As one of the most representative endocrine disrupting compounds, dioctyl phthalate (DEHP) is difficult to remove due to its bio-refractory characteristic. In this study, an immobilization technology was applied in an MBR system to improve the degradation of DEHP. The degradation efficiency of DEHP was significantly improved and the number of degradation genes increased by 1/3. A bacterial strain that could effectively degrade DEHP was isolated from activated sludge and identified as Bacillus sp. The degradation pathway of DEHP was analyzed by GC-MS. DEHP was decomposed into phthalates (DBP) and Diuretic sylycol (DEP), then further to Phthalic acid (PA). PA was oxidized, dehydrogenated, and decarboxylated into protocatechins, further entered the TCA cycle through orthotopic ring opening. The DEHP degrading strain was immobilized by sodium alginate and calcium chloride under the optimized immobilization conditions, and added to MBR systems. The removal rate of DEHP (5 mg/L) (91.9%) and the number of 3, 4-dioxygenase gene copies was significantly improved by adding immobilized bacteria. Micromonospora, Rhodococcus, Bacteroides and Pseudomonas were the dominant genuses, and the results of bacterial community structure analysis show that immobilization technology is beneficial to system stability. The results showed the potential applications of the immobilized technique in DEHP wastewater treatment in MBR.

中文翻译：

---

通过藻酸钠固定在MBR系统中的生化途径和邻苯二甲酸二辛酯（DEHP）的增强降解。

作为最具代表性的破坏内分泌的化合物之一，邻苯二甲酸二辛酯（DEHP）由于其生物难治性特性而难以去除。在这项研究中，固定化技术被应用于MBR系统中，以改善DEHP的降解。DEHP的降解效率显着提高，降解基因数量增加了1/3。从活性污泥中分离出可以有效降解DEHP的细菌菌株，并将其鉴定为芽孢杆菌。用GC-MS分析DEHP的降解途径。将DEHP分解为邻苯二甲酸酯（DBP）和利尿糖醛（DEP），然后进一步分解为邻苯二甲酸（PA）。PA被氧化，脱氢和脱羧成原儿茶素，并通过原位开环进一步进入TCA循环。在优化的固定条件下，用藻酸钠和氯化钙固定DEHP降解菌株，并将其添加到MBR系统中。通过添加固定化细菌，可显着提高DEHP（5 mg / L）的去除率（91.9％）和3，4-双加氧酶基因拷贝数。小单孢菌，红球菌，拟杆菌和假单胞菌是主要的属，细菌群落结构分析的结果表明固定化技术有利于系统的稳定性。结果表明固定化技术在MBR的DEHP废水处理中的潜在应用。通过添加固定化细菌可以显着改善4-dioxygenase基因的拷贝。小单孢菌，红球菌，拟杆菌和假单胞菌是主要的属，细菌群落结构分析的结果表明固定化技术有利于系统的稳定性。结果表明固定化技术在MBR的DEHP废水处理中的潜在应用。通过添加固定化细菌可以显着改善4-dioxygenase基因的拷贝。小单孢菌，红球菌，拟杆菌和假单胞菌是主要的属，细菌群落结构分析的结果表明固定化技术有利于系统的稳定性。结果表明固定化技术在MBR的DEHP废水处理中的潜在应用。