Removal of residual organic pollutants from pulp paper industry wastewater using bacterial strains Acinetobacter baumannii (OK582199) PC4 and Bacillus cereus (OK582201) PC10 via biostimulation and bioaugmentation process

Abstract

This study examines how native bacteria, combined with two specific aerobic strains (Acinetobacter baumannii PC4 and Bacillus cereus PC10), contribute to the detoxification of pulp and paper industrial wastewater (PPIW) through biostimulation and bioaugmentation processes. The growth of two native bacteria were stimulated in pulp paper industry wastewater by the addition of carbon (1% glucose) and nitrogen (0.5% peptone w/v). After the growth of these native bacteria in biostimulation process showed significant reduction in various physico-chemical parameters i.e. lignin (53%), color (46%), COD (76%), and BOD (86%). Similarly, reductions in various heavy metals were also observed, such as Fe (73%), Zn (36%), Cr (41%), Cu (22%), and Ni (65%). The growing native bacterial co-culture were identified as Enterobacter cloacae strain PC7 (OQ672613) and Bacillus sp. strain PCB (OK614116). However, the addition of Acinetobacter baumannii (OK582199) PC4 and Bacillus cereus (OK582201) PC10 enhanced the reduction of various physico-chemical parameters in range of 10–––28%. Consequently, the UV–Vis absorption peak showed reduction due to the decolorization of wastewater and degradation of various pollutants. Moreover, GC–MS analysis indicated that most of the compounds detected in the control were diminished after bacterial treatment. However, compounds such as Pentadecane, 2-Methyl, Silane (dodecylosy) trimethyl, Octadecanoic acid, trimethylsilyl ester, and Docasane were noted as recalcitrant. Additionally, new metabolic products such as 1-ethyl-5,6-dimethoxy-2,3-dihydroindole, Trimethylsily ether of glycerol, and 1-(Trimethylsilylmethyl1) dimethylsilyloxy tetradecane were detected. Due to degradation of various pollutants toxicity reductions were found up to 76% during a comparative evaluation between control and bacterial treated wastewater using the Phaseolus mungo L. seed germination test. Hence, it was concluded that the biostimulation and bioaugmentation process would be an effective technique for degrading residual organic pollutants from pulp and paper industrial wastewater (PPIW) for safe disposal.