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Showing papers on "Hydraulic retention time published in 1990"


Journal ArticleDOI
TL;DR: In this article, a new biofilter design offering simplified operation and increased performance is presented, based on large-scale industrial experiences, for carbon and nutrient removal were collected during extensive pilot tests.

68 citations


Journal ArticleDOI
TL;DR: In this paper, anaerobic fluidized bed (AFBR) was used for the treatment of low strength wastes, such as municipal sewage, at low temperature, since the process is able to maintain a large mass of active microorganisms and provides effective removal of TSS.

66 citations


Journal ArticleDOI
TL;DR: In this paper, a tracer, tritiated water, was injected at the entrance of each one of the facultative ponds at five facilities, and the resulting time distribution functions were used to calculate the mean hydraulic residence time and the extent of short-circuiting inside the ponds.

50 citations


Journal ArticleDOI
TL;DR: A five-month pilot study was conducted to examine the effectiveness of the upflow anaerobic sludge blanket (UASB) process for the treatment of effluent from a brewery in rural China.
Abstract: A five-month pilot study was conducted to examine the effectiveness of the upflow anaerobic sludge blanket (UASB) process for the treatment of effluent from a brewery in rural China. Results indicate that the process operated at 26°C could reduce over 89% of chemical oxygen demand (COD) and 92% of five-day biochemical oxygen demand (BOD\d5) from the brewery effluent, with a hydraulic retention time (HRT) of 13.3 hr and a COD loading rate of 4.9 kg COD/m³/day. The brewery effluent in this study on average contained 2,692 ppm COD and 1,407 ppm BOD\d5. The treated effluent on the other hand contained 295 ppm COD and 122 ppm BOD\d5; both of which could be further reduced should the suspended solids be more effectively removed. Overall, this process was operated satisfactorily and smoothly, as reflected by the constant effluent pH and gas production rate, as well as the consistently high degrees of reduction of COD and BOD\d5. Parameters such as sludge density, distribution of volatile suspended solids (VSS) and soluble COD in sludge bed, gas production rate, and nutrient levels are discussed.

45 citations


Journal ArticleDOI
TL;DR: In this paper, an anaerobic fluidized bed was operated as a methanogenic reactor with synthetic zeolite as support media, which decomposes acetic, propionic and butyric acids.

40 citations


Journal ArticleDOI
TL;DR: In this paper, anaerobic digestion of effluent from a petrochemical plant producing terephthalic acid has been tested using two Upflow Anaerobic Sludge Blanket (USAB) reactors.
Abstract: Anaerobic digestion of effluent from a petrochemical plant producing terephthalic acid has been tested using two Upflow Anaerobic Sludge Blanket (USAB) reactors. The reactors were seeded with two different inocula: one from an anaerobic stabilization pond receiving wasted sludge from the aerobic treatment plant of the petrochemical industry (reactor A); the other was an anaerobically adapted activated sludge from a municipal wastewater treatment plant (reactor B). At the beginning of the experiment, reactor A attained higher COD removal efficiencies and biogas production, but both reactors reached the same performances after 7 mo operation. The efficiencies in COD removal were low. At a 3 d hydraulic retention time (HRT), reactor A was loaded at 2.6 kg COD/m3 d and reactor B at 2.2 kg COD/m3 d. COD removals were 46.4 and 43.9% for reactor A and B, respectively. In view of these results, the UASB reactor does not appear as the most suitable treatment process for this kind of effluent.

34 citations


Journal ArticleDOI
TL;DR: In this paper, a new biofilter design offering simplified operation and increased performance is presented, which allows implementation of bio-filtration for small wastewater treatment plants, and data for carbon and nutrient removal were collected during extensive pilot tests, in order to optimize the biological and operational parameters of the filter.

30 citations


Journal ArticleDOI
TL;DR: In this article, the effect of ORP on the simultaneous removal of nitrogen and phosphorus, utilizing the oxic-anaerobic-oxic process, was investigated in a full-scale wastewater treatment plant which was designed as an extended aeration process.

27 citations


Journal ArticleDOI
TL;DR: In this article, a biorotor was used for sulphide removal from anaerobically treated paper mill wastewater, and the results showed that the upflow reaction was not suitable for this type of wastewater, at least in the configuration investigated.

24 citations


Journal ArticleDOI
TL;DR: In this article, the anaerobic digestion of the organic fraction of municipal solid waste sorted by plant was investigated in a 3 m3 stirred digester, operating under mesophilic conditions.

23 citations


Journal ArticleDOI
TL;DR: In this paper, the aerobic digestion of primary and secondary sludges was studied in air-lifted bioreactors at mesophilic and thermophilic temperatures.

Journal ArticleDOI
TL;DR: In this article, the maximum growth rate (μm) of acetoclastic methanogens was measured at ammonia concentrations between 0·55 and 0·74 mol/liter (7·7 and 10·4 g ammonia-N/liter) and a pH between 7·80 and 7·93.

Journal ArticleDOI
01 Jan 1990-Biomass
TL;DR: Anaerobic treatment of cheese whey using a 17·5 litre upflow anaerobic sludge blanket reactor was investigated in the laboratory over a range of influent concentration from 4·5 to 38·1 g COD litre−1 at a constant hydraulic retention time of 5 days, and showed two distinct reaction phases, acidogenic and methanogenic.

Journal ArticleDOI
TL;DR: It is found that granulation takes place only in acetate-fed systems but this process was slower and the resultant granules looser and less stable than those developed on sugar-starch substrate.
Abstract: The development of granular sludge in laboratory-scale upflow anaerobic sludge-blanket reactors was studied. Acetate was supplied as sole carbon source in order to select the acetotrophs Methanosarcina and Methanothrix. These microorganisms are dominant in methanogenic ecosystems and their ratio seems to control the speed of granulation. Changing the ratio of the above species was followed on the basis of their different F 420-coenzyme content. Five reactors were operated at the same hydraulic retention time but at different feed substrate concentrations. We found that granulation takes place only in acetate-fed systems but this process was slower and the resultant granules looser and less stable than those developed on sugar-starch substrate. In the range of feed acetate levels examined (0.5−0.3 g/1) higher concentrations of feed caused faster granulation of the sludge bed and, presumably, of the microbial population, and resulted in larger granules containing sludge that settled more readily. We found no evidence for selection pressure at substrate concentrations below 0.5 g/1 acetate in the reactor.

Journal ArticleDOI
TL;DR: In this paper, a laboratory-scale anaerobic filter in single-phase and two-phase systems was used to remove 30% of lipid on COD basis from cafeteria wastewater.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the treatment alternatives for high-strength acid waters from an edible oil refinery and determined an appropriate treatment system for high strength acid waters using a full-scale Dissolved Air Flotation (DAF) plant.

Journal ArticleDOI
TL;DR: Lebrato et al. as mentioned in this paper used a semicontinuous anaerobic digester for the treatment of wastewater from a cheese factory in a bath at 35 + 1'C, and magnetically stirred at 100 rpm.
Abstract: Lebrato, J., Perez-Rodriguez, J.L., Maqueda, C. and Morillo, E., 1990. Cheese factory wastewater treatment by anaerobic semicontinuous digestion. Resour. Consem. Recycl.,3: 193-199. The processing of wastewater from a cheese factory in a semicontinuous anaerobic digester was studied. The experimental set-up consisted of six thermostatically-controlled digesters in a bath at 35 + 1'C, and magnetically stirred at 100 rpm. The best feeding for the culture medium was 0.633 g l-t day-t. The minimum hydraulic retention time was nine days. The efficiency of treatment varied between 90 and 780/0. The composition of biogas was of high quality, with 670/o of methane, and no trace of H2S.

Journal ArticleDOI
TL;DR: In this article, a 50-liter rotating biological reactor was used to aerobically treat nejayote in a corn field, and the removal of organic compounds, evaluated as chemical and biochemical oxygen demand (COD and BOD), as well as reducing sugars, was monitored.

Journal ArticleDOI
TL;DR: In this article, two types of continuous bench-scale reactors (180 mL) fed with hydrolyzed manioc starch (15%, w/v): a two-phase reactor (liquid expanded-bed) and a threephase reactor (air expandedbed).
Abstract: Glucoamylase (E.C.3.2.1.3) covalently immobilized onto chitin particles (dst = 0.37 mm) was examined in two types of continuous bench-scale reactors (180 mL) fed with hydrolyzed manioc starch (15%, w/v): a two-phase reactor (liquid expanded-bed) and a threephase reactor (air expanded-bed). Several conditions of continuous operation were investigated, varying the biocatalyst load (16.7, 37.2, and 54 g/L) into the reactor and the hydraulic residence time. The best results were achieved with the two-phase reactor, which operated continuously for 20 d and showed a decrease of only 6% in conversion (starch to glucose). Conversion levels of 96% were obtained with a hydraulic residence time of about 4 h. A simple mathematical model was able to describe the experimental results of the two types of reactors considering biocatalyst deactivation.

Journal ArticleDOI
TL;DR: In this paper, a poultry processing plant in the southeastern U.S.A. was treated on site with a pilot-scale anaerobic packed-bed reactor, which had a working volume of 3.2 m 3, was filled with 15-cm diameter polyethylene random-pack media, and was operated at 35 ° C with a retention time of 21 hours and at a loading rate of 2.8 kgCOD/m 3 d −1.

Journal ArticleDOI
John Bolte1, D.T. Hill1
TL;DR: A simple mathematical model of steady-state attached-growth anaerobic fermenter kinetics is described, distinguished from conventional suspended-growth reactor models by its explicit consideration of bacterial concentration in the reactor system, based on hydraulic flow and influent volatile solids concentration.

Journal ArticleDOI
TL;DR: In this article, on-site measurements of sludge accumulation were conducted in aerated lagoons operating in small municipalities in Quebec and the results obtained are compared with those calculated using currently well known models.

Journal ArticleDOI
TL;DR: In this article, the effects of daily variation of flow on the performance of submerged anaerobic/aerobic biofilm systems were investigated both by laboratory study using synthetic wastewater and by field study using gray water.

Journal ArticleDOI
TL;DR: Aerobic digestion of primary and secondary sludges was studied in air-lift bioreactors at mesophilic and thermophilic temperatures in this article, where a VSS loading rate of 8.2 kg VSS per m3 per day was achieved.

Journal ArticleDOI
TL;DR: In this paper, the results of a pilot-scale aerated lagoon treating white-waters from a mechanical groundwood-based pulp and paper mill, and long-term operating experiences on two full scale aerated Lagoon systems are presented.