Enhanced Nitrogen Removal of Low C/N Ratio Wastewater by Coupling Fe(Ii)-Driven Autotrophic and Heterotrophic Denitrification Using Conductive Carrier PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Enhanced Nitrogen Removal of Low C/N Ratio Wastewater by Coupling Fe(Ii)-Driven Autotrophic and Heterotrophic Denitrification Using Conductive Carrier PDF full book. Access full book title Enhanced Nitrogen Removal of Low C/N Ratio Wastewater by Coupling Fe(Ii)-Driven Autotrophic and Heterotrophic Denitrification Using Conductive Carrier by Wenjuan Zhao. Download full books in PDF and EPUB format.
Author: Wenjuan Zhao
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The denitrification of low C/N ratio wastewater usually faces the issues of slow rate and low efficiency. Nitrogen removal rate can be greatly improved through heterotrophic denitrification by adding sufficient carbon source, but would greatly add the treatment cost. In this study, we report enhanced nitrogen removal of low C/N ratio wastewater by coupling Fe(II)-driven autotrophic and heterotrophic bioelectrochemical denitrification using conductive biofilm carrier. The introduction of conductive graphite carrier is proved to be able to enhance the Fe(II)-driven autotrophic denitrification. The bioreactor using graphite plate as biofilm carrier has a denitrification rate constant (kDN) of 0.016 h-1, which is 1.77 and 5 times as that of with non-conductive polypropylene and without carrier, respectively. The presence of Fe(II) and conductive graphite carrier promotes the denitrification of low C/N ratio wastewater. The kDN of the bioreactor for treatment wastewater with low C/N ratio of 0.76 with Fe(II) is 0.095 h-1, which is 5 times as that of without Fe(II). The reasons for the enhancement of the denitrification of low C/N ratio wastewater are probably that, the conductive carrier enhances the direct electron transfer and facilitates the growth of electroactive microorganisms, while the Fe(II) not only serves as electron donor but also plays the role of mediator and facilitate the mediated electron transfer, thus enhances the both Fe(II)-driven autotrophic and heterotrophic bioelectrochemical denitrification. Microbial community analysis show that the addition of Fe(II) changes the biofilm community composition and greatly enhances the enrichment of electroactive bacterium like Comamonas, and denitrifers such as Chryseobacterium and Castellaniella, in the conductive biofilm carrier under heterotrophic conditions. While the autotrophic conditions are beneficial to the enrichment of other microorganisms without denitrification function, such as soil Aquamicrobium Hydrotalea. This study provided a new strategy for enhancement of the denitrification low C/N ratio wastewater.
Author: Wenjuan Zhao
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The denitrification of low C/N ratio wastewater usually faces the issues of slow rate and low efficiency. Nitrogen removal rate can be greatly improved through heterotrophic denitrification by adding sufficient carbon source, but would greatly add the treatment cost. In this study, we report enhanced nitrogen removal of low C/N ratio wastewater by coupling Fe(II)-driven autotrophic and heterotrophic bioelectrochemical denitrification using conductive biofilm carrier. The introduction of conductive graphite carrier is proved to be able to enhance the Fe(II)-driven autotrophic denitrification. The bioreactor using graphite plate as biofilm carrier has a denitrification rate constant (kDN) of 0.016 h-1, which is 1.77 and 5 times as that of with non-conductive polypropylene and without carrier, respectively. The presence of Fe(II) and conductive graphite carrier promotes the denitrification of low C/N ratio wastewater. The kDN of the bioreactor for treatment wastewater with low C/N ratio of 0.76 with Fe(II) is 0.095 h-1, which is 5 times as that of without Fe(II). The reasons for the enhancement of the denitrification of low C/N ratio wastewater are probably that, the conductive carrier enhances the direct electron transfer and facilitates the growth of electroactive microorganisms, while the Fe(II) not only serves as electron donor but also plays the role of mediator and facilitate the mediated electron transfer, thus enhances the both Fe(II)-driven autotrophic and heterotrophic bioelectrochemical denitrification. Microbial community analysis show that the addition of Fe(II) changes the biofilm community composition and greatly enhances the enrichment of electroactive bacterium like Comamonas, and denitrifers such as Chryseobacterium and Castellaniella, in the conductive biofilm carrier under heterotrophic conditions. While the autotrophic conditions are beneficial to the enrichment of other microorganisms without denitrification function, such as soil Aquamicrobium Hydrotalea. This study provided a new strategy for enhancement of the denitrification low C/N ratio wastewater.
Author: Chongjun Chen
Publisher: Frontiers Media SA
ISBN: 2832519091
Category : Science
Languages : en
Pages : 137
Get Book Here
Book Description
Author: Ivan Zhu
Publisher: BoD – Books on Demand
ISBN: 9535132997
Category : Science
Languages : en
Pages : 122
Get Book Here
Book Description
Nitrification and denitrification are essential processes for aquatic ecological system and vital for human health. While ammonia is applied for disinfection together with chlorine to produce chloramine, excessive ammonia may cause nitrification and bacteria growth in water transmission pipeline. Since excessive discharge may cause eutrophication and deterioration of aquatic system, nitrate is regulated for wastewater discharge in sensitive areas. Further, nitrate needs to be monitored and controlled in drinking water treatment to protect against methemoglobinemia in bottle-fed infants.
Author: Javier Adrián Sánchez Guillén
Publisher: CRC Press
ISBN: 135164629X
Category : Technology & Engineering
Languages : en
Pages : 134
Get Book Here
Book Description
On a global scale, sewage represents the main point-source of water pollution and is also the predominant source of nitrogen contamination in urban regions. The present research is focused on the study of the main challenges that need to be addressed in order to achieve a successful inorganic nitrogen post-treatment of anaerobic effluents in the mainstream. The post-treatment is based on autotrophic nitrogen removal. The challenges are classified in terms of operational features and system configuration, namely: (i) the short-term effects of organic carbon source, the COD/N ratio and the temperature on the autotrophic nitrogen removal; the results from this study confirms that the Anammox activity is strongly influenced by temperature, in spite of the COD source and COD/N ratios applied. (ii) The long-term performance of the Anammox process under low nitrogen sludge loading rate (NSLR) and moderate to low temperatures; it demonstrates that NSLR affects nitrogen removal efficiency, granular size and biomass concentration of the bioreactor. (iii) The Anammox cultivation in a closed sponge-bed trickling filter (CSTF) and (iv) the autotrophic nitrogen removal over nitrite in a sponge-bed trickling filter (STF). Both types of Anammox sponge-bed trickling filters offer a plane technology with good nitrogen removal efficiency.
Author: Dilawar Farhan Shams
Publisher:
ISBN:
Category : Dairy farms
Languages : en
Pages : 233
Get Book Here
Book Description
Elevated nitrogen concentrations in dairy farm wastewater (DFW) demand alternative treatment technologies to meet increasingly stringent regulations. Treatment of DFW with an upflow bioreactor in combination with an aerobic unit and a secondary clarifier (UBRA process) offers advantages of increased biomass retention and faster conversion rates. However, research is needed firstly to establish the effect of different operational conditions and varying wastewater characteristics on system behaviour, and secondly to achieve complete nitrogen removal via post-denitrification without increasing the footprint. In this study, two lab-scale UBR-A systems, one fed with real DFW and the other with synthetic wastewater (SWW), were studied for the effect of wastewater characteristics and key operational variables of hydraulic retention time (HRT, 2-4 days), internal recycle ratio (R, 2-4) and solids retention time (SRT, >100 to 30 days). Additionally, enhancement in stability using attached media was investigated at R of 3 and 4, and at doubled carbon loading (with SWW). Finally, post-denitrification in both systems was investigated with a novel technique of retrofitting the clarifiers with alginate beads containing immobilised biomass and carbon source. In this connection, a batch study was first performed to identify suitable carbon sources for co-immobilisation among acetate, glucose, calcium tartrate, starch and canola oil on the basis of denitrification kinetics, stoichiometry and bead stability. The findings showed that in suspended growth, shorter HRT of 2 days significantly lowered (P0.05) nitrification whereas higher R3 proved unfavourable for denitrification in both systems especially with SWW (~60% drop in efficiency). Lowering the SRT produced similar performance however, kinetic rates were significantly increased in both systems. The HRT of 4 days, R=3 and SRT>100 days was established as the optimum operational regime in suspended mode. The attached growth media and COD/NO3-N ratio >8 (with SWW) enhanced the denitrification at R=4, raised the nitrification rate by ~55% and total nitrogen removal by ~12%. For both wastewaters, system behaviour was comparable in terms of performance and vertical solids profile in UBR. However, DFW exhibited significantly lower kinetic rates and yield coefficients, a smaller VSS/TSS ratio, and higher inert COD fraction. These outcomes indicated that DFW is not truly represented by SWW to depict system behaviour. From the batch study, the co-immobilised canola oil and starch exhibited significantly higher denitrification rates (1.05 mg/L/h and 0.72 mg/L/h respectively) and bead stability with low nitrite accumulation. Post-denitrification in the clarifier with starch and canola oil beads demonstrated denitrification efficiency of >90%. Duration of the denitrification phase increased with the raise in carbon fraction, alginate concentration and use of BaCl2 as hardening solution. However, due to prevalence of alginate lyase activity and phosphates, degradation of beads was faster than complete carbon consumption, and therefore necessitates the use of more stable gels.
Author: Amulya Miriyala
Publisher:
ISBN:
Category : Effluent quality
Languages : en
Pages : 98
Get Book Here
Book Description
Approximately 25% of households in the U.S. treat their wastewater onsite using conventional onsite wastewater treatment systems (OWTS). These systems typically include a septic tank or a series of septic tanks followed by a soil absorption system. They effectively remove biochemical oxygen demand (BOD), total suspended solids (TSS), fats and grease but are not designed to remove significant amounts of nitrogen. High nitrogen loading to coastal and ground waters can be dangerous to aquatic life and public health. Hence, there is a need for advanced onsite wastewater treatment systems that can effectively remove nitrogen. Making enhanced nitrogen removal for OWTS as our primary goal, a laboratory scale Hybrid Adsorption and Biological Treatment Systems (HABiTS) was developed and upon observation of its effective nitrogen removal capacity, a pilot demonstration study with two side-by-side HABiTS, one with recirculation and one without recirculation (only forward flow) were constructed and tested at the Northwest Regional Water Reclamation Facility in Hillsborough County (Florida). HABiTS employ biological nitrogen removal and ion exchange for effective nitrogen removal. HABiTS is a two-stage process which uses nitrification for the oxidation of ammonium to nitrate and ion exchange for ammonium adsorption that helps buffer transient loading and also acts as a biofilm carrier in its stage 1 biofilter and it uses tire-sulfur hybrid adsorption denitrification (T-SHAD) in its stage 2 biofilter. These sulfur pellets help promote sulfur oxidation denitrification (SOD) and tire chips are used for nitrate adsorption during transient loading conditions, as biofilm carriers for denitrifying bacteria, and can also be used as organic carbon source to promote heterotrophic denitrification because they leach organic carbon. For this research, HABiTS without recirculation is considered as the control system and the performance of HABiTS with recirculation was tested for its ability to further enhance nitrogen removal from HABiTS. Nitrified effluent recirculation is a common strategy employed in wastewater treatment for enhanced nitrogen removal. It is the reintroduction of semi-treated wastewater to pass through an anoxic pre-treatment chamber to achieve better quality effluent. Recirculation is said to improve and consistently remove nitrogen at any hydraulic loading rate and/or nitrogen concentration. This is because of the dilution of high BOD septic tank effluent with nitrified effluent which lowers COD:TKN ratio and also improves mass transfer of substrates in the stage 1 biofilter. Recirculation also provides some pre-denitrification in the pre-treatment chamber, thereby reducing nitrogen load on the system. The HABiTS with recirculation (R) was run at 1:1 ratio of nitrified effluent recirculation rate to the influent flow rate for 50 days, and at 3:1 ratio for the remaining period of this research (200 days). The forward flow system (FF) was run under constant conditions throughout the research and comparisons between the two systems were made for different water quality parameters (pH, DO, conductivity, alkalinity, TSS, chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP) and various nitrogen species). The final effluent ammonium results showed that the system with recirculation removed consistently > 80% NH4+-N during 1:1 and 3:1 recirculation ratios whereas the forward flow system achieved 57% removal. Further, an average of 81% total inorganic nitrogen (TIN) removal from the system influent was seen in the recirculation systems final effluent when compared to an average of 55% in forward flow systems final effluent. This research explains in detail, the impact of nitrified effluent recirculation on enhanced nitrogen removal in onsite systems and the results presented in this thesis proved that nitrified effluent recirculation provides promising enhanced nitrogen removal in an onsite wastewater treatment system.
Author: Marlene Roeckel
Publisher:
ISBN: 9781617284854
Category : Denitrification
Languages : en
Pages : 0
Get Book Here
Book Description
This book compares the process of denitrification/anaerobic digestion/nitrification for the simultaneous removal of nitrogen and carbon from organic loaded effluents. In the first type of process, nitrification and denitrification simultaneously take place in the same reactor (SND). In the second type of process, there is one hybrid reactor with internal recycle, in which denitrification and anaerobic digestion take place, followed by one aerobic reactor where nitrification occurs with recycle to the anoxic/anaerobic stage. This book analyses the different factors that affect both processes, such as: (1) Dissolved oxygen (DO), (2) Carbon and nitrogen ratio in the influent (C/N), (3) Hydraulic residence time (TRH), (4) Effect of the recycle ratio, and (5) Effect of the presence of salt (NaCl) in the influent.
Author: Mark R. Matsumoto
Publisher:
ISBN:
Category : Land treatment of wastewater
Languages : en
Pages : 88
Get Book Here
Book Description
The rapid infiltration (RI) land treatment process is a reliable, cost effective method for secondary and/or tertiary treatment of municipal wastewaters. When properly designed and operated, RI systems can achieve a significant level of nitrogen removal via coupled biological processes, namely nitrification-denitrification. Generally, it is believed that lower overall nitrogen levels can be achieved when influent wastewater is fully nitrified. However, at a specific RI facility located in Colton, CA higher nitrogen removals were observed when non-nitrified influent wastewaters were introduced. As a result, it was first hypothesized that an abiotic mechanism, ammonium adsorption, to the soils was occurring. This hypothesis, led to the conduct of an initial effort to evaluate the sorptive phenomenon that was occurring at this site. As a result of that initial effort, it was determined that ammonium adsorption was not occurring and that no nitrogen removal was observed under abiotic (sterile) conditions. Nitrogen removal was observed only under biotic conditions. Subsequent to that initial effort, a second study was conducted in an effort to confirm and better understand the biological nitrogen removal mechanisms that are occurring at the Colton RI facility. In addition, experiments were conducted to evaluate whether nitrogen removal could be enhanced at the facility via organic carbon amendment to the influent wastewater. For design purposes, a 2:1 mass ratio of organic carbon to nitrogen is recommended for nitrogen removal in RI systems. The normal organic carbon to nitrogen ratio at the Colton RI facility is 1:3, highly organic carbon deficient. Experimental systems were amended with additional organic carbon in the form of methanol. Additional organic carbon in the Colton RI facility influent water may improve the denitrification rate within some portions of the soil column.
Author: Changyong Wu
Publisher: Nova Science Publishers
ISBN: 9781536191400
Category : Technology & Engineering
Languages : en
Pages : 247
Get Book Here
Book Description
"Anaerobic-anoxic-oxic (A2/O) is one of the most widely used processes in municipal wastewater treatment plants for simultaneous biological nitrogen and phosphorus removal. The A2/O process has many advantages, such as simple configuration and short hydraulic retention time (HRT), etc. In addition, it is easy to operate. Therefore, A2/O will be continuously chosen as the main option in all kinds of newly designed and built wastewater treatment plants. Though the A2/O process has been used widely, it has some inherent contradictions which are difficult to overcome. For example, the contradiction between substrate competition and SRT makes the high nitrogen and phosphorus removal unable to be achieved simultaneously. As a result, the removal efficiency of the system cannot be further improved. In the past 10 years in China, the wastewater quality very obviously changed with the improvement of living conditions. At present, municipal wastewater with a low C/N ratio is rather common in most countries in the world. The lack of a carbon source will make the inherent contradictions of the A2/O process becomes serious. Therefore, the conventional design parameters of the A2/O process are needed to adjust or the configuration of the A2/O process should change to fit the change of the wastewater quality. According to this, this book systematically describes how to improve the nitrogen and phosphorus removal efficiency of municipal wastewater with low C/N ratio, and effectively utilize the carbon resource in the influent of wastewater. This publication is useful for students, researchers and engineers whose major focus is municipal and the environment"--
Author: United States. Environmental Protection Agency. Office of Technology Transfer
Publisher:
ISBN:
Category : Nitrification
Languages : en
Pages : 466
Get Book Here
Book Description
