SUSTAINABLE NITROGEN REMOVAL USING APPROPRIATE TECHNOLOGIES

Author(s):  
Krishnanand Maillacheruvu ◽  
Derek Hartmann

Nitrogen and phosphorus are two major pollutants that lead to eutrophication, adversely impact ecosystems, and lead to degradation of water quality, which impacts human health and sustainability. Pollution from point sources like wastewater and industry discharge is easier to control than non-point source pollution due to agricultural runoff and related activities. The USEPA is considering more strict standards for nitrogen and phosphorus discharge from point sources. The objective of this study was to use an appropriate low-cost wastewater technology to demonstrate removal of nitrogen from wastewater discharge using rotating biological contactors (RBCs) using different C:N ratios. The first-order nitrogen removal rate constant was found to be about 3.88 day-1 in experimental reactor systems, using RBC media from a local wastewater treatment plant (Greater Peoria Sanitary District). Phase I experiments, at C:N ratio of 2:1, with nitrogen removal rates of 60% in a single flow-through system. Phase II experiments for the limited carbon availability condition showed that the removal rate constant reduced by 30% and N-removal efficiency dropped to around 48%. Modeling showed that even under these conditions, multiple bioreactors operated in series could help achieve design treatment goals. The system achieved stability within a week of operation. Economics and sustainability issues are analyzed to determine if the process developed in this research is scalable to pilot-and full-scale conditions.

2018 ◽  
Vol 78 (9) ◽  
pp. 1843-1851 ◽  
Author(s):  
İ. Çelen-Erdem ◽  
E. S. Kurt ◽  
B. Bozçelik ◽  
B. Çallı

Abstract The sludge digester effluent taken from a full scale municipal wastewater treatment plant (WWTP) in Istanbul, Turkey, was successfully deammonified using a laboratory scale two-stage partial nitritation (PN)/Anammox (A) process and a maximum nitrogen removal rate of 1.02 kg N/m3/d was achieved. In the PN reactor, 56.8 ± 4% of the influent NH4-N was oxidized to NO2-N and the effluent nitrate concentration was kept below 1 mg/L with 0.5–0.7 mg/L of dissolved oxygen and pH of 7.12 ± 12 at 24 ± 4°C. The effluent of the PN reactor was fed to an upflow packed bed Anammox reactor where high removal efficiency was achieved with NO2-N:NH4-N and NO3-N:NH4-N ratios of 1.32 ± 0.19:1 and 0.22 ± 0.10:1, respectively. The results show that NH4-N removal efficiency up to 98.7 ± 2.4% and total nitrogen removal of 87.7 ± 6.5% were achieved.


2013 ◽  
Vol 67 (12) ◽  
pp. 2677-2684 ◽  
Author(s):  
M. Christensson ◽  
S. Ekström ◽  
A. Andersson Chan ◽  
E. Le Vaillant ◽  
R. Lemaire

ANITA™ Mox is a new one-stage deammonification Moving-Bed Biofilm Reactor (MBBR) developed for partial nitrification to nitrite and autotrophic N-removal from N-rich effluents. This deammonification process offers many advantages such as dramatically reduced oxygen requirements, no chemical oxygen demand requirement, lower sludge production, no pre-treatment or requirement of chemicals and thereby being an energy and cost efficient nitrogen removal process. An innovative seeding strategy, the ‘BioFarm concept’, has been developed in order to decrease the start-up time of new ANITA Mox installations. New ANITA Mox installations are started with typically 3–15% of the added carriers being from the ‘BioFarm’, with already established anammox biofilm, the rest being new carriers. The first ANITA Mox plant, started up in 2010 at Sjölunda wastewater treatment plant (WWTP) in Malmö, Sweden, proved this seeding concept, reaching an ammonium removal rate of 1.2 kgN/m3 d and approximately 90% ammonia removal within 4 months from start-up. This first ANITA Mox plant is also the BioFarm used for forthcoming installations. Typical features of this first installation were low energy consumption, 1.5 kW/NH4-N-removed, low N2O emissions, <1% of the reduced nitrogen and a very stable and robust process towards variations in loads and process conditions. The second ANITA Mox plant, started up at Sundets WWTP in Växjö, Sweden, reached full capacity with more than 90% ammonia removal within 2 months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period.


2013 ◽  
Vol 67 (12) ◽  
pp. 2761-2767 ◽  
Author(s):  
Ruihua Li ◽  
Jianmin Niu ◽  
Xinmin Zhan ◽  
Bo Liu

The efficacy of iron(II) sulfide (FeS)-based autotrophic denitrification in simultaneous nitrogen and phosphorus removal from wastewater was studied with batch experiments. It was efficient at a wide pH range of 5–9, and temperature range of 10–40 °C. The concentrations of NH4+-N, Mg2+ and HCO3− in the wastewater should be kept over 7.8, 0.24 and 30 mg L−1 for efficient nitrate (NO3−-N) reduction, respectively. The NO3−-N removal rate increased from 0 to 82 mg L−1 d−1 and then leveled off when the NO3−-N concentration increased from 0 to 415 mg L−1 and then to 700 mg L−1, respectively. The NO3−-N removal rate quickly increased, leveled off, and then sharply decreased when the PO43−-P concentration increased from 0 to 0.1 mg L−1, then to 114.0 mg L−1, and further to 683.8 mg L−1, respectively. The PO43−-P removal was over 98% when the PO43−-P concentration ranged 0–683.3 mg L−1. During treatment of the secondary effluent of a local municipal wastewater treatment plant containing NO3−-N of 14.9 mg L−1 and total phosphorus (TP) of 3.9 mg L−1, NO3−-N was reduced to 1.1 mg L−1 and TP was completely removed.


2008 ◽  
Vol 3 (1) ◽  
Author(s):  
V. Lina Cardoso ◽  
C. Esperanza Ramírez ◽  
E. Violeta Escalante

There are problems associated with sludge management in small treatment plants (<10 L/s) located in rural communities, due to costly conventional technology for sludge stabilization. Many of these plants have only sludge drying beds. Mexican Institute of Water Technology has proposed developing suitable low-cost technologies, one of which is vermicomposting a biodegradation system using earthworms of the species Eisenia foetida (earthworm) which stabilize sludge and reduce its pathogenicity. The objective of this work is to present two case studies where vermicomposting technology has been applied in Mexico. The first study corresponds to a plant where 4.8 m3/month of sludge are produced; for these wastes, a vermicomposting system was built and installed. The second study is a treatment plant where 9 m3/month of sludge are produced; experimental tests were conducted with sludge and water hyacinth and a vermicomposting system was designed. The vermicomposts were analyzed using parameters defined by Mexican standards. In regards to stabilization, TVS was reduced by 38% and the microbiological quality of the vermicompost was Class A and B, with a reduction in fecal coliforms and Helminth eggs according to NOM-004-SEMARNAT-2002. A CRETI (Corrosivity, Reactivity, Explosivity, Toxicity and Ignitability) analysis (NOM-052-SEMARNAT-2005) was used to show that the process reduced the concentration of releasable sulfides. The agronomic quality of the vermicompost exhibited a high content of organic matter comparable to many organic manures and high content of nutrients such as nitrogen and phosphorus. It is concluded that it is possible to improve the conditions of sewage sludge management in small plants of rural communities with a minimum investment (less than $10,000.00 USD) and with a requirement of a minimum area of 60 to 70 m2 for a production of less than 9 m3/month of dehydrated sludge (80% humidity).


Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1051 ◽  
Author(s):  
Zizhen Zhou ◽  
Tinglin Huang ◽  
Weijin Gong ◽  
Yang Li ◽  
Yue Liu ◽  
...  

A field scale experiment was performed to explore the nitrogen removal performance of the water and surface sediment in a deep canyon-shaped drinking water reservoir by operating WLAs (water-lifting aerators). Nitrogen removal performance was achieved by increasing the densities and N-removal genes (nirK and nirS) of indigenous aerobic denitrifiers. After the operation of WLAs, the total nitrogen removal rate reached 29.1 ± 0.8% in the enhanced area. Ammonia and nitrate concentrations were reduced by 72.5 ± 2.5% and 40.5 ± 2.1%, respectively. No nitrite accumulation was observed. Biolog results showed improvement of carbon metabolism and carbon source utilization of microbes in the enhanced area. Miseq high-throughput sequencing indicated that the denitrifying bacteria percentage was also higher in the enhanced area than that in the control area. Microbial communities had changed between the enhanced and control areas. Thus, nitrogen removal through enhanced indigenous aerobic denitrifiers by the operation of WLAs was feasible and successful at the field scale.


2021 ◽  
Author(s):  
Qihui Gu ◽  
Jun Ma ◽  
Jumei Zhang ◽  
Weipeng Guo ◽  
Huiqing Wu ◽  
...  

Abstract Sand filter (SFs) are common treatment processes for nitrogen pollutants removal in drinking water treatment plants (DWTPs). However, the mechanisms on the nitrogen-cycling role of SFs are still unclear. In this study, 16S rRNA gene amplicon sequencing was used to characterise the diversity and composition of the bacterial community in SFs from DWTPs. Additionally, metagenomics approach was used to determine the functional microorganisms involved in nitrogen cycle in SFs. Our results showed that Proteobacteria, Acidobacteria, Nitrospirae, and Chloroflexi dominated in SFs. Subsequently, 85 high-quality metagenome-assembled genomes (MAGs) were retrieved from metagenome datasets of selected SFs involving nitrification, assimilatory nitrogen reduction, and denitrification processes. Read mapping to reference genomes of Nitrospira and the phylogenetic tree of the ammonia monooxygenase subunit A gene, amoA, suggested that Nitrospira is abundantly found in SFs. Furthermore, according to their genetic content, a nitrogen metabolic model in SFs was proposed using representative MAGs and pure culture isolates. Quantitative real-time polymerase chain reaction (PCR) showed that ammonia-oxidising bacteria (AOB) and archaea (AOA), and complete ammonia oxidisers (comammox) were ubiquitous in the SFs, with the abundance of comammox being higher than that of AOA and AOB. Moreover, we identified a bacterial strain with a high NO3-N removal rate as Pseudomonas sp., which could be applied in the bioremediation of micro-polluted drinking water sources. Our study provides insights into functional nitrogen-metabolising microbes in SFs of DWTPs.


2007 ◽  
Vol 55 (8-9) ◽  
pp. 59-65 ◽  
Author(s):  
A. Onnis-Hayden ◽  
P.B. Pedros ◽  
J. Reade

An experimental study investigating the nitrogen removal efficiency from the recycle stream generated in the dewatering facility of the anaerobically digested sludge at the Deer Island wastewater treatment plant (WWTP) in Boston was conducted using a single submerged attached growth bioreactor (SAGB), designed for simultaneous nitrification and denitrification. The applied nitrogen loading to the reactor ranged from 0.7 to 2.27 kg-N/m3·d, and the corresponding total nitrogen (TN) removal rate ranged from 0.38 to 1.8 kg-N/m3·d. The observed nitrification rates varied from 0.42 kg-N/m3·d to 1.45 kg-N/m3·d with an ammonia load of 0.5 kg-N/m3·d and 1.8 kg-N/m3·d, respectively. An average nitrification efficiency of 91% was achieved throughout the experiment. Denitrification efficiency varied from 55%, obtained without any addition of carbon source, to 95% when methanol was added in order to obtain a methanol/nitrate ratio of about 3 kg methanol/kg NO3−-N.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1100 ◽  
Author(s):  
Ya-Wen Wang ◽  
Hua Li ◽  
You Wu ◽  
Yun Cai ◽  
Hai-Liang Song ◽  
...  

Rural runoff with abundant nutrients has become a great threat to aquatic environment. Hence, more and more attention has been focused on nutrients removal. In this study, an improved aerobic/anaerobic/aerobic three-stage water spinach constructed wetland (O-A-O-CW) was used to improve the removal of nitrogen and phosphorus of rural runoff. The removal rate of the target pollutants in O-A-O-CW was compared with the common matrix flow wetland as well as the no-plant wetland. The results showed that the O-A-O-CW significantly increased the chemical oxygen demand, total phosphorus, ammonium-nitrogen, nitrate, and total nitrogen removal rate, and the corresponding removal rate was 55.85%, 81.70%, 76.64%, 89.78%, and 67.68%, respectively. Moreover, the best hydraulic condition of the wetland, including hydraulic retention time and hydraulic loading, was determined, which were 2 days and 0.45 m3·m−2·day−1, respectively. Furthermore, the removal mechanism of the constructed wetland was thoroughly studied, which included the adsorption of nitrogen and phosphorus by the matrix and water spinach, and the nitrification and denitrification by the bacteria. The results demonstrated that the mechanisms of nitrogen removal in the new type wetland were principally by the nitrification and denitrification process. Additionally, adsorption and precipitation by the matrix are mainly responsible for phosphorus removal. These results suggested that the new O-A-O-CW can efficiently removal nutrients and enhance the water quality of the rural runoff.


2005 ◽  
Vol 52 (4) ◽  
pp. 9-17 ◽  
Author(s):  
S. Caffaz ◽  
R. Canziani ◽  
C. Lubello ◽  
D. Santianni

In recent years a completely autotrophic nitrogen removal process based on Anammox biomass has been tested in a few European countries in order to treat anaerobic supernatant and to increase the COD/N ratio in municipal wastewater. This work reports experimental results on a possible technical solution to upgrade the S. Colombano treatment plant which treats wastewater from the Florentine urban area. The idea is to use 50% of the volume of the anaerobic digester in order to treat external sewage sludge (as septic tank sludge) together with waste activated sludge and to treat the resulting effluent on a SHARON-ANAMMOX process in order to remove nitrogen from the anaerobic supernatant. Anaerobic co-digestion, tested in a 200 L pilot plant, enables low cost treatment of septic tank sludge and increases biogas production; however, it also increases the nitrogen load re-circulated to the WWTP, where nitrogen removal efficiency is already low (<50%), due to the low COD/N ratio, which limits predenitrification efficiency. Experimental results from a SHARON process tested in a lab-scale pilot plant show that nitrite oxidising bacteria are washed-out and steady nitrite production can be achieved at retention times in the range 1–1.5 days, at 35 °C. In a lab-scale SBR reactor, coupled with a nitration bioreactor, maximum specific nitrogen removal rate under nitrite-limiting conditions (with doubling time equal to about 26 days at 35 °C) was equal to 0.22 kgN/kgSSV/d, about 44 times the rate measured in inoculum Anammox sludge. Finally, a cost analysis of the proposed upgrade is reported.


2004 ◽  
Vol 49 (5-6) ◽  
pp. 273-279
Author(s):  
B.S. Lim ◽  
J.U. Kim ◽  
H.D. Park

This study was performed to increase the treatment efficiency and to reduce operation and maintenance costs of the existing nightsoil treatment plant. The existing nightsoil plant was not established by the nitrogen removal process, and was operated ineffectively with deterioration of treatment efficiency rate, and according to the demand of many operators, the expenses of operation and maintenance have become excessive. Modified plant has been changed through two steps. The first step, liquid decayed tank using closed oxidation ditch is operated to increase retention time only for nitrification. The second step, modified liquid decayed tank including anoxic tank is operated, it has an excellent nitrogen removal rate. In first step, when HRT was increased from 10 days to 13 days in liquid decayed tank including aeration tank using closed oxidation ditch, TN concentration of effluent appeared below 51 mg/l less than discharge limit, 60 mg/L. In second step, when anoxic tank and oxic tank were installed, HRT has been increased to 13 days and 26 days, respectively. Then average TN concentration of effluent was detected less than 13 mg/L for over one year. The simple process modified the existing two processes resulted in the reduction of costs for operation and maintenance in the personnel, chemical, and filter change sphere.


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