scholarly journals Biological Removal of Nitrates from Groundwater Resources in Saudi Arabia

2020 ◽  
Vol 14 (3) ◽  
pp. 2203-2213
Author(s):  
Essam J. Alyamani ◽  
Rayan Y. Booq ◽  
Ali H. Bahkali ◽  
Sulaiman A. Alharbi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Saudi Arabia ◽  
Removal Rate ◽  
Groundwater Resources ◽  
Nitrate Removal ◽  
Reduction Rate ◽  
Denitrifying Bacteria ◽  
Molecular Techniques ◽  
Microbial Cellulose ◽  
Denitrification Process

Groundwater is the main water source for many areas in Saudi Arabia and the only source of water in some areas. Many local studies have reported that high nitrate concentrations in some wells of groundwater. To provide safe drinking water, the excess amounts of nitrate have to be removed by bio-denitrification process. This study aims to develop a denitrifying biological filter using denitrifying bacteria immobilized on microbial cellulose for the removal of nitrates from water contaminated with nitrate. Denitrifying bacteria that can form biofilter on microbial cellulose were isolated from different regions in Saudi Arabia and were characterized by molecular techniques. They were evaluated for their ability to analyze nitrates and to develop biofilter to remove nitrates from contaminated water. In the results of this project, an optimal microbial cellulose production was achieved by Gluconacetobacter xylinus ATCC 23768 in the lab, which had facilitated the use of biofilter with the immobilized nitrate-reducing bacteria Pseudomonas aeruginosa. The reduction rate of nitrate was reached 1.9mg/L from the starting concentration of 100 mg/L after 18h. Promising results of nitrate removal rate on MC immobilized with Pseudomonas aeruginosa on biofilter at optimized lab conditions of pH, and proper carbon source were achieved. The results suggest that water contaminated with nitrate can be removed by the bio-denitrification process effectively.

Nitrate removal rate in a continuous column denitrification reactor using hydrogen generated by electrolysis with carbon anodes and stainless cathodes

2002 ◽  
Vol 46 (11-12) ◽  
pp. 39-44 ◽  
Author(s):  
S. Dadang ◽  
T. Kawanishi ◽  
N. Shimizu ◽  
Y. Hayashi
Keyword(s):  
Activated Carbon ◽  
Removal Rate ◽  
Tap Water ◽  
Nitrate Removal ◽  
Fixed Bed ◽  
Reduction Rate ◽  
Potassium Nitrate ◽  
Nitrite Reduction ◽  
Flow Process ◽  
Carbon Anodes

An autotrophic continuous denitrification process, using hydrogen generated by electrolysis with activated carbon anodes, was experimentally demonstrated to be an effective nitrate removal process. Several fixed bed columns with polypropylene packing and honeycomb shaped activated carbon anodes and stainless rod cathodes were set in a thermostat chamber at 30°C, and potassium nitrate enriched tap water as influent was supplied at various flow rates and electric currents. Although the anode is in the same column where microbial biomass grows, sufficient nitrate removal was observed. For example, almost complete removal of nitrate and nitrite was observed at a hydraulic retention time (HRT) as short as 1.8 h. A model assuming successive denitrification reactions and plug-flow process, nitrate reduction rate = k1[NO3−] [H2], and nitrite reduction rate = k2 [NO2−]H2]1.5 was proposed. Calculated results with k1 = 1.3 mmol−1 h−1 and k2 = 3.3 mmol−1.5•h−1 agreed well with all the experimental results.

Effective denitrification process by a low voltage in a multi-cathode bio-electrode film reactor

RSC Advances ◽  
2015 ◽  
Vol 5 (17) ◽  
pp. 13061-13067 ◽  
Author(s):  
Ruqiong Cao ◽  
Diwen Ying ◽  
Chenjun Li ◽  
Yalin Wang ◽  
Jinping Jia
Keyword(s):  
Low Voltage ◽  
Removal Rate ◽  
Nitrate Removal ◽  
Film Reactor ◽  
Denitrification Process

An outstanding nitrate removal rate of 16.8 NO3−–N mg L−1 h−1 was achieved by applying voltage of 0.25 V in a multi-cathode bio-electrode film reactor.

scholarly journals Effect of Denitrifying Bacterial Biomass and Carbon Sources on Nitrate Removal

2020 ◽  
Vol 14 (4) ◽  
pp. 2417-2424
Author(s):  
Essam J. Alyamani ◽  
Rayan Y. Booq ◽  
Ali H. Bahkali ◽  
Sulaiman A. Alharbi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Conventional Treatment ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Bacterial Biomass ◽  
Alkaline Ph ◽  
Biological Denitrification ◽  
Bacterial Inoculum ◽  
Denitrification Process

Denitrification based on immobilized microbial cellulose may offer an economical replacement for conventional treatment for nitrate removal. The environmental and bacterial biomass may influence the rate of biological denitrification processes. This study aimed to investigate the factors that affect denitrification rates, including carbon sources, pH, and bacterial inoculum. Different inoculum biomass of Pseudomonas aeruginosa and various carbon sources of glucose, sucrose, and cellulose with different concentrations were tested to assimilate 100 mg/L of KNO3 as nitrate source. Additionally, five additional inoculations, five different incubation time, and seven different pH levels were studied. The Pseudomonas aeruginosa isolates used different mineral media with three carbon sources, glucose, sucrose, and cellulose, with different concentrations at different rates to denitrify nitrate. The highest denitrification rate was with glucose after 18 hrs and was after 24 hrs when sucrose and cellulose were used, respectively. The bacterial biomass denitrification level was the highest, between 0.8% and 1% of OD600=1. Nitrate removal by Pseudomonas aeruginosa was the highest at pH 7, 8, and 9. This report suggests that when glucose is used as a carbon source, at neutral to alkaline pH, and 1% of denitrifying bacterial biomass, the highest level of biological denitrification process may be achieved.

scholarly journals Inhibitory Effect of Veterinary Antibiotics on Denitrification in Groundwater: A Microcosm Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Mahtab Ahmad ◽  
Meththika Vithanage ◽  
Kangjoo Kim ◽  
Ju-Sik Cho ◽  
Young Han Lee ◽  
...  
Keyword(s):  
Nitrate Removal ◽  
Inhibitory Effect ◽  
Denitrifying Bacteria ◽  
Nitrate Pollution ◽  
Veterinary Antibiotics ◽  
Naturally Occurring ◽  
Nitrite Production ◽  
Microcosm Study ◽  
Maximum Inhibition ◽  
Denitrification Process

Veterinary antibiotics in groundwater may affect natural microbial denitrification process. A microcosm study was conducted to evaluate the influence of sulfamethazine and chlortetracycline at different concentrations (0, 0.01, 0.1, and 1.0 mg/L) on nitrate reduction in groundwater under denitrifying condition. Decrease in nitrate removal and nitrite production was observed with the antibiotics. Maximum inhibition of nitrate removal was observed after seven days of incubation with 0.01 mg/L sulfamethazine (17.0%) and 1.0 mg/L chlortetracycline (15.4%). The nitrite production was inhibited with 1.0 mg/L sulfamethazine to 82.0% and chlortetracycline to 31.1%. The initial/final nitrate concentrations indicated that 0.01 mg/L sulfamethazine and 1.0 mg/L chlortetracycline were most effective in inhibiting activity of denitrifying bacteria in groundwater. After 12 days of incubation, the sulfamethazine biodegradation was observed whereas chlortetracycline was persistent. Sulfamethazine and chlortetracycline in groundwater could inhibit the growth and capability of naturally occurring denitrifying bacteria, thereby threatening nitrate pollution in groundwater.

scholarly journals Performance evaluation of ozonation for removal of antibiotic-resistant Escherichia coli and Pseudomonas aeruginosa and genes from hospital wastewater

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Farzaneh Baghal Asghari ◽  
Mohammad Hadi Dehghani ◽  
Reza Dehghanzadeh ◽  
Davoud Farajzadeh ◽  
Dariush Shanehbandi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Removal Rate ◽  
Reduction Rate ◽  
Ozone Treatment ◽  
Plate Count ◽  
Resistant Bacteria ◽  
Hospital Wastewater ◽  
Antibiotic Resistant ◽  
Hospital Wastewaters

AbstractThe performance of ozonation for the removal of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) using Escherichia coli and Pseudomonas aeruginosa carrying ARGs from hospital wastewaters was evaluated in this study. Bacterial inactivation was determined using plate count methods and real time PCR for ARG damage (Sul1, blatem, blactx, blavim and qnrS). The reduction rate of bacterial cells and ARGs was increased by different amounts of transferred ozone dose from 11 to 45 mg/L. The concentration of 108 cfu/ml bacteria was reduced  to an acceptable level by ozone treatment after a 5 min contact time,  Although the removal rate was much higher for concentrations of 106 cfu/ml and 104 cfu/ml bacteria. Overall, the tendency of gene reduction by ozonation from more to less was 16S rRNA > sul1 > blatem > blactx > qnrS > blavim. Given that plasmid-borne ARGs can potentially be transferred to other bacteria even after the disinfection process, our results can provide important insights into the fate of ARGs during hospital wastewater ozonation.

scholarly journals Ochrobactrum anthropi used to control ammonium for nitrate removal by starch-stabilized nanoscale zero valent iron

2017 ◽  
Vol 76 (7) ◽  
pp. 1827-1832 ◽  
Author(s):  
Jun Zhou ◽  
Qianyu Sun ◽  
Dan Chen ◽  
Hongyu Wang ◽  
Kai Yang
Keyword(s):  
Nitrate Reduction ◽  
Removal Rate ◽  
Nitrate Removal ◽  
Reduction Rate ◽  
Reduction Process ◽  
Zero Valent Iron ◽  
Ochrobactrum Anthropi ◽  
Iron Corrosion ◽  
Combined System ◽  
Nanoscale Zero Valent Iron

In this study, the hydrogenotrophic denitrifying bacterium Ochrobactrum anthropi was added in to the process of nitrate removal by starch-stabilized nanoscale zero valent iron (nZVI) to minimize undesirable ammonium. The ammonium control performance and cooperative mechanism of this combined process were investigated, and batch experiments were conducted to discuss the effects of starch-stabilized nZVI dose, biomass, and pH on nitrate reduction and ammonium control of this system. The combined system achieved satisfactory performance because the anaerobic iron corrosion process generates H2, which is used as an electron donor for the autohydrogenotrophic bacterium Ochrobactrum anthropi to achieve the autohydrogenotrophic denitrification process converting nitrate to N2. When starch-stabilized nZVI dose was increased from 0.5 to 2.0 g/L, nitrate reduction rate gradually increased, and ammonium yield also increased from 9.40 to 60.51 mg/L. Nitrate removal rate gradually decreased and ammonium yield decreased from 14.93 to 2.61 mg/L with initial OD600 increasing from 0.015 to 0.080. The abiotic Fe0 reduction process played a key role in nitrate removal in an acidic environment and generated large amounts of ammonium. Meanwhile, the nitrate removal rate decreased and ammonium yield also reduced in an alkaline environment.

Antibacterial Activity of Desert Truffles from Saudi Arabia Against Staphylococcus aureus and Pseudomonas aeruginosa

2017 ◽  
Vol 19 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Domenico Schillaci ◽  
Maria Grazia Cusimano ◽  
Stella Maria Cascioferro ◽  
Vita Di Stefano ◽  
Vincenzo Arizza ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Saudi Arabia ◽  
Desert Truffles

Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Drinking Water Treatment ◽  
Nitrate Content ◽  
Source Water ◽  
Nitrogen Gas ◽  
Negative Effect ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

scholarly journals An Exploration of Seaweed Polysaccharides Stimulating Denitrifying Bacteria for Safer Nitrate Removal

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3390
Author(s):  
Hui Zhang ◽  
Lin Song ◽  
Xiaolin Chen ◽  
Pengcheng Li
Keyword(s):  
Growth Rate ◽  
Bacillus Subtilis ◽  
Nitrate Removal ◽  
Denitrifying Bacteria ◽  
Soil Salinization ◽  
Nitrate Content ◽  
Weak Efficiency ◽  
N Accumulation ◽  
N Removal ◽  
Intensively Managed

Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO3−-N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO3−-N. More importantly, the increased NH4+-N content could avoid excessive loss of nitrogen, and less NO2−-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.

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