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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.
- Tunning processes for organic matter removal from slaughterhouse wastewater treated by immediate one-step lime precipitation and atmospheric carbonationPublication . Simão Madeira, Luís Miguel; Almeida, Adelaide; Rosa Da Costa, Ana; Mestre, Ana S.; Carvalho, Fátima; Ribau Teixeira, MargaridaAdsorption using unmodified/modified commercial activated carbons and constructed wetlands (CW) planted with Vetiveria zizanioides were evaluated as tuning processes for lowering chemical oxygen demand (COD) from slaughterhouse wastewater pretreated by the integrated process of immediate one-step lime precipitation and atmospheric carbonation. Powdered and granular activated carbons (PAC and GAC), and PAC and GAC incorporated with iron oxide nanoparticles (PACMAG and GACMAG) were used. COD removal using different adsorbent separation methods (i.e., sedimentation, filtration, or magnetic separation) was also evaluated. The adsorption results indicated that the best adsorbent doses and contact times of the studied adsorbents were 70 g L-1 and 5 min for PAC and PACMAG, and 60 g L-1 and 60 min for GAC and GACMAG. Under optimized conditions, GAC (75.7 +/- 1.0%) and GACMAG (73.5 +/- 2.1%) were more efficient than PAC (59.7 +/- 1.0%) and PACMAG (59.0 +/- 0.0%) in removing COD. The incorporation of iron oxide nanoparticles in GAC and PAC did not affect the adsorption of COD. The Temkin model was the best isotherm model found for PAC and PACMAG, while for GAC and GACMAG was the BET model. Pseudo-order n kinetic model was the best kinetic model found for all the adsorbents tested. There were no significant differences in the removal of COD between filtration and magnetic separations. Phytoremediation results indicated that increased COD removal efficiency occurred when the applied COD mass load decreased or when the bed depth was increased. Maximum COD removals of around 89.9-95.0% were achieved. Vetiveria zizanioides showed no signs of toxicity throughout the trials.
- Vertical flow constructed wetland as a green solution for low biodegradable and high nitrogen wastewater: A case study of explosives industryPublication . Madeira, Luís Miguel; Carvalho, Fatima; Teixeira, Margarida Ribau; Ribeiro, Carlos; Almeida, AdelaideThe removal of nitrogen compounds from a pretreated explosives wastewater in vertical flow constructed wetland planted with Vetiveria zizanioides (0.24 m(2) x 0.70 m), filled with light expanded clay aggregates (Leca (R) NR 10/20), was studied. Experiments under constant hydraulic load, 50 +/- 4 Lm(-2) d(-1) and 83 +/- 5 L m(-2) d(-1) without and with flooding level (25%), respectively, were made at different ammonium (3-48 mg NH4+-N L-1), nitrate (56-160 mg NO3--N L-1) and nitrite (0.3-1.1 mg NO2--N L-1) concentrations. Results indicate that without flooding level (unsaturated) the removal efficiencies obtained were 30 +/- 9, 7 +/- 1 and 96 +/- 2%, respectively to NH4+-N, NO3--N and NO2--N. When using flooding level and an external carbon source (C/N ratio from 1.3 +/- 0.19 to 2.5 +/- 0.20), the organic matter (COD) removal efficiencies were above 90%, 75% for NH4+-N and 55% to NO3--N. Increasing the C/N ratio from 2.9 +/- 0.21 to 4 +/- 0.22 did not contributed to upgrade the efficiencies of COD, NH4+-N and NO3--N removal. The denitrification process was occurred in aerobic conditions and nitrite production have ben occurred, probably due to the presence of aerobic conditions that inhibited partially denitrification. (C) 2021 Elsevier Ltd. All rights reserved.
- Optimization of atmospheric carbonation in the integrated treatment immediate one-step lime precipitation and atmospheric carbonation. The case study of slaughterhouse effluentsPublication . Madeira, Luís Miguel; Carvalho, Fátima; Almeida, Adelaide; Ribau Teixeira, MargaridaLong carbonation time has been a common feature in the integrated process composed by immediate one-step lime precipitation and atmospheric carbonation. This work aims to understand how carbonation time can be influenced by reaction pH, as well as how reactor area/volume ratio affects carbonation time and ammonia removal, using slaughterhouse wastewater due to its variable characteristics. In the integrated immediate one-step lime precipitation and atmospheric carbonation process, the immediate one-step lime precipitation re-sults showed that the reaction pH and the type of slaughterhouse wastewater influenced the removal, however, removals were the highest at reaction pH 12. In atmospheric carbonation process, the carbonation time required to reach pH 8 was independent of the reaction pH used. Additionally, at reaction pH 12, the reactor area/volume ratios applied (from 0 to 155.4 m2/m3) showed that higher reactor area/volume ratios caused lower carbonation time, but ammonia removal was not affected. For reactor area/volume ratios of 5 and 155.4 m2/m3, 15 and 1 days were spent to reduce the pH from 11.9 to 8.2, with removals of 71 and 82.6% for NH4+ and 10 and 79.1% for calcium, respectively. High removals of total Kjeldahl nitrogen (>= 71%), biological oxygen demand (>= 80%), ammonium nitrogen (>= 52%), total phosphorus (98%), total suspended solids (>= 52%), turbidity (>= 62%), absorbance at 254 nm (>= 87%), absorbance at 410 nm (>= 83%) and oils & fats (>= 47%) were obtained using immediate one-step lime precipitation and atmospheric carbonation integrated process to treatment slaughter-house wastewater, indicating that the these process is an efficient pretreatment for slaughterhouse wastewaters.
- Immediate one-step lime precipitation and atmospheric carbonation as pretreatment for low biodegradable and high nitrogen wastewaters: A case study of explosives industryPublication . Madeira, Luis; Almeida, Adelaide; Ribau Teixeira, Margarida; Prazeres, Ana; Chaves, Humberto; Carvalho, Fatima; Madeira, Luís Miguel SimãoThe treatment of some industrial wastewaters is complex, since they usually contain complex non-biodegradable organic compounds or toxic compounds which are not easily treatable. These compounds are not removed by biological treatment in wastewater treatment plants and they may affect the removal of ammonium, nitrate, organic nitrogen by these treatment systems. Therefore, this research proposes a new and innovative low-cost and easy-to-apply pre-treatment to treat low biodegradable and high nitrogen wastewaters, using explosive wastewaters as case study. The pre-treatment is composed by immediate one-step lime precipitation (IOSLM) and atmospheric CO2 carbonation (AC) processes. The novelty of the proposed pre-treatment is based firstly on the use of one reactant (hydrated lime) at high concentrations, added in one step, that produces immediately an abundant and insoluble precipitate able to sweep the organic matter and other contaminants from wastewater in a short time and ensure conditions (pH and Ca2+) for the AC process. Secondly, the AC process uses the sludge produced in IOSLM to keep pH high for longer, allowing ammonia removal while simultaneously the pH is reduced by spontaneous reactions with atmospheric CO2. IOSLM results showed 92.1 %, 98.2 % and 100 % of organic matter, oils and fats, and organic nitrogen removals, respectively, for the optimal hydrated lime dose (7.76 g L-1). In AC process 61 % of ammonium nitrogen was removed and pH reduced to 8.1 in 10 days.
- Reutilização de águas resultantes da produção de explosivos: caso de estudo empresa “X”Publication . Madeira, Luís Miguel Simão; Madeira, Luís Miguel Simão; Teixeira, Margarida Ribau; Carvalho, Maria de Fátima Nunes deAs águas residuais resultantes da produção dos explosivos da empresa “X” caraterizam-se físico-quimicamente por conterem uma elevada carga orgânica (5922 mg O2 L-1) com muito reduzida biodegradabilidade (CBO5/CQO = 0,009), concentrações de azoto muito elevadas (1553,9 mg N-NH4+ L-1 e 7233 mg NO3- L-1) e um teor de óleos e gorduras de 285,3 mg L-1. Com objetivo de tratar este efluente, desenvolveu-se um sistema de tratamento, que consistiu na precipitação química em meio básico com Ca(OH)2, carbonatação natural e afinação em zona húmida artificial plantada com Vetivera zizanioides. No processo de precipitação química estudou-se o efeito da dose de cal sobre vários parâmetros físico-químicos, tendo sido escolhida a dose de Ca(OH)2 de 7,76 g L-1 que eleva o pH da água a 10, resulta num efluente límpido e permite atingir remoções de CQO de 92%, óleos e gorduras de 98% e elimina totalmente a matéria orgânica azotada. O sobrenadante obtido apresenta um pH de cerca de 10 e foi neutralizado numa etapa de carbonatação com CO2 atmosférico. Ao fim de 11 dias conseguiu-se a remoção simultânea de 61 % de NH4+, que lhe confere potencialidades para ser utilizado como fertilizante em fertirrega. A etapa de precipitação produziu um precipitado abundante que sedimenta em manto para tempos de retenção hidráulica de 46 minutos com uma percentagem de lamas reduzida, 4,5 %. Adicionalmente foi avaliada a possibilidade de tratamento por zonas húmidas artificais com Vetivera zizanioides sob fluxo sub-superficial vertical, o que permitiu conhecer os processos biológicos envolvidos por análise de vários parâmetros, conhecer as melhores condições operatórias aplicadas para remover maiores cargas mássicas de azoto amoniacal e de nitratos. Apesar de o tratamento proposto ser viável, os resultados evidenciaram que ainda há necessidade de fazer melhorias no tratamento proposto na remoção de azoto amoniacal, matéria orgânica e nitratos.
- Industrial wastewater treatment using eco-innovative technologiesPublication . Madeira, Luís Miguel Simão; Madeira, Luís Miguel Simão; Teixeira, Maria Margarida da Cruz Godinho Ribau; Carvalho, Maria de Fátima Nunes deThe aim of this thesis is the development of a circular treatment sequence for (i) poorly biodegradable effluents with low C/N ratio and (ii) biodegradable effluents with high C/N ratio, using explosives wastewater and slaughterhouse wastewater as case studies, respectively. The proposed integrated treatment system comprises an immediate one-step lime precipitation (IOSLM) and atmospheric carbonation (AC), followed by constructed wetlands (CW) or adsorption, to allow reuse or disposal of the treated wastewater and the reuse of the sludge produced by the IOSLM process. High removals of chemical oxygen demand (COD) (92%), oils and fats (98%), organic nitrogen (100%) and NH4+ (63%) from explosives wastewater were achieved under optimized conditions of IOSLM (7.76 g L-1 of hydrated lime) and atmospheric carbonation (10 days and in the presence of sludge). Later, higher removals of nitrates (55%), COD (90%) and NH4+ (75%) were achieved in CW with 25% flooding rate, an external carbon source (ratio C/N of 1.3), nitrate load of 12 g m-2 d-1 and hydraulic load of 83 L m-2 d-1.
- Reuse of treated slaughterhouse wastewater from immediate one-step lime precipitation and atmospheric carbonation to produce aromatic plants in hydroponicsPublication . Madeira, Luís Miguel Simão; Ribau Teixeira, Margarida; Sérgio Nunes; Adelaide Almeida; Fátima CarvalhoThe transition from the linear economy paradigm to the circular economy in industrial wastewater treatment 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 to ensure environmental sustainability in all types of industries. The present work aimed to evaluate the suitability of the treated slaughterhouse wastewater (SWW) obtained by the integrated process composed of immediate one-step lime precipitation (IOSLM) and atmospheric carbonation (AC) for the production of aromatic plants by hydroponics. Results showed a significant increase in plant height of 177 and 147% and root length of 64 and 37% for Pennyroyal and Chocolate Peppermint plants, respectively, after 26 days. No signs of toxicity or symptoms of micronutrient deficiency were detected in aromatic plants.