Trichloroethylene removal from water by ferrate treatment

Abstract

In this study trichloroethylene (TCE) removal from model solutions and groundwater by ferrate treatment was investigated applying different initial TCE concentrations, ferrate dosages and pH values. TCE concentrations were measured both in the vapor and liquid phases of water samples with head space gas chromatograph mass spectrometer (HS/GC-MS) and solid phase micro-extraction gas chromatograph mass spectrometer (SPME/GC-MS) systems, respectively. Analytical data obtained by these methods were in good agreement and the deviations changed in the range of 1 and 7%. The optimum pH value for the ferrate treatment was pH=7. Applying ferrate in concentration of 50 mg/L for treatment of model solutions with TCE concentration of 0.1 and 1.0 mg/L (FeO 4 2-/TCE molar ratios 500 and 50), the removal efficiency values were 97 and 74%, respectively. However, in case of groundwater having the same TCE concentrations but additionally 28 mg/L organic carbon content, the removal efficiency decreased to 42 and 36%. It means the necessary ferrate dosage considerable depends on the chemical composition of contaminated groundwater to be treated.

Novel Oxidation Strategies for the In Situ Remediation of Chlorinated Solvents from Groundwater—A Bench-Scale Study

“…The attenuation of DCE (89%) and TCE (87%) was greater than that of PCE (59%). Our results agree with the experiments [8,9] that observed that, in the remediation of contaminated GW under flow-through conditions by S-nZVI and Fe(VI) treatments, higher efficiencies were achieved when employing S-nZVI rather than Fe(VI) under similar conditions. Because of the acidic media, Fe(VI) was more strongly retained in the soil column than S-nZVI particles.…”

“…This removal decrease in comparison with the previous experiments may be produced by the matrix effect. Since real GW contained more total organic carbon (TOC) than the synthetic GW (3 mg/L vs. <1 mg/L, respectively), the removal efficiency of the treatment may be decreased, as reported elsewhere [8]. Therefore, higher incubation times were required for the real GW matrix.…”

“…Even though they are well-known contaminants, chlorinated solvents are still a real environmental issue, as they are a large family of compounds and one of the most prevalent organic contaminants found in GW [7]. Some of these chlorinated solvents are known to be potential human carcinogens: trichloroethylene (TCE; a metallurgic-industry solvent) [6,8], tetrachloroethylene (perchloroethylene, PCE; a metallurgic-industry solvent) [9], and cis-1,2-dichloroethylene (DCE; a petrol-industry solvent) [7,10]. As a consequence, chlorinated solvents have been classified as persistent, mobile, and toxic (PMT) and very persistent and very mobile (vPvM) substances, as dictated by REACH [11].…”

Oxidative Degradation of Dimethyl Phthalate (DMP) by the Fe(VI)/H2O2 Process

“…Fe­(VI) synergistically affected oxidization, coagulation, sterilization, and deodorization during the water treatment process, and its degradation product is iron hydroxide, which can further absorb oxidation byproducts. In addition, various studies indicate that Fe­(VI) is a selective oxidizing agent that reacts with target compounds, such as phenol, chlorophenol, 3-methylphenol benzene series, methyl tert -butyl ether, acetaminophen, trichloroethylene, methanol, sulfite, and cyanide. − In addition, the final product of Fe­(VI) decomposition is ferric iron (Fe­(III) solid), which may play an important role in the subsequent water treatment process, such as adsorption and coagulation.…”

Past and present of electrochemical science in Hungary

“…The development of hydrogen-based fuel cells and their application were also a field of activity of György Inzelt's group [53]. Győző G. Láng and coworkers elaborated a procedure for the electrochemical generation of ferrate salts [54,55], which can eliminate even the chlorinated organic compounds, e.g., from polluted groundwater.…”