scholarly journals Photosynthetic oxygenation for urine nitrification

2018 ◽  
Vol 78 (1) ◽  
pp. 183-194
Author(s):  
Maarten Muys ◽  
Joeri Coppens ◽  
Nico Boon ◽  
Siegfried E. Vlaeminck
Keyword(s):  
Removal Rate ◽  
Oxygen Demand ◽  
Nitrifying Bacteria ◽  
Nutrient Recovery ◽  
Nitrification Rate ◽  
Photosynthetic Organisms ◽  
Synthetic Urine ◽  
Photosynthetic Oxygenation ◽  
Photo Bioreactor ◽  
First Time

Abstract Human urine accounts for only a fraction of the sewage volume, but it contains the majority of valuable nutrient load in wastewater. In this study, synthetic urine was nitrified in a closed photo-bioreactor through photosynthetic oxygenation by means of a consortium of microalgae and nitrifying bacteria. In situ production of oxygen by photosynthetic organisms has the potential to reduce the energy costs linked to conventional aeration. This energy-efficient strategy results in stable urine for further nutrient recovery, while part of the nutrients are biologically recovered in the form of valuable biomass. In this study, urine was nitrified for the first time without conventional aeration at a maximum photosynthetic oxygenation rate of 160 mg O2 gVSS−1 d−1 (VSS: volatile suspended solids). A maximum volumetric nitrification rate of 67 mg N L−1 d−1 was achieved on 12% diluted synthetic urine. Chemical oxygen demand (COD) removal efficiencies were situated between 44% and 83% at a removal rate of 24 mg COD gVSS−1 d−1. After 180 days, microscopic observations revealed that Scenedesmus sp. was the dominant microalga. Overall, photosynthetic oxygenation for urine nitrification is promising as a highly electricity efficient approach for further nutrient recovery.

scholarly journals Operational modifications for the development of nitrifying bacteria in a large-scale biological aerated filter and its impact on wastewater treatment

2018 ◽  
Vol 78 (8) ◽  
pp. 1704-1714 ◽  
Author(s):  
François-René Bourgeois ◽  
Frédéric Monette ◽  
Daniel G. Cyr
Keyword(s):  
Large Scale ◽  
Oxygen Demand ◽  
Bacterial Biofilm ◽  
Nitrifying Bacteria ◽  
Nitrification Rate ◽  
Total Biomass ◽  
Ammonia Oxidizing Bacteria ◽  
Operational Conditions ◽  
Nitrite Oxidizing Bacteria ◽  
Aerated Filter

Abstract To develop a better understanding for fixed biomass processes, the development of a nitrifying bacterial biofilm, as well as the performance of treatment during modifications to operational conditions of a full-scale submerged biological filter were examined. The development of the nitrifying biofilm was investigated at four depth levels (1, 2, 4 and 5 feet). The result of bacterial subpopulations analyzed by qPCR relative to the physico-chemical parameters of the wastewater during the various tests (sustained aeration, modified backwash parameters and inflow restriction) revealed an increase of the relative presence of nitrifying microorganisms throughout the biofilm (especially for nitrite oxidizing bacteria (NOB)), but this was not necessarily accompanied by a better nitrification rate. The highest observed nitrification rate was 49% of removal in the test cell during backwashing conditions, whereas the relative ammonia oxidizing bacteria (AOB) population was 0.032% and NOB was 0.008% of the total biomass collected. The highest percentage of nitrifying bacteria observed (0.034% AOB and 0.18% NOB) resulted in a nitrification rate of 21%. The treatment of organic matter determined by measuring the chemical and biochemical oxygen demand (COD, CBOD5) was improved.

scholarly journals Removal of organic and nitrogen in a novel anoxic fixed-bed / aerobic fluidized-moving bed integrated with a constructed wetland bio-reactor (A/O-FMCW)

2020 ◽  
Vol 167 ◽  
pp. 01001
Author(s):  
Changmiao Lai ◽  
Yu Sun ◽  
Yong Guo ◽  
Qin Cai ◽  
Ping Yang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Constructed Wetland ◽  
Removal Rate ◽  
Fixed Bed ◽  
Oxygen Demand ◽  
Integrated System ◽  
Nitrification Rate ◽  
Moving Bed ◽  
Influent Concentration

An innovative hybrid process was designed using an integrated bio-reactor based on an anoxic / aerobic process that combined a fixed bed and a fluidized-moving bed with a constructed wetland (A/OFMCW) to enhance the removal of organic material and nitrogen. The goal was to achieve stringent discharge standards for rural domestic wastewater treatment. A preliminary lab-scale investigation of about 130 days obtained an average COD (Chemical Oxygen Demand) removal rate as high as 92.2% at an average influent concentration of 319.5 mg/L. The average TN (Total Nitrogen) removal efficiency positively correlated with the attached-growth biofilm as observed by SEM (Scanning Electron Microscope), and declined from 79.1% to 53.2%. The was accompanied by a gradual increase in the average influent concentration from 16.73 to 52.01 mg/L despite the relative nitrification rate fluctuating between 92.5% and 97.9%. The entire integrated system improved the COD removal efficiency by nearly 36% and the TN by 14–28%. Classical autotrophic nitrification and heterotrophic denitrification were the main mechanisms responsible for the elimination of pollutants, and the latter was determined to be the limiting step. Overall, this study provides an effective and less expensive alternative method to apply or upgrade DWWT (Decentralized Wastewater Treatment).

scholarly journals The Influence of Mineral Fertilizer Combined With a Nitrification Inhibitor on Microbial Populations and Activities in Calcareous Uzbekistanian Soil Under Cotton Cultivation

2001 ◽  
Vol 1 ◽  
pp. 108-113 ◽  
Author(s):  
Dilfuza Egamberdiyeva ◽  
Muhiddin Mamiev ◽  
Svetlana K. Poberejskaya
Keyword(s):  
Nitrification Inhibitor ◽  
Mineral Fertilizer ◽  
Denitrifying Bacteria ◽  
Nitrifying Bacteria ◽  
Most Probable Number ◽  
Nitrification Rate ◽  
Nitrification Inhibitors ◽  
Probable Number ◽  
Soil Microbial ◽  
Soil Microbial Population

Application of fertilizers combined with nitrification inhibitors affects soil microbial biomass and activity. The objective of this research was to determine the effects of fertilizer application combined with the nitrification inhibitor potassium oxalate (PO) on soil microbial population and activities in nitrogen-poor soil under cotton cultivation in Uzbekistan. Fertilizer treatments were N as urea, P as ammophos, and K as potassium chloride. The nitrification inhibitor PO was added to urea and ammophos at the rate of 2%. Three treatments—N200P140K60(T1), N200P140 POK60(T2), and N200P140 POK60(T3) mg kg-1soil—were applied for this study. The control (C) was without fertilizer and PO. The populations of oligotrophic bacteria, ammonifying bacteria, nitrifying bacteria, denitrifying bacteria, mineral assimilating bacteria, oligonitrophilic bacteria, and bacteria group Azotobacter were determined by the most probable number method. The treatments T2 and T3 increased the number of oligonitrophilic bacteria and utilization mineral forms of nitrogen on the background of reducing number of ammonifying bacteria. T2 and T3 also decreased the number of nitrifying bacteria, denitrifying bacteria, and net nitrification. In conclusion, our experiments showed that PO combined with mineral fertilizer is one of the most promising compounds for inhibiting nitrification rate, which was reflected in the increased availability and efficiency of fertilizer nitrogen to the cotton plants. PO combined with mineral fertilizer has no negative effects on nitrogen-fixing bacteria Azotobacter and oligo-nitrophilic bacteria.

Characterization of New Nonstoichiometric Ferroelectric (Li0.95Cu0.15)Ta0.76Nb0.19O3 and Comparative Study With (Li0.95Cu0.15)Ta0.57Nb0.38O3 as Photocatalysts in Microbial Fuel Cells

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.

COD removal efficiency and mechanism of HMBR in high volumetric loading for ship domestic sewage treatment

2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Aeration Tank ◽  
Remarkable Effect ◽  
Cod Removal Efficiency ◽  
Volumetric Loading

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.

scholarly journals ACID ORANGE 52 DYE DEGRADATION BY ELECTROCATALYTIC PLUS PHOTOCATALYTIC TECHNIQUE AND INTERMEDIATES DETECTION

2018 ◽  
Vol 61 (4-5) ◽  
pp. 111
Author(s):  
Hui Zhao ◽  
Heng Zhong ◽  
Lei Sun ◽  
Alexander V. Nevsky ◽  
Dongsheng Xia
Keyword(s):  
Dye Degradation ◽  
Removal Rate ◽  
Degradation Mechanism ◽  
Oxygen Demand ◽  
Ionization Mass ◽  
Light Spectrum ◽  
Resource Saving ◽  
Acid Orange ◽  
Visible Part ◽  
Photocatalytic Processes

The degradation efficiency of Acid Orange 52 dye in an aqueous solutions using the combination of electrocatalytic and photocatalytic processes has been studied. Electrocatalytic and photocatalytic methods in practice reckon among advanced oxidation processes (AOPs). The effect of catalyst B dosage and irradiarion time on the rate of mentioned dye degradation was studied in the photocatalytic process. It was shown, that when Acid Orange 52 simulated dye wastewater was treated by electrocatalytic technique under optimal conditions with catalyst A, the decolorization treatment effect was 95 % in visible part of light spectrum (464 nm) and 38.6 % in ultraviolet part (270 nm), respectively. When the combined electrocatalytic-photocatalytic technique was processed with catalysts A and B, the color removal rate of dye could reach 99.3% (464 nm) and 91.5% (270 nm), respectively. The large amount of products of small mole weight was formed in the course of oxidation reaction. Moreover, the obtained values of chemical oxygen demand (COD) and total organic carbon (TOC) witnessed, that the combination of electrocatalytic and photocatalytic processes could significantly improve the biodegradability of dye as a whole．It was shown, that the removal rate of COD and TOC, respectively, were 54.3% and 72.8%. The reaction intermediates were determined by electrospray ionization-mass spectrometry (ESI-MS) analysis, and as a result, the probable degradation mechanism (pathway) has been proposed. The results of the work may be useful as theoretical bases for designing effective resource-saving, technically efficient and economically sound wastewater treatment systems, containing hardly biodegradable azo dyes.Forcitation:Zhao H., Zhong H., Sun L., Xia D., Nevsky A.V. Acid Orange 52 dye degradation by electrocatalytic plus photocatalytic technique and intermediates detection. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 111-118

scholarly journals Investigation of the Efficiency of Phosphorus Removal Using Anionic Resins From the Continuous Flow in the Waste Stabilization Pond Outlet: A Case Study of Kaboodrahang Wastewater Treatment Plant

2019 ◽  
Vol 6 (1) ◽  
pp. 16-20
Author(s):  
Ali Akbar Rahmani Sarmazdeh ◽  
Mostafa Leili
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Phosphorus Removal ◽  
Continuous Flow ◽  
Removal Rate ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Cold Season ◽  
Stabilization Pond ◽  
The Mean

This research mainly aimed to investigate phosphorus removal from stabilization pond effluent by using anionic resins in the continuous flow mode of operation due to high amounts of phosphorus in the wastewater treatment plant effluent of Kaboodrahang, western Iran, as well as the violation from a prescribed effluent standard to discharge receiving the surface waters. For this purpose, the pilot was made of a plexiglass cylinder and other equipment such as pump and other accessories, as well as Purolite A-100 resin. The reactor effects on the desired study parameters were assessed in two warm and cold seasons. The results showed that the phosphorus concentrations reduced from 7-10 mg/L to 4-7 mg/L and the rate of phosphorus removal was higher in the hot season compared to the cold season. Moreover, the optimum temperature and pH were obtained 21ºC and 8.5, respectively. The mean inlet biological oxygen demand (BOD) was 150 mg/L for both warm and cold seasons, where the highest removal rate of 17% was obtained in the cold season. The mean chemical oxygen demand concentration of the pilot was 250 mg/L for both seasons, and the highest removal rate was observed in the cold season with an efficiency of 18%. Regarding the total suspended solids with the mean inlet of 230 mg/L, the highest removal efficiency was obtained 6% in the warm season.

scholarly journals Treatment of Wastewater for Agricultural Applications in Regions of Water Scarcity

2021 ◽  
Vol 12 (5) ◽  
pp. 6336-6360
Keyword(s):  
Removal Rate ◽  
Oxygen Demand ◽  
Bacterial Count ◽  
Agricultural Fields ◽  
Total Bacterial Count ◽  
Industrial Sectors ◽  
Agricultural Applications ◽  
Electrocoagulation Process ◽  
Water Scarce ◽  
Animal Safety

This paper analyses the latest techniques for treating wastewater to make it suitable for agricultural applications in regions where irrigation water is scarce. Micro-filtration (MF) techniques yield a significant reduction in Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), and Total Bacterial Count (TBC) of wastewater, which makes it suitable to be used for irrigational purposes. Microbial Fuel Cell (MFC) technology is a viable solution for treating wastewater discharged from many industrial sectors, such as the food processing industry, for reclaiming water for agro-applications. Such industrial water may seal soil pores if directed untreated to agricultural fields. Concerning the treatment of microbial contamination of wastewater, the removal rate of pressurized membrane bio-booster (MBR) is significantly large for coliform and metals such as lead, copper, chromium, and arsenic. Both electrocoagulation and chemical coagulation are applied in the removal of oxidable chemicals from wastewater. However, the electrocoagulation process shows a higher efficiency in terms of removing COD. Contamination of agricultural fields with heavy metals is considered an adverse impact on the human and animal safety of discharging wastewater into agro-fields. Thus, removing such contaminants should be given the utmost priority in wastewater treatment, especially from industrial discharge, before they are directed to agricultural usage. Factors that govern the sustainability of a given method in a water-scarce region are also discussed.

scholarly journals Interaction of Operational and Physicochemical Factors Leading to Gordonia amarae-Like Foaming in an Incompletely Nitrifying Activated Sludge Plant

2012 ◽  
Vol 78 (23) ◽  
pp. 8165-8175 ◽  
Author(s):  
Pitiporn Asvapathanagul ◽  
Zhonghua Huang ◽  
Phillip B. Gedalanga ◽  
Amber Baylor ◽  
Betty H. Olson
Keyword(s):  
Steady State ◽  
Removal Rate ◽  
Statistical Significance ◽  
Oxygen Demand ◽  
Ammonium Ion ◽  
Content Type ◽  
Mixed Liquor ◽  
Physicochemical Changes ◽  
Cell Concentrations ◽  
Gordonia Amarae

ABSTRACTThe overgrowth ofGordonia amarae-like bacteria in the mixed liquor of an incompletely nitrifying water reclamation plant was inversely correlated with temperature (r= −0.78;P< 0.005) and positively correlated with the solids retention time (SRT) obtained a week prior to sampling (r= 0.67;P< 0.005). Drops followed by spikes in the food-to-mass ratio (0.18 to 0.52) and biochemical oxygen demand concentrations in primary effluent (94 to 298 mg liter−1) occurred at the initiation ofG. amarae-like bacterial growth. The total bacterial concentration did not increase as concentrations ofG. amarae-like cells increased, but total bacterial cell concentrations fluctuated in a manner similar to that ofG. amarae-like bacteria in the pseudo-steady state. The ammonium ion removal rate (percent) was inversely related toG. amarae-like cell concentrations during accelerated growth and washout phases. The dissolved oxygen concentration decreased as theG. amarae-like cell concentration decreased. The concentrations ofG. amarae-like cells peaked (2.47 × 109cells liter−1) approximately 1.5 months prior to foaming. Foaming occurred during the late pseudo-steady-state phase, when temperature declines reversed. These findings suggested that temperature changes triggered operational and physicochemical changes favorable to the growth ofG. amarae-like bacteria. Fine-scale quantitative PCR (qPCR) monitoring at weekly intervals allowed a better understanding of the factors affecting this organism and indicated that frequent sampling was required to obtain statistical significance with factors changing as the concentrations of this organism increased. Furthermore, the early identification ofG. amarae-like cells when they are confined to mixed liquor (107cells liter−1) allows management strategies to prevent foaming.

Assessment of the Effects of Ornamental Wetland Polyculture Combinations on Urban Sewage Treatment

2021 ◽  
Author(s):  
Min Wang ◽  
Yujue Zhou ◽  
Lin Xiang ◽  
Xiaoyang Ke ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Municipal Wastewater ◽  
Plant Biomass ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Wetland Plant ◽  
Urban Sewage ◽  
Thalia Dealbata ◽  
Cyperus Alternifolius

Abstract Previous studies have shown that wetland plants can treat wastewater in a cost-effective and sustainable way, however, the studies on the performance of ornamental wetland plant diversity in treating urban sewage were scarce. Therefore, this study was conducted to assess and select wetland polyculture combination that was effective in urban sewage treatment in subtropical areas. We formed five combinations out of six ornamental wetland plant species including Thalia dealbata, Cyperus alternifolius, Iris pseudacorus, Lythrum sastlicaria, Nymphaea tetragona, and Zantedeschia aethiopica. The growth state and removal effects of each plant combination were systematically measured and assessed. The results indicated all the combinations exhibited remarkable total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH­4+-N), and chemical oxygen demand chromium (CODcr) removal rate of 70.75%-77.67%, 63.86%-73.71%, 69.73%-76.85%, and 57.28%-75.69%, respectively. Additionally, pH was reduced to 7.54-8.00 in the sewage. The purification effect reached the best during 30-36th day. The comprehensive assessment showed the mixture of Thalia dealbata + Cyperus alternifolius, closely followed by Thalia dealbata + Cyperus alternifolius+ Lythrum sastlicaria, was highly effective at extracting various pollutants, and both of them could be used as favorable combinations to convert eutrophication and purify municipal wastewater. Linear regression showed that TP, TP, NH­4+-N, and CODcr. were significantly related to plant biomass, indicating that plant biomass essential indicator for screening purification plants. Our study highlighted the importance of plant diversity in biological wastewater treatment, however the competition between plants was suggested to take into consideration in future studies.

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