Organic matter and nitrogen removal at planted wetlands treating domestic septage with varying operational strategies

2014 ◽  
Vol 70 (2) ◽  
pp. 352-360 ◽  
Author(s):  
Valerie Siaw Wee Jong ◽  
Fu Ee Tang
Keyword(s):  
Organic Matter ◽  
Feeding Strategies ◽  
Operational Strategies ◽  
Loading Rates ◽  
Second Stage ◽  
Dosing Frequency ◽  
Lower Oxygen ◽  
Hydraulic Load ◽  
Filter Clogging ◽  
Engineered Wetland

A two-staged engineered wetland-based system was designed and constructed to treat raw domestic septage. Hydraulic loading rates (HLRs) of 8.75 and 17.5 cm/d were studied with four and eight daily dosings at the second stage of the system to investigate the influence of the regimes on septage treatment. Removal of organic matter (OM) was found to be HLR dependent, where the results indicated that the increase of HLR from 8.75 to 17.5 cm/d impaired the overall level of treatment in the wetland units. Effluent of wetland fed at HLR 17.5 cm/d presented significantly lower oxygen reduction potential and dissolved oxygen values than wetland fed at 8.75 cm/d, indicative of the occurrence of less aerobic and reductive conditions in the bed. The reoxygenation capability of the wetland units was found to be heavily affected by the dosing frequency especially under high hydraulic load (17.5 cm/d). NH3-N degradation was found to decrease with statistical importance when the wetland was flushed two times more frequently with smaller batches of influent. The number of hydraulic load fractionings did not seem to affect the level of treatments of OM and ammonia for both the wetlands fed under the lower HLR of 8.75 cm/d. Prediction of hydraulic limits and management of the feeding strategies are important in the vertical type of engineered wetlands to guarantee the treatment performance and minimize the chances of filter clogging.

Study on the performance of an up-flow aerated biofilter (UAB) in municipal wastewater treatments

1994 ◽  
Vol 30 (11) ◽  
pp. 25-33 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Satoshi Okabe ◽  
Tomochika Arata ◽  
Yuji Haruta
Keyword(s):  
Organic Matter ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Unique Feature ◽  
Aeration Rate ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Running Cost ◽  
And Performance ◽  
Activated Sludge Systems

A comprehensive wastewater treatment system that accomplishes oxidation of organic matter, nitrification, and denitrification was developed, and its characteristics and performance were investigated. A municipal wastewater was treated by an up-flow aerated biofilter (UAB), in which biofilms were developed on stainless meshes installed horizontally. This UAB exhibited a great potential ability of oxidation of organic matter, SS stabilization, and nitrification due to a unique aeration mechanism giving high DO concentrations with relatively low aeration rates. Another unique feature of the UAB was that attached biofilms on stainless meshes physically filtered out and/or adsorbed suspended solids in the wastewater in addition to the biological oxidation of organic matter. A stable nitrification could be achieved at HRT=10 hours corresponding to a hydraulic loading of 86 L m−2 d−1 and at a ratio of aeration rate to wastewater flow rate (A/W) of 2, which is considerably low as compared to aeration rates of typical activated sludge systems. This UAB system also could handle relatively high hydraulic loading rates. The UAB used in this study still have enough space to install more stainless meshes so as to reduce hydraulic loading rates resulting in the reduction of HRT and aeration rate, which leads to improvement of the system performance as well as reduction of the running cost.

Removal Efficiency of Three Cold-Climate Constructed Wetlands Treating Domestic Wastewater: Effects of Temperature, Seasons, Loading Rates and Input Concentrations

1999 ◽  
Vol 40 (3) ◽  
pp. 273-281 ◽  
Author(s):  
Trond Mæhlum ◽  
Per Stålnacke
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Domestic Wastewater ◽  
Cold Climate ◽  
Treatment Efficiency ◽  
Loading Rates ◽  
P Sorption ◽  
Percentage Points ◽  
Effects Of Temperature ◽  
Pre Treatment

This paper outlines the influence of temperature, flow rate and input concentrations on the treatment efficiency of organic matter and nutrients in constructed wetlands (CWs). Three integrated 10 PE systems with horizontal subsurface flow (HSF) treating domestic wastewater are described. Particular attention is devoted to: (1) aerobic pre-treatment in vertical-flow filters, (2) filter media with high phosphorus (P) sorption capacity, and (3) the treatment efficiency during winters. Aerobic pre-treatment followed by CW units including P sorption media removed most organic matter (BOD> 75%), P (> 90%) and total and ammonia N (40-80%). P retention was relatively stable in wetland filters, both with lightweight aggregates and ferruginous sand during 3-6 years of monitoring. Iron-rich sand from Bsh and Bs horizons of ferro-humic podzols was efficient for P sorption, but removal efficiencies of COD, TOC and SS were negative. The differences in efficiency between cold and warm periods were less than 10 percentage points for all parameters. It is anticipated that temperature effects are partially compensated by the large hydraulic retention time. The findings suggest that HSF systems do not require vegetation.

scholarly journals Biofiltration of Methane Fugitive Emissions from Landfills Using Scum from Municipal Wastewater Treatment Plants (Wwtp) as Alternative Substrate

2021 ◽  
Author(s):  
Waldir Nagel Schirmer ◽  
Erivelton César Stroparo ◽  
Marlon André Capanema ◽  
Douglas Luiz Mazur ◽  
José Fernando Thomé Jucá ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Methane Oxidation ◽  
Municipal Wastewater ◽  
Organic Matter Content ◽  
Matter Content ◽  
Municipal Wastewater Treatment ◽  
Packing Materials ◽  
Loading Rates ◽  
And Control

Abstract Biofilters have been recognized as key technology in the mitigation of greenhouse gases (GHG) emitted by landfills. This study aimed to evaluate the methane (an important GHG) oxidation efficiencies of two experimental biofilters at the municipal landfill of Guarapuava (Brazil) under normal conditions (control column), just using landfill cover soil with low organic matter content, and improved, exploiting dried scum from municipal wastewater treatment plant (SWWTP) mixed with the cover soil (enriched column, with a high organic matter content). The influence of parameters such as the methane inlet loading rates (22 and 44 gCH4.m− 2.d− 1), temperatures, methane concentration in the raw biogas, carbon/nitrogen ratio and moisture content of the packing materials on the oxidation of methane was also evaluated during 25 campaigns. The campaigns with the lowest methane loading rates applied to the biofilters showed the best methane oxidation efficiencies (98.4% and 89.5% in the enriched and control columns, respectively) as compared to campaigns with a higher load (92.6% and 82.6% in the enriched and control columns, respectively). In addition to the loading rates, the methane oxidation efficiencies were highly influenced by the organic matter content and C/N ratio of the packing materials evaluated.

scholarly journals An A2O-MBR system for simultaneous nitrogen and phosphorus removal from brewery wastewater

2019 ◽  
Vol 3 (1) ◽  
pp. 12-22
Author(s):  
Van Nu Thai Thien ◽  
Dang Viet Hung ◽  
Nguyen Thi Thanh Hoa
Keyword(s):  
Organic Matter ◽  
Phosphorus Removal ◽  
Day Treatment ◽  
Oxygen Demand ◽  
Phosphorus Release ◽  
Biological Phosphorus Removal ◽  
Brewery Wastewater ◽  
Nitrogen And Phosphorus ◽  
Loading Rates ◽  
N Removal

Anaerobic/Anoxic/Oxic – Membrane BioReactor (A2O-MBR) system was used to enhance simultaneous removal of nitrogen and phosphorus from brewery wastewater. The A2O unit containing microorganisms with short solids retention time (SRT) was employed mainly for removal of organic matter and phosphorus together with denitrification. The MBR containing microorganisms with long SRT was employed mainly for nitrification of NH4+-N and recirculation of NO3--N. The model of A2O-MBR system made from polyacrylic with the capacity of 49.5 liters was operated with hydraulic retention times decreased from 24, 18 to 12 hours corresponding to organic loading rates increased from 0.50, 0.75 to 1.00 kg COD/m3.day. The results showed that the model not only treated organic matter well but also nearly completely removed both nitrogen and phosphorus. For all three loading rates, chemical oxygen demand (COD) concentration decreased significantly in the anaerobic and anoxic compartments of the A2O unit, indicating that most of organic matter was utilized in the anaerobic and anoxic compartments for phosphorus release and denitrification, respectively. Nitrification in the MBR was almost perfectly completed, with average NH4 +-N removal efficiencies of over 98%. Denitrification in the anoxic compartment happened as much as possible. Demands for the development of PAOs, which were responsible for enhanced biological phosphorus removal (EBPR) processes, could be provided. For loading rate of 0.75 kg COD/m3.day, treatment efficiencies of COD, NH4+-N, total nitrogen (TN) and total phosphorus (TP) of the model were the highest as 95.4, 99.2, 86.7 and 84.6%, respectively. Output values of these parameters were within the limits of Vietnam National Technical Regulation on Industrial Wastewater (QCVN 40:2011/BTNMT), column A. The model of A2O-MBR system was capable of achieving effluents with very low nitrogen and phosphorus concentrations from brewery wastewater.  

Screening the retention of thirteen pesticides in a small constructed wetland

2003 ◽  
Vol 48 (5) ◽  
pp. 267-274 ◽  
Author(s):  
B.C. Braskerud ◽  
K. Haarstad
Keyword(s):  
Organic Matter ◽  
Redox Potential ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Water Purification ◽  
Aquatic Life ◽  
Retention Factors ◽  
Relative Retention ◽  
Hydraulic Load ◽  
High Redox Potential

When pesticides are used in arable watersheds, residues are usually found in the recipients. However, small constructed wetlands (CWs) in first and second order streams can reduce the loss of pesticides, since water purification processes are stimulated. This paper presents the results of adding 13 pesticides to a CW in Norway. The relative retention increased between 0 and 67% for the pesticides fluroxypyr, bentazone, dicamba, mecoprop, propiconazole, MCPA, dichlorprop, linuron, fenpropimorph, metalaxyl, metribuzin, metamitron and propachlor. In many cases, the CW reduced the peak concentrations to values regarded as non-toxic for aquatic life, even though the wetland covered less than 0.4% of the watershed surface area, and the average hydraulic load often was above 0.8 m d-1. Possible retention factors were adsorption to soil particles and organic matter, sedimentation of particles, low or high redox-potential, and biodegradation of nitrogen-rich pesticides. However, the retention processes are complex, and are not fully understood.

Elucidating trophic pathways of the most abundant fish larvae in northern Patagonia using δ13C and δ15N isotopes

2020 ◽  
Vol 650 ◽  
pp. 253-267
Author(s):  
A Bernal Bajo ◽  
LR Castro ◽  
D Costalago
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Fish Larvae ◽  
Trophic Position ◽  
Trophic Levels ◽  
Feeding Strategies ◽  
Late Winter ◽  
Terrestrial Organic Matter ◽  
Δ13c And Δ15n ◽  
Northern Patagonia

The alternation of the classic and microbial food-webs in spring and winter, respectively, and the trespass towards higher trophic levels represented by fish early stages, are not well understood in Patagonia. These trophic routes were investigated in the inner Sea of Chiloe, an estuary of high ecological relevance in northern Patagonia. The isotopic values of δ13C and δ15N of ichthyoplankton and particulate organic matter were analyzed in late winter and spring 2017 to evaluate whether seasonal changes (e.g. in the composition of the freshwater discharge) were reflected in the isotopic signals of fish larvae. For this purpose, larvae of dominant fish species with contrasting feeding strategies were collected up to 100 m depth. The inshore zone of northern Patagonia was characterized by a dominance of marine carbon production, with increasing input of terrestrial organic matter during winter. δ13C values < -25 ‰ at the outermost estuary stations indicated the influence of allochthonous carbon exported from the inshore area in spring. The δ13C-larval signature of the species of the lightfish Maurolicus parvipinnis, the pipefish Leptonotus blainvilleanus, and the rockfish Sebastes oculatus followed the isotopic signature of the particulate organic matter in both seasons, at inshore and the exchange (outer) zone. Food partitioning was detected between species, with Merluccius spp. at the highest trophic position and L. blainvilleanus at the lowest. The fish larval community reached more diverse and higher δ15N values in winter, when larvae likely fed on prey items of higher trophic level, or instead when the food-web was partly sustained by microbial sources. Our results showed seasonal variations in δ13C values, suggesting differences in the source of organic carbon incorporated by the studied fish larvae. Moreover, trophic plasticity at larval stages may be an important characteristic of this type of estuarine environment.

scholarly journals Dome C ultracarbonaceous Antarctic micrometeorites

2018 ◽  
Vol 609 ◽  
pp. A65 ◽  
Author(s):  
E. Dartois ◽  
C. Engrand ◽  
J. Duprat ◽  
M. Godard ◽  
E. Charon ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solar System ◽  
Absorption Band ◽  
Raman Spectra ◽  
Interplanetary Dust ◽  
Organic Component ◽  
Dust Particles ◽  
Interplanetary Dust Particles ◽  
Lower Oxygen ◽  
Carbonyl Absorption Band

Context. UltraCarbonaceous Antarctic MicroMeteorites (UCAMMs) represent a small fraction of interplanetary dust particles reaching the Earth’s surface and contain large amounts of an organic component not found elsewhere. They are most probably sampling a contribution from the outer regions of the solar system to the local interplanetary dust particle (IDP) flux. Aims. We characterize UCAMMs composition focusing on the organic matter, and compare the results to the insoluble organic matter (IOM) from primitive meteorites, IDPs, and the Earth. Methods. We acquired synchrotron infrared microspectroscopy (μFTIR) and μRaman spectra of eight UCAMMs from the Concordia/CSNSM collection, as well as N/C atomic ratios determined with an electron microprobe. Results. The spectra are dominated by an organic component with a low aliphatic CH versus aromatic C=C ratio, and a higher nitrogen fraction and lower oxygen fraction compared to carbonaceous chondrites and IDPs. The UCAMMs carbonyl absorption band is in agreement with a ketone or aldehyde functional group. Some of the IR and Raman spectra show a C≡N band corresponding to a nitrile. The absorption band profile from 1400 to 1100 cm-1 is compatible with the presence of C-N bondings in the carbonaceous network, and is spectrally different from that reported in meteorite IOM. We confirm that the silicate-to-carbon content in UCAMMs is well below that reported in IDPs and meteorites. Together with the high nitrogen abundance relative to carbon building the organic matter matrix, the most likely scenario for the formation of UCAMMs occurs via physicochemical mechanisms taking place in a cold nitrogen rich environment, like the surface of icy parent bodies in the outer solar system. The composition of UCAMMs provides an additional hint of the presence of a heliocentric positive gradient in the C/Si and N/C abundance ratios in the solar system protoplanetary disc evolution.

Anaerobic treatment of partly acidified wastewater in a two-stage expanded granular sludge bed (EGSB) system at 8°C

1997 ◽  
Vol 36 (6-7) ◽  
pp. 317-324 ◽  
Author(s):  
Jules B. van Lier ◽  
Salih Rebac ◽  
Piet Lens ◽  
Friso van Bijnen ◽  
Stefanie J. W. H. Oude Elferink ◽  
...  
Keyword(s):  
Specific Activity ◽  
Blot Hybridization ◽  
Effective Diffusion ◽  
Anaerobic Treatment ◽  
Anaerobic Sludge ◽  
Two Stage ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Second Stage ◽  
Sucrose Loading

Psychrophilic (8 °C) anaerobic treatment of partly acidified waste water was investigated using a two stage EGSB system with a total volume of 8.6 dm3. The reactor system was operated at an up-flow velocity of 10 m·h−1 and was fed with a sucrose-VFA mixture of 550–1100 mg COD dm−3. The average CODsol and VFA-COD removal efficiencies were 97 and 90 %, respectively, at total organic loading rates (OLR) ranging between 5.1–6.7 g COD dm−3·day−1, sucrose loading rates up to 1 g COD dm−3 day−1 and a hydraulic retention time (HRT) of 4 h. An increase in the sucrose loading rates resulted in a significant wash-out of biomass from the first stage. The second stage satisfactory served as a scavenger of non-degraded VFA from the first stage. Specific activity assays showed an increase of 15 % in the specific methanogenic activity of the sludge present in the second stage and a decrease of 9 % in the first stage. Apparently, an enrichment of methanogens and acetogens in the anaerobic sludge in the second stage took place at temperatures as low as 8°C. The acidogenic population became much more dominant in the first stage, resulting in a higher acidifying activity and a decreased methanogenic activity. 16S rRNA probe-techniques (dot blot hybridization) showed that the acetate consuming Methanosaeta (formerly Methanothrix) and the hydrogenotrophic Methanobrevibacter species (or relatives) were the most abundant methanogens present in the psychrophilic sludge. The ratio between bacterial and methanobacterial hybridization signal of the first stage was 3 times higher than that of the second stage. By using NMR techniques, a higher effective diffusion coefficient was found for the smaller sized granules in both reactors, which is in congruent with the higher maximum specific acetate degrading activity of the smaller granules.

Primary fermentation of soluble and particulate organic matter for wastewater treatment

1994 ◽  
Vol 30 (6) ◽  
pp. 53-62 ◽  
Author(s):  
Ricardo Françi GonÇalves ◽  
Anne Catherine Charlier ◽  
François Sammut
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Volatile Fatty Acids ◽  
Soluble Fraction ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Operating Conditions ◽  
Optimum Conditions ◽  
Hydraulic Load

A new reactor based on upflow sludge blanket technology (USB) for fermentation of both the particulate and soluble fractions of domestic wastewater is presented. The process is fed with the total wastewater flow, and carries out suspended solids (SS) retention, fermentation and clarification of the fermented effluent in a single reactor. The study was carried out using pilot scale reactors, under six different operating conditions with regards to hydraulic load (hydraulic retention time, HRT, varying between 1.1 and 4.3 hours) and at a constant temperature (20 ± 1°C). With regards to primary treatment, the process has been shown to ensure low SS residuals in the fermented effluent under all operating conditions tested. Very low residuals, with an average below 50 mg SS/l, were obtained with an upflow velocity of between 0.75 and 0.9 m/h. These trials have also highlighted the important role played by the adsorption of particulate organic matter on the biological flocs of the sludge blanket in the elimination of SS. Fermentation efficiencies are superior to those of existing fermenters, the results clearly proving that a majority of the volatile fatty acids produced originate from the soluble fraction of the wastewater. Under the optimum conditions tested, with an HRT = 2.8 hours, 0.17 mg HAc/mg total COD are produced, over 60% of which is generated by the fermentation of the influent soluble organic matter. Under these operating conditions, maximum solubilisation of the particulate fraction has been estimated at 0.13 mg of filtered COD/mg particulate COD (total COD-filtered COD).

scholarly journals The impact of fractionation of hydraulic load on oxidation performances of sand filters

2015 ◽  
Vol 6 (2) ◽  
pp. 325-332 ◽  
Author(s):  
Mahmoud Bali ◽  
Moncef Gueddari
Keyword(s):  
Organic Matter ◽  
Treatment Process ◽  
Ammonium Nitrogen ◽  
Treatment Technique ◽  
Treatment Efficiency ◽  
Sand Filters ◽  
Hydraulic Load ◽  
Filter Bed ◽  
The Impact ◽  
Daily Load

Infiltration–percolation is an extensive treatment technique aimed at eliminating organic matter, oxidizing nitrogen, and removing pathogens. The main purpose of this work is to evaluate the impact of fractionation of hydraulic load on oxidation performances of unsaturated sand filters. Experimental results showed that oxidation of organic matter and ammonium nitrogen has mainly occurred in the upper layers of the filter bed. They also showed that treatment efficiency increased with the increase of the thickness of the filtering mass and the fractionation of applied hydraulic load. The experiments pointed out the influence of the fractionation of daily load on oxidation capacity of the intermittent sand filter. Results showed that increasing the fractionation improves the purification capacity of the treatment process. The simulations showed that biomass growth is very sensitive to the fractionation of hydraulic load, and that the increase of the number of feeding–drainage cycles per day leads to accumulate purifying biomass in the upper layers of unsaturated filters.

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