This work investigated the pilot scale production of short chain fatty acids (SCFAs) from sewage sludge through alkaline fermentation and the subsequent membrane filtration. Furthermore, the impact ...of the fermentation liquid on nutrient bioremoval was examined. The addition of wollastonite in the fermenter to buffer the pH affected the composition of the carbon source produced during fermentation, resulting in higher COD/NH4-N and COD/PO4-P ratios in the liquid phase and higher content of propionic acid. The addition of wollastonite decreased the capillary suction time (CST) and the time to filter (TTF), resulting in favorable dewatering characteristics. The sludge dewatering characteristics and the separation process were adversely affected from the use of caustic soda. When wollastonite was added, the permeate flux increased by 32%, compared to the use of caustic soda. When fermentation liquid was added as carbon source for nutrient removal, higher removal rates were obtained compared to the use of acetic acid.
Wastewater treatment selection is a complex task usually addressed by applying separate tools for the correct assessment of multi-criteria evaluation. Novedar_EDSS integrates technical, ...environmental, economic and social assessment capabilities in one single platform. The aim of this work is to evaluate and demonstrate the capabilities of this environmental decision support system (EDSS). For that purpose, 4 case studies of real projects were selected to validate the results in the EDSS by comparing them with those from the study of alternatives performed by the decision makers. Moreover, 1 conceptual case study was applied to support the selection of the most properly strategy for plant retrofitting. Results have demonstrated that the EDSS provides key aspects when deciding the retrofitting process to apply and, when compared to real projects, it recommends analogue treatments as those applied in the projects, ranking them in the same order. Therefore, results in the validation process performed show that this tool provides a reliable basis to support decision makers to select properly treatment alternatives in wastewater treatment plant pre-design.
•Validation of a decision support system for wastewater treatment is performed.•5 case studies are selected (4 real and 1 conceptual) for new plant and retrofitting.•Results in the tool are compared with process flow diagrams in the real case studies.•The tool recommends analogous treatments as those selected by decision-makers.•Reliability of the tool in pre-design of wastewater treatment plants is demonstrated.
This article evaluates the viability of production systems that would allow the reconciliation of production, distributive equity, and preservation of natural resources, and shows the possibility of ...achieving these objectives on smaller areas than those required by the agricultural model prevailing in the region. Adaptations of MESMIS and emergetic evaluations were employed to assess the sustainability of two productive systems: 1) the typical local case of industrialized soybean farming with a high use of external inputs; and, 2) a diversified family farm production system. Results show that the mostly diversified and integrate system has better global sustainability values than industrialized system, even when utilized in smaller scale productive units.
Abstract
We provide a combinatorial description of the monoidal category generated by the fundamental representation of the small quantum group of
$$ \mathfrak{sl} $$
sl
2
at a root of unity
q
of odd ...order. Our approach is diagrammatic, and it relies on an extension of the Temperley–Lieb category specialized at δ = −
q
−
q
−1
.
We provide a combinatorial description of the monoidal category generated by the fundamental representation of the small quantum group of
sl
2
at a root of unity
q
of odd order. Our approach is ...diagrammatic, and it relies on an extension of the Temperley–Lieb category specialized at δ = −
q
−
q
−1
.
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