Biodegradation and bio-sorption of antibiotics and non-steroidal anti-inflammatory drugs using immobilized cell process

In the present study, the removal mechanisms of four antibiotics (sulfamethoxazole, sulfadimethoxine, sulfamethazine, and trimethoprim) and four non-steroidal anti-inflammatory drugs (acetaminophen, ibuprofen, ketoprofen, and naproxen) in immobilized cell process were investigated using batch reactors. This work principally explores the individual or collective roles of biodegradation and bio-sorption as removal routes of the target pharmaceuticals and the results were validated by various experimental and analytical tools. Biodegradation and bio-sorption were found as dominant mechanisms for the drug removal, while volatilization and hydrolysis were negligible for all target pharmaceuticals. The target pharmaceuticals responded to the two observed removal mechanisms in different ways, typically: (1) strong biodegradability and bio-sorption by acetaminophen, (2) strong biodegradability and weak bio-sorption by sulfamethoxazole, sulfadimethoxine, ibuprofen and naproxen, (3) low biodegradability and weak bio-sorption by sulfamethazine and ketoprofen, and (4) low biodegradability and medium bio-sorption by trimethoprim. In the sorption/desorption experiment, acetaminophen, sulfamethoxazole and sulfadimethoxine were characterized by strong sorption and weak desorption. A phenomenon of moderate sorption and well desorption was observed for sulfamethazine, trimethoprim and naproxen. Both ibuprofen and ketoprofen were weakly sorbed and strongly desorbed.     

Ecotoxicity evaluation of selected sulfonamides

Sulfonamides (SAs) are a group of antibiotic drugs widely used in veterinary medicine. The contamination of the environment by these pharmaceuticals has raised concern in recent years. However, knowledge of their (eco)toxicity is still very basic and is restricted to just a few of these substances. Even though their toxicological analysis has been thoroughly performed and ecotoxicological data are available in the literature, a systematic analysis of their ecotoxicological potential has yet to be carried out. To fill this gap, 12 different SAs were chosen for detailed analysis with the focus on different bacteria as well as non-target organisms (algae and plants). A flexible (eco)toxicological test battery was used, including enzymes (acetylcholinesterase and glutathione reductase), luminescent marine bacteria (Vibrio fischeri), soil bacteria (Arthrobacter globiformis), limnic unicellular green algae (Scenedesmus vacuolatus) and duckweed (Lemna minor), in order to take into account both the aquatic and terrestrial compartments of the environment, as well as different trophic levels. It was found that SAs are not only toxic towards green algae (EC₅₀ = 1.54-32.25 mg L⁻¹) but have even stronger adverse effect on duckweed (EC₅₀ = 0.02-4.89 mg L⁻¹) than atrazine - herbicide (EC₅₀ = 2.59 mg L⁻¹).     

Sequential development and exploitation of an exhaustible resource: do monopoly rights promote conservation?

This paper explores the problem of sequential exploitation of exhaustible resources by a monopolist, when a setup cost must be incurred to access the next pool. Under certain circumstances, the monopolist will always follow a more conservationist path of extraction and delay the introduction of new resource pools compared to a social planner. However, with other forms of consumer demand, the monopolist may exhaust the resource more quickly, especially if many new options will follow. These results may apply especially to depletable resources like antibiotics or biotech products, for which significant research and development costs are required, followed by monopoly rights conferred by patents.     

辽宁省生态清洁小流域抗生素监测及生态风险评估

于2021年10月对辽宁省生态清洁小流域抗生素的赋存浓度、分布特征进行了调查。采用风险商值法对小流域的抗生素生态风险进行评价。结果表明,辽宁省生态清洁小流域中8种抗生素均有不同程度检出,检出总质量浓度范围为0013～0.313 μg/L,平均值为0.072 μg/L;小流域中抗生素质量浓度均低于我国大部分河流和流域。不同类型抗生素空间分布规律差异明显,检测出的抗生素中,质量浓度最高的是罗红霉素（ROX）,检出率最高的是磺胺甲噁唑（SMX）;各监测点位抗生素组分的占比排序为：SMX＞ROX＞替米考星（TIC）＞氟苯尼考（FFC）;抗生素主要来源是畜禽养殖和生活污水。生态风险评价结果显示,ROX、脱水红霉素（ERY-H₂O）、诺氟沙星（NOR）和SMX存在高风险,其余种类呈现中、低风险。生态清洁小流域水体中暴露出的抗生素生态风险不容忽视,亟待进一步探究环境风险并采取有效的防治措施。     

长江江苏段抗生素的空间分布特征及典型污染来源分析

利用超高效液相色谱-三重四极杆质谱法,于2021年4月对江苏省长江干流12个监控断面、入江支流116个监控断面表层水中7大类42种抗生素的分布特征和浓度水平进行研究,并开展典型污染来源分析。结果表明,平水期长江干流42种抗生素总质量浓度范围为47.3～92.8 ng/L,处于较低水平;各入江支流抗生素总质量浓度范围为16.2～3 052 ng/L,干支流水体中检出品种以磺胺类、氯霉素类、林可酰胺类及大环内酯类为主;通过差异性比较发现,C市存在磺胺类抗生素污染的典型区域;典型污染溯源分析结果表明,工业废水可能是该地区环境水体中抗生素污染的来源之一。长江江苏段及地表水中各类抗生素普遍检出,虽然抗生素总量水平不高,但由制药废水、畜禽养殖、污水处理厂等污染源引入而引起的长期积累仍是隐患。研究结果为江苏省长江流域水环境抗生素污染控制和管理提供基础数据。     

Degradation and removal methods of antibiotics from aqueous matrices--a review

Over the past few years, antibiotics have been considered emerging pollutants due to their continuous input and persistence in the aquatic ecosystem even at low concentrations. They have been detected worldwide in environmental matrices, indicating their ineffective removal from water and wastewater using conventional treatment methods. To prevent this contamination, several processes to degrade/remove antibiotics have been studied. This review addresses the current state of knowledge concerning the input sources, occurrence and mainly the degradation and removal processes applied to a specific class of micropollutants, the antibiotics. In this paper, different remediation techniques were evaluated and compared, such as conventional techniques (biological processes, filtration, coagulation, flocculation and sedimentation), advanced oxidation processes (AOPs), adsorption, membrane processes and combined methods. In this study, it was found that ozonation, Fenton/photo-Fenton and semiconductor photocatalysis were the most tested methodologies. Combined processes seem to be the best solution for the treatment of effluents containing antibiotics, especially those using renewable energy and by-products materials.     

抗生素在环境中的迁移转化及生物效应研究进展

抗生素被长期大量地使用于人和动物的疾病治疗,同时作为饲料添加剂长期使用于畜牧业及水产养殖业。然而,大部分抗生素不能完全被机体吸收,大量的抗生素以原形或代谢物形式经由病人和禽畜粪尿排入环境,经不同途径进入土壤和水体,从而造成环境污染。多项研究显示在城镇废水和地表水中检测到了抗生素的存在,但关于抗生素在环境中的迁移转化及生物效应等研究资料很少。环境中的抗生素会对微生物、水生生物、土壤生物和植物等产生危害,并产生大量耐药菌,影响禽畜等的正常生长,进而对人类健康及整个生态系统构成威胁。为评估抗生素在环境中潜在的危害,本文就抗生素在环境中的迁移转化以及生物效应等多方面进行综述,并提出了今后研究的方向。     

Antibiotics along an alpine river and in the receiving lake with a catchment dominated by grazing husbandry

The livestock breeding industries face overuse of antibiotics, which has been intensively studied in recent years. However, the occurrence and fate of antibiotics as well as their potential threats to the aquatic environments in alpine and arid regions remain unclear. This study investigated the relationship of the occurrence and concentrations of antibiotics between the Kaidu River and Bosten Lake in a typical alpine basin in China. Hot spots with antibiotic pollution source were explored. The antibiotic concentrations in river water and suspended sediment (SPS) were 2.20-99.4 ng/L and 1.03-176 ng/g. The dominant antibiotics were tetracyclines, sulphacetamide, and ofloxacin in river water and sulfonamides, clarithromycin, roxithromycin, and ofloxacin in SPS. The apparent differences in pollution sources and landscapes in different reaches led to the obvious spatial patterns of antibiotics in the Kaidu River. Higher partition coefficient of antibiotic between SPS and water phases for sulfonamides than tetracyclines was because that tetracyclines strongly responded to clay contents while sulfonamides significantly responded to organic carbon contents in SPS. There were significant differences in detected antibiotic categories between the river and the lake. Fluoroquinolones (especially ciprofloxacin and enrofloxacin) were detected in the lake while sulphacetamide was only detected in the river. Therefore, the surrounding husbandry and aquaculture around the Bosten Lake was an important antibiotic pollution source in addition to inputs from the Kaidu River. This research suggested that alpine lakes could be an important sink of antibiotics in alpine dry regions, and thus impose greater threats to the aquatic ecosystem.     

小诺霉素发酵废水好氧生物处理试验研究

对具有强抑制性污染物的抗生素小诺霉素发酵废水，选择活性污泥、粉末活性炭（ＰＡＣＴ）、纯氧曝气等３种好氧生物处理法进行了比较试验。根据实验结果，小诺霉素发酵废水的生物降解呈抑制动力学，采用Ｍａｒｑｕａｒｔ方法对动力学模式进行参数估计。ＰＡＣＴ能够有效地降低降解过程中微生物受到的抑制作用，从而明显地改善了生物处理过程动力学。     

抗生素制药废水的混凝和生化处理研究

针对当前抗生素制药废水处理难题,以沈阳同联抗生素制药废水为研究对象,研究了物化法和生化法对抗生素废水的联合处理。首先采用硼泥和PAM对废水进行混凝处理,然后对混凝出水采用水解酸化-UASB-接触氧化-生物活性炭工艺进行生化处理。实验确定了此生化处理系统的最大流量为2000mL/d,水力停留时间为3d,CODCr容积负荷为4.41kg/m3.d。废水经过生物活性炭深度处理后CODCr可达600mg/d以下。