scholarly journals Pilot-scale study of a structured bed reactor for nitrogen and organic matter removal from sanitary sewage: advances and design challenges

2021 ◽  
Vol 10 (13) ◽  
pp. e589101321560
Author(s):  
Kiemi de Brito Murata ◽  
Bruno Garcia Silva ◽  
Carla Eloísa Diniz dos Santos ◽  
Dagoberto Yukio Okada ◽  
Rafael Brito de Moura ◽  
...  
Keyword(s):  
Organic Matter ◽  
Experimental Period ◽  
Pilot Scale ◽  
Intermittent Aeration ◽  
Total N ◽  
Optimal Balance ◽  
N Removal ◽  
Aeration System ◽  
Different Types ◽  
Nitrification And Denitrification

Simultaneous nitrification and denitrification (SND) is a process that can remove both nitrogen and organic matter in a single unit. Several bench-scale studies show that the structured bed reactors (STBR) subjected to recirculation and intermittent aeration have achieved a good performance for SND treating different types of wastewater. Thus, this study took a step forward and evaluated the efficiency and stability of treating domestic sewage in a pilot-scale STBR. COD removal efficiencies higher than 87% were achieved in the whole experimental period. The highest Total-N removal efficiency was approximately 74 ± 7% by adopting a hydraulic retention time (HRT) of 47.2 h and intermittent aeration (2 h aerated and 1 h non-aerated). The setup of the aeration system was an important mechanism to ensure the optimal balance between nitrification and denitrification in a pilot-scale system.

Simultaneous Nitrification-Denitrification Processes in Activated Sludge Plants: Performance and Applicability

1999 ◽  
Vol 40 (4-5) ◽  
pp. 187-194 ◽  
Author(s):  
C. Collivignarelli ◽  
G. Bertanza
Keyword(s):  
Activated Sludge ◽  
Waste Water Treatment ◽  
Electric Energy ◽  
Low Oxygen ◽  
Total N ◽  
Electric Energy Consumption ◽  
N Removal ◽  
Aeration System ◽  
Anoxic Basin ◽  
Removal Efficiencies

This paper deals with the development of technologies aimed to upgrade existing waste water treatment plants, paying attention to high process efficiencies and low costs. We established conditions for good N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimental process is based on establishing conditions in the biological reactor which allow simultaneous nitrification and denitrification without alternating (in time or in space) anoxic and aerobic phases; the aeration system is controlled by means of dissolved oxygen and/or redox potential measurements. The research was carried out on two real plants (design size: 2,500 p.e. and 440,000 p.e. respectively). The main advantages of this process (even if some aspects are still under investigation) are: total N removal efficiencies similar to a pre-denitrification process, without the need for an anoxic basin and decrease of operating costs (savings in electric energy consumption in particular) due to the low oxygen concentration required in the biological reactor.

Performance of plastic- and sponge-based trickling filters treating effluents from an UASB reactor

2013 ◽  
Vol 67 (5) ◽  
pp. 1034-1042 ◽  
Author(s):  
P. G. S. Almeida ◽  
A. K. Marcus ◽  
B. E. Rittmann ◽  
C. A. L. Chernicharo
Keyword(s):  
Organic Matter ◽  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Total N ◽  
Trickling Filters ◽  
N Removal ◽  
Anaerobic Sludge Blanket

The paper compares the performance of two trickling filters (TFs) filled with plastic- or sponge-based packing media treating the effluent from an upflow anaerobic sludge blanket (UASB) reactor. The UASB reactor was operated with an organic loading rate (OLR) of 1.2 kgCOD m−3 d−1, and the OLR applied to the TFs was 0.30–0.65 kgCOD m−3 d−1 (COD: chemical oxygen demand). The sponge-based packing medium (Rotosponge) gave substantially better performance for ammonia, total-N, and organic matter removal. The superior TF-Rotosponge performance for NH4+-N removal (80–95%) can be attributed to its longer biomass and hydraulic retention times (SRT and HRT), as well as enhancements in oxygen mass transfer by dispersion and advection inside the sponges. Nitrogen removals were significant (15 mgN L−1) in TF-Rotosponge when the OLRs were close to 0.75 kgCOD m−3 d−1, due to denitrification that was related to solids hydrolysis in the sponge interstices. For biochemical oxygen demand removal, higher HRT and SRT were especially important because the UASB removed most of the readily biodegradable organic matter. The new configuration of the sponge-based packing medium called Rotosponge can enhance the feasibility of scaling-up the UASB/TF treatment, including when retrofitting is necessary.

Source-process partitioning of soil N2O and CO2 production: nitrogen and simulated exudate additions

2020 ◽  
Author(s):  
Erin Daly ◽  
Guillermo Hernandez Ramirez
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Interactive Effect ◽  
Interactive Effects ◽  
Co2 Production ◽  
Site Preference ◽  
Total N ◽  
Urea Fertilizer ◽  
Nitrification And Denitrification ◽  
Source Partitioning

<p>Understanding the source partitioning of carbon dioxide (CO<sub>2</sub>) and nitrous oxide (N<sub>2</sub>O) fluxes from soil is integral for the characterization of total fluxes and the quantification of potential soil organic matter priming effects. Additionally, we utilized <sup>15</sup>N-N<sub>2</sub>O site preference data to analyze the process priming of microbial nitrification and denitrification on subsequent N<sub>2</sub>O fluxes. A 32-day laboratory incubation was designed to examine the effects of artificial exudate, nitrogen fertilizer and their potential interactive effects on CO<sub>2</sub> and N<sub>2</sub>O fluxes, soil organic matter source-priming and N<sub>2</sub>O process-priming. Artificial root exudate (ARE) consisting of a mixture of 99 atom% <sup>13</sup>C labelled compounds at three addition rates (0, 6.2, 12.5 mg C kg<sup>-1</sup> soil day<sup>-1</sup>) was applied daily for 21 days to microcosms with or without urea fertilizer, a subset of which was labelled with 5 atom % <sup>15</sup>N. Measurements of CO<sub>2</sub> and N<sub>2</sub>O fluxes, isotopic composition and N<sub>2</sub>O site preference were frequent throughout the duration of the experiment. Source partitioning of CO<sub>2</sub> fluxes showed that soil organic carbon (SOM-C) positive priming was significantly altered by additions of artificial exudate and urea (p < 0.001 and 0.001, respectively). When applied concurrently, urea addition had an antagonistic interactive effect on SOM-C sourced CO<sub>2</sub> fluxes (p < 0.001).  Source partitioning of N<sub>2</sub>O flux data revealed that soil organic matter nitrogen (SOM-N) was positively primed for N<sub>2</sub>O flux by the addition of urea fertilizer (p < 0.001), but positive SOM-N priming was reduced by an antagonistic interaction with artificial exudate application (p < 0.001). Further, examination of <sup>15</sup>N-N<sub>2</sub>O site preference found that the main processes by which N<sub>2</sub>O is formed (nitrification and denitrification) were differentially process-primed by the addition or absence of ARE. Cumulative denitrification and nitrification contributions to total N<sub>2</sub>O flux were both positively primed in the soils receiving both ARE and urea inputs relative to a control (50.0 ± 10.1 and 28.2± 8.0 μg N<sub>2</sub>O-N kg<sup>-1</sup>, respectively). In soils receiving only ARE application, denitrification-derived N<sub>2</sub>O was negatively primed relative to a control and thus contributed less to overall N<sub>2</sub>O flux (-9.5 ± 12.4 μg N<sub>2</sub>O-N kg<sup>-1</sup>) but nitrification-derived N<sub>2</sub>O was positively primed (17.2 ± 9.0 μg N<sub>2</sub>O-N kg<sup>-1</sup>).</p>

scholarly journals Evaluation of Different Biomedia Performance for River Purification: Preliminary Stage

2015 ◽  
Vol 773-774 ◽  
pp. 1365-1369
Author(s):  
Gasim Hayder ◽  
Lariyah Mohd Sidek ◽  
Hairun Aishah Mohiyaden ◽  
Hidayah Basri ◽  
Ahmad Fauzan Mohd Sabri ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Oxygen Demand ◽  
Time Frame ◽  
River Pollution ◽  
Pilot Scale ◽  
Laboratory Setup ◽  
N Removal ◽  
Different Types ◽  
Efficiency Performance

There is national concern about rivers pollution degree. The Malaysian Department of Irrigation and Drainage (DID) is running a project for river biological purification using biomedia to reduce the river pollution degree. This study aims to use different types of biomedia carrier for effective management of the river purification plant project. Water samples were collected and tested for various essential parameters. A biomedia laboratory setup was fabricated for the research with seven different types of biomedia, and water sampling was collected daily and weekly for analysis purposes. The experimental results show that the best removal efficiency was achieved by biomedia Type 1 and was 88% and 65.5% for biochemical oxygen demand (BOD) and chemical oxygen demand (COD), respectively. Followed by biomedia Type 3 achieved an average of 58 percentage for ammonia (NH3-N) removal. Overall, the best removal efficiency performance of biomedia Type 1 achieved the calculated rate of 68 %. The cleanest effluent was biomedia Type 4. For accumulated biofilm formation, the highest total volatile solid (TVS) was the biomedia Type 4. Finally, the best inclusive performance is biomedia Type 1. Future studies are recommended to conduct a pilot scale study with a longer time frame and to study these selective types of biomedia in anaerobic and anoxic condition.

Simultaneous nitrification-denitrification process in extended aeration plants: pilot and real scale experiences

1997 ◽  
Vol 35 (6) ◽  
pp. 53-61 ◽  
Author(s):  
G. Bertanza
Keyword(s):  
Waste Water ◽  
Waste Water Treatment ◽  
Electric Energy ◽  
Pilot Scale ◽  
Low Oxygen ◽  
Total N ◽  
Electric Energy Consumption ◽  
N Removal ◽  
Removal Efficiencies ◽  
Denitrification Process

This work deals with the study of technologies aimed to upgrade the existing waste water treatment plants, paying attention to high process efficiencies and low costs. We verified the possibility to reach high N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimented process is based on particular conditions, kept in the biological reactor, which allow simultaneous nitrification and denitrification, even without alternating (in time or in space) of anoxic and aerobic phases: aeration system is controlled by means of dissolved oxygen and redox potential measurements. Our research was carried out, for about three years, on a laboratory plant (V = 40 L) fed with synthetic waste water, a pilot scale plant (V = 1,400 L) fed with waste water coming from a real plant, and two full-scale plants (1,500-2,000 p.e.). The main advantages of the studied process are the following: high total N removal efficiencies (up to 90%) without the realization of new specific basins for the denitrification process; decreasing of operating costs (savings in Electric Energy consumption) due to the low oxygen concentration required in the biological reactor.

Impact of Nitrogen Management Practices on Total Nitrogen in the Fruits of High Productive Hamlin Orange Trees

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498e-498
Author(s):  
S. Paramasivam ◽  
A.K. Alva
Keyword(s):  
Crop Production ◽  
Management Practices ◽  
Fine Sand ◽  
Fruit Production ◽  
Perennial Crop ◽  
Total N ◽  
N Removal ◽  
Leaf N Concentration ◽  
N Rates ◽  
Orange Trees

For perennial crop production conditions, major portion of nutrient removal from the soil-tree system is that in harvested fruits. Nitrogen in the fruits was calculated for 22-year-old `Hamlin' orange (Citrus sinensis) trees on Cleopatra mandarin (Citrus reticulata) rootstock, grown in a Tavares fine sand (hyperthermic, uncoated, Typic Quartzipsamments) that received various N rates (112, 168, 224, and 280 kg N/ha per year) as either i) broadcast of dry granular form (DGF; four applications/year), or ii) fertigation (FRT; 15 applications/year). Total N in the fruits (mean across 4 years) varied from 82 to 110 and 89 to 111 kg N/ha per year for the DGF and FRT sources, respectively. Proportion of N in the fruits in relation to N applied decreased from 74% to 39% for the DGF and from 80% to 40% for the FRT treatments. High percentage of N removal in the fruits in relation to total N applied at low N rates indicate that trees may be depleting the tree reserve for maintaining fruit production. This was evident, to some extent, by the low leaf N concentration at the low N treatments. Furthermore, canopy density was also lower in the low N trees compared to those that received higher N rates.

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

Agricultural practices and diffuse nitrogen pollution in Denmark: empirical leaching and catchment models

1999 ◽  
Vol 39 (12) ◽  
pp. 257-264 ◽  
Author(s):  
Hans E. Andersen ◽  
Brian Kronvang ◽  
Søren E. Larsen
Keyword(s):  
Agricultural Land ◽  
Root Zone ◽  
Agricultural Practices ◽  
Animal Manure ◽  
Annual Runoff ◽  
N Leaching ◽  
N Loss ◽  
Total N ◽  
Model Calculations ◽  
N Removal

An empirical leaching model was applied to data on agricultural practices at the field level within 6 small Danish agricultural catchments in order to document any changes in nitrogen (N) leaching from the root zone during the period 1989-96. The model calculations performed at normal climate revealed an average reduction in N-leaching that amounted to 30% in the loamy catchments and 9% in the sandy catchments. The reductions in N leaching could be ascribed to several improvements in agricultural practices during the study period: (i) regulations on livestock density; (ii) regulations on the utilisation of animal manure; (iii) regulations concerning application practices for manure. The average annual total N-loss from agricultural areas to surface water constituted only 54% of the annual average N leached from the root zone in the three loamy catchments and 17% in the three sandy catchments. Thus, subsurface N-removal processes are capable of removing large amounts of N leached from agricultural land. An empirical model for the annual diffuse N-loss to streams from small catchments is presented. The model predicts annual N-loss as a function of the average annual use of mineral fertiliser and manure in the catchment and the total annual runoff from the unsaturated zone.

scholarly journals A Comparison of Two-Stage and Traditional Co-Composting of Green Waste and Food Waste Amended with Phosphate Rock and Sawdust

2021 ◽  
Vol 13 (3) ◽  
pp. 1109
Author(s):  
Edgar Ricardo Oviedo-Ocaña ◽  
Angélica María Hernández-Gómez ◽  
Marcos Ríos ◽  
Anauribeth Portela ◽  
Viviana Sánchez-Torres ◽  
...  
Keyword(s):  
Organic Matter ◽  
Product Quality ◽  
Food Waste ◽  
Phosphate Rock ◽  
Pilot Scale ◽  
Two Stage ◽  
Green Waste ◽  
Wet Weight ◽  
Two Phases

The composting of green waste (GW) proceeds slowly due to the presence of slowly degradable compounds in that substrate. The introduction of amendments and bulking materials can improve organic matter degradation and end-product quality. However, additional strategies such as two-stage composting, can deal with the slow degradation of green waste. This paper evaluates the effect of two-stage composting on the process and end-product quality of the co-composting of green waste and food waste amended with sawdust and phosphate rock. A pilot-scale study was developed using two treatments (in triplicate each), one being a two-stage composting and the other being a traditional composting. The two treatments used the same mixture (wet weight): 46% green waste, 19% unprocessed food waste, 18% processed food waste, 13% sawdust, and 4% phosphate rock. The traditional composting observed a higher degradation rate of organic matter during the mesophilic and thermophilic phases and observed thermophilic temperatures were maintained for longer periods during these two phases compared to two-stage composting (i.e., six days). Nonetheless, during the cooling and maturation phases, the two treatments had similar behaviors with regard to temperature, pH, and electrical conductivity, and the end-products resulting from both treatments did not statistically differ. Therefore, from this study, it is concluded that other additional complementary strategies must be evaluated to further improve GW composting.

Sign in / Sign up

Export Citation Format

Share Document