Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/1998
Publication Date: N/A
Interpretive Summary: Water pollution, such as contamination of rivers and streams with metals, can occur when animal manure or sewage sludge is land applied. The objective of this study was to determine if the amount of metals in runoff water from land fertilized with horse manure or sewage sludge could be reduced using aluminum sulfate (alum). A rainfall simulation study was conducted where horse manure or sewage sludge was applied either with or without alum. The runoff water from this study was analyzed for metals. Most metals were not affected by alum. Phosphorus runoff was reduced by more than 50% in runoff water from horse manure by treating the manure with alum. However, phosphorus runoff from sewage sludge was not affected; possibly because the forms of phosphorus in the sludge are already stabilized. This work shows that use of alum is a good way to prevent environmental pollution by phosphorus in horse manure, but that treating sewage sludge with alum would not be beneficial.
Technical Abstract: Land application of organic soil amendments can increase runoff concentrations of metals, which can cause adverse environmental impacts. Aluminum sulfate (alum) 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, Cd, 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 addition 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 fescue plots (six each for the manure and sludge). Alum was added to three of the manure-treated and three of the sludge-treated plots. Addition of manure or sludge had no effect on runoff concentrations of the majority of constituents. In some cases (e.g., Al, As, Fe, Zn), however, concentrations were near or in excess of threshold values recommended for marine wildlife protection. Alum addition increased runoff of Al, Ca, K and S, due likely to its composition and by the addition of lime to counteract the acidity of alum. Concentration decreases of more than 50% were noted for P for the horse manure treatment. No alum effect was detected for P in runoff from the sludge-treated plots, possibly due to relatively stable P forms in the sludge.