Performance of a Pilot-Scale High-Rate Anaerobic Side-stream Reactor (ASSR) Process: Minimized Sludge Production and Generation of Biogas

Integrated processes to reduce in situ the sludge production in wastewater treatment plants are gaining attention in order to facilitate excess sludge management. In contrast to post-treatments, such as anaerobic digestion which is placed between the activated sludge system and dewatering processes, integrated technologies are placed in the sludge return line. This study evaluates the application of an anoxic side-stream reactor (SSR) which creates a physiological shock and uncouples the biomass metabolism and diverts the activity from assimilation for biosynthesis to non-growth activities. The effect of this system in biological nutrient removal for both nitrogen and phosphorus was evaluated for the anaerobic, anoxic and aerobic reactors. The RedOx potential within the SSR was maintained at −150 mV while the sludge loading rate was modified by increasing the percentage of recycled activated sludge feed to the SSR (0 and 40% at laboratory scale and 0, 10, 50 and 100% at pilot scale). The use of the SSR presented a slight reduction of phosphorus removal but maintained the effluent quality to the required discharge values. Nitrogen removal efficiency increased from 75 to 86% while reducing the sludge production rate by 18.3%.

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Viability of nematode eggs in high rate algal ponds: the effect of physico-chemical conditions

Water Science & Technology ◽

10.2166/wst.2000.0683 ◽

2000 ◽

Vol 42 (10-11) ◽

pp. 371-374 ◽

Cited By ~ 8

Author(s):

S. Araki ◽

J. M. González ◽

E. de Luis ◽

E. Bécares

Keyword(s):

Hydraulic Retention Time ◽

Pilot Scale ◽

High Rate ◽

Sterile Water ◽

Egg Viability ◽

High Rate Algal Ponds ◽

Helminth Eggs ◽

Physico Chemical ◽

Nematode Eggs ◽

Chemical Conditions

The viability of Parascaris equorum eggs was studied in two experimental pilot-scale high-rate algal ponds (HRAPs) working in parallel with 4 and 10 days hydraulic retention time respectively. Semi-permeable bags of cellulose (15000 daltons pore size) were used to study the effect of physico-chemical conditions on the survival of these helminth eggs. Three thousand eggs were used in each bag. Replicates of these bags were submerged for 4 and 10 days in the HRAPs and egg viability was compared with that in control bags submerged in sterile water. After 4 days exposure, 60% reduction in viability was achieved, reaching 90% after 10 days, much higher than the 16% and 25% found in the control bags for 4 and 10 days respectively. Ionic conditions of the HRAP may have been responsible for up to 50–60% of the egg mortality, suggesting that mortality due to the ionic environment could be more important than physical retention and other potential removal factors.

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On-site and in situ bioremediation of wood-preservative contaminated groundwater

Water Science & Technology ◽

10.2166/wst.2000.0537 ◽

2000 ◽

Vol 42 (5-6) ◽

pp. 371-376 ◽

Cited By ~ 11

Author(s):

J.A. Puhakka ◽

K.T. Järvinen ◽

J.H. Langwaldt ◽

E.S. Melin ◽

M.K. Männistö ◽

...

Keyword(s):

Iron Oxidation ◽

Wood Preservative ◽

Pilot Scale ◽

High Rate ◽

Contaminated Groundwater ◽

Groundwater Temperature ◽

In Situ Bioremediation ◽

Contaminated Aquifer ◽

Fluidized Bed Process

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.

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Minimization of sludge production by a side-stream reactor under anoxic conditions in a pilot plant

Bioresource Technology ◽

10.1016/j.biortech.2012.11.055 ◽

2013 ◽

Vol 129 ◽

pp. 229-235 ◽

Cited By ~ 75

Author(s):

M. Coma ◽

S. Rovira ◽

J. Canals ◽

J. Colprim

Keyword(s):

Pilot Plant ◽

Anoxic Conditions ◽

Side Stream ◽

Sludge Production

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Macrokinetic Modeling of Chemical Oxygen Demand Removal in Pilot-Scale High-Rate Anaerobic Ponds

Environmental Engineering Science ◽

10.1089/ees.2009.0183 ◽

2010 ◽

Vol 27 (4) ◽

pp. 293-299 ◽

Cited By ~ 1

Author(s):

Miguel R. Peña

Keyword(s):

Chemical Oxygen Demand ◽

Oxygen Demand ◽

Pilot Scale ◽

High Rate ◽

Chemical Oxygen Demand Removal ◽

Macrokinetic Modeling

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Tilapia rearing with high rate algal pond effluent: ammonia surface loading rates and stocking densities effects

Water Science & Technology ◽

10.2166/wst.2018.285 ◽

2018 ◽

Vol 78 (1) ◽

pp. 49-56

Author(s):

I. A. Sánchez ◽

R. K. X. Bastos ◽

E. A. T. Lana

Keyword(s):

Weight Gain ◽

Oxygen Demand ◽

Pilot Scale ◽

Ammonia Nitrogen ◽

High Rate ◽

Surface Loading ◽

Loading Rates ◽

Total Weight Gain ◽

Low Weight ◽

Total Ammonia

Abstract In two pilot-scale experiments, fingerlings and juvenile of tilapia were reared in high rate algal pond (HRAP) effluent. The combination of three different total ammonia nitrogen (TAN) surface loading rates (SLR1 = 0.6, SLR2 = 1.2; SLR3 = 2.4 kg TAN·ha−1·d−1) and two fish stocking densities (D1 = 4 and D2 = 8 fish per tank) was evaluated during two 12-week experiments. Fingerlings total weight gain varied from 4.9 to 18.9 g, with the highest value (equivalent to 0.225 g·d−1) being recorded in SLR2-D1 treatment; however, high mortality (up to 67%) was recorded, probably due to sensitivity to ammonia and wide daily temperature variations. At lower water temperatures, juvenile tilapia showed no mortality, but very low weight gain. The fish rearing tanks worked as wastewater polishing units, adding the following approximate average removal figures on top of those achieved at the HRAP: 63% of total Kjeldahl nitrogen; 54% of ammonia nitrogen; 42% of total phosphorus; 37% of chemical oxygen demand; 1.1 log units of Escherichia coli.

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The main natural lows of high-rate coal pyrolysis

Thermal Science ◽

10.2298/tsci0302077c ◽

2003 ◽

Vol 7 (2) ◽

pp. 77-87 ◽

Cited By ~ 1

Author(s):

Nikola Chemyavsky

Keyword(s):

Fluidized Bed ◽

Total Yield ◽

Pilot Scale ◽

Thermal Conversion ◽

High Rate ◽

Coal Pyrolysis ◽

Heating Rates ◽

Method Of Calculation ◽

Entrained Flow ◽

Energy Technologies

The importance of coal pyrolysis studies for the development of energy technologies is evident, since pvrolysis is the first stage of any process of coal thermal conversion. In combustion, pyrolysis determines conditions of coal ignition and the rate of char after-burning, in gasification, pyrolysis determines total yield of gasification products. It must be noted that in modern energy technologies pyrolysis occurs at high late of coal particle heating (=10 K/s for different fluidized bed, or FB-technologies) or super-high-rate (>10**5 K/s for entrained-flow gasification), and in some of them at high pressure. In CETI during last 12 years the detailed study of pyrolysis in FB laboratory-scale PYROLYSIS-D plant and entramed-flow pilot-scale GSP-01 plant, was carried out. In this paper main results of mentioned investigations are given. Kinetic constants for bituminous coals and anthracite high heating rates in entrained flow for high temperatures (>1500 ?C and >1900 ?C), and in fluidized bed conditions in temperature range 972-1273 K. In order to describe data obtained in fluidized bed conditions, G--model based method of calculation of devolatization dynamics was suited to FB heating conditions. Calculated and experimental kinetic data are in good agreement. The result proves that at FB-pvrolysis conditions intrinsic mass-transfer limitations are negligible and devolatilization is really kinetic-controlled.

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