Arsenic treatment the rest of the story
Download
1 / 11

Arsenic Treatment The rest of the story - PowerPoint PPT Presentation


  • 75 Views
  • Uploaded on

Arsenic Treatment The rest of the story. Presented to:. Texas Commission on Environmental Quality October 25, 2005. Russell Fisher Turnstone Services The Woodlands, Texas (281) 419-0747. The Commercial Perspective. Locate prospects – anticipate the unmet need

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Arsenic Treatment The rest of the story' - zeheb


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Arsenic treatment the rest of the story

Arsenic TreatmentThe rest of the story

Presented to:

Texas Commission on Environmental Quality

October 25, 2005

Russell Fisher

Turnstone Services

The Woodlands, Texas

(281) 419-0747


The Commercial Perspective

  • Locate prospects – anticipate the unmet need

  • Qualify Prospects – gather data to understand need

  • Propose Solution - Satisfy customer’s need

Turnstone Services


The Need - Arsenic Treatment Objectives

Achieve compliance

Conserve the water resource

Define the Need – Gather Information

Aquifer characteristics

Water Quality Data - TCEQ

Usage information - PWS

Develop Arsenic Treatment Strategy

Associated regulatory issues

Technology Constraints

Unanticipated Consequences

Turnstone Services


Texas Groundwater is a Dynamic System

  • Sandstone Aquifers – highly variable over short dist

  • Intermittent Recharge – year to year rainfall variance

  • Regional climate variation – fluctuating water levels

  • Coastal faulting and subsidence

  • Geochemistry - the rock/water system

Turnstone Services


Understanding the Environment

Indicator Species

TDS - may require lowering of salt content

pH - activity of the hydrogen ion

Eh – electrode potential, activity of the electron

Ca/Mg – hardness, scale forming pH sensitive

Cl- – major contributor to TDS

HCO3- – contributes to TDS, limits F trmt

Turnstone Services



Common Redox Species In Ground Water

Oxidized Sand

Reduced Sand

Turnstone Services


Groundwater Redox Front

O2

H2O

Fe2O3

UO2+2

MoS2

HAsO4-

As2O3

H3AsO3

As2S3

MoO4-2

UO2

FeS2

Turnstone Services


Importance of redox potential

Redox state often dictates solubility

Fe(+III) insoluble, Fe(+II) low to moderate solubility

U(+IV) insoluble, U(+VI) highly soluble

Redox affects acid-base behavior, i.e. charge

H3AsO4 mild acid, H3AsO3 weak acid

HNO3 strong acid, HNO2 weak acid

Redox reactions affect pH

Ionization of weak acids: HCO3-1, H4SiO4

Turnstone Services


Typical Treatment Strategies

Rule #1: Match the Solution to the Problem

Turnstone Services


Summary

  • Understand geological setting – aquifer type, mineralogy

  • Analyze water sample for less known species

  • Interpret water analysis in context of aquifer geochemistry

  • Apply technologies that best address the problem

Turnstone Services


ad