Lagoons

Tank-style lagoons

Practice: Cover the lagoon

J. Mark Powell, Tom Misselbrook and Glen Broderick. 2006. Abating Ammonia Emission from Dairy Barns Through Feed, Herd and Bedding Management. Workshop on Agricultural Air Quality, page 1006.

Conclusions

Substantial reductions in ammonia loss from dairy farms can be achieved by reducing in-barn losses, by covering manure storage, and by incorporation of manure in the field. The following steps can be a guide for action:

  1. Remove excess protein from the cow’s diet. This normally saves on feed cost, as well as reducing ammonia N emissions.
  2. For new construction, floors that divert urine away from feces can reduce ammonia emissions. Slatted floors facilitate this, but there is still considerable loss of ammonia from the surface of the slatted floor.
  3. Select bedding (e.g. sand, pine shavings) that separate feces and urine, which reduce ammonia losses.
  4. Cover the manure storage. When organic bedding such as straw is used, a crust will form on the surface of the slurry pit. This reduces ammonia N losses and odors. Excessive agitation during unloading of the slurry from storage should be avoided.
  5. Incorporate manure in the field. However, this strategy needs to consider potential tradeoffs in situations where nitrate leaching may be a concern.

Practice: Control water temperature and pH (lower pH has lower emission rates)

W. Berg, M. Türk, and H. J. Hellebrand. 2006. Effects of Acidifying Liquid Cattle Manure with Nitric or Lactic Acid on Gaseous Emissions. Workshop on Agricultural Air Quality, page 497.

Conclusions

Adding nitric acid or lactic acid to liquid cattle manure gave different effects. Nitric acid could lower the pH value more efficiently. 1.3% by volume of 50% concentrated nitric acid were necessary to reach a manure pH of 4.5, whereas 3.7% by volume of 50% concentrated lactic acid were required to reach the same manure pH value. Advantages of lactic acid during acidifying were a considerably lower foam formation and a more innocuous handling than with nitric acid. Both lactic and nitric acid could reduce ammonia emissions effectively, the reduction rate was nearly 90  and 70% respectively. In contrast, the effects on nitrous oxide and methane were quite different for both acids. From the manure acidified with lactic acid, nearly no nitrous oxide was detected, more than 90% of the methane emission could be detained. From the manure acidified with nitric acid, a large amount of nitrous oxide was emitted. The measured mean headspace concentration was about one order of magnitude higher than that of the control. The methane emission was about 25% of the control.  Ammonia emissions can be reduced effectively with nitric acid as well as with lactic acid. Lactic acid has a better abatement effect on methane emissions than nitric acid. Nitric acid is not an advisable emissionmabatement technique.

Practice: Separate liquids and solids

A. A. Szögi and M.B. Vanotti. 2006. Reduction of Ammonia Emissions from Swine Lagoons Using Alternative Wastewater Treatment Technologies. Workshop on Agricultural Air Quality, page 1155.

Abstract

There is a need for treatment technologies that can effectively address environmental concerns associated with ammonia (NH3) emissions from anaerobic lagoons, typically used to manage manure. To meet this need, we conducted a study to determine the effects of water quality improvement in swine lagoons on NH3 emission rates using alternative wastewater treatments. This determination was done in three contiguous swine production units that had similar animal production management and lagoons with similar surface area (about 0.9 ha each), but their waste management was substantially different. In the first production unit, a full-scale wastewater treatment plant produced a clean effluent that in turn converted the old lagoon into a water storage pond. In the second production unit, the traditional anaerobic lagoon treatment method was maintained as a control. In the third production unit, raw flushed manure was treated through a solid-liquid separation system before anaerobic lagoon storage. Passive flux samplers were used to measure simultaneously the NH gas fluxes from the lagoons receiving treated water and the traditional anaerobic lagoon.

Ammonia emissions from the traditional anaerobic lagoon (control) totaled 12,540 kg N/lagoon/year (13,633 kg N/ha/year). This result compares to lower NH3 emissions of 3,355 kg N/lagoon/yr (or 3,647 kg N/ha/yr) from the anaerobic lagoon with solid-liquid separation and 1,210 kg N/lagoon/yr (or 1,311 kg N/ha/yr) from the converted lagoon. In the anaerobic lagoon with solid-liquid separation, total annual NH3 emissions were reduced by 73% with respect to those of the traditional lagoon. In the converted lagoon, remarkable water quality improvements such as lower N concentrations substantially reduced annual NH3 emissions by 90% with respect to those found in the traditional anaerobic lagoon. These results overall demonstrate that alternative new wastewater technologies can substantially reduce ammonia emissions from confined swine production.

Conclusions

There is a need for treatment technologies that can effectively address environmental concerns associated with anaerobic lagoons. In particular, reduction of NHemissions is a major environmental concern associated with confined swine production. In order to meet this need, two new wastewater treatment systems were demonstrated at full-scale in two of three 4,360-pig production units on a finishing farm in Duplin Co., NC. One treatment system combined solid-liquid separation with removal of N and P from the liquid phase, and the other wastewater treatment system consisted of solid-liquid separation before anaerobic lagoon storage. The third production unit was kept as a control using traditional anaerobic lagoon treatment.

In summary our findings indicate:

  1. Ammonia emissions from the traditional anaerobic lagoon totaled 12,540 kg N/lagoon/year (13,633 kg N/ha/year). This result compares to lower NHemissions of 3,355 kg N/lagoon/yr (or 3,647 kg N/ha/yr) from the anaerobic lagoon with solid-liquid separation, and 1,210 kg N/lagoon/yr (or 1,311 kg N/ha/yr) from the converted lagoon.
  2. Although water quality improvements were modest in anaerobic lagoon with solid-liquid separation, total annual NHemissions were reduced by 73% with respect to those of the traditional lagoon
  3. Remarkable water quality improvements such as lower N concentrations in the converted lagoon substantially reduced annual NHemissions by 90% with respect to those found in the traditional anaerobic lagoon.