Tannery effluent was assessed as a carbon source for biological sulphate reduction in a pilot-scale upflow anaerobic sludge blanket (UASB), stirred tank reactor (STR) and trench reactor (TR). Sulphate removals of between 60-80% were obtained in all three reactors at total sulphate feed levels of up to 1800 mg l(-1). Sulphate removal in the TR (400-500 mg SO4 l(-1) day(-1)) and UASB (up to 600 mg SO4 l(-1) day(-1)) were higher than those obtained in the STR (250 mg SO4 l(1) day(-1)). A change in operation mode from a UASB to a STR had a large impact on chemical oxygen demand (COD) removal efficiencies. COD removal rates decreased by 25% from 600-700 mg COD l(-1) day(-1) to 200-600 mg COD l(-1) day(-1). The TR had an average COD removal rate of 500 mg COD l(-1) day(-1). Large quantities of sulphide were produced in the reactors (up to 1500 mg l(-1)). However due to the elevated pH in the reactor, only a small amount was in the form of H2S and thus the odour problem normally associated with biological sulphate reduction was not present.
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http://dx.doi.org/10.1016/j.watres.2004.03.030 | DOI Listing |
Molecules
November 2024
Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
The use of mixed cultures in gas fermentations could reduce operating costs in the production of liquid chemicals such as alcohols or carboxylic acids. However, directing reducing equivalents towards the desired products presents the challenge of co-existing competing pathways. In this study, two trickle bed reactors were operated at acetogenic and chain elongating conditions to explore the fate of electron equivalents (ethanol, H, and CO) and test pH oscillations as a strategy to target chain-elongated products.
View Article and Find Full Text PDFWater Sci Technol
December 2024
Regional Environment Conservation Division, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan; Research Center of Water Environment Technology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Anaerobic treatment of sulfur-rich wastewater is challenging because sulfide greatly inhibits the activity of anaerobic microorganisms, especially methanogenic archaea. We developed an internal phase-separated reactor (IPSR) that removed sulfide prior to methanogenesis by gas stripping using biogas produced in the reactor. The IPSR was fed with synthetic wastewater containing a very high sulfide concentration of up to 6,000 mg S L with a chemical oxygen demand (COD) of 30,000 mg L.
View Article and Find Full Text PDFMar Drugs
November 2024
National Food Institute, Technical University of Denmark, Kemitorvet Bygning 202, 2800 Kongens Lyngby, Denmark.
Microalga presents a promising source of high-value food ingredients such as protein, omega-3 fatty acids, and vitamins. To fully unlock its potential, a thorough understanding of how cultivation conditions affect both growth and the nutritional composition is required. Hence, this study aimed to test and model the effects of temperature, light intensity, and salinity on biomass productivity and the final contents of protein, eicosapentaenoic acid (EPA), and vitamin K using response surface methodology (RSM).
View Article and Find Full Text PDFiScience
November 2024
Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS B3H 4R2, Canada.
Floating interfacial solar evaporation offers a land-saving, eco-friendly, and low-infrastructure alternative for freshwater production. However, challenges include maximizing heat localization, preventing salt accumulation, and operating under harsh environmental conditions. This work demonstrates a plasmonic titanium carbide (TiC) nanoparticle (NP)-based floating solar desalination system that produces clean water using sunlight on saline water sources.
View Article and Find Full Text PDFPLoS One
November 2024
Grupo de Investigación en Limnología Tropical, FES Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, México.
River hydrology shapes the sources, concentration, and stoichiometry of organic matter within drainage basins. However, our understanding of how the microbes process dissolved organic matter (DOM) and recycle nutrients in tropical rivers needs to be improved. This study explores the relationships between elemental DOM composition (carbon/nitrogen/phosphorus: C/N/P), C and N uptake, and C mineralization by autochthonous bacterioplankton in the Usumacinta River, one of the most important fluvial systems in Mexico.
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