Extraction and analysis of long chain fatty acids adsorbed onto active and inactivated anaerobic sludge

Extraction and GC analysis of the adsorbed long chain fatty acids onto active and inactivated sludge taken from two EGSB reactors fed with oleic acid as the sole carbon source at 6 kgCOD/m3.day was determined. No gradual acclimation of sludge to this LCFA was performed. Active sludge had been overloaded with oleic acid in a previous experiment and a possible retrieval of its activity was investigated. However the results revealed that the average removal efficiency was as low as 35% and only 19% of the biogas was methane. In the inactive reactor COD removal efficiency was 14%, corresponding only to physical adsorption, because no methane was produced. Extraction and analysis of the adsorbed fatty acids revealed that in the active sludge palmitic acid was the dominant fatty acid, in average, 3 to 52 times higher than oleic acid. In the inactivated sludge the main fatty acid detected was oleic acid, 8 times higher than palmitic acid

Sequencing adsorption and degradation cycles towards the methanization of long chain fatty acids : comparison between granular and suspended sludge

The aim of the present work was to study the maximum potential methane production in batch assays of sludge samples taken along the operation of two EGSB reactors (RI inoculated with granular sludge and RII inoculated with suspended sludge) fed with increasing oleic acid concentrations between 2 and 8 gCOD/l (HRT=1 day). After removing the residual substrate, the sludge was incubated in batch vials without any added carbon source. A maximum methane production rate of 152±21 mlCH4(STP)/gVS.d was obtained for the RII-suspended sludge taken on day 70, when oleate at a concentration of 2 g COD/l was fed with a cosubstrate (50% COD). The maximum plateau achieved in the methane production curve was 1145±307 mlCH4(STP)/gVS, obtained for the RII-suspended sludge taken on day 162, when oleate was fed as the sole carbon source at 6 g COD/l. Methanization rate of the adsorbed substrate was enhanced under stirring conditions and was inhibited by adding oleic acid. Extraction and GC analysis confirmed that the main adsorbed substrate was palmitate, and not oleate, as previously suspected. These results evidence the advantage of sequencing adsorption and degradation cycles for the treatment of effluents with high lipid content

Anaerobic degradation of oleic acid by suspended and granular sludge : identification of palmitic acid as a key intermediate

The aim of the present work was to study the maximum potential methane production in batch assays of sludge samples taken along the operation of two EGSB reactors (RI inoculated with granular sludge and RII inoculated with suspended sludge) fed with increasing oleic acid concentrations between 2 and 8 gCOD/l (HRT = 1 day). After removing the residual substrate, the sludge was incubated in batch vials without any added carbon source. A maximum methane production rate of 152 ± 21 mlCH4(STP)/gVS.day was obtained for the suspended sludge taken on day 70, when oleate at a concentration of 2 g COD/l was fed with a co-substrate (50% COD). The maximum plateau achieved in the methane production curve was 1145 ± 307 mlCH4(STP)/gVS, obtained for the suspended sludge taken on day 162, when oleate was fed as the sole carbon source at 6 g COD/l. The methanization rate of the adsorbed substrate was enhanced under stirring conditions and was inhibited by adding oleic acid. Extraction and GC analysis confirmed that the main adsorbed substrate was palmitate, and not oleate. Accumulated palmitate adsorbed onto the sludge and further β-oxidation was inhibited when in the presence of oleic acid. If oleic acid was removed from the medium β-oxidation proceeded with methane production. Suspended sludge was more efficient than granular sludge

Olive Mill wastewater bioremediation by Bjerkandera paranensis: a sustainability and technological evaluation

Remediation of olive mill wastewater (OMW) is an important issue associated with olive-oil manufacturing, a widespread activity in the Mediterranean area. This high organic loading effluent contains water, organic acids, high-molecular-weight polyphenols such as tannins, antocyanins and catechins, which are considered to be responsible for its brownish black colour and toxic properties. The composition of OMWs is highly variable with respect to each individual component, depending on the process conditions and on the agricultural specificities. In this work, the ability of a “white-rot” fungus, Bjerkandera paranensis, to use undiluted OMW from a two phase process mill (COD = 11.1 gl-1; Phenol Content = 3.9 gl-1; ColourAbs395nm = 7.8) as a substrate was studied. The biodegradation potential of B. paranensis was assessed monitoring several physico-chemical parameters. A chronic ecotoxicity test (Vibrio fisheri growth inhibition test) was carried out to follow the detoxification ability of this fungus. In work, the results demonstrate that OMW was a suitable medium for cultivation of B. paranensis, with corresponding changes in the physico-chemical properties of the OMW. The results showed that B. paranensis removed 93% phenols and 54% COD from the culture medium within 21 days of treatment. In addition, the IC50s values obtained for the different treated samples showed a significant decrease in the effluent chronic toxicity to V. fischeri when the OMW pH was adjusted to 6.0 prior to the treatment (71.8 %), highlighting the OMW detoxification capacity of B. paranensi

New approaches to olive mill wastes bioremediation

Remediation of olive mill wastewater (OMW) is an important issue associated with olive-oil manufacturing, a widespread activity in the Mediterranean area. This high organic loading effluent contains water, organic acids, high-molecular-weight polyphenols such as tannins, antocyanins and catechins, which are considered to be responsible for its brownish black colour and ecotoxic properties. The composition of OMWs is highly variable with respect to each individual component, depending on the process conditions and on the agricultural specificities. Thus, different approaches are applicable concerning to OMW treatment and valorisation , considering the specificities of its production and in particular the oil extraction process. Besides there are several physical, physico-chemical, biological and combined processes to OMW detoxification, each may represent an opportunity for a specific condition. It is important to explore new possibilities that are both environmentally sustainable and economically viable. Under the biological processes the use of fungi and in particular white-rot fungi present a potential interesting alternative for depollution and biological chemicals production or for protein production for feeding. In this aspect we have been testing the ability of a “white-rot” fungus, Bjerkandera paranensis, to use undiluted OMW from a two phase process mill. A chronic ecotoxicity test (Vibrio fisheri growth inhibition test) demonstrated that the growth of this fungus contributed for a significant decrease of the OMW ecotoxicity and demonstrating the potential for further studies with this strain for an alternative biological route to OMW treatment and valorization

Influence of up-flow velocity on the performance of an anaerobic filter under oleic acid overloads

An upflow velocity of 0.21 m h−1 was optimal to minimize the effect of organic shocks (from 6 to 30 kg COD m−3 d−1) when operating an upflow anaerobic filter for the treatment of an oleic acid-based effluent (50% w/v COD). This value represented the transition between a mass transfer controlled regime and a kinetic regime. Under hydraulic shock loads, an increase in upflow velocity from 0.3 to 0.4 m h−1 decreased the removal efficiency from 68 to 51%

Mobilidade em cidades de média dimensão: o caso da cidade de Faro

Recentemente em Portugal, finais 2013, através do projeto de investigação INLUT - “Integração dos usos do solo e transportes em cidades de média dimensão”, que está a ser desenvolvido em parceria por quatro Universidades Portuguesas (IPCB, FAUTL, UTAD e UALG) e financiado pela FCT – Fundação para a Ciência e a Tecnologia, realizaram-se inquéritos gerais à mobilidade em quatro cidades de média dimensão (Faro, Santarém, Vila Real, e Castelo Branco) com o principal objetivo de se analisar a relação entre os usos do solo e os padrões de deslocação da população residente. Com o presente artigo pretende-se apresentar a metodologia seguida, e uma síntese dos resultados obtidos nos 1257 inquéritos à mobilidade realizados à população residente no perímetro urbano de Faro e Montenegro/Gambelas, nas seguintes variáveis: dados da amostra, identificação das áreas homogéneas da área de estudo, distribuição espacial dos inquiridos por local de residência, sexo e estrutura etária dos inquiridos, habilitações literárias, situação face ao mercado de trabalho, potencial de mobilidade, posse de veículos, número de viagens em um dia, hora de início da primeira viagem, apresentação das atitudes (perfil do inquirido), rendimento mensal liquido do aglomerado, cadeia de atividades, taxa de imobilidade, número médio de viagens, tempo médio gasto em viagens, os motivos, as cadeias de atividades realizadas, o modo de transporte escolhido, principais razões da escolha do modo de transporte, número de transbordos efetuados, entre outras. Dado que em Portugal, nas últimas duas décadas, têm vindo a ser realizados inquéritos à mobilidade geral em duas cidades de grandes dimensões: a cidade de Lisboa e a cidade do Porto com a finalidade de estudar os padrões de deslocação dos residentes e visitantes e melhorar a oferta de transportes públicos nas áreas metropolitanas destas duas grandes cidades, apresenta-se também uma breve análise comparativa entre os padrões de mobilidade da cidade de Faro, com os padrões de mobilidade da grande cidade de Lisboa.info:eu-repo/semantics/publishedVersio

Functional and conservation value of fruits - a lab approach

[EN] Fruits are a relevant source of phenols and ascorbate, biomolecules which scavenge reactive oxygen species. For this reason, they are considered as healthy for the human being. Fruits quality depends on their levels of antioxidants and enzyme activities that ensure their conservation. The aim of this work was to plan and execute a laboratory class of Enzymology, a discipline of Biochemistry degree of University of Évora, Portugal, for determining the functional and conservation value of three different fruits types, sold in the market of Évora, Portugal. The development of this activity allowed that students of a pilot class participate in a laboratory activity which intended to compare the content of phenols, ascorbate, and polyphenol oxidase enzyme activity present in apple, peach and blueberries pulp. At Lab activity, the students successfully determined markers of functional and conservation value of selected fruits. The skills acquired by the students, in terms of obtaining fruit pulp and their composition in antioxidants, stimulated their commitment degree on the application of biochemistry in the everyday, acquiring thereby significant learning, with a high degree of satisfaction.This work was funded by National Funds through FCT - Foundation for Science and Technology under the Project UID/AGR/00115/2013.Alves-Pereira, I.; Capela-Pires, J.; Candeias, M.; Ferreira, R. (2020). Functional and conservation value of fruits - a lab approach. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):427-435. https://doi.org/10.4995/HEAd20.2020.11082OCS42743530-05-202

Knowledge-based fuzzy system for diagnosis and control of an integrated biological wastewater treatment process

A supervisory expert system based on fuzzy logic rules was developed for diagnosis and control of a lab- scale plant comprising anaerobic/anoxic/aerobic modules for combined high rate biological N and C removal. The design and implementation of a computational environment in LabVIEW for data acquisition, plant operation and distributed equipment control is described. A step increase in ammonia concentration from 20 to 60 mg N/L was applied during a trial period of 73 hours. Recycle flow rate from the aerobic to the anoxic module and by-pass flow rate from the influent directly to the anoxic reactor were the output of the fuzzy system that were automatically changed (from 34 to 111 L/day and from 8 to 13 L/day, respectively), when new plant conditions were recognized by the expert system. Denitrification efficiency higher than 85% was achieved 30 hours after the disturbance and 15 hours after the system response at an HRT as low as 1.5 hours. Nitrification efficiency gradually increased from 12 to 50% at an HRT of 3 hours. The system proved to properly react in order to set adequate operating conditions that timely led to recover efficient N and C removal rates.Fundação para a Ciência e a Tecnologia , Fundo Social Europeu - BD/1299/2000 , BD/13317/2003