Wyniki wyszukiwania - BazTech

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Dynamic modelling of an anaerobic reactor treating coffee wet wastewater via multiple regression model

Guardia-Puebla Yans, Llanes-Cedeño Edilberto, Domínguez-León Ana Velia, Arias-Cedeño Quirino, Sánchez-Girón Victor, Morscheck Gert, Eichler-Löbermann Bettina

Journal of Water and Land Development

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2021

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no. 50

229--239

EN

A multiple regression model approach was developed to estimate buffering indices, as well as biogas and methane productions in an upflow anaerobic sludge blanket (UASB) reactor treating coffee wet wastewater. Five input variables measured (pH, alkalinity, outlet VFA concentration, and total and soluble COD removal) were selected to develop the best models to identify their importance on methanation. Optimal regression models were selected based on four statistical performance criteria, viz. Mallow’s Cp statistic (Cp), Akaike information criterion (AIC), Hannan–Quinn criterion (HQC), and Schwarz–Bayesian information criterion (SBIC). The performance of the models selected were assessed through several descriptive statistics such as measure of goodness-of-fit test (coefficient of multiple determination, R2; adjusted coefficient of multiple determination, Adj-R2; standard error of estimation, SEE; and Durbin–Watson statistic, DWS), and statistics on the prediction errors (mean squared error, MSE; mean absolute error, MAE; mean absolute percentage error, MAPE; mean error, ME and mean percentage error, MPE). The estimated model reveals that buffering indices are strongly influenced by three variables (volatile fatty acids (VFA) concentration, soluble COD removal, and alkalinity); while, pH, VFA concentration and total COD removal were the most significant independent variables in biogas and methane production. The developed equation models obtained in this study, could be a powerful tool to predict the functionability and stability for the UASB system.

2

Sustainable management of wastewater: Theoretical design of combined upflow anaerobic reactors and artificial wetlands systems

Guardia-Puebla Yans, Llanes-Cedeño Edilberto, Rodríguez-Pérez Suyén, Arias-Cedeño Quirino, Sánchez-Girón Victor, Morscheck Gert, Eichler-Löbermann Bettina

Journal of Water and Land Development

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2020

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no. 47

66--76

EN

Anaerobic digestion (AD) is an adequate alternative to treat wastewater generated from fruit and vegetable processing (FVWW); likewise, in recent years, artificial wetlands (AWs) have been applied as a post-treatment process for anaerobically pre-treated wastewater. The objective of this work was to design a sustainable treatment system for FVWW composed of upflow anaerobic reactors (UASB) with phase separation and an AW system that receive the anaerobically pretreated effluent. Using the design methodologies for the UASB reactors and artificial wetlands with sub-surface flow (AW-SSF), the parameters of the combined AD-AW system that treat a wastewater flow of 300 m3∙d–1 were calculated. The UASB acidogenic system was adjusted to a hydraulic retention time (HRT) of 10 h and organic loading rate (OLR) of 13.84 kg COD m–3∙d–1; meanwhile, the methanogenic and cascade UASB reactors with OLRs of 10.0 and 3.0 kg COD m3∙d–1, and HRTs of 11 and 10 h, respectively, achieve a high COD removal efficiency (above 94%), and an overall biogas production rate of 1.53 m3 of biogas per m3 of reactor capacity per day. According to the results obtained with the theoretical design, anaerobic-wetland combined system achieves an overall efficiency greater than 98%. The wastewater treated by the proposed system will allow the reuse of 30% of the water used in the washing of fruits and vegetables.

3

Effect of hydraulic loading rate and vegetation on phytoremediation with artificial wetlands associated to natural swimming pools

Guardia-Puebla Yans, Pérez-Quintero Fernando, Rodríguez-Pérez Suyén, Sánchez-Girón Victor, Llanes-Cedeño Edilberto, Rocha-Hoyos Juan, Peralta-Zurita Diana

Journal of Water and Land Development

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2019

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no. 40

39--51

EN

The treatment of pool water, whether for recreational or sporting purposes, by phytoremediation is widely applied. This work evaluates two artificial vertical flow wetlands, one on a real scale and the other on a laboratory scale, which have been planted with Typha domingensis, for the treatment of pool water in the climatic conditions of the city of Santiago de Cuba. When the hydraulic load applied to the real scale wetland was less than 0.25 m3∙m–2∙d–1, the levels of organic and microbiological contamination in the pool were below the maximum limits allowed by Cuban standards. At a laboratory scale, the presence of vegetation favoured the elimination of nitrogen compounds (nitrates and ammonium) and organic materials (BOD and COD). This behaviour is explained by the presence of processes of assimilation of organic compounds, or by the action of microorganisms associated with the rhizome of plants, which establish a symbiotic mechanism favourable to phytodepuration. The minimum concentration of ammonium obtained in outflow from the laboratory-scale reactor without vegetation reached a value of 2.15 mg∙m–3, which is within the limits allowed by the sanitary regulations.

PL

Fitoremediacja jest szeroko stosowana do oczyszczania wody w rekreacyjnych i sportowych basenach pływackich. W pracy oceniono dwa sztuczne mokradła: jeden w rzeczywistej skali i drugi w skali laboratoryjnej, które obsadzono Typha domingensis w celu oczyszczania wody w basenie w klimatycznych warunkach Santiago de Cuba. Kiedy obciążenie hydrauliczne układu w skali rzeczywistej było mniejsze od 0,25 m3∙m–2∙d–1, stężenie zanieczyszczeń organicznych i mikrobiologicznych było mniejsze niż maksymalne limity wyznaczone przez kubańskie normy. W skali laboratoryjnej obecność roślinności sprzyjała eliminowaniu związków azotowych (azotanów i jonów amonowych) oraz materii organicznej (BZT i ChZT). Taki efekt tłumaczy się występowaniem procesów asymilacji związków organicznych lub aktywnością mikroorganizmów powiązanych z kłączami roślin, które tworzą symbiotyczny system korzystny dla oczyszczania. Minimalne stężenie jonów amonowych mierzone na odpływie z laboratoryjnego reaktora bez roślinności wynosiło 2,15 mg∙dm–3; mieściło się więc w granicach dopuszczalnych przez normy sanitarne.