The present work is a laboratory-scale study of perchlorate (ClO4-) degradation using Proteus sp. LMNCRE in a batch reactor. The average hourly value of perchlorate degradation rate in this system was 1.95 mg/L at optimum pH 7.5 and 0.25% NaCl salinity. The microbial growth and degradation kinetics have been studied to a variety of ClO4- levels (0 to 100 mg/L) under anoxic conditions. The biomass optical-density value of strain gradually increased from 0-0.37 during the operating period of 30h. The perchlorate level in which the bacterium could withstand for effective removal was found to be 75 ± 2.0 mg/L with zero order reaction coefficient (k) of 2.08 mg/L/h. The observed anoxic degradation rate of strain was 87.0 ± 0.6 % within 12 h of incubation period at 25 mg/L of initial perchlorate level. From the experimental findings, the uptake of perchlorate by the bacterium is suggested to obey a zero-order substrate-utilising kinetic model, allowed the growth rates constants to be determined. © Copyright 2016 Inderscience Enterprises Ltd.

Muruganandam L

Department of Chemical Engineering

School of Chemical Engineering

Vellore Campus

Anoop Raj J.R

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

Microbial growth and degradation kinetics of perchlorate by Proteus sp. LMNCRE in a batch reactor system

International Journal of Environment and Sustainable Development

The present work is a laboratory-scale study of perchlorate degradation using Proteobacterium ARJR SMBS in a stirred tank bioreactor (STBR). Anaerobically grown cultures of ARJR SMBS exposed to a variety of levels within the range 30 to 150 mg L-1 under anoxic conditions have been studied. The chloride released was measured and the average value found to be 43.55 mg L-1. The average daily value of perchlorate degradation rate in this system was 17.24 mg L-1 at optimum pH 7.5 and 0.25% NaCl salinity. The mixed liquor suspension solids of the system gradually increased from 0.025-0.156 g L-1 during the operating period of 55 days. Mass balance indicated that the chloride produced was 0.45 mole per mole of perchlorate. The salinity of the system varied from 2.50-18.46 g L-1, dependent primarily upon the inlet perchlorate concentration. The degradation mechanism, which obeyed a first-order substrate-utilizing kinetic model, allowed the growth rates and the half-saturation constants to be determined. The maximum observed anoxic growth rates (0.83-1.2 h-1) for ARJR SMBS in a synthetic effluent (SE) were considerably higher than in real effluent (RE) (0.45-0.59 h-1). The biomass yield of ARJR SMBS in STBR was higher in SE (1±0.4 mg L -1) than in RE (1±0.1 mg L -1). From the experimental findings, the uptake of perchlorate by the bacterium is suggested to be a non-interfacially-based mechanism. Under steady state operating condition the performance of the reactor was comparatively lower for RE than for SE but still offers significant control over the degradation of perchlorate under full-scale conditions. © 2013 Taylor and Francis Group, LLC.

Environmental Technology

Biodegradation of perchlorate from real and synthetic effluent byProteobacteriumARJR SMBS in a stirred tank bioreactor system

Metal oxide nanoparticles (NPs) are known to possess strong antimicrobial properties. Aluminum oxide NPs have wide-range applications in industrial as well as personal care products. In the absence of prior reports on the antimicrobial properties of alumina NPs for a wide concentration range, the principal objective of the present work was to study the growth-inhibitory effect of alumina NPs over a wide concentration range (10-1000 μg/mL) on an environmentally relevant gram-negative model microorganism, Escherichia coli. The mean diameter of the NPs was determined to be 179 nm in aqueous dispersion used for this study, and surface area was determined to be 21.23 m2/g. The concentration of 1000 μg/mL was found to be moderately inhibitory for bacteria. Almost negligible dependence of growth rate on the concentration of the NPs was observed. The extracellular protein content was found to be slightly lower in case of cells interacting with 1000 μg/mL alumina than the uninteracted control cells. Fourier transform-infrared studies established differences in structure between interacted and uninteracted cells. Alumina NPs showed a mild growth-inhibitory effect, only at very high concentrations, which might be due to surface charge interactions between the particles and cells. Free-radical scavenging properties of the particles might have prevented cell wall disruption and drastic antimicrobial action. This laboratory-scale study suggests that alumina NPs may only exhibit mild toxicity toward microorganisms in the environment. From the Clinical Editor: Metal oxide NPs, inluding aluminum oxide NPs, are known to possess strong antimicrobial properties. The study demonstrated a mild to moderate growth-inhibitory effect of alumina NPs over a wide concentration range (10-1000 μg/mL) on Escherichia coli. Almost negligible dependence on the concentration was observed. © 2009 Elsevier Inc. All rights reserved.

Nanomedicine: Nanotechnology, Biology and Medicine

Antimicrobial sensitivity of Escherichia coli to alumina nanoparticles

Environmental Science & Technology

Perinatal Exposure to Perchlorate, Thiocyanate, and Nitrate in New Jersey Mothers and Newborns

Separation and Purification Technology

Treatment of perchlorate in drinking water: A critical review

Bergey’s Manual® of Systematic Bacteriology

Bacteria that Respire Oxyanions of Chlorine

Journal	International Journal of Environment and Sustainable Development
Publisher	Inderscience Publishers
ISSN	1474-6778
Open Access	No