Livestock waste: ecological solutions for management

What is livestock manure and how can it be sustainably managed and treated?

In the agricultural and livestock sector, one of the most important aspects is the collection, management and treatment of livestock waste. This is the result of livestock farming, especially intensive farming. 

It is essential to treat them properly, both so that they can be disposed of in the correct way, without spreading them in the environment, and so that resources (economic, water) are not wasted, and because, thanks to the latest technologies and treatment plants, these wastes can be transformed and reused. For example, into biogas.

Let's find out together what these wastes are and how they are treated.

What is livestock manure?

Livestock wastes (also known as "livestock effluents") are the collection of solid and liquid wastes from domestic and farm animal husbandry. It generally consists of feed and food leftovers, solid and liquid manure, and water used for watering or washing animals.

On small to medium sized farms, i.e. with a rather limited number of animals, animal waste is usually present in the form of manure; its disposal is not a major problem as it is used as fertilizer. 

However, large and intensive livestock farms produce excessive amounts of manure that cannot be reused as fertilizer. There is therefore a risk that, if not properly disposed of, it could become a pollutant, contaminating soil and surface water.

For this reason, there are specific laws for the treatment and management of livestock manure: Legislative Decree 152/2006.

How livestock manure is treated

Before understanding how livestock manure is treated and managed, we need to keep in mind a fundamental distinction, namely that based on palatability. This is the ability of manure to be treated as a solid or liquid/liquid material, depending on the amount of dry matter it contains. Thus, we distinguish

• Palatable effluents: they contain a significant amount of dry matter, tend to be more solid and can therefore be moved "with a shovel". They are therefore solid wastes, such as manure, sewage sludge, dried poultry manure and compost from wastewater;
• Non-palatable effluents: they contain low concentrations of dry matter and are therefore more liquid. These are the liquid effluents such as sewage and manure. Since they cannot assume a stable form, they must be placed in special containers.

Storage for subsequent disposal of inedible livestock manure (i.e., primarily manure) can be accomplished in a number of ways. The most common and effective are:

• Buried tanks: these are an excellent collection method, although they can be more cumbersome to implement than other solutions. In fact, they require a large earth movement and must be protected by a fall-proof fence with gates for the introduction of mixers and pipes;
• Above-ground tanks: these are a more practical, convenient and immediate solution than underground tanks; however, they still require an underground collection tank, the lifting sump and the construction of special equipment to load the effluent. They can be made of concrete or galvanized steel;
• Flexible cisterns: they have a large capacity and can be assembled, disassembled and moved at will;
• Rammed earth lagoons: compared to tanks, they are more difficult to manage and require more land occupation and extensive use of workers to maintain the embankments.

The most innovative solutions: biogas conversion

A solution that is becoming increasingly popular on large farms and ranches is biogas and biomethane plants. These systems allow the collection, management and conversion of biogas from animal manure into a sustainable energy source that reduces waste and pollutants produced by intensive livestock operations.

Biogas is a gaseous mixture produced by the anaerobic digestion and decomposition of organic material, such as livestock manure and its byproducts.

In a biogas plant, wastewater from intensive livestock farms is fed into a special digester. Then, using special hoppers, biomasses such as 

• Waste from the agricultural industry
• and agricultural by-products - such as corn, wheat, sorghum and grain.

The biogas can then be refined and cleaned in biomethane plants. Biomethane (99 percent methane) has the same conditions and characteristics of use as methane: it can be stored, transported or injected into the natural gas grid or used to generate electricity in cogeneration plants.

Plants and solutions proposed by IDRO Group

The IDRO Group has acquired a great deal of experience in the design and construction of specific installations for the agricultural and livestock sectors.

In addition to the construction of tanks for the collection of livestock manure, the Group also designs and supplies solutions tailored to the needs of modern livestock farms and farms, such as deodorization plants and biogas production plants.

In fact, Idro Group designs and builds plants for the production of biogas from agricultural or livestock waste, with different capacities, from 50kW to 1000kW.

In this way, farms can valorize their waste and reduce their waste disposal costs. Idro's solutions also include desulphurization plants for upgrading to biomethane.

The Group's many years of experience in the field and its highly specialized team enable Idro to identify the optimal solution in response to the specific peculiarities of the farm. To learn more, do not hesitate to contact us.