本文選題：殼聚糖 + 溶菌酶��； 參考：《湖南大學》2015年碩士論文

【摘要】：本文以強化活性污泥沉降及脫水性能為目標,研究了殼聚糖和溶菌酶聯(lián)合調(diào)理污泥對污泥沉降性能、脫水速度以及脫水程度的影響,確定了殼聚糖和溶菌酶最佳投加量、最優(yōu)加藥方式及最優(yōu)實驗條件。實驗通過測量污泥Zeta電位、分析和研究污泥絮體形態(tài)結構以及污泥上清液SMP的EEM光譜,對污泥脫水機理進行了初步探討。殼聚糖作為弱陽離子型高分子絮凝劑,可以顯著改善污泥的沉降性能,聯(lián)用時可以克服溶菌酶調(diào)理污泥導致污泥沉降性能變差的缺點。通過單因素及正交實驗確定了殼聚糖的最佳投加量為0.01g/gDS,溶菌酶最佳投加量為0.10g/gDS,最優(yōu)加藥次序為殼聚糖+溶菌酶聯(lián)用調(diào)理污泥。在此條件下,污泥初期沉降速度達到7.13mm/min左右,相比原泥提高將近14倍,真空抽濾泥餅含水率降至為71.3%,污泥比阻降至0.25×1 012m/kg,比原泥分別下降了23.3%和95.8%。此外,通過實驗還進一步確定了殼聚糖和溶菌酶聯(lián)用調(diào)理污泥時的最優(yōu)實驗條件：污泥最佳濃度范圍為15000-25000mg/L,最佳調(diào)理溫度為30℃,最佳調(diào)理pH值為7。通過觀測發(fā)現(xiàn),污泥Zeta電位、絮體形態(tài)結構、分形維數(shù)和EPS對污泥沉降及脫水性能具有重要影響。由于殼聚糖和溶菌酶分子均含有陽離子氨基基團,適量的殼聚糖和溶菌酶調(diào)理可以壓縮污泥雙電層,降低污泥吲電位。0.01g/gDS殼聚糖+0.10g/gDS溶菌酶聯(lián)用時污泥(?)電位由原泥的4.23mV降低至0.28mV,促進了污泥脫穩(wěn)、絮凝。未經(jīng)藥劑調(diào)理的污泥絮體細小分散,二維分形維數(shù)D2值僅為1.48；殼聚糖的絮凝作用使得污泥膠體絮凝形成碩大絮體,污泥絮體顆粒D2值升至1.69,但絮體結構疏松,內(nèi)部存在較多孔隙；溶菌酶調(diào)理進一步壓縮污泥絮體,減少絮體內(nèi)部孔隙,因此兩者聯(lián)用調(diào)理時污泥絮體大而致密,D2值升至最大值1.74,污泥沉降、脫水速度變快。對污泥上清液溶解性有機物SMP的EEMs分析表明,SMP的主要成分為類蛋白質(zhì)、類腐殖質(zhì)和類富里酸,其熒光特征峰中心位置分別在(Ex/Em=280/350)、(Ex/Em=290/370)、(Ex/Em=230/385、360/450)附近。污泥經(jīng)殼聚糖調(diào)理后類蛋白熒光峰強度變化不大,而經(jīng)殼聚糖+溶菌酶調(diào)理后類蛋白熒光峰強度相對原泥增加25.8%。實驗結果表明,殼聚糖調(diào)理主要對污泥膠體顆粒起脫穩(wěn)、絮凝作用,不會改變污泥溶液中的有機物質(zhì)成分；溶菌酶調(diào)理時,一方面通過溶胞作用致使大量與細胞分泌有關的色氨酸類蛋白質(zhì)溶出,同時胞內(nèi)水分也流出,另一方面改變了EPS成分組成和結構,導致EPS中的類蛋白物質(zhì)溶出并擴散到污泥上清液中形成SMP物質(zhì),同時也使EPS束縛的水分釋放。因此先投加殼聚糖調(diào)理污泥時,膠體顆粒凝聚形成了大顆粒絮體,再經(jīng)溶菌酶調(diào)理破壞污泥細胞壁結構,改善污泥EPS成分組成和結構,釋放微生物細胞內(nèi)水分和EPS束縛的水分,從而顯著改善污泥脫水性能。
[Abstract]:In order to enhance the sedimentation and dewatering performance of activated sludge, the effects of chitosan and lysozyme on sludge sedimentation, dewatering rate and dewatering degree were studied, and the optimum dosage of chitosan and lysozyme was determined. Optimal dosing method and optimal experimental conditions. By measuring sludge Zeta potential, analyzing and studying the morphological structure of sludge floc and the EEM spectrum of sludge supernatant SMP, the mechanism of sludge dehydration was preliminarily discussed. Chitosan as a weak cationic macromolecule flocculant can significantly improve the settling performance of sludge and can overcome the shortcoming of sludge sedimentation caused by lysozyme conditioning sludge. The optimum dosage of chitosan and lysozyme was 0.01g / g DS and 0.10g / g DS by single factor and orthogonal experiment respectively. The optimal dosage order was chitosan lysozyme combined with sludge conditioning. Under these conditions, the initial settling rate of sludge reached about 7.13mm/min, which was nearly 14 times higher than that of raw sludge. The water content of vacuum filter cake was reduced to 71.3%, and the specific sludge resistance was decreased to 0.25 脳 10 12 m / kg, which was 23.3% and 95.8% lower than that of raw sludge, respectively. In addition, the optimum conditions of sludge conditioning with chitosan and lysozyme were determined: the optimum concentration range of sludge was 15000-25000mg / L, the optimum conditioning temperature was 30 鈩，

本文編號：1915761