Integrated anaerobic treatment of dairy industrial wastewater and sludge

Abstract

Performance parameters were studied in an alternative full-scale dairy effluent treatment system comprising two anaerobic sludge-blanket reactors in parallel arrangement with upward flow, internal fat-separation by flotation, external lamella settler and floated material digester. Reactors were initially inoculated with flocculent sludge and granulated in a high-load stage. Using loading rates up to a maximum 5.5 kg COD/m(3) x d-hydraulic residence time of 17 hours- reactor efficiency was found to remain stable around 90% of COD. Average sludge digester efficiency using a loading rate of 3.5 kgVS/m(3) x d with a lipid content of 47% of COD amounted to 78% of VS (87% of lipid removal). LCFA inhibition as assayed using palmitate was found to depend not only on the palmitate concentration but also on the palmitate-to-biomass concentration ratio.

Use of Bacteria and Yeast Strains for Dairy Wastewater Treatment

“…Significant variations in COD (80-95000 mg/l) and BOD (40-48000 mg/l) have been reported by various investigators of dairy wastewater [10]. The pH varies in the range of 4.7-11 whereas the concentration of suspended solids (SS) varies in the range of 0.024-4.5 g/l [11]. …”

Rate of change in concentration of organic compounds and nutrients in municipal and dairy wastewater treated in full technical SBR scale

“…Data on qualitative and quantitative characteristics of raw dairy sewage are relatively well-documented [4][5][6][7][8][9][10][11][12][13][14][15][16], but at the same time there are serious gaps in relation to the municipal sewage with a specific share of industrial (dairy) wastewater. For this reason, it is impossible to compare the results with literature data.…”

“…Quantity of dairy sewage is characterized by high seasonal variations (20% increase in spring and summer). Additional oscillations relate to the daily and hourly shift work dependent on the size, production profile, and shifts at milk processing plant [4][5][6][7][8][9][10][11][12]. Biological treatment of dairy wastewater is high-efficient due to the significant share of easily biodegradable substances [13][14][15][16].…”

Anaerobic degradation of dairy wastewater in intermittent UASB reactors: influence of effluent recirculation

“…and HRT of 24 h. Performance parameters were studied [19] in an alternative full-scale dairy effluent treatment system comprising two anaerobic sludge blanket reactors in parallel arrangement with upward flow, internal fat-separation by flotation, external lamella settler and floated material digester. Reactors were initially inoculated with flocculent sludge and granulated in a high-load stage.…”

“…Improvements in UASB reactors allow the degradation of dairy wastewater without previous fat removal [19,21] with important reduction in installation and operation costs [13,19] and lower environmental impacts. [19] The performance of anaerobic reactors is generally assessed in terms of COD removal efficiency which for dairy wastewaters may attain values as high as 98%.…”