Technology Database  Technologies of salvaging PURIFICATION OF POULTRY AND CATTLE FARM SEWAGE BY THE METHOD OF GROWING NUTRIENT YEAST
Purification
Of Poultry And Cattle Farm Sewage By The Method Of Growing Nutrient Yeast
An original installation for
purifying sewage from poultry and cattle farms by the method of growing nutrient
yeast has been developed and tested. The basic unit of the installation is a
highly efficient energy-saving fermenter of the authors' own design. New
technological know-how embodied in the installation precludes the discharge of
sewage and makes possible the production of high-quality protein.
Two types of fermenters - one
vertical, the other horizontal - have been designed, made, and tested. The
photograph shows the vertical fermenter, which can be used on small farms and
also to produce yeast in industrial units.
The proposed method of purifying
poultry and cattle farm sewage is based on the two-stage biological treatment of
the sewage. It involves the cultivation of highly productive, fast-growing
strains of yeast, which can assimilate biogenic elements (nitrogen, phosphates,
potassium, etc.) from the environment and accumulate a biomass containing up to
50% protein.
A high degree of sewage purification
is achieved:
- in ammonium nitrogen, from 500 to 5 mg/1;
- in phosphates, from 600 to 4.5 mg/1;
- in nitrites, below 0.02 mg/l;
- in nitrates, below 45 mg/1, and in
- chemical oxygen demand (COD), below 150 mg/1.
Analyses of samples taken from
different stages of the fermentation process point to low contents of nitrogen
and phosphorus in the sewage at the optimal moment of the process. The nitrogen
and phosphorus are bound organically in the yeast cells, and this enhances the
quality of the yeast, which is then used as livestock feed.
 The development and operation of
a pilot plant, in the course of which nutrient yeast was grown in the new
installation and was then used as feed for two groups of animals, demonstrated
the following.
The contents of harmful
substances in the sewage had declined to an amount making it possible to end its
discharge and recycle it.
Tests of the nutrient value of
the yeast confirmed its high effectiveness. No adverse effect of the produced
nutrient yeast on the meat, internal organs, or blood of swine that had been fed
yeast-enriched rations could be detected. Only favorable results were recorded.
The protein matter obtained from
purified sewage can be utilized as a valuable material in other industries.
The new method makes possible a
closed-circuit water supply, with the purified sewage being piped to barns where
animals are kept. There are so far no analogs of the proposed waste-free
purification technology, and none is expected to appear before the beginning of
the next century.
Source: SciTecLibrary.ru
Publishing date: October 26, 2000
To make an inquiry on the technology you are interested in
Back
| 
