My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in JEQ

  1. Vol. 38 No. 2, p. 814-821
     
    Received: Jan 18, 2008
    Published: Mar, 2009


    * Corresponding author(s): jrwhite@lsu.edu
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/jeq2008.0033

Alum Application to Improve Water Quality in a Municipal Wastewater Treatment Wetland

  1. Lynette M. Malecki-Browna,
  2. John R. White *b and
  3. M. Seesc
  1. a Soil and Water Science, Univ. of Florida, Gainesville, FL 32611
    b Louisiana State Univ., 3239 Energy Coast and Environment Bld., Baton Rouge, LA 70803
    c Orlando Easterly Wetlands, Wastewater Div., 25155 Wheeler Rd., Christmas, FL 32709

Abstract

Nutrient removal in treatment wetlands declines during winter months due to temperature. A 3-mo (wintertime) mesocosm study was conducted to determine the effectiveness of alum in immobilizing P as well as other nutrients during this period of reduced treatment efficiency. Eighteen mesocosms, triplicate alum, and three controls or no alum were established with either Typha spp., Schoenoplectus californicus, or SAV (Najas guadalupensis-dominated). Alum was delivered by timer at a rate of 0.81 g Al m−2 d−1 and parameters measured included: pH, soluble reactive phosphorus (SRP), total phosphorus (TP), dissolved organic carbon (DOC), dissolved inorganic nitrogen (DIN), total kjeldahl nitrogen (TKN), and soluble aluminum (Al). Alum-treated mesocosms had significantly lower pH values (8.1) than controls (8.8), but well within the elevated pH range for aluminum toxicity. Alum significantly reduced all measured water column nutrients with the exception of ammonium N, which remained unaffected, and particulate P, which increased. This study demonstrated that seasonal low-dosage alum application to different vegetation communities in a treatment wetland can significantly improve treatment efficiencies for SRP (87 vs. 58%) and TP (62 vs. 44%) but also increase DOC (19 vs. 0%) and TKN (12 vs. −3%) removal capacity to a lesser degree. Alum applications within close proximity of the treatment wetland effluent points should be implemented with caution due to the production of alum floc-bound P which could potentially affect discharge permit compliance for total suspended solids or total P.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2009. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyAmerican Society of Agronomy, Crop Science Society of America, and Soil Science Society of America