ABSTRACT
Anionic surfactants like sodium dodecyl sulphate (SDS), due to its extensive disposal to water bodies cause detrimental effects to the ecosystem. Among the various attempts to reduce the after effects of these toxicants, microbial induced bioremediation serves as a promising strategy. The current study aimed to develop a three stage bioreactor to remediate anionic surfactants in wastewater using effective bacterial isolates. Screening of effective SDS biodegraders led to isolation of Pseudomonas aeruginosa (MTCC 10311). Treatment of synthetic effluent with an immobilized packed bed reactor at a flow rate of 5 mL h-1 resulted in 81 ± 2% SDS eliminations and 70 ± 1% reduction in chemical oxygen demand (COD) in five cycles (6 h per cycle). The hydraulic retention time of the reactor was found to be 6 h. Combinatorial usage of a three stage bioreactor, involving aeration, adsorption with low cost scrap rubber granules and treatment with immobilized Pseudomonas aeruginosa, successfully reduced SDS concentrations and COD of wastewater to 99.8 ± 0.1% and 99 ± 1%, respectively, in 18 h by continuous treatment. Half-life of the three stage bioreactor was 72 h. In addition to reducing the surfactant concentrations, this novel bioreactor could resolve the surfactant associated foaming problems in treatment plants, which make it more unique.
Subject(s)
Bioreactors , Sodium Dodecyl Sulfate/chemistry , Wastewater/chemistry , Water Pollutants, Chemical/chemistry , Biodegradation, Environmental , Pseudomonas aeruginosa/isolation & purification , Surface-Active Agents , Waste Disposal, Fluid/methods , Water MicrobiologyABSTRACT
Sodium dodecyl sulfate (SDS) is one of the main components in the detergent and cosmetic industries. Its bioremediation by suitable microorganism has received greater attention. Pseudomonas aeruginosa MTCC 10311 was isolated from detergent contaminated soil which had degraded 96% of SDS in 48 hrs. Attempts were made to study the metabolic byproducts of SDS degradation using GC-MS analysis. Analysis of ether extracts of surfactant established the sequential production of Dodecanol, Dodecanal and Decanoic acid. At this point, the pathway diverged into the formation of acid residues through beta oxidation. This SDS degrading isolate, Pseudomonas aeruginosa can be exploited for decontamination of detergent contaminated waste water.
Subject(s)
Environmental Pollutants/metabolism , Pseudomonas aeruginosa/metabolism , Sodium Dodecyl Sulfate/metabolism , Biodegradation, EnvironmentalABSTRACT
The anionic surfactant sodium dodecyl sulphate (SDS), the core components of detergent and cosmetic product formulations, contributes significantly to the pollution profile of sewage and wastewater of all kinds. In this study, 44 SDS degrading strains were isolated by soil enrichment methods and the utilization efficiency was assessed by methylene blue active substances (MBAS) assay and High performance liquid chromatography (HPLC) method. Isolate S2 which showed maximum degradation was identified as Pseudomonas aeruginosa MTCC 10311 based on phenotypic features and 16 S rDNA typing. The isolate was found to harbor plasmid within the size range of 9-10 kb. The cured derivative of SDS degrading Pseudomonas aeruginosa was obtained at a frequency of 10.7% by incubation with ethidium bromide (500 mg ml(-1) at 40 degrees C. 96% of SDS degradation occurred at 1500 ppm level within 48 hr of incubation, whereas higher concentration of SDS (10000 ppm) showed only 20% degradation. The optimum temperature and pH was 30 degrees C and 7.5, respectively. The additional supplementation of carbon and nitrogen source increased the degradation capacity from 93 to 95% and 90 to 96% respectively within 36 hrs of incubation.
Subject(s)
Pseudomonas aeruginosa/metabolism , Sodium Dodecyl Sulfate/metabolism , Surface-Active Agents/metabolism , Biodegradation, Environmental , Hydrogen-Ion Concentration , Phylogeny , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/genetics , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Sodium Dodecyl Sulfate/chemistry , Surface-Active Agents/chemistry , TemperatureABSTRACT
Reffing of coconut husk, the majorprocess in quality coir fibre extraction, causes serious pollution with brackish water lagoons of Kerala. An attempt is made to treat the coconut husk leachate by using a laboratory scale UASB-reactor The experiment was conducted with loading of leachate from 1 kg of fresh coconut husk. The anaerobic treatment was done continuously The parameters like VFA, pH, COD and polyphenols were analysed regularly during the evaluation of the reactor performance. The polyphenol, VFA and COD were diminished gradually with time. The pH of the reactor during the study was found to be in the range of 6-8. The biogas production was increased with loading and about 82% of the total COD/kg husk could be converted to biogas. The maximum polyphenol loading in the reactor was reached to about 298.51 mg/l of husk.
