Effect of hydraulic retention time on the electro-bioremediation of nitrate in saline groundwater

Bioelectrochemical systems (BES) have proven their capability to treat nitrate-contaminated saline groundwater and simultaneously recover value-added chemicals (such as disinfection products) within a circular economy-based approach. In this study, the effect of the hydraulic retention time (HRT) on nitrate and salinity removal, as well as on free chlorine production, was investigated in a 3-compartment BES working in galvanostatic mode with the perspective of process intensification and future scale-up. Reducing the HRT from 30.1 +/- 2.3 to 2.4 +/- 0.2 h led to a corresponding increase in nitrate removal rates (from 17 +/- 1 up to 131 +/- 1 mgNO3--N L-1d-1), although a progressive decrease in desalination efficiency (from 77 +/- 13 to 12 +/- 2 %) was observed. Nitrate concentration and salinity close to threshold limits indicated by the World Health Organization for drinking water, as well as significant chlorine production were achieved with an HRT of 4.9 +/- 0.4 h. At such HRT, specific energy consumption was low (6.8 center dot 10-2 +/- 0.3 center dot 10-2 kWh g-1NO3--Nremoved), considering that the supplied energy supports three processes simultaneously. A logarithmic equation correlated well with nitrate removal rates at the applied HRTs and may be used to predict BES behaviour with different HRTs. The bacterial community of the bio-cathode under galvanostatic mode was dominated by a few populations, including the genera Rhizobium, Bosea, Fontibacter and Gordonia. The results provide useful information for the scale-up of BES treating multi-contaminated groundwater

FITORREMEDIACI ´ ON DE SUELOS CON BENZO(a)PIRENO MEDIANTE MICROORGANISMOS AUT ´ OCTONOS Y PASTO ALEM ´ AN Echinochloa polystachya (H.B.K.) Hitchc.

La capacidad del pasto alemán (Echinochloa polystachya) asociado a poblaciones autóctonas de bacterias y hongos para limpiar suelos contaminados con benzo(a)pireno fue evaluada. Se realizó un experimento en invernadero con un arreglo factorial 2x4x2 en un diseño completamente al azar y cuatro repeticiones por tratamiento: (1) suelos con cero (≤ 0.0002 mg kg−1) y 100 mg kg−1 de benzo(a)pireno, (2) cuatro tipos de in´oculos (sin microorganismos, con bacterias, con hongos, y con asociación bacterias-hongos), y (3) dos del pasto alemán (con rizosfera y sin rizosfera). La medición de bacterias y hongos se realizó con el método de recuento en cajas Petri. La extracción del benzo(a)pireno se efectuó con el procedimiento del método EPA 3540C, utilizando hexano y acetona en proporci´on 70:30. Para el control de calidad, a cada 10 muestras experimentales se utilizaron una muestra testigo (con ≤ 0.0002 mg kg−1 de BaP determinado con el m´etodo EPA 8270D) y un blanco. La limpieza de la muestra se basó en el procedimiento del método EPA 3630C. La degradación del benzo(a)pireno en las muestras de suelo se determinó por espectrofotometría UV/visible a 381 nm, y la producción de biomasa vegetal por peso seco. Las bacterias, los hongos y la asociación bacterias-hongos registraron poblaciones mayores a los 60 d´ıas y significativamente diferentes (p = 0.05) entre los tratamientos con rizosfera del pasto alemán en suelo con 100 mg kg−1 de benzo(a)pireno

Rural regional governance in the United States: the case of the Resource Conservation and Development Program

Rural governance has drawn considerable attention from both local government officials and scholars in the United States since the early 1990s. It is touted as a way to mitigate the limitations of the traditional government unit-based approaches to problem solving and decision making and to foster partnerships across both jurisdictional boundaries and sectors (public, private, and nonprofit). Established in 1962, the Resource Conservation and Development (RC&D) program of the U.S. Department of Agriculture provides a unique model of rural regional governance. Acting as a coalition of governments, private businesses, individuals, and interest groups, the RC&D program provides the flexibility needed to deal with issues at the appropriate spatial scale. It incorporates aspects of both grassroots and governmental organizations and can bring together local interests and expertise with governmental policy and support in service provision, problem solving, and economic development. The approach does not necessarily entail loss of power on the part of the state, but it does provide a mechanism for local people to exercise their agency, to tackle their problems, and to decide which elements of their lives they want to sustain

Contagious Diseases and Social Structure: Turkey during the Covid-19 Pandemic

Communication Studies in Pandemic: The Panorama of Turkey / Peter Lang AG -- ISBN:978-363186258-2 -- 2021.

A New Species of Pera (Euphorbiaceae) from Amazonian Brazil

Volume: 21Start Page: 169End Page: 17

Uma nova esp\ue9cie de Pera (Peraceae) end\ueamica de Manaus, Amazonas, Brasil / A new species of Pera (Peraceae) endemic to Manaus, Amazonas, Brazil

Volume: 61Start Page: 77End Page: 8