The Micro- And Nanosecond Discharges in Gas Bubbles for Water Disinfection and Purification

Abstract

Purpose. Comparison of electrical circuits of experimental plants for obtaining micro-and nanosecond discharges in gas bubbles in water and comparing the experimental results obtained for disinfecting water using such discharges. Methodology. To obtain high-voltage pulses on the load in the form of a gas bubbles and a layer of water with a frequency of more than 2000 pulses per second, a method of generating micro-and nanosecond pulses using high-voltage pulse generators based on a pulse transformer (PT) according to Tesla, with a transistor opening switch IGBT in the low-voltage part of the circui. A current-limiting resistor with a resistance R cl = 24 k is used to protect the transistor switch at microsecond discharges. At nanosecond discharges, a multi-gap spark gap is used to sharpen the front of high-voltage pulses. We used a capacitive voltage divider with a division factor of K d = 7653 to measure voltage pulses, a shunt with a resistance of R s = 2.5  for measuring current pulses. RIGOL DS1102E digital oscilloscope with a 100 MHz bandwidth was used as a recording device. Results. The effect of micro-and nanosecond discharges in gas bubbles on microorganisms was experimentally investigated. It was possible to reduce the biochemical oxygen consumption of water during microsecond discharges, reduce the turbidity of water, and improve its organoleptic qualities. The energy released in a single pulse with microsecond discharges W µ ≈ 17 mJ, with nanosecond discharges W n ≈ 7.95 mJ. At nanosecond discharges, complete inactivation of E.coli bacteria was achieved. The disinfecting and purifying action of nanosecond pulses is better compared to microsecond pulses due to an increase in the amplitude of the pulsed voltage up to 30 kV, and a pulsed current of up to 35 A. Originality. The possibility of effective microbiological disinfection of water using nanosecond discharges in gas bubbles at low specific energy consumption has been experimentally shown. Practical value. The obtained experimental results on water disinfection using micro-and nanosecond discharges offer the prospect of industrial application of installations using such discharges for disinfecting and purification wastewater, swimming pools, and posttreatment of tap water. References 9, figures 3. Key words: high-voltage generator, micro-and nanosecond pulses, discharge in gas bubbles in water, disinfection and water purification by discharges, inactivation of microorganisms.

Disinfecting water treatment and purification, neutralization and conversion of gas emissions from enterprises using highvoltage pulse discharges

“…В [14] показана возможность использования полученных наносекундных импульсов в газовых пузырях в воде для уменьшения концентрации аммиака NH 3 на 37% (с 57 мг/л до 35,7 мг/л) при обработке раствора NH 4 NO 3 в воде в течение t=18 мин импульсами длительностью t p ≈60 нс, со средней амплитудой импульсов напряжения U≈30 кВ, средней амплитудой импульсов тока I≈25 А, частотой следования f rpt ≈2381 имп/с. При обработке 3 л водопроводной воды, обсемененной бактериями E.coli с концентрацией 10 6 КОЕ/см 3 , при помощи таких же импульсов в течение 7 минут по данным лаборатории КП «Санэпидсервис» (г. Харьков), достигнута 100 -процентная инактивация бактерий [15].…”

Energy characteristics for nanosecond current interrupter of semiconductor-magnetic pulse generator’s terminal stage

“…SMPGs [1,2] are a class of convertor technology, that were originally developed for powering microwave emitters and pumping gas lasers [3], where the sharpness of the pulse front plays a primary role. Over the last decade, SMPG has become more and more widely used in electric discharge technologies for water purification and disinfection [4,5], for air ionization by streamer discharge to remove toxic impurities [6,7], as well as for agricultural processing [8] or food pasteurization [9]. A low-temperature plasma of barrier or corona discharges of specified technologies is a main tool for processing the primary medium (material) to eliminate harmful substances in it.…”