Arsenic in drinking water resources and, especially, in groundwater, represents a severe health problem for millions of people in affected regions. This paper investigates a removal technology combining non-thermal plasma at a reaction time of 30 min, which has improved the downstream coagulation and the filtration efficiency. The results show removal rates of total arsenic over 98%. In addition, WHO limits of less than 10 μ $\mathrm{g}$ ${\mathrm{L}}^{-1}$ could be achieved in both batch and continuous set-ups. A difference in effective over potential of the NTP reaction of 32 $\mathrm{m}$ $\mathrm{V}$ over a reaction using air as oxidant was calculated. Kinetic data of arsenic concentrations over time fitted a pseudo first-order reaction. The proposed process combination has shown to be a simple and energy-saving alternative compared to conventional oxidation and adsorption technologies by exploiting the ’enhancer’ effect of ozone and other reactive oxygen species within the NTP.

The increasing research in the field of polymeric multi-channel membranes has shown that their mechanical stability is beneficial for a wide range of applications. The more complex interplay of formation process parameters compared to a single-channel geometry makes an investigation using Design of Experiments (DoE) appealing. In this study, seven-channel capillary membranes were fabricated in a steam–dry–wet spinning process, while varying the composition of the polymer solution and the process temperatures in a three-level fractional factorial linear screening design. The polymers polyvinylidene flouride (PVDF) was the chemically resistant main polymer and polyvinylpyrrolidone (PVP) was added as hydrophilic co-polymer. Scanning electron microscopy and atomic force microscopy were applied to study the membrane morphology. Fabrication process conditions were established to yield PVDF/PVP multi-channel membranes, which reached from high flux (permeability P = $321.4$ $\mathrm{L}$ / ${\mathrm{m}}^2$ / $\mathrm{h}$ /bar, dextran 500 $\mathrm{kDa}$ retention R = 18.3%) to high retention (P = $66.8$ $\mathrm{L}$ / ${\mathrm{m}}^2$ / $\mathrm{h}$ /bar, R = 80.0%). The concentration of the main polymer PVDF and the molecular weight of the co-polymer PVP showed linear relations with both P and R. The permeability could be increased using sodium hypochlorite post-treatment, although retention was slightly compromised. The obtained membranes may be suitable for micro- or ultra-filtration and, at the same time, demonstrate the merits and limitations of DoE for multi-channel membrane screening.