The Behavior of Ni(II), Cr(III), and Zn(II) in Biological Wastewater Treatment Process

Abstract

aThe purpose of this research was to investigate the effects of Ni(II), Cr(III), and Zn(II) on a Department of Applied the treatment performance of sequencing batch reactor (SBR) system. The kinetics of Chemistry, Oita University, adsorption study showed that the pseudo second-order reaction model provided the best Oita 870-1192, Japan description of the data obtained. From the Langmuir isotherm, the maximum adsorption capacities of Ni(II), Cr(III), and Zn(II) were 30 mg/g, 23 mg/g, and 18 mg/g, respectively. Cr(III) and Ni(II) were found to exert a more pronounced inhibitory effect on the bioactivity of the microorganisms compare to Zn(II). The increase of Cr(III) and Ni(II) concentration from 5 to 10 mg/L caused significant effect on the suspended solids (SS) and total organic carbon (TOC) removal efficiency in SBR system but vice versa in the case of Zn(II). The addition of powdered activated carbon (PAC) and termination of metal ions addition into SBR systems were carried out to investigate the capability of system recovery from the toxic effects of metal. Das Verhalten von Ni(II), Cr(III) und Zn(II) bei der biologischen Abwasserbehandlung

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“…These results agree with Ref. 20 where the effects of Cr, Cu and Zn on the performance of sequencing batch reactor systems such as TOC, SS, and MLSS were examined. From the data, Cd is less adsorbed but more toxic than Ni.…”

“…The adsorption profile of Cu, Cd, Zn, Ni, and Cr by activated sludge indicates that adsorption occurs in two stages: a rapid surface binding followed by a slow intracellular diffusion [19][20][21] . Dried sludge, which is non-living biomass, is generally used for adsorption studies because it eliminates the problem of heavy metal toxicity.…”

“…As with the adsorption profile of metals by activated sludge, the adsorption efficiency of metals by dried sludge was rapid in the first phase and was followed by a slow phase. The determination of contact time as well as adsorption efficiency is important in selecting a retention time period suitable to achieve optimum operation in a biological reactor 20 . Generally, the results obtained show that the activated sludge and dried sludge could be used as bio-adsorbants in removing heavy metals from wastewater.…”

Influence of the activated sludge system configuration on heavy metal toxicity reduction

“…Stasinakis et al (2002) evaluated the effect of Cr(VI) by determining the maximum specific growth rate (l m ) and yield coefficient (Y H ) values by oxygen uptake rate (OUR) and volatile suspended solids (VSS) measurement methods and their results revealed that the presence of Cr(VI) concentrations equal or greater than 10 mg l -1 in unacclimatized biomass caused an inhibitory effect mostly on substrate oxidation, while in acclimatized biomass, anabolic pathways were inhibited more. Ong et al (2005) investigated the effects of metal containing wastewater on activated sludge process and capability of system recovery from the toxic effects of metal ions. Cr(III) and Ni(II) were found to exert a more pronounced inhibitory effect on bioactivity of the microorganisms in comparison to Zn(II).…”

Acute and Chronic Toxicity of Acid Mine Drainage to the Activated Sludge Process

“…Those researchers suggested that bridge binding between negatively charged polymeric groups and cations and/or surface charge reduction as cations bind to negatively charged sites on the floc surface bring flocs closer together and aid settling. Alternatively, Ong et al (2005) suggested that the likely cause for observed improvement in settleability after adding metal solutions to activated sludge reactors was a decrease in filamentous bacteria. In the present study, consistent filament abundance values do not indicate loss of filamentous bacteria; settleability most likely remained good because of cations in the AMD aiding coagulation (Jin et al 2003;Rao et al 1992) and the flocculation of Fe oxyhydroxide precipitates onto suspended solids (Johnson and Younger 2006).…”