【摘要】：焦化廢水是由復雜的有機污染物構成的,這些有機物性質(zhì)穩(wěn)定,其中一些具有致毒和致癌的性質(zhì),通常COD值很高,但BOD/COD值卻很低,很難被生物降解,處理難度比較大。因此,焦化廢水屬于典型的難以治理并且具有毒性的廢水。喹啉作為本次實驗焦化廢水中含量最高的有機物,具有潛在致癌性,又難以降解,是目前廢水中比較難處理的有機物之一。粘土礦物在自然界中分布非常廣泛,并且具有許多優(yōu)異而又無可替代的性能,因其具有比表面積大、吸附能力強、陽離子交換能力強等特點,是一種優(yōu)良的環(huán)境修復材料,正逐漸被廣泛應用與關注。本次實驗首先將喹啉作為目標污染物,分離能夠降解喹啉的微生物,然后針對喹啉的不完全降解產(chǎn)物,繼續(xù)分離再降解微生物,使其COD進一步地降低。另外利用經(jīng)過化學還原后的含鐵粘土礦物,在好氧條件下產(chǎn)生羥基自由基,對焦化廢水中有機污染物進行無選擇性的氧化,以達到降低出水COD目的。同時將粘土礦物和微生物共同作用于焦化廢水,分為兩種:1、先微生物再粘土礦物。2、先粘土礦物再微生物。對比分析,尋找最有效地降低焦化廢水COD的方法。針對污染物喹啉,分離出兩株可以共同降解喹啉的微生物,Alcaligenes faecalis和Mesorhizobium sp.。Alcaligenes faecalis降解喹啉的最適pH、溫度、鹽度分別為8.0、30℃、0.3%,而底物的濃度在500mg/L及以下時,可將其完全降解,另外對于苯酚降解也具有重要的作用。同時Alcaligenes faecalis降解喹啉過程中喹啉中的部分N釋放為NH3-N,并且對于產(chǎn)物二羥基喹啉濃度進行了定量分析。通過LC-MS的定性分析,得出了兩株菌共同作用后產(chǎn)物的成分,提出了可能的兩條降解途徑,一條為左側(cè)苯環(huán)結構的開環(huán),另一條為右側(cè)含氮雜環(huán)的開環(huán)。上述結果表明兩種菌可以共存,并且Mesorhizobium sp.可以更深度降解喹啉。將微生物和含鐵粘土礦物應用于焦化廢水,相比于微生物的降解作用,化學還原后的粘土礦物對于焦化廢水出水COD的去除率更高,去除效果更好。微生物-粘土礦物模式和粘土礦物-微生物模式,整體上兩者最終的COD去除率基本一致。微生物的降解作用在前期的效果更好,因此將微生物-粘土礦物模式選為最優(yōu)的焦化廢水COD去除模式。
[Abstract]:Coking wastewater is composed of complex organic pollutants, some of which have toxic and carcinogenic properties. The COD value is usually very high, but the BOD/ COD value is very low, so it is difficult to be biodegraded and difficult to treat. Therefore, coking wastewater is a typical wastewater which is difficult to treat and toxic. Quinoline, as the organic matter with the highest content in coking wastewater of this experiment, has the potential carcinogenicity and is difficult to degrade, so quinoline is one of the most difficult organic compounds to be treated in the wastewater at present. Clay minerals are widely distributed in nature, and have many excellent and irreplaceable properties. Because of their large specific surface area, strong adsorption ability and strong cation exchange ability, clay minerals are a kind of excellent environmental remediation materials. It is gradually being widely used and paid attention to. In this experiment, quinoline was first used as the target pollutant to isolate the microorganisms that could degrade quinoline, and then to the incomplete degradation products of quinoline, the microorganisms were further separated and redegraded, and the COD of the microorganisms was further reduced. In addition, the organic pollutants in coking wastewater were oxidized non-selectively by using iron-containing clay minerals after chemical reduction to produce hydroxyl radicals under aerobic conditions, in order to reduce the effluent COD. At the same time, clay minerals and microorganisms act together on coking wastewater, and they are divided into two kinds: 1, the first microorganism is followed by clay mineral. 2, the first clay mineral is followed by microorganism. By comparison and analysis, the most effective method to reduce COD in coking wastewater was found. For the pollutant quinoline, the optimum pH, temperature for the degradation of quinoline by, Alcaligenes faecalis and Mesorhizobium sp..Alcaligenes faecalis was 8.0, 30 鈩，

本文編號：2432948