Combination of adsorption and biological treatment in a SBR for colour elimination in municipal wastewater with discharges of textile effluents

ischarge of textile wastewaters (WW) to municipal wastewater treatment plants (MWWTPs) entails the presence of colour in the final effluent. It causes a negative impact on the environment and, additionally, hinders an efficient disinfection by UV lamps. In this work, a combined process consisting of the addition of powdered activated carbon (PAC) to a sequencing batch reactor was studied. The main objective was to reduce WW colour in order to obtain transmittance values in the final effluent above 60%, measured at a wavelength of 254 nm, with the aim of ensuring disinfection with UV lamps. Experiments were performed with both simulated wastewater (SWW) including the azo dye Reactive Black 5 and WW from a MWWTP receiving discharges from textile mills. Biosorption increased the transmittance of the effluent around 25% for SWW and 24% for WW, in comparison with the values measured in the influent. The PAC concentrations for the achievement of a value of 60% in the transmittance of the treated water were 250 and 400 mg/L for the simulated effluent and for the WW, respectively. PAC had to be periodically added in order to cover its loss in the waste sludge.Authors thank Depuracion de Aguas del Mediterraneo S.A. for its support in the work.Ferrer-Polonio, E.; Iborra Clar, A.; Mendoza Roca, JA.; Iborra Clar, MI. (2014). Combination of adsorption and biological treatment in a SBR for colour elimination in municipal wastewater with discharges of textile effluents. Desalination and Water Treatment. 55(7):1915-1912. doi:10.1080/19443994.2014.929979S1915191255

Brine recovery from hypersaline wastewaters from table olive processing by combination of biological treatment and membrane technologies

[EN] The fermentation brines from table olive processing (FTOP) are hypersaline effluents (conductivities higher than 75 mS·cm-1) with high organic matter concentrations (COD around 10 g·L-1), which also include phenolic compounds (between 700 and 1500 mg TY·L-1). In this work, an integrated process for the FTOP reuse as brine in the table olive processing has been evaluated. This integrated process consisted of a biological treatment followed by a membrane system, which included ultrafiltration (UF) plus nanofiltration (NF). The biological treatment was carried out by 6 L laboratory sequencing batch reactor (SBR). UF and NF were performed in laboratory plants for flat membranes of 0.0125 and 0.0072 m2, respectively. Each stream generated during the FTOP treatment (SBR effluent, and UF and NF permeates) were evaluated. The SBR eliminated around 80% of COD and 71% of total phenols concentration. In the final NF permeate the COD concentration was lower than 125 mg·L-1; while the turbidity, colour and phenolic compounds, were completely removed.The authors of this work thank the financial support of CDTI (Centre for Development Technological Industrial) depending on the Spanish Ministry of Science and Innovation.Ferrer-Polonio, E.; Carbonell Alcaina, C.; Mendoza Roca, JA.; Iborra Clar, A.; Alvarez Blanco, S.; Bes-Piá, M.; Pastor Alcañiz, L. (2017). Brine recovery from hypersaline wastewaters from table olive processing by combination of biological treatment and membrane technologies. Journal of Cleaner Production. 142:1377-1386. doi:10.1016/j.jclepro.2016.11.169S1377138614

Comparison of two strategies for the start-up of a biological reactor for the treatment of hypersaline effluents from a table olive packaging industry

Biological treatment of hypersaline effluents with high organic matter concentrations is difficult to carry out and it can require a long start-up phase. This is the case of the treatment of fermentation brines from the table olive packaging (FTOP) industries. These effluents are characterized by conductivity values around 90 mS/cm, COD around 15,000 mg/L and total phenols concentration around 1000 mg/L. In this work, FTOP has been treated in two sequencing batch reactors (SBRs) operated in parallel. In each SBR a different start-up strategy has been carried out. In the SBR-2, biomass was previously acclimated to high salinity using simulated wastewater without phenolic compounds, meanwhile in the SBR-1, FTOP was added from the beginning of the start-up. Results indicated more operational problems in the SBR-2 consisting in a higher deflocculation that drove to high turbidity values in the effluent. Besides, at the end of the start-up, the SBR-1 reached higher COD removal efficiencies than SBR-2 (88% and 73%, respectively). In both reactors, an increase in gamma-Proteobacteria in the microbial population was observed for increasing conductivities. In addition, phenols were completely removed in both reactors at the end of the start-up, what implied very low toxicity values in the effluent.The authors of this work thank the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation.Ferrer-Polonio, E.; Mendoza Roca, JA.; Iborra Clar, A.; Alonso Molina, JL.; Pastor Alcañiz, L. (2015). Comparison of two strategies for the start-up of a biological reactor for the treatment of hypersaline effluents from a table olive packaging industry. Chemical Engineering Journal. 273:595-602. doi:10.1016/j.cej.2015.03.062S59560227

Cognitive sophistication and deliberation times

Differences in cognitive sophistication and effort are at the root of behavioral heterogeneity in economics. To explain this heterogeneity, behavioral models assume that certain choices indicate higher cognitive effort. A fundamental problem with this approach is that observing a choice does not reveal how the choice is made, and hence choice data is insufficient to establish the link between cognitive effort and behavior. We show that deliberation times provide an individually-measurable correlate of cognitive effort. We test a model of heterogeneous cognitive depth, incorporating stylized facts from the psychophysical literature, which makes predictions on the relation between choices, cognitive effort, incentives, and deliberation times. We confirm the predicted relations experimentally in different kinds of games