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.     

Removal of 17β-estradiol in laccase catalyzed treatment processes

The removal of 17β-estradiol （E2） in laccase catalyzed oxidative coupling processes was systematically studied in this work. We focused on the influence of pH and natural organic matter （NOM） on the performance of the enzymatic treatment processes. It was found that the optimal pH for E2 removal was between 4 and 6. The removal of E2 was slightly inhibited in the presence of NOM. Enzymatic transformation of E2 was second-order in kinetics with first-order to both the concentrations of the enzyme and contaminant. Mass spectrum （MS） analysis suggested that coupling products were formed through radical-radical coupling mechanism. The results of this study demonstrated that laccase catalyzed oxidative coupling process could potentially serve as a treatment strategy to control steroid estrogens.     

人工甜味剂环境行为研究进展

人工甜味剂是一类人工合成或半合成的蔗糖取代物,由于人们对饮食健康的关注而被越来越广泛地应用于食品和饮料中.但是大多数人工甜味剂在人体内几乎不被代谢就随尿液和粪便直接排到生活污水中.近年,几种典型的甜味剂在水体中广泛被检出且浓度较高,同时研究发现部分甜味剂难以降解,因此人工甜味剂已被视为新型有机污染物而得到关注.本文就人工甜味剂在水处理设施中的行为及其在环境来源和分布的相关研究进行了综述,总结了水处理设施和水环境中甜味剂的污染特征规律,并对今后的研究进行了展望.     

城市地表系统POPs多介质循环过程与模拟研究进展

城市地表系统(USS)是陆地表层系统的重要组成部分,而以不透水面覆盖为主要特征的城市土地利用/覆被变化(LUCC)时空过程,打破了系统原有自然地理格局与过程,影响不同介质和界面间的物质循环与能量流动,改变POPs等污染物的循环过程与机理,是城市环境变化和人地相互作用的指示器与重要驱动力,是城市生态环境规划与管理保护的关键依据.本文总结了城市LUCC对POPs多介质分布迁移的影响,包括单介质中POPs的时空分布特征和POPs多介质迁移累积过程;从城市POPs多介质归趋模拟和基于GIS的城市多介质归趋模拟等方面,讨论了城市POPs多介质循环过程归趋模拟的主要进展;展望今后研究中需要重点解决的科学问题:基于不透水面的城市LUCC信息精确提取及与POPs排放输入等相关数据的同化集成; POPs多介质多界面迁移、转化过程与城市LUCC的耦合机理;城市LUCC背景下POPs循环过程、机制的关键模型参数的构建与获取;基于GIS和城市POPs循环过程与机理的、具有高时空分辨率的城市多介质归趋模型(UMFM)的构建与应用.     

Degradation of bisphenol A by photo-fenton processes

The photo-Fenton reactions, which could yield hydroxyl radicals via the catalytic degradation of H₂O₂ by Fe(II), were focused as one of the abiotic degradation processes of bisphenol A (BPA) in surface waters. At pH 6, in the presence of H₂O₂ only, 32% of BPA was degraded after 120?min of irradiation. However, 97% of BPA was degraded in the presence of both H₂O₂ and Fe(II). Without light irradiation, no BPA degradation was observed even in the presence of Fe(II) and H₂O₂. These results show that photo-Fenton processes are effective in the natural attenuation of BPA in surface water. In addition, the presence of humic acids (HAs), which were of more aliphatic nature, resulted in enhancing BPA degradation via the photo-Fenton processes. Therefore, HAs can be one of the important factors in enhancing the degradation of BPA in surface water via the photo-Fenton processes.     

Ecological processes and sustainability

SUMMARY

Ecology has developed from its position as an obscure science to being at the interface of science and public policy. The impact of mankind can be described in ecological terms relating to population size, energy use and non-renewability. Sustainable development needs to be addressed on the basis of knowledge of ecological processes which maintain the environment in a state of change; the processes need to be conserved, not maintained in any particular state. Recent advances in the understanding of ecological processes are reviewed to highlight the potential contribution of this knowledge to the development of a sustainable policy. At the level of the population the significance of considering the extinction risks in the framework of spatio-temporal dynamics is now established indicating opportunities for planning land use more precisely to sustain biodiversity. Whilst the maintenance of habitats is generally the key to the persistence of biodiversity, they must be viewed as ever-changing mosaics within which cycles of succession, best described by Markovian sets of probabilities, are occurring continually. The extent to which these probabilities are distorted will determine whether the ecosystem returns to the same system or moves to a novel one. At the global level, biogeochemical cycles have a certain flexibility in relation to fluxes and stocks, hence pollution must be defined by relating the flow rate of the substance to this flexibility, which often permits the accommodation of anthropogenic perturbations. Non-sustainable processes can be defined in ecological terms, thus providing functional definitions of a sustainable policy and of sustainable development.     

Sustainability in manufacturing processes: practices performed in metal forming,casting, heat treatment,welding and electrostatic painting

ABSTRACT

This article aims to list the main sustainable practices developed in the processes of metal forming, casting, heat treatment, welding and electrostatic painting. When analysed the literature about sustainable manufacturing, a predominance of studies about machining is observed and the processes mentioned are few explored in academic studies. The research strategy used to reach the objective was systematic literature review, conducted for each process cited. Many sustainable practices were identified with prominence of better materials use and energy efficiency. The authors of this article believe that the information presented here can be useful for researches in their future studies and for industry professionals interested in improving manufacturing processes.     

基于硫酸自由基的高级氧化技术研究及应用进展

由于硫酸自由基(SO4-.)具有很高的氧化还原电位,过硫酸盐(S2O82-)活化高级氧化技术作为一种新型氧化技术在环境工程领域具有巨大应用潜能。介绍了热活化、光活化、过渡金属离子三种活化过硫酸盐产生SO4-.的方式,在环境保护方面的现状研究与应用进展,主要涉及受有机污染土壤和地下水的修复、难降解有机废水和废气的处理,阐述了SO4-.高级氧化技术处理各种有机污染物的机理,指出了基于SO4-.的高级氧化技术在处理应用中存在的局限性和未来发展方向。     

乌海市夏季臭氧污染特征及基于过程分析的成因探究

乌海市地形复杂,周边工业园区分布密集,近年来夏季O₃污染问题突出,且污染特征与形成机制尚不明确,分析乌海市O₃变化特征,探究O₃污染形成机制对该区域大气污染防治具有重要意义.本文在分析乌海市2018年6~8月3次持续O₃污染过程特征的基础上,利用WRF-CMAQ模式系统进行模拟并根据过程分析输出结果对污染的成因进行了深入分析,探讨了区域输送和局地光化学反应对乌海市O₃的影响.结果表明,乌海市夏季O₃呈现"单峰"的日变化特征,近地面O₃与向下短波辐射和气温显著呈正相关,与相对湿度呈负相关;空间分布上,乌海市3个工业园区白天和夜间均为O₃低值区,乌海西南部宁夏石嘴山地区、乌海城区和西北部乌兰布和沙漠地区白天为O₃高值区;过程分析结果表明,输送和化学过程及其相对大小对乌海市O₃有决定性影响,6月和7月的污染过程中局地光化学反应和输送共同导致O₃显著升高,且化学过程的影响是输送的两倍左右,8月O₃的升高主要为输送作用的贡献;进一步对输送作用进行分解可知偏南和西北方向的输送对O₃的升高有较大贡献,结合前体物的排放,可能的传输来源为宁夏银川、石嘴山及巴彦淖尔等区域,因此,乌海市应在控制本地排放的基础上,加强区域联防联控,减少区域传输对O₃的影响.     

The representation of cyanobacteria life cycle processes in aquatic ecosystem models

Two simplified versions of a numerical life cycle model for diazotrophic cyanobacteria (of the order Nostocales) are developed and evaluated. Both consider two-life cycle stages, one growing, nitrogen-fixing stage and one stage that combines the resting, germinating and vegetative stages. The versions differ in the vertical resolution of the non-diazotrophic stage: version 1 collects the biomass in one layer at the bottom, version 2 considers sinking and rising of biomass explicitly. The results of the two versions are compared with a complex cyanobacteria life cycle model which describes four different life cycle stages each with two internal quotas for energy and nitrogen. The two simplified approaches show a good agreement with respect to the main characteristics of cyanobacteria dynamics (timing and duration of blooms, magnitude of nitrogen fixation, interannual variability). Our model study shows that both simplified approaches are suitable to be implemented into three-dimensional coastal or lake models.