Treating water contg. organic matter and nitrate, giving potable water - by ozone treatment giving assimilable cpds., and filtering through two layer fixed bed contg. heterotrophic microorganism

摘要

Water treatment comprises: (a) intense treatment with O3, giving direct mineralisation of part of the organic substances and breaking down part to low-mol. and assimilable organic gas., (b) passing the O3-treated water through a fixed bed reactor with an upper, O3-reducing coarse layer of filter C, and a lower filter bed of fine sand to separate the water, contg. solid particles, into solid and liq. The fixed bed reactor contains a heterotrophic microorganism which assimilates the organic low-mol. prods. of the O3 treatment and breathes The mol. O2 in the water, leading to a deficit in mol.O2. The process is continued until, as a result of the consumption of mol. O2. redn. or breakdown of nitrate occurs because of further breakdown of organic, low-mol. substances still present, by extn. of O from nitrate by the microorganism. There may be a further disinfection stage with more O3 after the active C filtration. The process of nitrate breakdown by extn. of O from the nitrate by the microorganism can be prolonged by addn. of nutrients to the raw water before the O3 treatment; the duration of the process and thus the breakdown of nitrate are then determined by the amt. of assimilable low mol. organic substances remaining available. USE/ADVANTAGE - For prepn. of rotable water from ground, spring or surface water contaminated by nitrates and organics, at levels too low for enzymatic splitting without external influence.