232 Articles found
IWA Publishing Articles
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Anaerobic digestion of post-hydrothermal liquefaction wastewater for improved energy efficiency of hydrothermal bioenergy processes
Hydrothermal liquefaction (HTL) is a promising process for converting wet biomass and organic wastes into bio-crude oil. It also produces an aqueous product referred to as post-hydrothermal liquefaction wastewater (PHWW) containing up to 40% of ...
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Preparation of N-doped ZnO-loaded halloysite nanotubes catalysts with high solar-light photocatalytic activity
N-doped ZnO nanoparticles were successfully assembled into hollow halloysite nanotubes (HNTs) by using the impregnation method. The catalysts based on N-doped ZnO-loaded HNTs nanocomposites (N-doped ZnO/HNTs) were characterized by X-ray ...
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Thermochemical pretreatment of lignocellulose residues: assessment of the effect on operational conditions and their interactions on the characteristics of leachable fraction
Annually, large amounts of agricultural residues are produced in Chile, which can be turned into a good opportunity to diversify the energy matrix. These residues have a slow hydrolysis stage during anaerobic digestion; therefore, the ...
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Photocatalytic removal of 2-nitrophenol using silver and sulfur co-doped TiO<sub>2</sub> under natural solar light
To overcome the drawback of poor solar light utilization brought about by the narrow photoresponse range of TiO2, a silver and sulfur co-doped TiO2 was synthesized. Using the prepared catalyst, solar photocatalytic degradation of 2-nitrophenol ...
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Comparison between the photocatalytic degradation of single and binary azo dyes in TiO2 suspensions under solar light irradiation
Textile industries discharge a large quantity of colored wastewater which is harmful to the ecosystem. In this study, two kinds of dyes were investigated: the mono azo Acid Orange 7 (AO7) and diazo Reactive Green 19 (RG19). The photocatalytic ...
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Anaerobic digestion of mixed microalgae cultivated in secondary effluent under mesophilic and thermophilic conditions
The anaerobic digestion of mixed indigenous microalgae, grown in a secondary effluent, was evaluated in batch tests at mesophilic (35°C) and thermophilic (50°C) conditions. Under mesophilic conditions, specific methane production varied from 178 ...
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CFD simulation of an unbaffled stirred tank reactor driven by a magnetic rod: assessment of turbulence models
A simulation of an unbaffled stirred tank reactor driven by a magnetic stirring rod was carried out in a moving reference frame. The free surface of unbaffled stirred tank was captured by Euler–Euler model coupled with the volume of fluid (VOF) ...
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Fabrication and characterization of CdS doped TiO2 nanotube composite and its photocatalytic activity for the degradation of methyl orange
CdS doped TiO2 nanotube composite was fabricated by chemical bath deposition, and was characterized by the structural, spectral and photoelectrochemical properties. The results of the structural and spectral properties showed that CdS particles ...
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Applications and limits of theoretical adsorption models for predicting the adsorption properties of adsorbents
The objective of this study is to evaluate the applicability of adsorption models for predicting the properties of adsorbents. The kinetics of the adsorption of NO3− ions on a PP-g-AA-Am non-woven fabric have been investigated under equilibrium ...
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Anaerobic treatment of crude glycerol from biodiesel production
In this study, we evaluated the use of an up-flow anaerobic sludge blanket (UASB) reactor to treat crude glycerol obtained from cottonseed biodiesel production. The laboratory-scale UASB reactor (7.0 L) was operated at ambient temperature of ...
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Modelling GAC adsorption of biologically pre-treated process water from hydrothermal carbonization
Granular-activated carbon (GAC) adsorption of biologically pre-treated process waters from hydrothermal carbonization (HTC) of different materials was investigated. Overall, isotherms showed that most of the dissolved organic substances are ...
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Evaluation of the simultaneous biogas upgrading and treatment of centrates in a high-rate algal pond through C, N and P mass balances
The simultaneous capture of CO2 from biogas and removal of carbon and nutrients from diluted centrates in a 180 L high-rate algal pond (HRAP) interconnected to a 2.5 L absorption column were evaluated using a C, N and P mass balance approach. The ...
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Implementation strategies and a cost/benefit comparison for compliance with an environmental flow regime in a Mediterranean river affected by hydropower
Compliance with the Water Framework Directive (WFD) of the European Union requires water managers to establish environmental flow regimes (EFR) in rivers across the continent. Few water agencies have examined the economic and social welfare ...
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Partial carbonized nanoporous resin for uptake of lead from aqueous solution
Four partial carbonized nanoporous resins (PCNRs), based on organic xerogel compounds, were synthesised by the sol–gel method from pyrogallol and formaldehyde mixtures in water using picric acid as catalyst. The PCNRs were prepared at different ...
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Evaluation of thermal steam-explosion key operation factors to optimize biogas production from biological sludge
Thermal steam-explosion is the most extended hydrolysis pretreatment to enhance anaerobic digestion of sludge. Thermal hydrolysis key parameters are temperature (T) and time (t), and the generally accepted values reported from full-scale ...
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Strategies for recovering inhibition caused by phenolic compounds in a short-cut nitrogen removal reactor treating coal gasification wastewater
Different strategies, including extension of hydraulic retention time (HRT), dilution, and addition of powdered activated carbon (PAC) and super-powdered activated carbon (S-PAC), were investigated for the quick recovery of nitrifying bacteria ...
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Aniline chlorination by <italic>in situ</italic> formed Ag–Cl complexes under simulated solar light irradiation
Ag speciation in a chloride medium was dependent upon the Cl/Ag ratio after releasing into surface water. In this study, the photoreaction of in situ formed Ag–Cl species and their effects on aniline photochlorination were systematically ...
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Water-saving analysis on an effective water reuse system in biodiesel feedstock production based on <italic>Chlorella zofingiensis</italic> fed-batch cultivation
The micralgae-based biofuel obtained from dairy wastewater (DWW) is considered a promising source of energy. However, this process consumes water due to the concentration of wastewater being normally too high for some micoralgae cultivation, and ...
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Simultaneous production and separation of biohydrogen in mixed culture systems by continuous dark fermentation
Hydrogen production by dark fermentation is one promising technology. However, there are challenges in improving the performance and efficiency of the process. The important factors that must be considered to obtain a suitable process are the ...
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Power use methods for optimal design of WDS: history and their use as post-optimization warm starts
This paper describes an extension to the optimal power use surface (OPUS) methodology, which consists of applying a metaheuristic post-optimization process after a network has been designed through the OPUS algorithm. Four different types of ...