Abstract: A dielectric barrier discharge plasma reactor device for plasma-based gas and liquid purification. The device comprises a series of electrodes arranged in rows of alternating polarity so as to form a series of triangular modules in which the spacing between adjacent electrodes is less than or equal to the diameter of an individual electrode. When an electrical power supply is connected to the electrodes, an electrical discharge is produced which reacts with the constituents of the fluid to produce activated radicals. The device further comprises a fluid swiveling device which facilitates homogenous flow of the contaminated fluid through the reactor by providing effective mixing between activated radicals and fluid, such that toxins contained in the fluid are attacked and decomposed by the radicals. A number of alternative embodiments of the fluid swiveling device are described.