Search results for "Biomass"

Hybrid moving bed biofilm reactors: a pilot plant experiment.

2008

The growing increment of the urbanization and on the other hand, the even more strict effluent limits imposed by the Water Framework Directive for the receiving water body quality state have lead to a need of upgrading several existing WWTP. With this respect HMBBR systems are an innovative solution since allow to upgrade existing high loaded WWTP without building new tanks. However, some uncertainties in their design, maintenance as well as performance have to be addressed due to their recent acquisition compared with well consolidated technologies such as activated sludge systems. In this light, a data gathering campaign on a HMBBR pilot plant has been performed. The aim was to detect the…

Modelling of hybrid moving bed biofilm reactors: a pilot plant experiment.

2007

In recent years there has been an increasing interest in the development of hybrid biofilm reactors, especially in the upgrading of existing WWTP that are no longer able to respect concentration limits. In fact, today's challenge is the achievement of a good aquatic state for the receiving water bodies according to the Water Framework Directive requirements, which indeed limit even more the continuous emissions, i.e. coming from WWTP. This paper presents the setting up of a mathematical model for the simulation of a hybrid MBBR system; the model calibration/validation has been carried out considering a field gathering campaign on an experimental pilot plant. The main goal is to gain insight…

Consensus based distributed estimation of biomass concentration in reverse osmosis membranes

2015

The correct estimation of biofilm formation in industrial environments, such as reverse osmosis plants, has become a topic of great interest. The occurrence of this natural process is the cause of huge economic losses due to a decrease of performance and maintenance costs in these plants. Current solutions based on water pretreatment or the dozing of biocides are not effective due to the lack of information about the state of the biofilm in the water system. In this work, we propose the use of a wireless sensor network that, based on the measurement of the biofilm thickness growth at the substratum of each sensor, estimates the biomass concentration within the biofilm, and, eventually, the …

Energy and environmental impacts of Energy related products (ErP): a case study of biomass-fuelled systems

2014

Abstract Energy-related Products (ErP) account for a large proportion of European energy and natural resource consumption. In 2007, ErP were responsible for the consumption of about 239 Mtoe of electricity and about 555 Mtoe of fuels. In order to reduce the energy and environmental impacts of these products, the European Commission published the Directive 2009/125/EC on the eco-design of ErP. This Directive represents a key component of European policy for improving the energy and environmental performances of products in the internal market. In this context, it is important to develop scientific research aimed at assessing the energy and environmental impacts of ErP, and at defining their …

Nonlinear control of an activated sludge aeration process: use of fuzzy techniques for tuning PID controllers

1999

In this paper, several tuning algorithms, specifically ITAE, IMC and Cohen and Coon, were applied in order to tune an activated sludge aeration PID controller. Performance results of these controllers were compared by simulation with those obtained by using a nonlinear fuzzy PID controller. In order to design this controller, a trial and error procedure was used to determine, as a function of error at current time and at a previous time, sets of parameters (including controller gain, integral time and derivative time) which achieve satisfactory response of a PID controller actuating over the aeration process. Once these sets of data were obtained, neural networks were used to obtain fuzzy m…

Partial stability for specific growth rate control biotechnological fed-batch processes

2004

In this paper, the problem of the specific growth rate control in biological reactions in fed-batch mode is dealt with. It is assumed that only part of the state is measurable on-line, namely biomass and volume. Moreover, no estimation of the specific growth rate is used. An unbounded manifold is tracked using a partial state feedback. Then, techniques for partial stability, i.e., only with respect to part of the variables, are used in order to analyze the problem.

Assessing the gasification potential of five woodchips species by employing a lab-scale fixed-bed downdraft reactor

2015

Abstract This paper is aimed to assess the performance of air blown fixed-bed downdraft gasification of local lignocellulosic biomasses which in perspective of Southern Norway are both available and sustainable. Long rotation forest crops birch, oak and spruce, coupled with energy crops poplar and willow were used as feedstocks. The gasification conditions undertaken were widely varied in-terms of air (∼3.20–4.20 N m3/h) and fuel flow (∼1.70–2.10 kg/h) so that the corresponding equivalence ratio (ER) differed (0.19–0.80) and ultimately reflected to other operational parameters such as bed temperature (∼550–760 °C maximum), producer gas yield (∼1.50–2.30 N m3/kg, wet base), cold gas efficien…

Development of Biomass and Gas Cofiring Technology to Reduce Greenhouse Gaseous Emissions

2007

Plankton participation in the performance of three constructed wetlands within a Mediterranean natural park.

2019

Abstract The contribution of plankton in the performance of three constructed wetlands (CWs) within the Albufera de Valencia Natural Park has been analyzed, taxonomic group by group, over a two-year operation period in the different sectors of each CW: horizontal subsurface-flow –A–, free-water surface flow –B– and lagoons –C–. Tancat de la Pipa CW (TPCW) only contains B–C sectors, while the others have all three types. Treatment efficiency of each sector type on the taxonomic groups was evaluated by calculating frequency of phytoplankton reduction (or zooplankton production), mass removal (or production) efficiencies and rates, and accumulated removed phytoplankton mass (or produced zoopla…

Modelling the metabolic shift of polyphosphate-accumulating organisms

2014

Enhanced biological phosphorus removal (EBPR) is one of the most important methods of phosphorus removal in municipal wastewater treatment plants, having been described by different modelling approaches. In this process, the PAOs (polyphosphate accumulating organisms) and GAOs (glycogen accumulating organisms) compete for volatile fatty acids uptake under anaerobic conditions. Recent studies have revealed that the metabolic pathways used by PAOs in order to obtain the energy and the reducing power needed for polyhydroxyalkanoates synthesis could change depending on the amount of polyphosphate stored in the cells. The model presented in this paper extends beyond previously developed metaboli…