Assessment of combined toxicity of heavy metals from industrial wastewaters on Photobacterium phosphoreum T3S

Abstract

This research work is focusing on the toxicities of heavy metals of industrial origin to anaerobic digestion of the industrial wastewater. Photobacterium phosphoreum T3S was used as an indicator organism. The acute toxicities of heavy metals on P. phosphoreum T3S were assessed during 15-min half inhibitory concentration (IC50) as indicator at pH 5.5-6. Toxicity assays involved the assessment of multicomponent mixtures using TU and MTI approaches. The results of individual toxicity indicated that the toxicity of Cd, Cu and Pb on P. phosphoreum increased with increasing concentrations and there was a linear correlation. The 15-min IC 50 values of Cd, Cu and Pb were 0.537, 1.905 and 1.231 mg/L, respectively, and their toxic order was Cd [ Pb [ Cu. The combined effects of Cd, Cu and Pb were assayed by equivalent concentration mixing method. The results showed that the combined effects of Cd ? Cu, Cd ? Pb, Cu ? Pb, Cd ? Cu ? Pb were antagonistic, antagonistic and partly additive. The combined effect of three heavy metals was partly additive.

Implications of co-contamination with aged heavy metals and total petroleum hydrocarbons on natural attenuation and ecotoxicity in Australian soils

“…One possible explanation is that these metals concentrations are less than their EC50 (Zeb et al 2016); in addition, the combined TPH concentration in these soil samples was very low (25 mg kg -1 ). number of copies of the alkB gene, the gene of interest in this study, in comparison to soil samples with lower TPH concentration (Table 3).…”

“…The most dominant factor regarding the toxicity was the presence of Pb; elevated toxicity was observed in samples with a relatively high concentration of Pb. A previous study (Zeb et al 2016) showed that the toxicity of Pb, as a single contaminant, was 0.046 TU for V. fischeri. However, in this study Pb showed a much higher level of toxicity as it is combined with other contaminants.…”

Comparison of Joint Effect of Acute and Chronic Toxicity for Combined Assessment of Heavy Metals on Photobacterium sp.NAA-MIE

“…Standard procedure was adopted to prepare metal stock solutions ranging over (0.5, 1, 10, 100 and 1000 ppm or mg/L) by dissolving the AAS grade metal in deionized water. The solutions were freshly prepared [ 13 ]. Ten concentrations of the tested metals were prepared from stock solutions to carry out a preliminary experiment in triplicate to determine the suitable metal concentration array for determining the half maximal inhibitory concentration IC 50 of each tested metal.…”

“…Unfortunately, the analysis of the total amount of heavy metals is unable to represent the full environmental behaviors and ecological effects of heavy metals [ 11 ]. Numerous studies deal with risk effects of single metal types, while in reality the aquatic organisms are often exposed to mixtures of metals [ 12 , 13 ]. Thus, the effects of co-existing multiple chemicals cannot be ignored and interactions of components in a mixture might cause significant changes in the properties of its constituents [ 14 ].…”

Rapid detection and toxicity assessment of ochratoxin A by Photobacterium leiognathi in drinking water

“…Relative luminescence unit (RLU) was obtained by expression (1), which was developed by mean luminosity unit of test samples (LU) and blank controls (LU 0 ) (Zeb et al, 2017). The luminescence inhibition ratio (I%) was calculated by expression (2) to evaluate the effect of different concentrations of OTA on P. leiognathi at each time point (Bosch-Orea et al, 2017).…”