【摘要】：全球水污染愈發(fā)嚴(yán)重,發(fā)展更好的污水處理技術(shù)成為了一項重要研究內(nèi)容。相比其它方法,使用辣根過氧化酶(HRP)催化雙氧水降解有機污染物具有綠色環(huán)保的獨特優(yōu)勢。天然辣根過氧化酶易受到環(huán)境影響而失活,本論文通過對天然辣根過氧化酶在分子層面上進(jìn)行凝膠包裹,制成納米凝膠酶,并通過納米粒度儀和酶標(biāo)儀等儀器,對凝膠酶粒徑大小和熱穩(wěn)定性進(jìn)行表征;然后選用染料工業(yè)中常見的染料作為降解對象(鹽酸副品紅、靛藍(lán)胭脂紅、直接紅81、剛果紅和偶氮熒光桃紅等),利用天然的辣根過氧化酶和納米凝膠酶對之進(jìn)行降解研究,對比分析不同染料的最佳降解條件,以及納米凝膠酶對不同染料的降解效率和規(guī)律,最后對酶回收嘗試循環(huán)使用。本論文首先對辣根過氧化酶(HRP)進(jìn)行化學(xué)修飾,通過與氨基的反應(yīng)接枝雙鍵到HRP表面,進(jìn)而與羧酸甜菜堿丙烯酰胺(CBAA)發(fā)生自由基聚合反應(yīng),成功制備了HRP的納米凝膠酶,其粒徑大小約為78納米。納米凝膠酶不但保持了辣根過氧化酶的原有活性,而且在熱穩(wěn)定性上要優(yōu)于天然的辣根過氧化酶。在所有的降解實驗中,納米凝膠酶的降解效果都要好于辣根過氧化酶;辣根過氧化酶和納米凝膠酶在較寬的pH值范圍、過氧化氫濃度范圍和30℃-60℃都具有一定的降解能力。多種染料的對比研究發(fā)現(xiàn),HRP及納米凝膠酶對含有多氨基染料的降解效果最好,幾乎能達(dá)到100%,并且納米凝膠酶的降解效率幾乎是辣根過氧化酶的兩倍;而對含有磺酸基染料的降解效果較差。在回收實驗中,由于降解產(chǎn)物對酶有一定的影響,辣根過氧化酶和納米凝膠酶在經(jīng)過一次降解后活性都有不同程度的下降,但總體來說,納米凝膠酶的活性損失程度較小。在工業(yè)染料廢水中加入吸附劑是現(xiàn)代污水處理的有效且重要方法之一。殼寡糖(COS)表面有許多氨基,是一種倍受歡迎的吸附劑。本論文探究了殼寡糖作為吸附劑對染料降解的影響。研究表明,加入一定濃度的殼寡糖,對于含有磺酸基的染料來說,有助于提高染料的脫色率,對于含有較多氨基的染料來說,加入殼寡糖會降低染料脫色的速率,但不會影響最后的降解率;殼寡糖的濃度越高,對染料的脫色效果越明顯,但是過高濃度會造成一定的浪費,所以1%的殼寡糖是一個比較合適的濃度。由于氧自由基主要集中在納米凝膠酶內(nèi)部或表面,為了更好的將染料從溶液中去除,本論文還嘗試通過化學(xué)反應(yīng),將殼寡糖接枝到納米凝膠酶上;后續(xù)的染料降解實驗表明,將殼寡糖接枝到納米凝膠酶上以后,能夠有效地增強納米凝膠酶對染料的降解能力。
[Abstract]:The development of better sewage treatment technology has become an important research content because of the serious water pollution in the world. Compared with other methods, the use of horseradish peroxidase (HRP) to catalyze the degradation of organic pollutants by hydrogen peroxide has the unique advantage of green environmental protection. Natural horseradish peroxidase is easy to be inactivated by environment. In this paper, the natural horseradish peroxidase was encapsulated on the molecular level to make nanogel enzyme. The particle size and thermal stability of the gelatinase were characterized, and then the common dyes in the dye industry were selected as the degradation objects (Para-fuchsin Hydrochloride, Indigo Carmine, Indigo Carmine). Direct red 81, Congo red and azo fluorescent peach red, etc.), the degradation of these dyes was studied by using natural horseradish peroxidase and nanogel enzyme, and the optimum degradation conditions of different dyes were compared and analyzed. The degradation efficiency and regularity of different dyes by nanogel enzyme were also studied. In this paper, the horseradish peroxidase (HRP) was chemically modified, and the HRP nanogel was successfully prepared by grafting the double bonds with amino groups onto the surface of HRP, and then by free radical polymerization with carboxylate betaine acrylamide (CBAA). The particle size is about 78 nm. The nanogel enzyme not only maintains the original activity of horseradish peroxidase, but also has better thermal stability than natural horseradish peroxidase. In all the degradation experiments, the degradation effect of nano-gel enzyme was better than that of horseradish peroxidase, and the degradation ability of horseradish peroxidase and nano-gel enzyme was in a wide pH range, hydrogen peroxide concentration range and 30 鈩，

本文編號：2182152