CE 510 Hazardous Waste Engineering Department of Civil Engineering Southern Illinois University Carbondale Instructor: Dr. L.R. Chevalier Lecture Series 12 Design of Selected Pathway Applications

Course Goals  Review the history and impact of environmental laws in the United States  Understand the terminology, nomenclature, and significance of properties of hazardous wastes and hazardous materials  Develop strategies to find information of nomenclature, transport and behavior, and toxicity for hazardous compounds  Predict the behavior of hazardous chemicals in surface impoundments, soils, groundwater and treatment systems  Assess the toxicity and risk associated with exposure to hazardous chemicals  Application of scientific principles of hazardous wastes to their design, management, remediation and treatment

Sorption by GAC  Has along history of use as a treatment for municipal, industrial, and hazardous waste streams  Is a relatively non-specific adsorbent and is effective for removing many organic and some inorganic contaminants from liquid and gaseous phases

Sorption Design Application GAC Contactors  Design Procedures:- outcomes of design effort are: Mass and volume of carbon necessary to treat a given volume of water before regeneration is required System configuration (number of columns in series Proposed dimension of the system

Sorption design Application C/Co vs. service time C/Co Time in operation

Sorption design Application  GAC Design Methods Mass loading or Isotherm Data method  Uses loading values (isotherm data) for specific contaminants  Does not account for non-equilibrium conditions Operating line method  Accounts for mass transfer and diffusion into pores within the carbon Finite Element Method  Accounts for mass transfer, dispersion and competitive sorption by different contaminants

Schematic of a GAC system Source: USEPA

Pilot column Studies  Effective procedure for designing full-scale GAC contactors  Relative contaminant concentration is measured as a function of time  Water to be treated is pumped through a series of columns that are 5-10 cm in diameter and 2-3 m deep.  Contaminant concentration is measured as a function of time, and the data are converted to relative contaminant concentration.

System configuration of pilot scale GAC evaluation

Analysis of Pilot System Data  Most common method is the graphical analysis of the breakthrough curve.  Bed Depth-Service Time (BDST) analysis is used in drinking water and industrial hazardous waste treatment  Horizontal lines are drawn through each curves at C/C o =0.10 and C/C o =0.90 which represent break-through and exhaustion points respectively.

Analysis of Pilot System Data

 The horizontal distance between the exhaustion line and breakthrough line is defined as the height of the adsorption zone (D). t = ax + b

Analysis of Pilot System Data

System Scale-Up

Class Example

Solution Spreadsheet