Sustainable water use in the poultry industry

One clear example of this is the Mazzraty poultry processing plant in Qatar, equipped with a well thought-out water management system. The facility is designed to not waste or leave behind residual material from before, during or after processing. Mazzraty benefits from this cycle by reusing cleaned wastewater from the factory as irrigation water for the surrounding fields of land.

Poultry meat is really the protein of the future, as its CO2 emissions are naturally low. Another reason is that chicken production requires far fewer resources, such as fertilizer and land use.

Water isn’t lost

Other figures also provide evidence that poultry meat is a sustainable protein source. A study by Bill and Melinda Gates Foundation confirmed that chickens are also far more water-efficient. Using 2,000 liters of water to produce 1 kilo of chicken meat, chicken production uses a fairly modest amount of water. Just to compare, 1 kilo of chocolate needs 17,000 liters of water. However, ‘water use’ doesn’t mean that this water is ‘lost’. Recycling options are available to treat the water and make it fit for a renewed use. The poultry industry has elaborated solutions for this.

Mazzraty and Marel

The Mazzraty poultry facility is located in a desert, where nothing grows. However, it is not that far away from the Persian Gulf, so Mazzraty is able to get water from there to the plant. It is an expensive project, including a desalination process (to separate the sea salt), in which the government has heavily invested too.

Having secured the water supply in this way, the plant has plenty of water available. However, Mazzraty realizes how precious the value of water is in the desert. At the same time, the company is concerned about the impact of its activities on the environment. For this reason, a lot of attention was paid to treating the plant’s wastewater. For this, Mazzraty called in the help of Marel Water Treatment. "The main challenges our customers are facing include issues with water supply, energy use, increasing operating costs and increasing concentrations of pollutants", says Maarten ter Woerds, Business Unit Manager at Marel.

Collecting

It all starts already in the processing plant itself. The water used in the processing departments, such as defeathering, evisceration, and chilling is carefully caught in gutters and directed to the water treatment installation. Water which has been used for transport or cleaning, such as offal transport, crate washing, carcass washing, machine cleaning and room cleaning, is also collected and drained to the water treatment facilities.

Physical pretreatment

Mazzraty’s water treatment system is a fine example of how modern water treatment installations look like today. All waste water is collected in the pump pit, which is the source for Marel Water Treatment to start the BioArt water purification. First, the physical pretreatment takes place. The pumped up water passes the Static Screen, a fine screen drum sieve which collects all coarse parts larger than 1mm and discharges them. Then, in a DaFinci® Dissolved Air Flotation unit, air is injected from the bottom, so that the ‘micro bubbles’ in the polluted water pick up all fat material on their way to the surface. This pollution now floats at the surface where it will automatically be scraped off and discharged. Thus far, the process is straightforward, and already takes out half of the pollution.

Biological process

The other half, however, is more difficult to eliminate. A biological process is required to remove the dissolved pollution; bacteria need to come to help. First, the waste water enters the selector basin. In this basin, the best working floc forming type is stimulated to outgrow the other type (filamentous bacteria, which would cause a lot of foam and don’t settle well).

After this, the water flows to the next basin. In this very large basin with surface aeration, the BioArt principle separates sludge from clean water.

Aeration

During production time of the processing plant, the aeration basin continues to collect waste water until production stops. The aerator in the middle of the basin is a floating device, which can go up and down with the water level; the water level rises during factory production and lowers during the purification process. The aerator adds oxygen to the water to stimulate the sewage-digesting bacteria. The waste in the factory water is exactly the right nutrition for these ‘good’ bacteria to do their job well. The biological process will start to decompose the pollution and convert it to biological sludge and purified water. Once digested, the sludge accumulates on the bottom of the basin and the purified water is drained from the top, transported to the clean water basin.

The remaining sludge on the bottom can be thickened and dewatered to make it more compact. After this, Mazzraty can dispose of it.  

This separation process takes a couple of hours and then the basin is ready to collect the waste water of the next shift, the next day, making it a discontinuous process.

Irrigation

In the direct surroundings of the poultry processing plant, four large green circles in the middle of the yellow sand plain catch the eye. This is irrigated land, made fertile with the help of Mazzraty’s used water. Besides usage for truck washing, the purified water is excellently fit for irrigation of the otherwise dry land. Mazzraty manages to drive four center pivot systems with this recycled water to irrigate four quarter sections (each 800x800m, 125 acres). Mazzraty grows mainly grass, which they can use in their feed mills.

By reducing CO2 emission, reusing waste water, irrigating and producing chicken feed, Mazzraty demonstrates one of the most sustainable ways of working in the poultry industry.

Water treatment