Author Archives: zongliu

Proper Lagoon Management to Reduce Odor and Excessive Sludge Accumulation

Livestock and poultry operations frequently use anaerobic lagoons as liquid waste storage and treatment structures. In a lagoon, organic waste is diluted with water and bacteria decompose the organic matter. During decomposition, solids that cannot be liquefied by bacteria settle out as sludge. The treated liquid and dilution water, called effluent, are used by livestock and poultry producers as fertilizer. Effluent also can be recycled for manure handling in a flush system. Efficiency To be efficient, a lagoon must be properly designed. The size of a lagoon is… Read More →

Solid-Liquid Separation of Animal Manure and Wastewater

Livestock and poultry producers are seeking alternative treatments for animal manure and process-generated wastewater to reduce excessive nutrient loading and odor potential of liquid manure storage structures. Solid-liquid separation is the partial removal of organic and inorganic solids from a mixture of animal manure, open-lot runoff and process-generated wastewater, also known as liquid manure. Liquid manure systems are popular among livestock and poultry operations because they make manure easy to handle, store, treat biologically in lagoons and land apply. The manure pits and gutters also are easy to… Read More →

Land Application of Poultry Lagoon Effluent

Abstract Excess levels of plant nutrients are being applied to soils when effluent from waste treatment lagoons is repeatedly irrigated on small parcels of land adjacent to large poultry operations. Therefore, field research was conducted at College Station and Overton, TX, to evaluate the effects of poultry lagoon effluent on soil, vegetation and surface runoff quality. Two cropping systems, bermudagrass and a bermudagrass/ryegrass rotation, and three application rates, 0, 538 and 1076 kg N/ha/yr, were studied in experimental plots 1.2 m wide and 2.4 m long, from February… Read More →

Composting Horse Manure

Uncontrolled stockpiles of horse manure can be an unsightly, smelly and fly-infested mess. Stockpiles also can cause runoff pollution in nearby streams and ponds. For horse enthusiasts, veterinarians and operators of boarding stables, handling and disposing of horse manure can pose numerous challenges. Frequently, operators of equine facilities and large-animal veterinary clinics must pay someone to take the manure off the property. However, there is an excellent way to stimulate demand for a product that would otherwise be a liability. Composting manure can eliminate a messy problem and… Read More →

Techno-economic assessment of dairy manure granulation

Continued growths in number of milking cows, milk productivity per cow and number of concentrated animal feeding operations (CAFO) are all leading to increases in quantity and concentration of manure. Under these conditions, poor manure management practices coupled with uncertainty in rain events pose a greater threat to the health of surrounding ecosystems, in addition to the economic loss of manure nutrients as runoff. This study presents a comprehensive model of granulation as an advanced processing alternative for dairy manure. Granulation offers an opportunity to improve manure characteristics,… Read More →

Use of cationic polymers to reduce pathogen levels during dairy manure separation

(View original article)  Various separation technologies are used to deal with the enormous amounts of animal waste that large livestock operations generate. When the recycled waste stream is land applied, it is essential to lower the pathogen load to safeguard the health of livestock and humans. We investigated whether cationic polymers, used as a flocculent in the solid/liquid separation process, could reduce the pathogen indicator load in the animal waste stream. The effects of low charge density cationic polyacrylamide (CPAM) and high charge density cationic polydicyandiamide (PDCD) were… Read More →

Particulate Matter: What Is It and Why Does It Matter to Agriculture?

Particulate matter (PM) is the term applied to dust and other small particles that are suspended in the air. The Environmental Protection Agency (EPA) regulates PM as a pollutant because it can cause health problems when inhaled. There are two categories of PM— coarse and fine. Coarse PM, typically found near roadways and dusty industries, is made up of particles larger than 2.5 micrometers and smaller than 10 micrometers in diameter. Fine PM, found in smoke and haze, is made up of particles 2.5 micrometers in diameter and… Read More →

Composting Large Animal Carcasses

Livestock producers and large-animal veterinarians face a growing problem in rural Texas—what to do with dead animals. Rendering services are getting more expensive and harder to come by, and just leaving carcasses to predators and the forces of nature is not acceptable. So what are the options? Except for poultry, you can bury dead animals as long as you do not pollute ground or surface water. Incineration, biodigestion and chemical digestion are other disposal methods, but they are expensive, complicated or both. Composting is a simple, low-cost disposal… Read More →

Manure to Energy: Understanding Processes, Principles and Jargon

Today the spotlight in the United States is on the increasing world demand for energy and the high cost of oil and natural gas. This has heightened interest in alternative and renewable energy sources, such as bio fuels, forests, wind, solar and animal manure. While demand for hydrocarbon energy (energy from crude oil, natural gas and coal) will continue to rise, renewable energy will become more important in the coming years. This publication uses the following figure as a simple illustration of potential sources of energy from biomass,… Read More →

Calibration of Poultry Litter Applicators

Poultry litter has been used for many years in Texas as an alternative to commercial fertilizer. The poultry litter not only has the N (nitrogen), P (phosphorus), K (potassium) benefits, but it adds organic matter and all other essential nutrients to the soil. Proper precautions must be taken in order to prevent contamination of groundwater and runoff, while regulating soil P and N levels.