The operational conditions for the electro-advanced oxidation process using the Fenton-type reaction of the ferrous ion (Fe²⁺) and hypochlorous acid were discussed in this research. In the process, hypochlorous acid is supplied by the anodic oxidation of the chloride ion (Cl^-) and Fe²⁺ is supplied by the cathodic reduction of the ferric ion (Fe³⁺). 1, 4-Dioxane was used as the hydroxyl radical probe. As the results of the 1, 4-dioxane degradation test, higher current efficiencies of 1, 4-dioxane degradation were observed at pHs of up to 3.0, current densities of up to 2.8 mA·cm^-2, Cl^- concentrations of 10-200 mM, and iron concentrations of 1.0-4.0 mM. In addition, the experimental results showed that the Fe³⁺, the initial iron species was more effective than Fe²⁺, because excessive Fe²⁺ acted as a radical scavenger. A current efficiency of 74.2% was achieved at pH 2.5 as well as a current density of 2.8 mA·cm^-2 at an initial Fe³⁺ concentrations of 1.0 mM and an initial Cl^- concentrations of 100 mM; the current efficiency achieved using Fe²⁺ instead of Fe³⁺ was only 44.9%.

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A novel setup of granulated microwave discharge electrodeless lamps (MDELs) fabricated using vacuum UV-transparent quartz envelopes was used for treating wastewater, which in the present case was an aqueous solution of 1, 4-dioxane. The granulated MDELs were assessed in the self-ignition of the lamps on irradiation of low microwave power and in the wastewater photodegradation. 1, 4-Dioxane was photodecomposed in a flow reactor containing 20 of such MDELs. The photodegradation was analyzed by decreasing of 1, 4-dioxane concentration and total organic carbon (TOC). A conventional rod-shaped MDEL and a commercial low-pressure mercury lamp electrode were used to compare the performance of the novel granulated MDELs. The dominant performance of the MDELs was established by measuring the photodegradation rate per surface area of the irradiated wastewater and the applied electric power of the lamps. The decomposition dynamics of 1, 4-dioxane was investigated further using the number of passes through the flow reactor with the 20 MDELs under 80 W of microwave power. The photodegradation of 93% was achieved by passing wastewater through the flow reactor three times. Photodegradation intermediates were analyzed by the LC-MS technique. Basically, the photodegradation of 1, 4-dioxane occurs by the ^·OH radical attack of the ring, which then leads to ring opening.

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