Rejuvenation of Failed Soil Absorption Systems

Abstract

The use of hydrogen peroxide as an oxidizing agent was shown to be effective for rejuvenating wastewater soil absorption systems which have failed due to crust or organic mat buildup. The amount of hydrogen peroxide required is dependent on the soil type and the thickness of the crust. Silty soils require greater hydrogen peroxide loading rates for rejuvenation than do sandy soils. Experiments performed on cores of various soil types which contained wastewater derived organic mats indicated that loading rates on the order of 0.125 lb H 2 O 2 /sq ft to 0.250 lb H 2 O 2 /sq ft (0.61 kg/m² to 0.371 kg/m²) of absorption bed area were sufficient to rejuvenate sandy soils; while silty soils required loading of at least 0.50 lb H 2 O 2 /sq ft (2.44 kg/m²). Rejuvenation of sandy soils to almost the initial percolation rate of the soil before crust development could be achieved using 7.5% H 2 O 2 — 15.0% H 2 O 2 , rather than the potentially dangerous 30% H 2 O 2 — 35% H 2 O 2 solutions recommended in the literature.