ResumoO monitoramento ambiental dos chamados microcontaminantes ou micropoluentes vem ganhando grande interesse da comunidade científica desde os anos 1970. Nesse grupo de contaminantes estão incluídos fármacos de diversas classes, produtos de limpeza e higiene pessoal, substâncias aplicadas na produção de plásticos e resinas, pesticidas, hormônios naturais e seus subprodutos, entre outros compostos. A principal via de contaminação do meio ambiente com fármacos e desreguladores endócrinos (DE) é o lançamento de esgotos in natura e tratado. Nesse contexto, este artigo compila dados de ocorrência de fármacos e DE no afluente e efluente de estações de tratamento de esgoto (ETE), discute os mecanismos envolvidos na sua remoção em ETE e faz uma análise comparativa da remoção de tais compostos em diferentes sistemas de tratamento.Palavras-chave: microcontaminantes; esgoto; tratamento. AbstractThe environmental monitoring of the so-called micropollutants has gained great interest since the 1970s. In this group of compounds are included several classes of pharmaceuticals, cleaning and personal care products, substances applied in plastics and resins, pesticides, natural hormones and their byproducts, among others. The main route of contamination of the environment with pharmaceuticals and endocrine disrupting compounds (EDC) is through the discharge of raw and treated sewage. Thus, this paper summarizes data on the occurrence of pharmaceuticals and EDC in raw and treated sewage, provides information regarding the mechanisms involved in their removal and compares their removal in different treatment processes.

No abstract

Dissolved gases produced within engineered anaerobic processes subsequently create a fugitive emission which can have financial, environmental and health and safety implications. Whilst desorption technology has been used to control dissolved gases in the drinking water sector, there is considerably less understanding of its deployment in wastewater for which there are numerous existing and emerging challenges. This review therefore focuses on existing and proposed technological approaches to gas desorption in engineered anaerobic wastewater processes, with specific emphasis on technology compatibility and downstream gas phase management. Simplified engineered solutions such as diffused aeration and multi-tray aerators appear robust solutions for implementation into wastewater. However, these processes are characterised by a low mass transfer coefficient and require high gas to liquid ratios (G/L) to achieve reasonable separation, which suggests their suitability is limited to small scale applications, in which gas recovery is not a priority. Packed columns and membrane contactors afford process intensification through increasing interfacial area which favours large scale applications; although both will require prefiltration technology to obviate media clogging. Vacuum or steam is the preferred driving force for separation when gas recovery is sought, while sweep-gas is energetically favoured. Sweep-gas has been used for gas recovery by operating at G/L toward the equilibrium value, which somewhat constrains mass transfer. Process selection must therefore be weighted on whole life cost, but will also be dependent upon process scale, financial (e.g. incentivisation) and non-financial (e.g. carbon) instruments, which are strongly influenced by regional policy.

No abstract

This work investigated the occurrence of pharmaceuticals and endocrine disrupting compounds (EDCs) in raw sewage (from Belo Horizonte city, Minas Gerais state, Brazil) and assessed their behavior in demo-scale upflow anaerobic sludge blanket reactors (UASB reactors) operated at different hydraulic retention times (HRT). The dissolved concentration of the studied micropollutants in the raw and treated sewage was obtained using solid phase extraction (SPE) followed by analysis in a liquid chromatography system coupled to a hybrid high resolution mass spectrometer consisting of an ion-trap and time of flight (LC-MS-IT-TOF). The natural (estradiol) and synthetic (ethinylestradiol) estrogens were hardly detected; when present, however, their concentrations were lower than the method quantification limits. The concentrations of bisphenol A and miconazole in raw sewage were similar to that reported in the literature (around 200 ng L⁻¹ and hardly detected, respectively). The antibiotics sulfamethoxazole (median 13.0 ng L⁻¹) and trimethoprim (median 61.5 ng L⁻¹), and the other pharmaceutical compounds (diclofenac and bezafibrate, with median 99.9 and 94.4 ng L⁻¹, respectively) were found in lower concentrations when compared with reports in the literature, which might indicate a lower consumption of such drugs in Brazil. The UASB reactors were inefficient in the removal of bisphenol A, and led to an increased concentration of nonylphenol in the effluent. The anaerobic reactors were also inefficient in the removal of diclofenac, and led to a partial removal of bezafibrate; whereas, for sulfamethoxazole there seemed to be a direct relationship between the HRT and removal efficiencies. For trimethoprim the sludge retention time (SRT) seemed to play an important role, although it was only partially removed in the UASB reactors.