Topic
Hydraulic retention time
About: Hydraulic retention time is a research topic. Over the lifetime, 6406 publications have been published within this topic receiving 151005 citations.
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TL;DR: A laboratory-scale, two-stage, continuously stirred tank reactor was developed to remove struvite to prevent problems associated with its deposition, and the effects of various process parameters such as retention time, pH, recycling rate, and ammonium concentration were examined.
Abstract: Deposition of struvite within the infrastructure of wastewater treatment works can cause significant operating difficulties. A laboratory-scale, two-stage, continuously stirred tank reactor was developed to remove struvite to prevent problems associated with its deposition. Before any experimental work was conducted, the mixing regime within the system was determined using a pH-tracer response method. Perfect mixing conditions were achieved once the stirring speed reached 500 rpm. Experiments were conducted examining the effects of various process parameters such as retention time, pH, recycling rate, and ammonium concentration. By increasing the hydraulic retention time, the residual magnesium concentration decreased, with the optimum conditions occurring at 125 minutes.
52 citations
TL;DR: F Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used for evaluating the transformations undergone by the nitrogen‐rich protein components of blood after digestion, proving that a reduction in volatile content and aliphatic structures of biowastes along with an increase in the degree of aromaticity occurred during the digestion process.
Abstract: The potential of anaerobic digestion for the treatment of poultry blood has been evaluated in a co‐digestion process. The organic fraction of municipal solid waste (OFMSW) was employed as the co‐substrate to avoid digestion inhibition by dilution of nitrogen content and improvement of biodegradability. A semi‐continuous mesophilic anaerobic digester was studied with a hydraulic retention time (HRT) of 36 days and an organic loading (OLR1) of 1.5 kg VSSfeed m−3 d−1. The normal operational conditions of the reactor were altered with the application of an OLR2 of 2.0 kg VSSfeed m−3 d−1 for a short period causing an imbalance in the process. The reduction of the OLR to initial conditions allowed the recovery of the system. The digestion process reached a final specific gas production (SGP) and a methane yield of 0.33 and 0.20 m3 kg−1 VSSfeed, respectively, maintaining low total and free ammonia concentrations. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to gai...
52 citations
TL;DR: Pure cellulose with average diameters of 20 and 50 μm were treated in laboratory-scale CSTRs to study the effect of pH, reactor hydraulic retention time (HRT), and substrate concentration on the rate of anaerobic acidogenesis for those two cellulose particle sizes.
Abstract: Pure cellulose with average diameters of 20 and 50 μm were treated in laboratory-scale CSTRs to study the effect of pH, reactor hydraulic retention time (HRT), and substrate concentration on the rate of anaerobic acidogenesis for those two cellulose particle sizes. The pH effect was studied using a particle size of 20 μm at an HRT of 48 hours while controlling the pH at levels of 5.2, 5.6, 6.0, 6.4, and 6.8. After determining that a pH of 5.6 was optimum, the effect of HRT was evaluated by operating the reactors at HRTs of 24, 36, 48, 60, and 72 hours for both the 20 and 50 μm cellulose sizes. After finding that an HRT of 48 hours was sufficient for acidogenesis, the effect of organic loading rate (OLR) was studied by varying the OLR between 2 and 8 g/L/day
52 citations
TL;DR: In this paper, sludge was acclimated using synthetic effluent containing various bisphenol A (BPA) concentrations in sequential aerobic activated sludge reactors (SBRs), and the results indicated that a positive correlation existed between sludge toxicity and the influent BPA concentration.
52 citations
TL;DR: In this paper, a mixed culture packed bed bioreactor was set up to digest anaerobically, under an acidogenic condition, a water solution of a cheese whey powder.
Abstract: Volatile fatty acids (VFAs) were produced using cheese whey as feedstock. A mixed culture packed bed bioreactor was set up to digest anaerobically, under an acidogenic condition, a water solution of a cheese whey powder. Batch tests pointed out that the whole VFAs production process occurred via two sequential phases: (a) conversion of lactose into lactic acid and (b) conversion of lactic acid into a mixture of VFAs. Furthermore, the same tests showed that the ceramic material Vukopor S10 can be used as an effective support for cell immobilization in anaerobic fermentation processes. The effect of the hydraulic retention time (HRT) and organic loading rate (OLR) were then studied in a benchtop bioreactor operated continuously. By a HRT of 6 days, ORL of 4.2 g/L/d, and pH 5.8–6, 16 g·L–1 of total VFAs were produced, with a yield higher than 75% (CmolVFAs·Cmollactose–1). Characterization with Illumina-based sequencing suggested that high VFAs productivities were obtained when microbial community structures ...
52 citations