Showing papers on "Hydraulic retention time published in 2015"
TL;DR: The results suggest that biodegradation and photodegradation are the most important removal pathways, whereas volatilization and sorption were solely achieved for hydrophobic compounds with a moderately high Henry's law constant values such as musk fragrances.
334 citations
TL;DR: A novel simultaneous nitrification denitrification and phosphorous removal-sequencing batch reactor (SNDPR-SBR) enriched with PAOs (phosphorus accumulating organisms), DPAOs (denitrifying PAOs), and GAOs (glycogen accumulating organisms) was developed to achieve the simultaneous nutrient and carbon removal treating domestic wastewater with low carbon/nitrogen ratio.
261 citations
TL;DR: In this paper, a critical review focusing on biofilm reactors for anaerobic treatment of dairy wastewaters of varying strengths is provided, where the effects of organic loading rate and hydraulic retention time on the performance of bioreactors are discussed and operational problems are summarized.
205 citations
TL;DR: The effects of hydraulic residence time (HRT), reactive brilliant red X-3B (ABRx3) proportion and COD concentration on the electricity production of CW-MFC and the degradation characteristics of ABRX3 were investigated and the highest decolorization rate and electricity production were obtained when HRT was 3 days.
199 citations
TL;DR: The results showed that maximum removal efficiencies of soluble COD were reached at a DO >0.3 mg O2/L, SRT > 0.5 days and HRT > 15 min, which indicates that minimizing the oxidation of the soluble C OD in the high-rate activated sludge process is difficult.
196 citations
TL;DR: In this paper, the authors studied the effect of hydrothermal pretreatment prior to batch and continuous reactors for enhancing microalgae methane yield and found that pretreatment increased organic matter solubilisation (8-13%), anaerobic digestion rate (30-90%), and final methane yield (17-39%).
163 citations
TL;DR: Toxicity studies indicated that microbial treatment favors detoxification of simulated wastewater and the detection of oxido-reductive enzyme activities suggested the enzymatic reduction of azo bonds prior to mineralization.
133 citations
TL;DR: The performance of a pilot scale anaerobic membrane bioreactor coupled to an external ultrafiltration membrane treating municipal wastewater at 18±2°C, was evaluated over three years of stable operation.
132 citations
TL;DR: In this article, a two-stage thermophilic fermentation and mesophilic methanogenic process for biohythane production from palm oil mill effluent (POME) was investigated.
127 citations
TL;DR: This work aimed to study the microbial community dynamics during hydraulic and organic overload shocks in anaerobic reactors treating agro-industrial wastes, as well as during the recovery period, finding both overloads were correlated to an increase in Bacteroidetes and Actinobacteria phyla and with a drop in Syntrophomonadaceae and Pseudomonad Families families.
109 citations
TL;DR: The combined carbon capture/nutrient removal process relies on optimisation of a number of process parameters acting synergistically, principally microalgal strain, C:N:P load and balance, CO2 and liquid residence time, light intensity and quality, temperature, and reactor configuration.
TL;DR: Increased temperature had no effect on the steady-state COD removal efficiency with both reactors stabilized at 68-75%.
TL;DR: The upflow anaerobic sludge blanket reactors seeded with cow dung manure and activated sludge of a dairy wastewater treatment plant (UASBASDIT) were used to treat raw domestic wastewater of medium strength.
TL;DR: In this article, a membrane bioreactor (MBR), a hybrid moving bed biofilm reactor (HBMR) and a hybrid MBBR-MBR with carriers in the anoxic and aerobic zones of the bioreactors were compared with the same urban wastewater and compared.
TL;DR: In this paper, a moving bed biofilm reactor (MBBR) was examined removing organic carbon and nitrogen from municipal wastewater through simultaneous nitrification and denitrification (SND) process, and two numerical independent variables, hydraulic retention time (HRT) and dissolved oxygen (DO), and one categorical variable, type of packing media, were selected.
Abstract: In this study, a moving bed biofilm reactor (MBBR) was examined removing organic carbon and nitrogen from municipal wastewater through simultaneous nitrification and denitrification (SND) process To assess the process performance, two numerical independent variables, hydraulic retention time (HRT) and dissolved oxygen (DO), and one categorical variable, type of packing media, were selected The effects of the numerical variables were investigated at three levels, 4, 8 and 12 h for HRT and 2, 3 and 4 mg/L for DO, while two levels of the categorical variable (Ring form and Kaldnes-3) were examined The packing media used were different in the structure and geometry but similar to specific surface area (500 m 2 /m 3 ) The experiments were carried out at two parallel reactors The process was analyzed and modeled by monitoring 10 dependent responses Maximum COD removal efficiency was found to be 85 and 88%, respectively, for the system with Ring form and Kaldnes-3 at HRT of 12 h and DO of 4 mg/L The results showed that the system with Ring form could achieve more TN removal efficiency than that of the process with Kaldnes-3, indicating that anoxic condition is favored with Ring form due to its structure geometry In all the conditions tested, nitrite oxidizing bacteria (NOB) was dominant species It implies more nitrite production from the ammonia oxidizing bacteria (AOB) activity which leads to increase NOB growth The maximum denitrification rates for Ring form and Kaldnes-3 were obtained 90 and 70 mg N/Ld, respectively at DO of 3 mg/L and HRT of 8 h Overall, the changes in the system with Ring form media at different conditions have been more compared to that in the system with Kaldnes-3, indicating more stability of the system operated with Kaldnes-3 As a conclusion, the biofilm in the Ring form showed lower stability compared to that of the system with Kaldnes-3
TL;DR: Anaerobic co-digestion of dried pellet of exhausted sugar beet cossettes with pig manure was investigated in a semi-continuous stirred tank reactor (SSTR) under mesophilic conditions to evaluate the methane productivities and volatile solids removal.
TL;DR: Bisphenol-A (BPA) was analyzed in 499 liquid and 347 solid samples collected from twenty-five wastewater treatment plants to investigate parameters affecting BPA occurrence, removal, and fate and showed the best performance in the biological aerated filter and membrane bioreactor processes.
TL;DR: The aim of this study was to investigate the effect of hydraulic retention time (HRT) on hydrogen and methane production using a two-stage anaerobic process and at lower HRT the process appeared to be inhibited and/or overloaded.
TL;DR: Biofilm reactors are efficient in removing micro-pollutants and could be considered as an option for advanced treatment in small wastewater treatment plants.
TL;DR: In this article, the C/N ratio of food waste was adjusted by mixing with rice husk which has low biodegradability, which indicated higher buffering capacity of digester.
TL;DR: This study demonstrated that PVDF/TiO2 nanocomposite membranes had a better antifouling property for high-density algae cultivation and wastewater polishing.
TL;DR: Bio-hydrogen production from sugarcane vinasse in anaerobic up-flow packed-bed reactors (APBR) was evaluated and LDP was the most appropriate material for hydrogen production among the materials evaluated.
TL;DR: This study utilizes the unique merits of an 8-L laboratory upflow anaerobic sludge blanket (UASB) reactor for treating synthetic wastewater containing trichloroethylene (TCE) and found that a tremendous rise of TCE removal efficiency from HRT of 5 h to H RT of 10 h was found.
Abstract: This study utilizes the unique merits of an 8-L laboratory upflow anaerobic sludge blanket (UASB) reactor for treating synthetic wastewater containing trichloroethylene (TCE). The reactor was operated at different hydraulic retention times (HRT) of 25, 20, 15, 10, and 5 h. TCE removal efficiency decreased from 99 to 85 % when the HRT was lowered down from 25 to 5 h, as well as chemical oxygen demand (COD) removal efficiency (from 95 to 84.15 %). Using Illumina 16S rRNA gene MiSeq sequencing, we investigated the evolution of bacterial communities in the anaerobic sludge under five different conditions of HRT. In total, 106,387 effective sequences of the 16S rRNA gene were generated from 5 samples that widely represented the diversity of microbial community. Sequence analysis consisting of several novel taxonomic levels ranging from phyla to genera revealed the percentages of these bacterial groups in each sample under different HRTs. The differences found among the five samples indicated that HRT had effects on the structures of bacterial communities and the changes of bacterial communities associated with the effect of HRT on the performance of the reactor. Sequence analyses showed that Bacteroidetes and Firmicutes were the dominant phyla. It is notable that the class Dehalococcoidia was found in the samples at HRT of 5, 10, 20, and 25 h, respectively, in which there were some dechlorination strains. Moreover, a tremendous rise of TCE removal efficiency from HRT of 5 h to HRT of 10 h was found.
TL;DR: The anaerobic baffled reactor is an energy-positive technology that can be used for biologically enhanced primary treatment of raw municipal wastewater in cold climates and stoichiometric production of methane.
TL;DR: Analysis of energy production rate suggests that beverage wastewater is a high energy yielding feedstock, and can replace 24% of electricity consumption in a model beverage industry.
TL;DR: A 60-L membrane aerated biofilm reactor (MABR) was successfully employed to treat landfill leachate, which contained very high concentrations of refractory chemical oxygen demand (COD) and ammonium as discussed by the authors.
TL;DR: The low HRT reduced relative abundance of Clostridiaceae and accelerated the proliferation of lactic acid producers and ethanol producers in the UASB and PBR, which were mainly from the families Ruminococcaceae and Leuconostocaceae.
TL;DR: In this paper, the effect of uncoupling between solids retention time and hydraulic retention time (HRT) and the SRT/HRT ratio on algal growth and nutrient (N and P) removal in an algal membrane bioreactor (A-MBR) with a tanks-in-series configuration was investigated.
TL;DR: The horizontal flow mode for MSL led the system to denitrifying satisfactorily as it ensured relatively long hydraulic retention time (HRT), ideal anoxic condition and adequate organic substrates supply, and higher water spraying frequency benefited intermittent feeding system for pollutants removal.
TL;DR: In this article, a 180-L algal-bacterial photobioreactor interconnected to a 2.5L external absorption column was used for the simultaneous treatment of diluted anaerobically digested or raw vinasse and biogas upgrading.
Abstract: Novel operational strategies to reduce the O 2 concentration in the upgraded biogas were evaluated in a 180 L algal–bacterial photobioreactor interconnected to a 2.5 L external absorption column during the simultaneous treatment of diluted anaerobically digested or raw vinasse and biogas upgrading. The lowest biomethane O 2 levels (0.7 ± 0.2%) were recorded when raw vinasse was fed directly into the absorption column, which resulted in CO 2 and H 2 S removals from biogas of 72 ± 1% and 100 ± 0%, respectively. Process operation at a Hydraulic Retention Time (HRT) of 7 d under the above configuration also supported the maximum total carbon, nitrogen and phosphorus removals of 72 ± 4%, 74 ± 3% and 78 ± 5%, respectively. Biomass productivity ranged from 11.4 ± 1.8 to 13.5 ± 2.2 g m − 2 d − 1 during microalgae cultivation in diluted anaerobically digested vinasse, while this productivity increased to 16.9 ± 0.7 g m − 2 d − 1 when feeding diluted raw vinasse. The good settling characteristics of the algal–bacterial flocs resulted in an average harvesting efficiency of 98.6 ± 0.5% at a HRT in the settler of 23 min, regardless of the treated vinasse. The morphological and molecular characterization of the microbial communities showed a high microalgae diversity and bacterial species richness, regardless of the operational conditions (Shannon–Wiener indices ranging from 2.8 to 3.3).