摘要
摘要
房地产产权抗生素类废水处理技术高能耗与低效率之间的矛盾是亟待解决的技术难题。目前被广泛采用的高级氧化技术存在处理费用高、矿化不完全的问题。由于抗生素具有杀菌抑菌的特性，生物法不能单独完成抗生素废水的处理。工程上广泛采用高级氧化法和生物降解联合工艺进行抗生素废水处理，其中抗生素的氧化程度是该工艺高效低耗的关键调控因子。光催化氧化-生物降解直接耦合技术(VPCB)与上述传统工艺相比，对抗生素废水处理具有潜在优势。VPCB体系中，可生物降解的光催化中间产物能够被微生物直接利用，避免了过度氧化并提高了矿化效率。然而，目前还鲜见VPCB技术用于降解抗生素类废水的报道，其所涉及到的关键科学问题就是载体内部的生物膜是否能维持活性并发挥生物降解功能。
论文选择盐酸四环素（TCH）作为模式污染物，首先探讨了VPCB对TCH 降解的效能与机制。以多孔海绵为载体，以银掺杂的二氧化钛为光催化剂，以活性污泥为生物种源，成功的制备了光催化生物降解直接耦合复合载体。与单独的光催化反应（VPC）相比，VPCB对TCH的降解速率提高了10%。光催化反应积累的骈四苯的大分子中间产物能够被VPCB中的生物进一步的降解。生物膜观察和溶解性微生物代谢产物分析（SMPs）结果进一步阐明VPCB载体内部的生物膜未受到显著伤害。VPCB中的生物群落结构演替过程中，耐TCH的菌属（Methylibium）、带有TCH抗性基因的菌属（Runella）、和降解芳香化
合物及其衍生物的菌属（Comamonas和Pudomonas）丰度显著增加。此外，VPCB对TCH 的矿化效率较光催化氧化提高了23%。可见，VPCB中生物降解对提高TCH降解速率和矿化效率起到了关键作用。擘组词
采用外加醋酸盐的手段，探讨进一步提高生物活性对VPCB中TCH降解的影响。外加NaAc后，生物膜中的活菌比例从56%提高至86%，生物膜活性显著提高，VCPB对TCH的降解效率从90%提高至95%，降解速率常数提高了~40%，出水溶解性化学需氧量（SCOD）分别降低了5.2和16.1 mg/L。同时，生物群落结构演替并富集了Thauera、Pudomonas、Runella等与TCH或其中间产物降解有关的菌属，强化了TCH光催化产生的中间产物的降解。中间产物分析结果进
一步揭示投加NaAc后VPCB中产生的一些含π-π共轭体系的小分子中间产物能被微生物进一步降解。这说明基于外加电子供体的策略提高生物活性，不仅能够强化光催化氧化作用，还能有效避免光催化中间产物的累积。
论文首次探讨了VPCB在抗生素类废水处理领域的应用，解析了典型抗生素TCH在VPCB中的降解行为和降解途径，发现了生物降解在VPCB技术中的关键作用和自我调节机制，并提出了外加电子供体的策略进一步提高TCH的降解效率和矿化效率。论文研究结果为抗生素废水高效降解提供了新的思路。
意大利留学签证关键词：光催化氧化；生物降解；直接耦合；四环素；降解途径；共代谢
Abstract
Abstract
For the antimicrobial wastewater treatment, high energy consumption and low efficiency is an emergency technical problem to be solved. The widely ud advanced process (AOPs) has the problem of high processing cost and incomplete mineralization, and the biodegradation of antibiotics is basically impossible in theory due to the nature of antibiotics. Then combining biodegradation with an AOP has been propod as a more effective means for the antimicrobial wastewater treatment in engineering. For the subquent biological treatment, obtain specific biodegradable intermediates in the AOP process is a key factor to achieve the purpo of high efficiency and low consumption using this approach. Compared with the traditional process above, the recently developed intimate coupling photocatalysis and biodegradation (VCPB) technology, in which AOPs and biodegradation occur together, has a potential advantage for the antibiotic wastewater treatment. VPCB could avoid the peroxide and improve the mineralization efficiency as biodegradable photocatalytic intermediates are removed as they are formed, focusing the chemical oxidant on the non-biodegradable fraction. H
中考答案owever, to the best of our knowledge, VCPB has not been ud for antibiotic treatment, in which the compounds are quite complex, and the challenging issue is how bacteria could survive in and respond to antibiotics.
亿邮In this study, we lected tetracycline hydrochloride (TCH) as a model pollutant and investigated TCH degradation behavior and mechanism of the VPCB protocol by comparing their results with tho of photocatalysis or biodegradation individually. We ud silver-doped titanium dioxide (Ag/TiO2) as the visible light-responsive photocatalyst. We coated porous carriers with Ag/TiO2and then cultivated the un-acclimated activated sludge to format biofilms on the carriers; thus, intimate coupled photocatalysis and biodegradation (VPCB) system could be t up when illuminating the carriers with visible light. When coupled with biodegradation, the pudo-first-
order simulated kinetic constants for the VPCB protocol were 0.240 ± 0.010 h-1, in comparison with 0.220 ± 0.016 h-1 for the individual photocatalysis (VPC) protocol, suggesting the obviously enhanced degradation efficiency of VPCB. At the same time, the larger ring molecules intermediate accumulated in VPC was utilized by microorganism and achieved further degradation under VPCB.
吃英语怎么说
Compared with the biological degradation (B), the biofilm inside the VPCB carrier was successfully protected. The SEM and SMPs results showed that the photocatalytic oxidation of VPCB could reduce the inhibitory effect of TCH on the biofilm. The new genus Methylibium which could survive in the TCH wastewater, the Runella which had the TCH resistance gene, Comamonas and Pudomonas which possd the ability to u the aromatic derivatives, became more abundant, indicating that the biofilm in VPCB could be adapted to the toxicity of TCH through the adjustment of the biological community structure. In addition, VPCB incread the mineralization efficiency of TCH by 23% compared with VPC. Biodegradation of photocatalytic intermediates was a key factor to increa TCH degradation and mineralization in the VPCB system.
And then acetate was ud as co-substrates to improve the condition of biofilms when encountering TCH, we investigated the effect of additional of acetate on the TCH degradation in the VPCB. After adding acetate as the external electron donor, the living cell ratio incread from 56% to 86%, and the degradation efficiency of VCPB on TCH was improved from 90% to 95% with an increment of the degradation rate constant by 40%, and SCOD removal by 5.2 and 16.1 mg/L respectively.Meanwhile, the adjustment of the biological community structure, which enriched the Thauera, Runella and Pudomonas, enhanced the degradation of the micromolecular intermediate
product which contains π-π conjugate groups aromatic hydrocarbon structures, as they were not detected in VPCB after the reaction.This suggested that additional NaAc as the electron donor could maintain the biomass and metabolic activity of the biofilm, improve the removal efficiency of TCH by the rapid u of intermediate products and effectively avoid the accumulation of photocatalytic intermediates.
In this work, we successfully realized the degradation of the typical antibiotic,
Abstract
TCH, in a visible light induced ICPB reactor for the first time and investigated the degradation behavior and pathway of TCH. The results interestingly revealed that biofilms were not damaged by TCH, but could regulate themlves to degrade photocatalytic generated intermediates by community structure succession, and thus accelerate the TCH photocatalytic degradation. And we found one practicable strategy to improve the degradation and minerlization of TCH was to provide extra metabolic electron donors in VPCB. This work provides an efficient technology for antibiotic wastewater treatment and is beneficial to the further understanding of the process of VPCB with the theoretical and practical significance.
Keyword：Photocatalysis oxidation; Biodegradation; Intimate coupling; Tetracycline;妻子和女儿
Degradation pathway; Co-metabolism公民参与
