Cultivation of granular sludge with hypersaline oily wastewater

Abstract

a b s t r a c tThe time required to stabilise mature aerobic granules is rather variable. In addition, cultivation time and the structural characteristics of granules seem to be related to the nature of wastewater influent. Granular sludge has been used for the treatment of several industrial wastewaters, but nothing has been reported about wastewater characterized by the simultaneous presence of hydrocarbons and high chloride concentration. In this work, the authors analysed the granulation process and performance as well as the physical characteristics of aerobic granules in two Granular Sequencing Batch Airlift Reactors (GSBARs), fed with acetate-based synthetic wastewater in reactor 1 (R1) and with a mixture of real and simulated slop (R2). The results obtained in 100 days show that full granulation was achieved in both reactors. The granules in R2 developed more quickly, but they appeared slightly unstable and more susceptible to breaking. Despite high salt concentration, the efficiency of phosphorous and carbon removal was satisfactory. Low nitrification activity was observed in R1, confirming that a longer time is necessary to obtain the acclimation of autotrophic biomass in aerobic granules. In R2 the combined effect of salinity and hydrocarbons caused the inhibition of the autotrophic biomass, with the consequence that nitrification was absent. Hydrocarbons were initially removed by adsorption afterwards by biological degradation with a removal efficiency of over 90%.

Treatment of high strength industrial wastewater with membrane bioreactors for water reuse: Effect of pre-treatment with aerobic granular sludge on system performance and fouling tendency

“…AGS have been successfully implemented for the treatment of both municipal and industrial wastewater. The literature studies demonstrated that aerobic granules feature a compact and thick structure, thus ensuring a great ability to withstand adverse environmental conditions, such as loading variation, obtaining very high effluent quality at the same time [17][18][19][20]. Indeed, the granular sludge features very high settling ability and allows to maintain higher biomass concentrations, thus reducing the plant footprint [21].…”

Effect of extended famine conditions on aerobic granular sludge stability in the treatment of brewery wastewater

“…A significant consumption, however, was observed during the famine phase in which substrate is present in limiting concentrations and bacteria utilize EPS as carbon and energy source for endogenous respiration (Zhu et al, 2012a;Corsino et al, 2015). However, no information was available on how the EPS characterization under different lengths of the famine phase affects granular stability in treating actual high-strength wastewaters.…”

Characteristics of Nitrogen Removal and Extracellular Polymeric Substances of a Novel Salt-Tolerant Denitrifying Bacterium, Pseudomonas sp. DN-23

“…In addition, it has been reported that EPS contributes to the adsorption and adhesion of metal ions and organic pollutants because of the hydrophobic and hydrophilic regions in their structures (Jia et al, 2016). Microorganisms growing in unfavorable conditions produce additional EPS to protect themselves by balancing osmotic pressure (Tourney et al, 2009;Corsino et al, 2015). Nowadays, many researchers have reported the importance of EPS in forming granules and biofilms.…”