Batch Test Screening of Industrial Product/Byproduct Filter Materials for Agricultural Drainage Water Treatment

Barry Allred

doi:10.3390/w9100791

Abstract

Filter treatment may be a viable means for removing the nitrate (NO3−), phosphate (PO43−), and pesticides discharged with agricultural drainage waters that cause adverse environmental impacts within the U.S. on local, regional, and national scales. Laboratory batch test screening for agricultural drainage water treatment potential was conducted on 58 industrial product/byproduct filter materials grouped into six categories: (1) high carbon content media; (2) high iron content media; (3) high aluminum content media; (4) surfactant modified clay/zeolite; (5) coal combustion residuals; and (6) spent foundry sands. Based on a percent contaminant removal criteria of 75% or greater, seven industrial products/byproducts were found to meet this standard for NO3− alone, 44 met this standard for PO43−, and 25 met this standard for the chlorinated triazine herbicide, atrazine. Using a 50% or greater contaminant removal criteria, five of the industrial product/byproduct filter materials exhibited potential for removing NO3−, PO43−, and atrazine together; eight showed capability for combined NO3− and PO43− removal; 21 showed capability for combined PO43− and atrazine removal; and nine showed capability for combined NO3− and atrazine removal. The results of this study delineated some potential industrial product/byproduct filter materials for drainage water treatment; however, a complete feasibility evaluation for drainage water treatment of any of these filter materials will require much more extensive testing.

Highlights

In humid regions, such as the Midwest U.S, agricultural drainage practices commonly employ buried pipe networks to remove excess soil moisture by lowering the shallow water table, which in turn improves crop yields
Nitrate-nitrogen (NO3 − -N), phosphate-phosphorous (PO4 3− -P), and atrazine removal calculated as mg of contaminant per g of filter material is provided in the Appendix A Tables A1–A6
An in-line filter treatment system located on the main collector pipe near the subsurface drainage system outlet could be a viable means for removing NO3 −, PO4 3−, and pesticides from drainage waters before these waters are released into local streams, rivers, and lakes

Summary

Introduction

In humid regions, such as the Midwest U.S, agricultural drainage practices commonly employ buried pipe networks to remove excess soil moisture by lowering the shallow water table, which in turn improves crop yields. −, PO43−, or atrazine) is important information and will require extensive contaminant 4 , or atrazine) is important information and will require extensive generalizations for the filter materials tested regarding NO3−, PO43−, or atrazine removal mechanisms laboratory examination with adsorption isotherm and reaction kinetics batch tests. Nitrate removal by activated carbon (AC1, AC2, AC3, AC4, and AC5) and generalizations for the filter materials tested regarding NO3 − , PO4 3− , or atrazine removal mechanisms surfactant modified clay/zeolite (SMC1, SMC2, SMZ1, and SMZ2) is likely due to adsorption caused can bebypostulated.

Methods

Results

Conclusion