmland Soils-Crops Around Different Types of Chemical Industrial Park,X833
  12. Transfer and Transformation of Cu in Black Soil-Crop System and In-sit Immobilization Mechanism,X53
  13. Investigation of Community Structure of Ectomycorrhizal Fungi in Abandoned Copper Mine and Effects of Colonization of Ectomycorrhizal Fungi on Growth of Tree Seedlings in Copper Tailings,X173
  14. Construction and Application of the Transgenic Yeast Strain Expressing Metallothionein,Q78
  15. Study on Soils and Rice Polluted by Heavy Metals in Yancheng City,X53
  16. Spectrum Variation of Vegetation in Yanzhou Coal Mine Area and Heavy Metal Stress Characteristic,X173
  17. Environmental Effects of Poisonous and Harmful Substances in the Typical Industrial Solid Wastes,X705
  18. Risk Assessment & Spatial Distribution of Soil Nutrients and Heavy Metal in Fenhe Reservoir Surrounding,S158
  19. Heavy metal ions on methane -oxidizing bacteria growth characteristics of,X172
  20. Chromium Oxya vivo accumulation and the impact of antioxidant systems,X174
  21. Positive and negative environmental friendly surfactant aqueous two-phase extraction system, the role of research,O647.2

CLC: > Environmental science, safety science > Processing and comprehensive utilization of waste > General issues > Exhaust gas processing and utilization
© 2012 www.DissertationTopic.Net  Mobile