Use

Primary treatment of residential grey waters.

The sand/grease trap is installed near the kitchen drains, laundry

and bathroom to separate grease, foam, vegetable and animal

fats and other solid particles in the wastewater.

Operation

The system uses gravity to eliminate all the solid particles

heavier than water and deposits them on the bottom of the tank.

Furthermore, oils, fats and substances lighter than water are

separated by flotation; this phenomenon reduces the presence

of oily substances, which tend to coat biological materials thus

preventing oxidation.

Maintenance

For the correct management of DG/DG-PRO and to achieve the

required purification results, please follow these guidelines:

•

Regularly inspect (every 2 months) the DG/DG-PRO to verify

that no coarse materials have accidentally blocked the pipes;

•

Once a year (or more frequently if necessary) carry out the

removal of sludge and separated oils and greases. Such

removal must be carried out by a specialized company.

•

As provided for by the Consolidated Act on Water (Legislative

Decree 152/06 as amended), and suggested by the

normal hygiene practice, periodically inspect and wash the

inspection well.

Specification Item

RESIDENTIAL WASTEWATER

PRIMARY TREATMENT

Sand/grease trap manufactured in rotational polyethylene, in a

single structure, free of joints and equipped with inlet and outlet

holes, and inspection and sampling lids. Suitable for underground

installation.

The Sand/Grease trap is sized according to the UNI EN 1825-2:

2003

For the calculation of the place settings, the discharge coming

from the kitchens was considered (density factor fd=1), the

wastewater temperature below 60°C (temperature factor ft=1),

the use of detergents or rinsing substances (detergents and rinse

substances factor fr=1.3), the volume of water used per meal of

50 litres (restaurant), as peak flow factor 8.5 (restaurant) and as

average daily duration of 4 hours operation for “minimum place

settings” and 6 hours for “maximum place settings”.

PROJECT PARAMETERS

NS = corresponds to the nominal size of the grease trap given by the flow

rate expressed as l/s multiplied by coefficients related to the temperature,

the density of the grease/oil and the influence of detergents, as indicated

in UNI EN 1825

Degreaser minimum volume

l/NS

240

Concentration of animal and vegetable

oils and fats

mg/l

200

21

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