纳米零价铁对糖蜜酒精废水两级厌氧处理的影响

Effect of nano zero valent iron on treatment of molasses alcohol wastewater by a two-stage anaerobic digestion system

采用两级厌氧方式处理糖蜜酒精废水,向一级上流式厌氧污泥床反应器(up-flow anaerobic sludge bed,UASB)中添加纳米零价铁(nano zero valent iron,NZVI),以降低硫化物对厌氧消化过程的抑制,提高糖蜜酒精废水两级处理的效果。添加NZVI后,不同负荷下化学需氧量(chemical oxygen demand,COD)一级去除率比未添加NZVI时高,最终保持在55%左右;硫酸根一级去除率为73%左右;COD二级去除率和总去除率最终分别稳定在33%和70%左右,硫酸根二级去除率和总去除率最终分别稳定在73%和93%左右;一级和二级厌氧出水中硫化物质量浓度最大分别为363.9和452.4 mg/L。反应器COD负荷达到28 kg/(m 3·d)时,产甲烷菌(methane producing bacteria,MPB)和硫酸盐还原菌(sulfate reducing bacteria,SRB)电子流比重分别稳定在86%和14%左右。

The two-stage anaerobic treatment of molasses alcohol wastewater was carried out,nano zero valent iron(NZVI)was added to the first up-flow anaerobic sludge bed(UASB)reactor to reduce the inhibition of sulfide on anaerobic digestion process and improve the efficiency of two-stage anaerobic digestion system.The removal rate of chemical oxygen demand(COD)in the first reactor under different organic loading rates was higher than that without NZVI addition,the final removal rate was about 55%;the removal rate of sulfate was about 73%;the removal rate of COD in second reactor and the total removal rate were about 33%and 70%,respectively;the second reactor and total removal rates of sulfate were about 73%and 93%,respectively;the maximum sulfide concentration in the first and second stage anaerobic effluent was 363.9 and 452.4 mg/L,respectively.When the COD organic loading rate of the reactor reached 28 kg/(m 3·d),the specific gravity of methane producing bacteria(MPB)and sulfate reducing bacteria(SRB)was about 86%and 14%,respectively.