Treating Industrial Discharges by Thermophilic Sulfate Reduction Process with Molasses as Electron Donor

Abstract

Thermophilic sulfate reduction process with molasses as an electron donor was investigated for the removal of zinc from rayon industry wastewater. Sulfide rich effluent from the process was used to remove zinc as zinc sulfide precipitate. The investigations with sulfate reduction process were conducted with synthetic (Stage I) as well as real wastewater from Rayon industry (Stage II) as feed. The effect of feed COD: sulfate ratio, which is the key factor for operating the sulfate reduction process, was focused on in this study. The experimental results showed that the process could achieve a high sulfate conversion rate of about 7.22 +/- 1.91 g SO4 l(-1).d(-1) at COD: sulfate ratio of 1.5:1 and 7.20 +/- 2.27 g SO4 l(-1).d(-1) at COD: sulfate ratio of 3:1 during stage I and stage II, respectively. At the end of the operation of stage II, a maximum sulfide production of 496.2 mg S l(-1) was achieved at COD: sulfate ratio of 3:1. Furthermore, sulfide rich effluent from sulfate reduction process was used for zinc sulfide precipitation. The results showed that more than 95% of zinc was removed from a high sulfate-containing wastewater.

Temporal hydrochemical and microbial variations in microcosm experiments from sites contaminated with chloromethanes under biostimulation with lactic acid

“…Part of this acetate proceeded from the lactate fermentation (31.9 % of the added lactate remained at the end of the experiment). The increase in acetate reveals that the fermentation processes supply electrons to the medium, favoring sulfate-reducing conditions (Liamleam and Annachhatre, 2007). The earlier sulfate decline in the BLA considerably improved the efficiency of CT and CF degradation ( Figure 1C) given that the competition for electrons with CT and CF was minimized (see section 4.3. in the SD).…”

Bioelectrochemical enhancement of organic matter mineralization and sulfate reduction during acidogenesis

“…Reversely, ethanol, butyrate and propionate in R1 were less than in R2. Ethanol, butyrate and propionate provided more electrons than acetate for sulfate reduction (ΔG 0' of sulfate reduction by ethanol, butyrate, propionate and acetate were –132.7, –103.8, –75.8 and –47.3 kJ mol ‐1 , respectively). Based on the VFAs content, the acidification efficiencies of the two reactors (MEC and control) were 88.2% and 60.1%, respectively (Fig.…”

Metal Removal and Recovery from Mining Wastewater and E-Waste Leachate

“…Indeed, the excess sulfide produced in the bioreactor when exposed to the air can be converted biologically or 80 chemically into sulfate or elemental sulfur via sulfide oxidation process (Lens et al, 2002;Sahinkaya et al, 2011;Zhang et al, 2008). Metal recovery can be coupled to S 0 recovery, which can be used in other industrial processes, i.e., sulfuric acid production or as an electron donor for denitrification (Dutta et al, 2008;Liamleam et al, 2007b;Wang et al, 2011).…”