Showing papers on "Hydraulic retention time published in 2019"
TL;DR: The feasibility of achieving stable operation in the treatment of 50 mg/L ammonia wastewater with a micro granule-based PN/A reactor and ex-situ activity tests showed the activity of NOB was well limited through DO regulation in the reactor provide an alternative Pn/A process configuration for low-strength wastewater treatment by sustaining microstate granules.
156 citations
TL;DR: This is the first detailed investigation into the metabolic capabilities of microbial communities involved in efficient treatment of raw incineration leachate within biomethanogenic reactors that did not require a long start-up period.
94 citations
TL;DR: Results showed that the degradation of both drugs is favoured when the aqueous matrix presents low concentration of carbonates, and the higher the Hydraulic Retention Time (HRT) employed in the assays, thehigher the bacterial inhibition.
88 citations
TL;DR: Gas chromatography-mass spectrometry (GC-MS) analysis reveals catechol and 2-naphthol were observed as intermediate metabolites for naphthalene degradation and modified Stover-Kincannon model was applied for biodegradation kinetic.
88 citations
TL;DR: In this paper, a micro-electrolysis-intensified subsurface-flow constructed wetlands (ME-SSFCWs) including iron scraps and biochar were operated to investigate the effect of micro-cell electrophoresis substrate on nitrogen and phosphorus removal performance together with the related kinetics and possible pathways.
83 citations
TL;DR: This study aimed at investigating the effects of two improving strategies on PNEDPR, decreasing both anaerobic and anoxic reaction time for shortening HRT and temporarily discharging orthophosphate-rich supernatant for balancing the competition between phosphorus and glycogen accumulating organisms.
79 citations
01 Sep 2019
TL;DR: In this paper, the performance of a 160 L anaerobic biofilm single-stage reactor in treating food waste (FW) was investigated, and three kinetic models, the first-order kinetic model, the modified Gompertz model, and the logistic function model were used to fit the cumulative biogas production experimental data.
Abstract: A large quantity of food waste (FW) is generated annually across the world and results in environmental pollution and degradation. This study investigated the performance of a 160 L anaerobic biofilm single-stage reactor in treating FW. The reactor was operated at different hydraulic retention times (HRTs) of 124, 62, and 35 days under mesophilic conditions. The maximum biogas and methane yield achieved was 0.934 L/g VSadded and 0.607 L CH4/g VSadded, respectively, at an HRT of 124 days. When HRT decreased to 62 days, the volatile fatty acid (VFA) and ammonia accumulation increased rapidly whereas pH, methane yield, and biogas yield decreased continuously. The decline in biogas production was likely due to shock loading, which resulted in scum accumulation in the reactor. A negative correlation between biogas yield and volatile solid (VS) removal efficiency was also observed, owing to the floating scum carrying and urging the sludge toward the upper portion of the reactor. The highest VS (79%) and chemical oxygen demand (COD) removal efficiency (80%) were achieved at an HRT of 35 days. Three kinetic models—the first-order kinetic model, the modified Gompertz model, and the logistic function model—were used to fit the cumulative biogas production experimental data. The kinetic study showed that the modified Gompertz model had the best fit with the experimental data out of the three models. This study demonstrates that the stability and performance of the anaerobic digestion (AD) process, namely biogas production rate, methane yield, intermediate metabolism, and removal efficiency, were significantly affected by HRTs.
73 citations
TL;DR: For the investigated factors, the ammonia, nitrate and C/N were the most significant ones influencing the microbial communities, further nitrogen removal pathways and performances and both could achieve more efficient nitrogen removal in planted SFCWs than the unplated.
70 citations
TL;DR: Insight is provided into the transformation of organic matters produced by SAFL in a denitrification system and acted as a guide for the subsequent advanced treatment.
69 citations
TL;DR: In this work, the removal efficiency of naproxen and salicylic acid decreased when the HRT dropped from 4 to 3d in the absence of external aeration, which suggests that biodegradation played a key role in their removal.
67 citations
TL;DR: Batch tests showed that AOB, anammox bacteria and n-DAMO microorganisms were indeed jointly responsible for the nitrogen removal, and this one-stage PNAM process can potentially be applied to treating high-strength wastewater, such as anaerobic sludge digestion liquor or landfill leachate.
TL;DR: This study focused on the long-term stability of a novel two-stage partial-nitritation/anammox (PN/A) process treating municipal wastewater with fluctuated water quality, and found the "overconsumption of ammonium" under anaerobic conditions was observed in ANA-EGSB.
TL;DR: Thiobacillus sp.
TL;DR: Results showed how the co-digestion enhanced the anaerobic digestion of microalgal biomass, since primary sludge is a more readily biodegradable substrate, which increased the methane production by 65% and reduced the risk of ammonia toxicity.
TL;DR: The performance of photosynthetic biogas upgrading coupled to wastewater treatment was evaluated in an outdoors high rate algal pond (HRAP) interconnected to an absorption column at semi-industrial scale and the type of wastewater was identified as a key operational parameter.
TL;DR: In this paper, an attempt has been made to utilize chocolaterie wastewater as substrate in upflow anaerobic microbial fuel cell (UAMFC) for simultaneous waste treatment and power generation.
TL;DR: In this article, a two-stage thermophilic (55°C) for biohythane production from palm oil mill effluent (POME) was operated at hydraulic retention time (HRT) of 2 days and organic loading rate (OLR) of 275 gCOD/L⋅d.
TL;DR: In this paper, the main organic co-substrates were classified according to their source and reviewed their application in anaerobic co-digestion of WAS, and the influence of temperature, pH, organic loading rate, hydraulic retention time, C/N ratio, digester type and pretreatment method on biogas production was extensively discussed.
Abstract: Anaerobic digestion is a versatile biotechnology to treat waste activated sludge (WAS), the main by-products of biological wastewater treatment, because it can achieve simultaneously energy recovery (biogas) and pollutant reduction (organic matter, pathogens). However, the potential of biogas production from mono-digestion of WAS is usually limited by the imbalance carbon to nitrogen (C/N) ratio of WAS and ammonia accumulation. Anaerobic co-digestion, simultaneous digestion of two or more substrates, should be a feasible option to resolve these disadvantages. The abundant organic wastes from municipal, industrial, and agricultural field have been the ideal co-substrates because they not only can balance the substrate nutrient to obtain the optimal C/N ratio, but also can adjust pH and dilute the toxic materials to mitigate the inhibition to methanogens, consequently improving the yield of biogas, especially methane. This paper classified the main organic co-substrates according to their source and reviewed their application in anaerobic co-digestion of WAS. Then the influence of temperature, pH, organic loading rate, hydraulic retention time, C/N ratio, digester type and pretreatment method on biogas production was extensively discussed. Finally, this review brought forward the challenges and outlooks of anaerobic co-digestion in the future.
TL;DR: In this paper, the authors evaluated the influence of organic loading rate in bio-hydrogen production from dairy wastewater in an anaerobic fluidized-bed reactor inoculated by natural fermentation of the wastewater used during the operational period.
Abstract: The present study evaluated the influence of organic loading rate in biohydrogen production from dairy wastewater in an anaerobic fluidized-bed reactor inoculated by natural fermentation of the wastewater used during the operational period. The support material for biomass adhesion was shredded tire. The reactor had a working volume of 908.4 cm3. Biohydrogen production was evaluated using three different organic loading rates (OLR) of 28.7 kgCOD m−³d−1, 53.2 kgCOD m−³d−1 e 101,7 kgCOD m−³d−1 corresponding to the Hydraulic Retention Time (HRT) of 8 h (2.7 L d−1), 6 h (3.6 L d−1) and 4 h (5.4 L d−1), respectively. The hydrogen yield decreased with increasing organic loading rate (OLR) from 2.56 ± 0.62 mol H2 mol carbohydrate−1 to 0.95 ± 0.28 mol H2 mol carbohydrate−1 as the OLR increased from 28.65 kgCOD m−³d−1 to 95.76 kgCOD m−³d−1. The hydrogen content in the biogas (volume of H2/ volume of biogas) produced and the highest volumetric production were respectively 35.72 ± 9.43% and 0.80 ± 0.21 LH2 h−1 L−1 obtained when the OLR was 53.25 ± 7.81 kgCOD m−³d−1. The main metabolites produced were acetic acid (67.15%-87.42%) and ethanol (6.01%-13.09%). Increasing the applied OLR also caused an increase in bacterial diversity as evidenced by the highest value of the Shannon-Wiener index (2.811) corresponding to the operational phase of the highest OLR (95.76 ± 29.10 kgCOD m−³d−1).
TL;DR: In this paper, an industrial scale plant has been constructed for annual treatment of 657,000m3 real petrochemical wastewater of 4649,±′651′mg/l COD and more than 50,000 mg/l petrochemicals, where the plant system is divided into four parts, and the treatment process mainly functions in a 2200,m3 anaerobic expanded granular sludge bed (EGSB) bioreactor and a 10,000 m3 aerobic activated sludge (AS) Bioreactor with the hydraulic retention
TL;DR: In this paper, the CO2 feeding strategy and hydraulic retention time were used to increase selectivity towards n-butyrate and n-caproate over acetate, while maintaining high production rate and electron recovery.
TL;DR: In this paper, the potential of dark fermentative hydrogen production from cheese whey in an acidogenic anaerobic structured-bed reactor (ASTBR) was investigated, and an ADM1-based, unstructured kinetic model was developed and fitted to the obtained temporal profiles.
TL;DR: In this article, the MBBR process was used as a biological process to remove diazinon and similar pesticides from synthetic wastewater by moving bed biofilm reactor (MBBR) using the response surface methodology (RSM).
Abstract: Diazinon is one of the most widely used organophosphate pesticides classified by the World Health Organization (WHO) as “moderately hazardous” Class II, and its removal from water is of unquestionable importance. The aim of this study was the optimization of diazinon biodegradation from synthetic wastewater by moving bed biofilm reactor (MBBR) using the response surface methodology (RSM). The variables such as initial diazinon concentration (10–50 mg/L), hydraulic retention time (HRT) (12–36 h) and a filling fraction (25–75) were studied according to the RSM. The highest diazinon removal efficiency using the biological process was 97.66, under the conditions, i.e. (HRT= 36 h, filling fraction= 75 and diazinon concentration = 10 mg/L). The quadratic model was well fitted with test results (R2 = 0.986). Moreover, the kinetics of the biological process showed that removal of diazinon from synthetic wastewater adhered to the second-order model (Grau) with a high correlation coefficient (R2 = 0.97). The results showed that the MBBR process can be effectively used as a biological process to remove diazinon and similar pesticides. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.
TL;DR: The described combination of two bioelectrochemical systems system proved to be effective for groundwater denitrification, both in terms of mass of nitrate removed and volume treated.
TL;DR: A combined heterotrophic-sulfur-autotrophic system (CHSAS) was established to simultaneously reduce perchlorate and nitrate in water and revealed that sulfur (S0) disproportionation can be inhibited by shortening the HRT and reducing the acetate dosage.
TL;DR: Results showed that the system started-up in 27 days for brewery wastewater and then stably operated under various temperature, initial COD and pH conditions, which showed fast start-up and strong robustness, and provides a base for the scale-up of this novel technology.
TL;DR: Results indicated the high-solids co-digestion by AnMBR is a promising approach to maximize the bioenergy conversion from the co-substrate of CPW and WAS.
TL;DR: Evaluated the performance of an inverse fluidized bed (IFB) bioreactor with anerobic biomass immobilized onto Kaldness-K1 media as the biosupport material for selenite removal and recovery as selenium nanoparticle from waste stream found ammonium bicarbonate was most suitable and lactate was found to be the preferred carbon substrate.
Abstract: This study evaluated the performance of an inverse fluidized bed (IFB) bioreactor with anerobic biomass immobilized onto Kaldness-K1 media as the biosupport material for selenite removal and recovery as selenium nanoparticle from waste stream. The effect of different process parameter and nutrient supplement on selenium removal was first studied in a batch system using serum bottles. The results revealed that among the different nitrogen substrates, ammonium bicarbonate was most suitable, whereas, lactate was found to be the preferred carbon substrate with 98% selenite removal efficiency and 90% COD removal. Later studies with the continuously operated IFB bioreactor operated at different hydraulic retention time (HRT) and different influent selenite concentrations revealed an efficient removal of selenite at 24 h HRT and 1.0 mM of influent Se (IV). Furthermore, selenium nanoparticles formed at the bottom of the bioreactor were successfully recovered with a recovery efficiency in the range 35–58% with a maximum recovery obtained at 1.0 mM selenite concentration and 24 h HRT. The extracellular produced selenium nanoparticles were found to be spherical in shape with 90–150 nm in size. Fourier transform infrared (FTIR) spectroscopy confirmed the presence of extracellular polymeric substances (EPS) as capping agent on the outer surface of Se nanoparticles.
TL;DR: Nitrogen recovery rate:light irradiance ratios and photosynthetic efficiency significantly decreased when hydraulic retention time was further shortened to 1 day, probably due to a rise in the substrate turbidity which reduced the light availability in the culture.
TL;DR: In this paper, an oleaginous alga Scenedesmus obliquus that was isolated from the dairy wastewater was examined for its bioremediation of municipal wastewater.