Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/1998
Publication Date: N/A
Interpretive Summary: Land application of animal manure and sewage sludge can increase runoff concentrations of heavy metals and phosphorus. Alum (aluminum sulfate) additions to animal manures have been shown to reduce both heavy metal runoff and phosphorus runoff from fields fertilized with manure. The objective of this work was to determine the effect of alum additions to horse manure and sewage sludge on heavy metal runoff. Horse manure and municipal sewage sludge was applied to small plots cropped to tall fescue. Phosphorus runoff was significantly lower in alum-treated horse manure than normal manure. Phosphorus runoff was not affected by alum addition in sludge. Calcium, potassium and sulfur runoff was higher from alum-treated manure and sludge. Trace metal runoff was not affected by alum treatment.
Technical Abstract: Land application of organic soil amendments can increase runoff concentrations of metals, such as Fe and Zn, metaloids such as B and As, and non-metals, such as P and S that have the potential for causing adverse environmental impacts. Aluminum sulfate or alum (Al2(SO4)3.14H2O), can reduce concentrations of some materials in runoff from sites treated with organic amendments. The objectives of this study were to (a) quantify concentrations of selected constituents (Al, As, B, Ca, Cad, Co, Fe, K, Mg, Mn, Mo, Na, P, Pb, S, Se, Ti, and Zn) in runoff from plots treated with horse manure (mixed with stall bedding) and municipal sludge, (b) assess runoff quality effects of alum additions to those treatments, and (c) determine time variations in concentrations of the constituents. Horse manure and municipal sludge were applied to twelve 2.4 by 6.1 m plots (six each for the manure and sludge). Alum was added to three of the manure-treated and three of the sludge-treated plots. Simulated rainfall was applied to the 12 treated plots and to three control plots. Alum addition increased runoff of Ca, K, and S, due to its composition and by the addition of lime to counteract the acidity of the alum. Although the abstract of this publication also states that Al was affected by alum addition, it was not, as indicated in the results and discussion of this paper (i.e. - there was a mistake in the abstract). Phosphorus was reduced by alum addition in the horse manure, but not in the sludge. Heavy metal concentrations were not affected by alum.