Performance and biomass kinetics of activated sludge system treating dairy wastewater

Abstract

The performance and bio‐kinetic coefficients of the activated sludge process (ASP) treating synthesised dairy wastewater were evaluated in a lab‐scale setup. The step‐loading experiment showed that the chemical oxygen demand (COD) removal efficiency, in general, increased with increasing influent wastewater COD concentration from 180 to 1200 mg/L (correlation coefficient was 0.80). The COD removal efficiency ranged from almost 80–88.4% depending on the COD concentration of the influent wastewater. Also, it could be stated that the ASP was probably underfed with organics at COD concentrations <725 mg/L. Monod, Moser, Contois and Chen & Hashimoto substrate utilisation models, relating the growth of micro‐organisms to substrate utilisation, were employed to describe the bio‐kinetics of the ASP at an organic loading rate of 1200 mg/L. Amongst them, the Contois and Monod models predicted the bio‐kinetic reactions of the ASP very well with coefficient of determination (R2) values of 0.95 and 0.93, respectively. The estimated bio‐kinetic coefficients of the Contois model (on COD basis) were as follows: half‐velocity constant (0.20 mg/L), maximum substrate utilisation rate (3.13 per day), biomass yield coefficient (0.68), endogenous decay coefficient (0.07 per day) and maximum specific growth rate (2.13 per day).

The effects of salinity on nitrification using halophilic nitrifiers in a Sequencing Batch Reactor treating hypersaline wastewater

“…These results indicated that higher salinity selection pressure stimulated the growth of halophilic nitrifier with low K s and μ max . K s is an important biological factor and determines the relative affinity of a microorganism towards its substrate 20 . The selected nitrifiers, with low K s when salinity was high, indicated strong affinity for the ammonium.…”

Variability of dairy wastewater characteristics in Piatnica – one of the largest and most advanced milk processing plants in Poland

“…Q5 = COD/Ptot (5) 3 Results Table 4 summarizes the characteristics of dairy wastewater from the milk processing plant in Piatnica in 2016 and 2017. The factor affecting the efficiency of pollutant removal from wastewater is their composition.…”

“…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 [1][2][3][4][5][6][7][8][9][10][11][12][13]. Dairy wastewater is normally treated by physical, biological and chemical processes and the various possibilities are presented in fig.…”

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].…”