Showing papers on "Hydraulic retention time published in 2016"
TL;DR: This study demonstrates the SANI process can be potentially implemented for the treatment of saline sewage by reducing the amount of space needed by 30-40% compared with conventional activated sludge plants in Hong Kong.
135 citations
TL;DR: The developed CEAD achieved efficient nitrate removal from water without organics, which is suitable for practical application, and was performed using organic-free influent using iron-carbon micro-electrolysis carriers.
124 citations
TL;DR: The results demonstrated that the mass ratio of carbohydrate to protein could provide a good indication of microalgal settling performance, rather than sole component composition or total extracellular polymeric substances.
119 citations
TL;DR: Great TOC was released during bioreactor operation with fresh woodch chips, whereas organic C release was low when the columns were packed with naturally weathered woodchips, and nitrate-N removal showed a stepped increase with temperature.
Abstract: Woodchip denitrification bioreactors, a relatively new technology for edge-of-field treatment of subsurface agricultural drainage water, have shown potential for nitrate removal. However, few studies have evaluated the performance of these reactors under varied controlled conditions including initial woodchip age and a range of hydraulic retention times (HRTs) and temperatures similar to the field. This study investigated (i) the release of total organic C (TOC) during reactor start up for fresh and weathered woodchips, (ii) nitrate (NO-N) removal at HRTs ranging from 2 to 24 h, (iii) nitrate removal at influent NO-N concentrations of 10, 30, and 50 mg L, and (iv) NO-N removal at 10, 15, and 20°C. Greater TOC was released during bioreactor operation with fresh woodchips, whereas organic C release was low when the columns were packed with naturally weathered woodchips. Nitrate-N concentration reductions increased from 8 to 55% as HRT increased. Nitrate removal on a mass basis (g NO-N m d) did not follow the same trend, with relatively consistent mass removal measured as HRT increased from 1.7 to 21.2 h. Comparison of mean NO-N load reduction for various influent NO-N concentrations showed lower reduction at an influent concentration of 10 mg L and higher NO-N reductions at influent concentrations of 30 and 50 mg L. Nitrate-N removal showed a stepped increase with temperature. Temperature coefficient () factors calculated from NO-N removal rates ranged from 2.2 to 2.9.
113 citations
TL;DR: In this article, the performance of two 75-L high rate algal ponds (HRAPs) treating slaughterhouse wastewater was evaluated for 115 days with the aim of growing microalgae to produce biofuels (biodiesel, methane).
102 citations
TL;DR: In this article, high rate, high efficiency thiosulfate-driven autotrophic denitrification and denitritation with Thiobacillus denitrificans dominated biofilms were achieved in fluidized-bed reactors (FBRs) operated at 20.0,±-2.0 and 30.2, respectively.
95 citations
TL;DR: This study investigated the efficiency of a pyrrhotite autotrophic denitrification biofilter technology for simultaneous N and P removal from wastewater lacking organic matter and found a potential for P recovery from wastewater.
95 citations
TL;DR: The AFBR presented a stable operation and excellent performance, indicated by the increased methane production rate at each shortened HRT, and recirculation of the AFBR effluent to the CSTR was effective in providing alkalinity, maintaining the pH in optimal ranges (5.0-5.3) for the hydrogen producing bacteria.
93 citations
TL;DR: The basic pretreatment demonstrated a very good action on the hydrolysis of the lignin and cellulose, and permitted a biogas production of about 18NL/L with a methane content of almost 80%v/v, thus permitting a process yield of about 83% to be obtained.
91 citations
TL;DR: In this article, the influence of hydraulic retention time (HRT) on the organic matter, nutrient removal, settling properties and the biochemical methane potential using a granular microalgae-bacteria system in a high rate algal pond was evaluated.
Abstract: BACKGROUND
The use of microalgae–bacteria systems is particularly attractive for wastewater treatment, and the generated biomass can be further used for methane production. The aim of this study was to evaluate the influence of the hydraulic retention time (HRT) on the organic matter, nutrient removal, settling properties and the biochemical methane potential using a granular microalgae–bacteria system in a high rate algal pond.
RESULTS
The primary microorganisms present in the system were constituted by diatoms, green filamentous microalgae and bacteria. At 2 d of HRT the system showed the lowest performance while high chemical oxygen demand (COD) (>92%), ammonium (>85%) and phosphorus (up to 30%) removal was observed at 6 and 10 d of HRT. High settling velocities (up to 8 m h−1) were observed due to agglomerates and granules as dominant structures. The highest methane yield and production rates (348 mL CH4 g−1 VS and 56 mL CH4 g−1 VS d−1) were observed with the biomass obtained at 10 d of HRT.
CONCLUSION
Flocs and granules were the dominant structures in the system. High settling velocities and low effluent total suspended solids concentrations were obtained at higher HRT. An inverse relationship between HRT and the biochemical methane potential was observed. © 2016 Society of Chemical Industry
91 citations
TL;DR: In this article, the authors investigated the technical possibilities of hydrogen and methane production from palm oil mill effluent (POME) in two-stage continuous phase with recirculation of the digestate sludge.
TL;DR: In this paper, two moving-bed biofilm reactors (MBBR1 and MBBR2) filled with different carrier media (Kaldnes K1 and Mutag Biochip, respectively) were subjected to increasing organic loading rates for 700 days.
TL;DR: A novel method of two-phase anaerobic digestion where the acid reactor is operated at low pH 4.0 was proposed and investigated to examine the possibility of efficient degradation of lactate and to identify their optimal operating conditions.
TL;DR: Overall, current study depicted the possibility of utilizing RW as substrate in MFC for power generation along with its treatment and showed good substrate degradation but took longer HRT which resulted in significantly low substrate degradation rate.
TL;DR: High-throughput sequencing analysis demonstrated significant change of bacterial diversity in the first oxic reactor after a long-term operation and dominant bacteria genus Nitrosomonas was shown to be responsible for NH4(+)-N removal and nitrite accumulation under low DO levels.
TL;DR: This study investigated the simultaneous effects of hydraulic retention time (HRT) and pH on the continuous production of VFAs from food waste leachate using response surface analysis, revealing that pH has a dominant effect on the specific VFA production (PTVFA) within the explored space.
TL;DR: In this article, a study was conducted on pilot scale horizontal and vertical subsurface flow constructed wetland (VFCW) systems for the treatment of greywater and the fate of emerging contaminants in these systems was evaluated.
TL;DR: The used of fixed bed biofilm not only obviated the need of additional solid/liquid separation in the side-stream for salt accumulation control and phosphorus recovery, but effectively quarantined the biomass from the FO membrane, achieving a significant reduction in FO membrane fouling in the BF-FOMBR.
TL;DR: In this article, a pilot high rate algal pond (HRAP) interconnected to an external CO2-H2S absorption column via settled broth recirculation was used to simultaneously treat a synthetic digestate and to upgrade biogas to a bio-methane with sufficient quality to be injected into natural gas grids.
Abstract: A pilot high rate algal pond (HRAP) interconnected to an external CO2–H2S absorption column via settled broth recirculation was used to simultaneously treat a synthetic digestate and to upgrade biogas to a bio-methane with sufficient quality to be injected into natural gas grids. An innovative HRAP operational strategy with biomass recirculation based on the control of algal-bacterial biomass productivity (2.2, 4.4 and 7.5 g m− 2 d− 1) via settled biomass wastage was evaluated in order to enhance nutrient recovery from digestate at a constant hydraulic retention time. The influence of the recycling liquid to biogas (L/G) ratio on the quality of the upgraded biogas was assessed. The bio-methane composition under a L/G ratio of 1 (0.4 ± 0.1% CO2, 0.03 ± 0.04% O2, 2.4 ± 0.2% N2 and 97.2 ± 0.2% CH4) complied with the technical specifications of most European bio-methane legislations regardless of the biomass productivity established. The HRAP operational strategy applied allowed increasing the N and P recovery from 19 and 22% to 83 and 100%, respectively, when the biomass productivity was increased from 2.2 to 7.5 g m− 2 d− 1. Finally, the dynamics of microalgae and bacteria population structure were characterized by morphological identification and Denaturing Gradient Gel Electrophoresis analysis.
TL;DR: The results show that COD from mature leachate did not bring obvious inhibition effects to anammox, and under concentrations of influent ammonia and COD, the removal efficiencies of TN and C OD reached 94% and 62% respectively.
TL;DR: Since the methane production rate improved significantly with decreasing HRT, the trade-off between yield and productivity was obtained at 15 days HRT.
TL;DR: The hybrid MBBR-MBR ap performed best regarding chemical oxygen demand (COD) and total phosphorus (TP) removals, with values of 85.82 ±-2.12% and 81.42 ± 3.85%, respectively.
TL;DR: In this article, a modified two-sludge system consisting of AAO and BCO (Anaerobic anoxic oxic-biological contact oxidation) was developed, which achieved the simultaneous removal of both nitrogen and phosphorus.
TL;DR: In this article, a literature review surveys the previous and current researches on the co-digestion of anaerobic processes and examines the synergies effect of co digestion with cattle manure and pays attention to different operational conditions like operating temperature, organic loading rate (OLR), hydraulic retention time (HRT), chemical oxygen demand (COD), and volatile solid (VS) removal efficiency and biogas or methane production.
Abstract: This literature review surveys the previous and current researches on the co-digestion of anaerobic processes and examines the synergies effect of co-digestion with cattle manure. Furthermore, this review also pays attention to different operational conditions like operating temperature, organic loading rate (OLR), hydraulic retention time (HRT), chemical oxygen demand (COD) and volatile solid (VS) removal efficiency and biogas or methane production. This review shows that anaerobic mono-digestion of cattle manure usually causing poor performance and stability. Anaerobic studies were generally performed under mesophilic conditions maintained between 35 and 37 °C. Organic waste loading rate generally ranges from 1 to 6 g VS–COD L−1 day−1 stable condition in anaerobic digester. Generally, studies show that HRT for co-digestion of fruit–vegetables waste and industrial organic waste appears to exceed 20 days. However, the anaerobic co-digestion process is generally operated at HRT of between 10 and 20 days. VS and COD removal efficiency usually reaches up to 90 % due to co-digestion with different type organic waste. Methane–biogas production is generally obtained between 0.1 and 0.65 L CH4–biogas g−1 VS.
TL;DR: The results experiments revealed the importance of immediate adsorption onto the colloidal particles in supernatant of MBR sludge and subsequently removed by membrane filtration for the recalcitrant pharmaceutical compounds.
TL;DR: An innovative plant configuration based in an UASB reactor coupled to a hybrid aerobic membrane bioreactor designed for sustainable treatment of municipal wastewater at ambient temperatures and low hydraulic retention time has shown to be more efficient than conventional technologies for those OMPs which are prone to be biotransformed under anaerobic conditions.
TL;DR: It was found that the sole intermittent aeration strategy is not a sufficient method for successful suppression of nitrite oxidizing bacteria in MBBR and the best performance of the process was achieved in IFAS mode.
TL;DR: Results from this proof of concept support the application of MAAS in wastewater treatment for Swedish conditions to reduce aeration, precipitation chemicals and CO2 emissions.
TL;DR: The species diversity and microbial community examined by the Illumina MiSeq method demonstrated the fact of two-sludge system, and the improved community structure by long-term optimization was prominent comparing with the seed sludge.
TL;DR: In this study, the effects of nitrogen, phosphate and trace elements supplementation were investigated in a semi-continuously operated upflow anaerobic sludge blanket system to enhance process stability and biogas production from sugarcane vinasse.