Arsenic treatment the rest of the story
Sponsored Links
This presentation is the property of its rightful owner.
1 / 11

Arsenic Treatment The rest of the story PowerPoint PPT Presentation

  • Uploaded on
  • Presentation posted in: General

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

Download Presentation

Arsenic Treatment The rest of the story

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 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

The lesser know elements of water chemistry

Turnstone Services

Common Redox Species In Ground Water

Oxidized Sand

Reduced Sand

Turnstone Services

Groundwater Redox Front













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


  • 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

  • Login