engleski

UV-VIS Spectophotometric determination of Cu, Fe, Ni and Zn during wastewater treatment in HRTB

Several regulations were adopted for industrial wastewater discharges. Thus wastewater treatment prior to discharge to a water body (stream, river, bay, etc.) is necessary to meet the conditions given in the respective regulations. Different bioreactor types with microbial biofilm are the most promising systems for the treatment of metal contaminated waters. A horizontal rotating tubular bioreactor (HRTB) is designed as a combination of a thin layer and a biodisc reactor and its use for heavy metals removal from wastewater was investigated. Heavy metals removal process in HRTB was studied in continuos mode and wastewater samples were drawn along the bioreactor length. In order to make decisions for the further optimization steps a fast and simple as well as on-site applicable method for the determination of the given metals was needed. The UV-VIS spectrophotometric determination of Cu, Fe, Ni and Zn using sodium diethyldithiocarbamate, 1, 10-phenathroline, dimethylglyoxime, and 2-{;[alpha-(2-Hydroxy-5-sulfophenylazo)-benzylidene]-hydrazino};-benzoic acid monosodium salt (=zincon monosodium salt) as reagents respectively, was optimized and validated. To avoid inferences by the yellowish hue of the samples there were diluted 1:20 with distilled water prior to complexation. The limits of detection are 0.045, 0.04, 0.04, and 0.01 mg/L for Cu, Fe, Ni and Zn, respectively. The recovery for all elements is in range from 98 % up to 104 %. The uncertainty of measurement for all metals under study was approx. 5 %. The same samples were then analyzed by inductively coupled plasma optical emission spectrometry. The results obtained by both methods were compared using a paired t-test. No statistically significant differences were found.

UV-VIS determination; heavy metals (Cu; Fe; Ni; Zn); horizontal rotating tubular bioreactor; wastewater treatment

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