升流式污泥床对无机废水中氮硫转化及相互影响

采用无机含氨和硫酸盐(SO₄^2-)废水作为升流式污泥床(USB)反应器进水,研究了其对铵(NH₄⁺)和SO₄^2-的去除以及不同高度污泥层含氮、硫元素的转化途径.结果表明在反应器进水口处由于进水自含氧(外源性氧)和兼性厌氧菌受到氧化应激产生过氧化氢(内源性氧),两种“氧”共同存在下,反应器内生物脱氨量(以氮计)最高达40mg/L左右,且在USB反应器不同高度污泥层含氮化合物和含硫化合物的转化途径不同.在反应器底部污泥层,颗粒污泥表面氨氧化菌利用O₂将氨(NH₄⁺)氧化成亚硝酸盐(NO₂^-),在颗粒污泥内部厌氧氨氧化菌利用NH₄⁺和NO₂^-生成氮气(N₂)和硝酸盐(NO₃^-);同时,O₂

Mechanisms of biological conversion and removal of nitrogen and sulfur from the inorganic influent in Upflow Sludge Bed Reactor

The inorganic wastewater containing ammonium and sulfate was used as influent of upflow sludge bed (USB) reactor, and the removal of ammonium and sulfate and the transformation of nitrogen and sulfur elements in the sludge layers with different heights were studied. The results show that at the inlet of the reactor, the influent water contained dissolved oxygen (exogenous oxygen) and facultative anaerobes subjected to oxidative stress to produce hydrogen peroxide (endogenous oxygen). In the coexistence of two kinds of "oxygen", the biological deamination amount (calculated as nitrogen) in the reactor was up to about 40mg/L, and the conversion pathways of nitrogen-containing compounds and sulfur-containing compounds in the sludge layer varied with the position (height) of the USB reactor. In the sludge layer at the bottom of the reactor, ammonia oxidizing bacteria on the surface of granular sludge used molecule oxygen to oxidize ammonium to nitrite, and anaerobic ammonia oxidizing bacteria inside the granular sludge used ammonium and nitrite to generate nitrogen gas and nitrate; at the same time, the presence of oxygen made the anaerobic granular sludge in the sludge layer at the bottom of the reactor be cracked and produced a small amount of organic matter; the sulfate-reducing bacteria in the granular sludge use organic matter to reduce sulfateto form sulfide ion; and sulfur autotrophic denitrifying bacteria utilize nitrite/nitrate to re-oxidize sulfide to sulfate. In the upper sludge layer of the reactor, due to the existence of only a small amount of endogenous oxygen, the sulfur autotrophic denitrifying bacteria could only use a small amount of nitrite/nitrateto oxidize sulfide to sulfur element. The removal of ammonium and the circulation of sulfatewere realized in the sludge layer at the bottom of the USB reactor, and the removal of sulfatewas achieved in the upper sludge layer.