Industrial and household fatty waste can be divided into two categories – "yellow" and "brown" fat. The first category fatty waste can be used for the secondary processing of animal feed additives, production of soaps, oils, cosmetics and skin care products. This type of waste can be composted either. The second type of fat is collected in fat catchers or generated as waste in other industrial processes, collected from pipes by mechanical. This fat is not recycled and must be handled according to the existing waste management requirements. Biodegradable organic waste of this origin can be incinerated, decayed or composted [8].
Thus biological treatment processes are commonly used to remove emulsified lipids from waste water and drain pipes. All biological methods could be grouped in two major classes: aerobic and anaerobic processes. During anaerobic treatment, fats are hydrolyzed to glycerol and long-chain fatty acids (LCFA) followed by subsequent β-oxidation [9; 10; 11]. Fat hydrolysis is not the rate- limiting step of treatment; however, millimolar concentrations of long-chain fatty acids are capable of inhibiting the growth of numerous microorganisms. Consequently, the occurrence of LCFA presents a serious problem for anaerobic cleanup systems [10; 12]. During aerobic treatment grease are converting into harmless solids, CO2 and H2O. Moreover, LCFA are degraded by sequential removal of two-carbon atoms via the β-oxidation pathway, resulting in release of a fatty acid shorter by two carbons and acetyl-CoA, which is then subsequently oxidized to carbon dioxide by the tricarboxylic acid cycle [13].
JSC “Biocentras” suggest a very effective and innovative lipid-rich wastewater and pipelines clogged by lipids cleaning and composting of wastes rich in grease complex technology. Firstly, lipids from wastewater and from drain pipes surfaces are removing mechanically, and remaining lipids are treated with a culture of active microorganisms Enterobacter aerogenes E13 (a stem degrading lipids), Arthrobacter sp. N3 (the stem degrading aliphatic compounds) and Bacillus coagulans Š1 (the stem degrading complex peptide linkage). Item, this mixture of microorganisms could be using in grease traps and septic tanks, so it’s able to avoid repeated cleaning of theirs. Air pollution by compounds, emitting unpleasant odors is reduced by using microorganisms. Furthermore, microorganisms compose a lively biofilm and protect the clogging of drainpipe. Concentrated fatty waste obtained by mechanical removal, are composted in specially equipped places. These wastes are neutralized using active cultures of these microorganisms. Previous research has shown that this bacterial compositions created by JSC “Biocentras" breakdown effectively the fat in the water and soil and can therefore be applied to speed up composting. Developed technology is attractive for cleaner production/pollution prevention approach, as well as meets strict environmental and hygiene requirements.
The aim of experiments was to optimize complex grease wastes utilization complex technology, i.e. to set main optimal technological parameters of lipid-rich wastewater, drainpipes, contaminated by grease, cleaning and composting process.