Catalytic and Non-Catalytic Treatment of Industrial Wastewater under the Exposure of Non-Thermal Plasma Jet

Abstract

Freshwater is only 2.5% of the total water on the Earth and rest is contaminated or brackish. Various physical and chemical techniques are being used to purify the contaminated water. This study deals with catalytic plasma treatment of contaminated water collected from different sites of Faisalabad-Pakistan. A non-thermal DC plasma jet technique was used to treat the water samples in the presence of TiO2 catalyst. The plasma-assisted catalytic treatment introduced some oxidative species (O3, H2O2, HO2−, OH−) in the water. These species reacted with pollutants and cause the degradation of harmful contaminants, especially dyes. The degradation of dye sample during plasma treatment was more pronounced as compared to other samples. pH, conductivity and TDS of dye containing sample decreased after catalytic plasma treatment. The degradation of organic pollutants increased due to presence of several oxidants, such as TiO2, ferrous ions and hydrogen peroxide. FT-IR analysis revealed the degradation of some functional groups during treatment process and confirmed the effectiveness of the process. The residue of the treated samples was consisted of amines, amides and N-H functional groups. XRD analysis showed the presence of Alite, Ferrite, aluminate, Si, S and some heavy metals in the residue. The effect of plasma treatment on activity of gram-negative Escherichia coli (E. coli) bacteria in water was also checked. The bacterial activity was reduced by almost 50% after 2 min of plasma treatment.

Optical characterization of non-thermal plasma jet energy carriers for effective catalytic processing of industrial wastewaters

“…The disposal of industrial effluents and heavy metals in water bodies raises the human health concerns, poisons the wildlife, and damages the long-term ecosystem 3 . Toxins in industrial effluents promote the reproductive failure, immune suppression and acute poisoning 4 . The bacterial strains in water release toxins in digestive tracts, which cause nausea, watery diarrhea, vomiting, renal failure and dehydration.…”

“…With conventional water treatment techniques, such as chlorination, coagulation, adsorption, ultra-sonication, etc., it is difficult to eliminate all the harmful contaminants from the water. Recently, some advanced oxidation techniques like irradiation of high energy electrons, oxidation using ozone, ionizing radiations exposure, carbon absorption, plasma exposure and sonolysis have been practiced for the treatment of contaminated waters 4 .…”

“…The reactive oxygen radials and nitrogen oxides in plasma jet not only kill the living organisms but decompose the organic and inorganic compounds as well 4 , 8 . If a suitable photocatalyst is added to the contaminated water, the plasma treatment of polluted water may be more effective.…”

“…All these phases show octahedral structures but differ in the arrangement of their octahedral units 10 , 11 . Anatase phase is the most prominent commercial phase of TiO 2 due to its better stability and photocatalytic activity as compared to rutile and brookite phases 4 . TiO 2 nanoparticles are also known for good surface acidity, good thermal and chemical stabilities and low toxicity potential 12 .…”

Ultrasonic Bioconversion of Silver Ions into Nanoparticles with Azadirachta indica Extract and Coating over Plasma‐Functionalized Cotton Fabric

“…The functional groups textiles are modified with wet chemical treatment, laser treatment, treatment with chitosan, treatment with UV radiations, treatment with ultrasound waves and low temperature plasmas [20–21] . The atmospheric pressure dielectric barrier discharge (DBD) plasmas are sustained by introducing at least on dielectric layer between the metallic electrodes [22–23] . DBD plasma treatment of textiles produces negative radicals on the exposed surface.…”