Salicylic-Acid-Mediated Enhanced Biological Treatment of Wastewater

Abstract

Activated sludge represents a microbial community which is responsible for reduction in pollution load from wastewaters and whose performance depends upon the composition and the expression of degradative capacity. In the present study, the role of salicylic acid (SA) has been evaluated for acclimatization of activated sludge collected from a combined effluent treatment plant followed by analysis of the physiological performance and microbial community of the sludge. The biodegradative capacity of the acclimatized activated sludge was further evaluated for improvement in efficiency of chemical oxygen demand (COD) removal from wastewater samples collected from industries manufacturing bulk drugs and dyes and dye intermediates (wastewater 1) and from dye industry (wastewater 2). An increase in COD removal efficiency from 50% to 58% and from 78% to 82% was observed for wastewater 1 and wastewater 2, respectively. Microbial community analysis data showed selective enrichment and change in composition due to acclimatization by SA, with 50% of the clones showing sequence homology to unidentified and uncultured bacteria. This was demonstrated by analysis of partial 16S rDNA sequence data generated from dominating clones representing the metagenome which also showed the appearance of a unique population of clones after acclimatization, which was distinct from those obtained before acclimatization and clustered away from the dominating population.

Detection of Ammonia-Oxidizing Archaea in Fish Processing Effluent Treatment Plants

“…The increasing number of publications in the field of wastewater engineering in recent years clearly indicates the widespread interest in ammonia oxidizing microbes [9,23]. The use of salicylic acid to enhance the bioremediating potential of microbes and a consequent reduction of BOD and COD has been studied [24]. Though the potential role of AOA in waste water treatment is discussed, the role of heterotrophic bacteria also seems imminent as seen from the simultaneous nitrification and denitrification performing bacterium Diaphorobacter sp.…”

Integrated Perspective for Effective Bioremediation

“…The examples which are extensively reported are catechol or salicylate as intermediates of hydrocarbon metabolisms. The introduction of these kinds of intermediates at low levels can turn on the genes of native population in natural attenuation process and also could be exploited with bioaugmentation protocols [53]. Apart from the main component to be biodegraded, the intermediates, if toxic, also need to be taken care of.…”

“…An added advantage of this process is that it saves time as the biomass is already in an active state [110]. Similar acclimatization process was also applied on activated sludge from combined effluent treatment plant by salicylic acid [53].…”

Biofilm coupled with UV irradiation for phenol degradation and change of its community structure

“…In addition, Thauera sp. strain MZ1T was a floc-forming bacterium isolated from the wastewater treatment plant and played a role on degrading organic pollutions in industries manufacturing drugs and dyes [34,35]. However, the capacity of Thauera to degrade phenol has not been reported yet.…”