RUNOFF OF METALS FROM ALUM‐TREATED HORSE MANURE AND MUNICIPAL SLUDGE¹

Abstract

Land application of organic soil amendments can increase runoff concentrations of metals such as Fe and Zn, metalbids 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(S04)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, Cd, Co, Fe, K, Mg, Mn, Mo, Na, P, Pb, 5, 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. Simulated rainfall (64 mmlh) was applied to the 12 treated plots and to three control (no treatment) plots. The first 0.5 h runoff was sampled and analyzed for the constituents described above. 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 5, due likely to its composition and by the addition of lime to counteract the acidity of alum. Concentration decreases of more than 50 percent 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. Runoff concentrations of Al, As, Fe, K, Mn, and P followed an approximately first-order decline with respect to time. Runoff concentrations of Ca and 5, however, peaked during the second runoff sample (four minutes following initiation of runoff), suggesting that differences in mobility and/or transport mechanisms exist among the materials investigated.(KEY TERMS: manure; sludge; metals; runoff.)1Paper No.

Comparing hiking, mountain biking and horse riding impacts on vegetation and soils in Australia and the United States of America

“…In tethering areas or other places where horse densities are higher the amounts of nutrients added can start to affect local vegetation favouring species adapted to higher nutrients (Mouissie et al, 2005;Westendorf, 2009). It can also increase the risk of runoff into local water ways affecting riverbank and aquatic biota (Edwards et al, 1999;Westendorf, 2009). …”

“…In addition to the impacts due to human waste Kirkpatrick, 2003, 2005;Bridle et al, 2006) that would be associated with all three activities, horses themselves produce large amounts of waste. Horses manure (faeces and urine) contain nitrogen, phosphorous and various heavy metals (Edwards et al, 1999;Westendorf, 2009). In stables, farms, paddocks and natural areas, the management of horse waste is an important environmental issue particularly where it may contaminate waterways (Edwards et al, 1999;Westendorf, 2009).…”

“…Horses manure (faeces and urine) contain nitrogen, phosphorous and various heavy metals (Edwards et al, 1999;Westendorf, 2009). In stables, farms, paddocks and natural areas, the management of horse waste is an important environmental issue particularly where it may contaminate waterways (Edwards et al, 1999;Westendorf, 2009). The amount of dung produced by an adult horse (400-600 kg body weight) per day is of the order of 17-26 kg, while for urine it is around 5-7 l per day (Mastsui et al, 2003).…”

Impact of chemical amendment of dairy cattle slurry on phosphorus, suspended sediment and metal loss to runoff from a grassland soil

“…Previous studies have found that there was no risk of increased 92 metal release posed by chemical amendment of poultry litter (Moore et al, 1998), dirty water 93 (McFarland et al, 2003), or horse manure (Edwards et al, 1999). The present study examines the 6 94 effect of chemical amendment of dairy cattle slurry on both P and metal (namely Al, Fe and Ca) 95 losses to runoff.…”

Investigation of the Inorganic and Organic Phosphorus Forms in Animal Manure

“…For goat, sheep, and horse manure, P t ranged from 10.3 to 13.1 g kg −1 , 7.2 to 10.7 g kg −1 , and 5.4 to 12.4 g kg −1 , respectively. The literature has shown values of 5.6, 5.6, and 3.8 g kg −1 for goat, sheep, and horse manure, respectively (Edwards et al, 1999; Loh et al, 2005; McDowell and Stewart, 2005). The similar total P in horses and ruminant animals is probably a result of a very similar diet, based on a fibrous diet compared with a grain diet as in nonruminant animals.…”