Combined photosynthesis and mechanical aeration for nitrification in dairy waste stabilisation ponds

2003 ◽  
Vol 48 (2) ◽  
pp. 137-144 ◽  
Author(s):  
J.P.S. Sukias ◽  
R.J. Craggs ◽  
C.C. Tanner ◽  
R.J. Davies-Colley ◽  
J.W. Nagels
Keyword(s):  
Electrical Power ◽  
Oxygen Demand ◽  
Aquatic Organisms ◽  
Ammonia Toxicity ◽  
Nitrifying Bacteria ◽  
Matched Pair ◽  
Total N ◽  
N Removal ◽  
Algal Photosynthesis ◽  
Mechanical Aeration

New Zealand has 16,500 dairy farms (avg. 220 cows), with cows kept on pasture throughout the year. During the 9-month dairy season, the cows are milked twice a day (averaging 2.5-3 h per day in the dairy parlour). Urine and faecal wastes deposited in the dairy parlour are washed away with high pressure hoses, using large volumes of water. A common method of treatment is in simple two-pond (anaerobic/facultative) lagoon systems, which remove about 95% of suspended solids and BOD5, but only 75% of total-N prior to discharge. High concentrations of ammoniacal-N in the effluent can cause toxicity to aquatic organisms in receiving waters. Mechanical aeration of the second (facultative) lagoon to promote nitrification improves effluent quality by reducing oxygen demand and potential ammonia toxicity to streamlife. Mechanical aeration however is associated with considerable mixing, which may prevent algae from optimising photosynthesis in the facultative lagoon. A series of experiments was undertaken which tested the efficiency of mechanical aeration and then attempted to combine it with daytime algal oxygen production in order to maximise ammonia conversion to nitrate, while minimising costs to the farmer. An experimental facility was developed by dividing a large facultative lagoon into two, producing a matched pair of lagoons, operated in parallel with influent flow split equally. Over successive dairy seasons, various aeration regimes were compared. Continuous aeration promoted nearly complete nitrification of the ammoniacal-N (99% removal), and effluent BOD was approximately halved. However the continuous mixing reduced algal biomass, and thus daytime algal photosynthesis. Night-only aeration permitted greater algal photosynthesis to occur, as well as halving electrical power consumption. Ammoniacal-N removal reduced to 90% (10 g m-3 remaining in the effluent), while BOD removal was also lower than in the continuously aerated lagoon (59 and 69% respectively). Providing a series of biofilm attachment surfaces for nitrifying bacteria by suspending geotextile material close to the surface in the pond in consistently aerobic water resulted in improved ammoniacal-N removal efficiency (93%) with night aeration, but still lower removal than continuous aeration.

Simultaneous autotrophic denitrification and nitrification in a low-oxygen reaction environment

2014 ◽  
Vol 70 (4) ◽  
pp. 729-735 ◽  
Author(s):  
Ganapathy Ramanathan ◽  
Christopher M. Sales ◽  
Wen K. Shieh
Keyword(s):  
Residence Time ◽  
Oxygen Demand ◽  
Autotrophic Denitrification ◽  
Low Oxygen ◽  
Total N ◽  
N Removal ◽  
Bioreactor System ◽  
The Mean ◽  
The Stability ◽  
Ammonia Oxidising Bacteria

The occurrence of autotrophic denitrification and nitrification activities by ammonia-oxidising bacteria and nitrite-oxidising bacteria is studied in a bioreactor system operable at low-dissolved oxygen (DO) and at variable oxygen influx rates. At a loading of 3.6 mg NH4+–N/h into the bioreactor, simultaneous autotrophic denitrification and nitrification contributed to NH4+–N removal over oxygen influxes of 2–14 mg O2/h and DO <0.5 mg/L. The maximum autotrophic denitrification (or total-N removal) rates were achieved in a narrow oxygen influx band of 3–5 mg O2/h, where it accounted for up to 36% of NH4+–N removal. At oxygen influx >16 mg O2/h and DO >2 mg/L, autotrophic denitrification ceases and roughly 90% of feed NH4+–N is oxidised to NOX−–N. The stability of total effluent chemical oxygen demand (COD) over the range of oxygen influxes tested confirms the absence of heterotrophic denitrification in the bioreactor. The long solids residence time of the stable biomass zone (21 days) led to production of effluent COD as a result of cell decay, and thus effluent COD was used to calculate more accurately the mean cell residence time.

scholarly journals Nitrogen removal from ammonium-contaminated groundwater using dropping nitrification–cotton-based denitrification reactor

2021 ◽  
Author(s):  
A. K. Maharjan ◽  
K. Mori ◽  
K. Nishida ◽  
T. Toyama
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Denitrifying Bacteria ◽  
Electron Donors ◽  
Nitrifying Bacteria ◽  
Contaminated Groundwater ◽  
Total N ◽  
N Removal ◽  
Denitrification Reactor ◽  
Synthetic Groundwater

Abstract A novel dropping nitrification–cotton-based denitrification reactor was developed for total nitrogen (N) removal from ammonium (NH4+)-contaminated groundwater. The nitrogen removal ability of the reactor was evaluated for 91 days. A 1 m-long dropping nitrification unit was fed with synthetic groundwater containing 30 mg-NH4+-N/L at a flow rate of 2.16 L/d. The outlet of the dropping nitrification unit was connected to the cotton-based denitrification unit. The NH4+ present in the groundwater was completely oxidized (>90% nitrification efficiency) by nitrifying bacteria to nitrite (NO2–) and nitrate (NO3–) in the dropping nitrification unit. Subsequently, the generated NO2– and NO3– were denitrified (96%–98% denitrification efficiency) by denitrifying bacteria in the cotton-based denitrification unit under anoxic conditions. Organic carbons released from the cotton presumably acted as electron donors for heterotrophic denitrification. Nitrifying and denitrifying bacteria were colonized in higher abundance in the dropping nitrification and cotton-based denitrification units, respectively. The total N removal rate and efficiency of the dropping nitrification–cotton-based denitrification reactor for 91 days were 58.1–66.9 mg-N/d and 96%–98%, respectively. Therefore, the dropping nitrification–cotton-based denitrification reactor will be an efficient, sustainable, and promising option for total N removal from NH4+-contaminated groundwater.

scholarly journals Enrichment and application of nitrifying activated sludge in membrane bioreactors

2017 ◽  
Vol 76 (11) ◽  
pp. 2888-2894 ◽  
Author(s):  
Xiaolin Sheng ◽  
Rui Liu ◽  
Lujun Chen ◽  
Zihua Yin ◽  
Jianfeng Zhu
Keyword(s):  
Activated Sludge ◽  
Culture Medium ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Membrane Bioreactors ◽  
Nitrifying Bacteria ◽  
Side Stream ◽  
N Removal ◽  
Negative Effect ◽  
Chemical Oxygen Demand Concentration

Abstract In this study, nitrifying bacteria were enriched in a membrane bioreactor (MBR, R1) and their bioaugmentation effectiveness was evaluated in another two MBRs (R2 and R3). Nitrifying activated sludge (NAS) with high nitrification activity of up to 3,000 mg-N/(L·d)−1 was successfully enriched in R1. The results showed that chemical oxygen demand concentration of 100–200 mg/L had no negative effect on NAS enrichment but reduced the ratio of bacterial nitrifiers. Moreover, the cell concentration of nitrifying bacteria in NAS, which was 3.1 × 1011 cells/L, was similar to that of the commercial bacterium agent. For the bioaugmentation test, the reactor inoculated with 14% NAS achieved a 23% higher NH4+-N removal efficiency than that of the uninoculated reactor. Along with the improvement of nitrification performance, the bacterial nitrifiers abundance and microbial richness remarkably increased after bioaugmentation. These results suggested that the MBR system could efficiently enrich nitrifying bacteria using organic carbon containing culture medium, and potentially act as a side-stream reactor to enhance the nitrification function of the wastewater treatment plant.

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.

Nitrification potential of attached biofilms in dairy farm waste stabilisation ponds

2000 ◽  
Vol 42 (10-11) ◽  
pp. 195-202 ◽  
Author(s):  
R. J. Craggs ◽  
C. C. Tanner ◽  
J. P. Sukias ◽  
R. J. Davies-Colley
Keyword(s):  
New Zealand ◽  
Dairy Farm ◽  
Pond Water ◽  
Oxygen Availability ◽  
Ammonia Toxicity ◽  
Waste Stabilisation Ponds ◽  
Nitrification Potential ◽  
N Removal ◽  
Mechanical Aeration ◽  
Farm Waste

Dairy farm waste stabilisation ponds are a major source of ammoniacal-N to surface waters in New Zealand. Ammoniacal-N is of particular concern in New Zealand where native aquatic invertebrates appear to be very sensitive to ammonia toxicity. This paper investigates improvement of ammoniacal-N nitrification in dairy farm facultative ponds with mechanical aeration and provision of biofilm attachment surfaces. Biofilm was grown on surfaces at different depths (0.1 m, 0.2 m and 0.6 m) under three mechanical aeration regimes (no aeration, night-only aeration and continuous aeration). Nitrification potential of biofilm was determined as the rate of ammoniacal-N removal in bioassays with ammoniacal-N spiked pond water or culture medium under controlled conditions (20°C, pH 7.0, constant stirring, DO 2–3 g m−3, dark). The nitrification potentials (0.30 g N m−2 biofilm d−1 to 2.17 g N m−2 biofilm d−1) of biofilm-coated surfaces were largely controlled by oxygen availability and consistency of supply in the pond. Nitrification potentials were high where oxygen availability was high, such as close to the pond surface where atmospheric re-aeration and algal photosynthesis were prevalent. Nitrification potentials of biofilms incubated at depth were enhanced by mechanical aeration, with higher values achieved under the continuous aeration regime and at more turbulent sites closer to the aerator.

Some Physicochemical Parameters of Wastewater from an Oil Industry at Point of Discharge in Port Harcourt, Rivers State, Nigeria

2020 ◽  
Vol 6 (2) ◽  
pp. 23-28
Author(s):  
O. A. F Wokoma ◽  
◽  
O. S Edori ◽  
Keyword(s):  
Physicochemical Parameters ◽  
Oxygen Demand ◽  
Aquatic Organisms ◽  
Oil Industry ◽  
World Health ◽  
Port Harcourt ◽  
Water Association ◽  
Wastewater Samples ◽  
Health Organization ◽  
Rivers State

Wastewater samples were collected from an oil industry at the point of discharge for a period of two years, from January 2018 – December 2019. The wastewater samples were analyzed for different physicochemical parameters such as temperature, turbidity, total dissolved solids (TDS), total suspended solids (TSS), conductivity, pH, alkalinity, salinity, total hydrocarbon content (THC), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) to examine their conformity to fulfill requirements as recommended by World Health Organization (WHO), Federal Ministry of Environment (FME) and Drinking Water Association (DWA). The results indicated that all the parameters in the discharged wastewater were within acceptable limits of the regulatory bodies. The field data showed that the investigated firm conformed to the law by carrying out proper procedures before discharging the effluents into the public drain and river. Therefore, the release of wastewater from the industry doesn't constitute a danger to the environment as well as aquatic organisms. Keywords: Physicochemical parameter, wastewater discharge, oil industry, environment, contaminants

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.

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 Digestate Liquid Fraction Treatment with Filters Filled with Recovery Materials

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Ilaria Piccoli ◽  
Giuseppe Virga ◽  
Carmelo Maucieri ◽  
Maurizio Borin
Keyword(s):  
Chemical Oxygen Demand ◽  
Total Nitrogen ◽  
Liquid Fraction ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Green Technology ◽  
Filling Material ◽  
Community Interactions ◽  
Material Particle ◽  
N Removal

Constructed wetlands (CWs) represent a green technology for digestate liquid fraction (DLF) treatment. However, previous research has warned about their performance when treating wastewater with high suspended solid and organic loads. In addition, the high NH4-N concentration typical of this wastewater can compromise vegetation establishment and activity. In view of this, a digestate pretreatment is needed. This study aimed to test the performance of filters filled with recovery materials, such as brick and refractory material, for DLF pretreatment. The effect on DLF physical (electrical conductivity, pH, dissolved oxygen, and temperature) and chemical (total nitrogen, ammonia–nitrogen, nitrate–nitrogen, total phosphorus, soluble phosphorus, and chemical oxygen demand) characteristics was monitored during eight weekly cycles. The effect of filtration on total nitrogen and ammonia–nitrogen removal began after about one month of loading, suggesting that an activation period is necessary for bacteria. For effective N removal, the presence of multiple digestate recirculations per day through the filters appears mandatory to guarantee the alternation of nitrification and denitrification conditions. For P removal, filling material particle size appeared to be more important than its composition. Unclear performances were observed considering chemical oxygen demand. Further studies on filling media and microbial community interactions, and the long-term efficiency of filters, are desirable.

PHYSICO-CHEMICAL AND SOME HEAVY METALS CONCENTRATION ANALYSES ON THREE COMMON SPECIES OF FISH IN TUNGAN KAWO RESERVOIR KONTAGORA, NIGER STATE, NIGERIA

2021 ◽  
Vol 5 (1) ◽  
pp. 223-232
Author(s):  
Mohammed Jr. Kinta ◽  
A. V. Ayanwale ◽  
U. N. Keke ◽  
Y. I. Auta ◽  
B. S. Adama ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Oxygen Demand ◽  
Aquatic Organisms ◽  
Common Species ◽  
Human Consumption ◽  
Long Term Effects ◽  
Aquatic Life ◽  
Physico Chemical ◽  
Fish Samples

Developing countries like Nigeria are faced with increased in generation of domestic, industrial and agricultural wastes, with a large percentage moving. This study evaluates the physico-chemical and some heavy metals concentration in three common species of fish from Tungan Kawo reservoir Kontagora, Nigeria; using standard methods between (July 2018 – February 2019); at four different sampling stations of human activities on the water. Five heavy metals were evaluated (Lead, Copper, Manganese, Iron and Chromium) in the fish samples. Phosphate (0.4 – 2.5) mg/L, Nitrate (3.2 – 7.5) mg/L, Temperature (27 – 32.4) 0C, Dissolved Oxygen (2.4 – 5.2 mg/L), Conductivity (81 – 125 µS/cm), Biochemical Oxygen Demand (1.9 – 4.4 mg/L), Alkalinity (mg/L) and Total Dissolved Solids (117 – 198) ppm were within the standard for drinking water and survival of fish.  However, the pH (6.3 – 9.8) was above the standard for NIS and WHO drinking water but can support aquatic life. Iron (0.64 ± 0.072 mg/kg) was the most highly concentrated in Synodontis clarias while lead (0.01 ± 0.013 mg/kg) was the lowest in Oreochromis niloticus and Coptidon zillii (formerly Tilapia zillii. This current finding indicates that the water is safe for both aquatic life and domestic purpose but not suitable for direct human consumption without being properly treated. However, there is the need for regular monitoring of the heavy metals load in this water body and the aquatic organisms because of the long term effects

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