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- Integrated process of immediate one-step lime precipitation, atmospheric carbonation, constructed wetlands, or adsorption for industrial wastewater treatment: A reviewPublication . Simão Madeira, Luís Miguel; Carvalho, Fátima; Almeida, Adelaide; Ribau Teixeira, MargaridaThe transition from the linear economy paradigm to the circular economy in industrial wastewater treatment systems is on the global agenda. The search for new simple, eco-innovative, and low-cost processes for treating industrial wastewater, which can also be used by small and medium-sized industries, has been a constant challenge especially when environmental sustainability is considered. So, a new integrated industrial wastewater treatment system has been developed that includes the immediate one-step lime precipitation process (IOSLM) and atmospheric carbonation (AC), followed by constructed wetlands (CWs) or adsorption. The current review provides an overview of industrial wastewater treatment strategies for high- and low-biodegradable wastewater. A background on functionality, applicability, advantages and disadvantages, operating variables, removal mechanisms, main challenges, and recent advances are carried out for each process that makes up the IOSLM+AC+CW/adsorption integrated system. The prospects of the IOSLM+AC+CW/adsorption integrated system are also discussed. Not neglecting the improvements that still need to be made in the integrated treatment system as well as its application to various types of industrial wastewater, this review highlights that this treatment system is promising in industrial wastewater treatment and consequent by-product recovery. The IOSLM+AC integrated system showed that it can remove high amounts of organic matter, total suspended solids, oils and fats, phosphorus, and ammonium nitrogen from industrial effluents. On the other hand, constructed wetlands/adsorption can be alternatives for refining effluents still containing organic matter and nitrogen that were not possible to remove in the previous steps.
- pH adjustment for seasonal control of UF fouling by natural watersPublication . Ribau Teixeira, Margarida; Rosa, Maria JoãoNatural surface waters in Algarve, Portugal, have important seasonal variations in natural organic matter (NOM) content, that influences ultrafiltration (UF) performance. This paper addresses the evaluation of the pH adjustment for seasonal control of UF fouling at a laboratory scale, using a plate and frame polysulphone membrane of 47 kDa MWCO. Results of two types of natural water (clear water, 3-5 NTU, and turbid water, 33-34.6 NTU) and three different water pH values (acid, neutral and basic) demonstrated that the pH adjustment could be used for seasonal control of UF fouling: when the water has less NOM (in dry periods, clear water), the acid pH will improve the UF performance, while during and after intense rainfall periods (turbid water with high NOM concentration) basic pH will be advantageous, because it minimizes membrane fouling. This behaviour is explained for clear water in terms of charge effects on membrane size. For turbid water, the electrostatic repulsion between membrane surface and NOM and turbidity particles is reduced at pH 4.13 and protonation of the NOM functional groups decreases the hydrodynamic radii of humic substances while increasing their hydrophobicity and their tendency to adsorb. Therefore, a dense fouling layer develops and flux is lower at pH 4.13 than at pH 8.33. These results together with the observed raw water feed concentrations decline and rejection decrease with WRR confirm the extensive adsorption on the membrane enhanced by the moderate hardness cation of this water.
- Social life cycle analysis as a tool for sustainable management of illegal waste dumping in municipal servicesPublication . Santos, Ana Carina; Mendes, Paula; Ribau Teixeira, MargaridaSome wastes are illegally dumped on public/private areas, causing several aesthetic, environmental,economic and social negative impacts and representing a public hazard. These sites need to be treatedand managed and this task is often a responsibility of municipalities, representing high costs. However,there is a lack of strategies for the municipal management of these degraded areas that minimize costs,restore the ecological value of the area and eliminate the public hazard. This work proposes a conceptualmodel for the management of illegal dumping degraded areas by municipal services, based on a sociallife cycle assessment (SLCA). The model proposed is an open-participatory management tool whichsupplies the information needed for the waste management strategy for illegal waste deposit sites.Methods to evaluate and apply SLCA in this context are scarce. Therefore, SLCA is presented as a tool thatcan be applied to organisations in strategic analysis and structuring complex decision-making processesin order to identify optimisation potentials. It combines an environmental and a socio-economicassessment, contributing to the full assessment of products and services within the context of sustain-able development. The framework intends to promote the improvement of social conditions and thesocio-economic performance of a product throughout its life cycle for all the stakeholders involvedwithin the context of sustainable development. Illegal deposits sites of Construction and DemolitionWastes (CDW) in municipalities are used as a case study for model implementation. The outputs of thismodel are: i) understanding the real situation of the illegally deposited wastes; ii) management practicescomparing and integrating environmental, social, and economic objectives; iii) open-participatorymanagement; iv) orientations to strategy definition; v) use of the life-cycle product principle contrib-uting to a circular economy; and vi) assisting with municipalities performance.
- Monitoring of hazardous substances at Alcantarilha’s WTP, PortugalPublication . Rosa, Maria João; Cecilio, T.; Ribau Teixeira, Margarida; Viriato, M.; Coelho, R.; Lucas, HelenaA monitoring programme of hazardous substances was implemented in Alcantarilha’s water treatment plant (Algarve, Portugal) since 2002, in addition to the legally established monitoring of standard physical, chemical and microbiological parameters. The objective of this programme was to ensure the drinking water quality regarding the waterborne disease organisms Cryptosporidium, Giardia, Salmonella, Pseudomonas aeruginosa, enterovirus and cyanobacteria, and the potentially harmful chemicals aluminium, cyanotoxins, and disinfection by-products (THM) and their precursors (TOC, DOC, UV254nm, SUVA). Most of these parameters are new and still not regulated by the Portuguese and the European legislation. Data presented in this study refer to the period of August 2002 to October 2003. Results show that, despite the seasonal variations of the raw water quality, concentrations of the hazardous substances in the supplied drinking water were far below the legal standards and the WHO’s and EPA guideline values, demonstrating the high removal efficiencies of this treatment plant.
- Estratégia de sustentabilidade para a aplicação da análise do ciclo de vida à gestão de resíduos de construção e demolição em serviços municipaisPublication . Santos, Ana Carina; Mendes, Paula; Ribau Teixeira, MargaridaO sector da construção civil constitui uma actividade muito antiga que consome muitos recursos naturais e cuja gestão dos seus resíduos, Resíduos de Construção e Demolição (RCD), só recentemente começou a suscitar algumas preocupações. A significativa quantidade de RCD gerada pelo sector da construção civil é hoje um grande problema a ser enfrentado pelas empresas construtoras e pelos serviços municipais. A forma descontrolada como os RCD têm sido produzidos e geridos em Portugal, tem introduzido dificuldades acrescidas na obtenção de soluções conducentes à valorização/eliminação dos RCD como um todo. Urge reduzir e reciclar os RCD, adoptando uma atitude de uma forma preventiva, criar condições para uma intervenção mais criteriosa e sustentável. O presente trabalho visa discutir os aspectos relacionados com o diagnóstico da gestão de RCD através da Análise SWOT, para posterior aplicação da Avaliação do Ciclo de Vida (ACV), apontando possíveis usos desta ferramenta na dinâmica urbana, providenciando informação necessária para aferir do estado da gestão dos RCD em serviços municipais, bem como ajudar na monitorização do progresso, através de uma gestão sustentável, como é o caso da Divisão de Higiene Urbana e Resíduos Sólidos (DHURS) da Câmara Municipal de Loulé (CML). Como resultado deste estudo, apresentam-se as linhas gerais prioritárias de actuação para o desenvolvimento da ACV.
- Environmental impacts on soil and groundwater at airports: origin, contaminants of concern and environmental risksPublication . Nunes, L.; Zhu, Y.-G.; Stigter, T. Y.; Monteiro, José Paulo; Ribau Teixeira, MargaridaEnvironmental impacts of airports are similar to those of many industries, though their operations expand over a very large area. Most international impact assessment studies and environmental management programmes have been giving less focus on the impacts to soil and groundwater than desirable. This may be the result of the large attention given to air and noise pollution, relegating other environmental descriptors to a second role, even when the first are comparatively less relevant. One reason that contributes to such ‘‘biased’’ evaluation is the lack of systematic information about impacts to soil and groundwater from airport activities, something the present study intends to help correct. Results presented here include the review of over seven hundred documents and online databases, with the objective of obtaining the following information to support environmental studies: (i) which operations are responsible for chemical releases?; (ii) where are these releases located?; (iii) which contaminants of concern are released?; (iv) what are the associated environmental risks? Results showed that the main impacts occur as a result of fuel storage, stormwater runoff and drainage systems, fuel hydrant systems, fuel transport and refuelling, atmospheric deposition, rescue and fire fighting training areas, winter operations, electrical substations, storage of chemical products by airport owners or tenants, and maintenance of green areas. A new method for ranking environmental risks of organic substances, based on chemical properties, is proposed and applied. Results show that the contaminants with the highest risks are the perfluorochemicals, benzene, trichloroethylene and CCl4.
- Biogas production from microalgal biomass produced in the tertiary treatment of urban wastewater: assessment of seasonal variationsPublication . Barros, Raúl; Raposo, Sara; Morais, Etiele; Rodrigues, Brígida; Lourenço Afonso, Valdemira; Gonçalves, Pedro; Marques, José; Cerqueira, Ricardo; Varela, João; Ribau Teixeira, Margarida; Barreira, LuísaThe valorization of microalgal biomass produced during wastewater treatment has the potential to mitigate treatment costs. As contaminated biomass (e.g., with pharmaceuticals, toxic metals, etc.) is often generated, biogas production is considered an effective valorization option. The biomass was obtained from a pilot facility of photobioreactors for tertiary wastewater treatment. The pilots were run for one year with naturally formed microalgal consortia. The biogas was generated in 70 mL crimp-top vials at 35 °C, quantified with a manometer and the methane yield measured by gas chromatography. A maximum biogas production of 311 mL/g volatile solids (VS) with a methane yield of 252 mL/g VS was obtained with the spring samples. These rather low values were not improved using previous thermo-acidic hydrolysis, suggesting that the low intrinsic biodegradable organic matter content of the consortia might be the cause for low yield. Considering the total volume of wastewater treated by this plant and the average amount of methane produced in this study, the substitution of the current tertiary treatment with the one here proposed would reduce the energy consumption of the plant by 20% and create an energy surplus of 2.8%. The implementation of this system would therefore contribute towards meeting the ambitious decarbonization targets established by the EU.
- Nanofibrillated cationic cellulose derivatives as flocculants for domestic wastewater treatmentPublication . Ribau Teixeira, Margarida; Ismail, Abdullah; Medronho, Bruno; Alves, Luís; Pedrosa, Jorge F.S.; Ferreira, Paulo J.T.; Serrão Sousa, Vânia; Rosa Da Costa, AnaNatural-based coagulants have emerged as a reliable option to implement more sustainable operations and management of wastewater treatment plants. This work aims at evaluating the use of cationic nanofibrillated celluloses (cNFC) as novel bio-based flocculants to treat domestic wastewaters by the most widely employed treatment process – coagulation/flocculation. Two cNFC samples were prepared with different charge densities and tested as coagulant/flocculants using different water characteristics. The effect of cNFCs was studied by measuring the residual turbidity and dissolved organic carbon. The aggregation mechanism and kinetics of flocculation were also evaluated. Results show that cNFC can be used as an efficient flocculant to treat medium and high DOC waters since they considerably reduce turbidity (turbidity removals varied between 66.0 % and 85.7 % for the waters and cNFCs tested) without increasing dissolved organic carbon. Instead, cNFC removed dissolved organic carbon from domestic wastewaters (between 22.1 % and 65.5 % of DOC removals for the waters and cNFCs tested), which is a novel remarkable finding and a step forward in this knowledge area. High density charged cNFC revealed superior removal capacity at lower doses than the commercial coagulant FeCl3.
- Recuperação de água industrial utilizando tecnologia de membranasPublication . Ribau Teixeira, Margarida; Rosa, Maria JoãoSão descritos resumidamente os fundamentos sobre membranas e processos de separação com membranas. As aplicações mais frequentes dos processos de separação com membranas no tratamento de água residual industrial são discutidos. O tratamento das águas industriais através da tecnologia de membranas permite a recuperação de produtos de elevado valor económico, para além de permitir a reutilização da água do processo.
- A rapid small scale evaluation of ultrafiltration performance for surface water treatment at Alcantarilha’s WTW (Algarve, Portugal)Publication . Ribau Teixeira, Margarida; Lucas, Helena; Rosa, Maria JoãoA rapid small scale evaluation of ultrafiltration (UF) performance with and without physicalchemical pre-treatment was performed to up-grade the conventional treatment used for drinking water production in Alcantarilha’s WTW, Algarve, Portugal. Direct UF and pre-ozonation/ coagulation/ flocculation/ sedimentation/ UF (O/C/F/S/UF) were evaluated using polysulphone membranes of different apparent molecular weight cut-off (MWCO) (15-47 kDa). The results indicated that (i) UF is an effective barrier against microorganisms, including virus larger than 80 nm; (ii) for surface waters with low to moderate SUVA values, direct UF performance is equivalent or better than the conventional treatment in terms of residual turbidity, while UV254nm and TOC residuals require the use of O/C/F/S/UF; (iii) the permeate quality improves with the membrane apparent MWCO decrease, especially for the direct UF, although the conventional treatment performance is never reached using UF; (iv) membrane fouling and adsorption phenomena are more severe in direct UF than in O/C/F/S/UF sequence (preozonation decreases the membrane foulants by decreasing their hydrophobicity) and these phenomena increase with the membrane hydraulic permeability and, particularly, with the membrane apparent MWCO.