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Fulltext The role of general practitioners in home oxygen therapy

Khoo SB

Malays Fam Physician, 2007;2(2):58-63.
PMID: 25606082 MyJurnal

Recommendation of oxygen therapy must include clear indication and benefits of its use, appropriate prescription, vigilant monitoring and appropriate methods of delivery. Home oxygen therapy is expensive, inconvenient and cumbersome; it should be recommended only if benefits outweigh the disadvantages and adverse effects of oxygen. GPs play an important supportive and supervisory role in the use of long-term oxygen therapy (LTOT) to improve mortality of patients with chronic hypoxaemia. Prescription of short burst oxygen therapy (SBOT) for palliation of breathlessness is without clear evidence of its efficacy. GPs can prescribe SBOT when other secondary causes of breathlessness are excluded or treated, when breathlessness is not relieved by other treatments and if an improvement can be documented in patients.

Matched MeSH terms: Oxygen Inhalation Therapy*
Fulltext Heritable variation in swimming performance in Nile tilapia (Oreochromis niloticus) and negative genetic correlations with growth and harvest weight

Mengistu SB, Palstra AP, Mulder HA, Benzie JAH, Trinh TQ, Roozeboom C, et al.

Sci Rep, 2021 May 26;11(1):11018.
PMID: 34040080 DOI: 10.1038/s41598-021-90418-w

Nile tilapia is predominantly produced in smallholder ponds without aeration. We hypothesize that Nile tilapia with high oxygen uptake efficiency (O2UE) may perform better under these conditions than Nile tilapia with low O2UE. Critical swimming speed (Ucrit, in cm s-1) is a potential indicator for O2UE. Our objectives were to estimate variance components for Ucrit and fish size at swim testing early in life, and genetic correlations (rg) between Ucrit with harvest weight (HW) and daily growth coefficient (DGC) later after grow-out in a non-aerated pond. Substantial heritability was found for absolute Ucrit (0.48). The estimated rg between absolute Ucrit and fish size at testing were all strong and positive (range 0.72-0.83). The estimated rg between absolute Ucrit and HW, and absolute Ucrit and DGC were - 0.21 and - 0.63 respectively, indicating that fish with higher absolute Ucrit had lower growth in the non-aerated pond as compared to fish with lower absolute Ucrit. These results suggest a juvenile trade-off between swimming and growth performance where fish with high Ucrit early in life show slower growth later under conditions of limited oxygen availability. We conclude that Ucrit in Nile tilapia is heritable and can be used to predict growth performance.

Matched MeSH terms: Oxygen Consumption/genetics
Optimization via response surface methodology of palm kernel shell biochar for supplementary cementitious replacement

Nusrat Aman AM, Selvarajoo A, Lau TL, Chen WH

Chemosphere, 2023 Feb;313:137477.
PMID: 36509190 DOI: 10.1016/j.chemosphere.2022.137477

The use of sustainable materials in the construction industry has been on the rise recently. Studies have proven that the use of conventional concrete and its raw materials has a negative impact on the environment. Research on incorporating biochar as a supplementary cementitious material has been recently evolving and has shown that the attributes of biochar are highly affected by the pyrolysis parameters. These attributes have enhanced the properties of biochar concrete and mortar composite. This paper identifies the different physiochemical properties exhibited by palm kernel shell biochar through optimization by response surface methodology. Focusing on some of the properties of biochar that have proven beneficial when used as a cement replacement. Very limited research has used optimization tools for the production of biochar with the intention of using it as a cement substitute. Pyrolysis was conducted by a tubular furnace at different temperature ranges from 200 °C to 800 °C. The biomass and biochar have been analyzed with TGA and FESEM-EDX. The targeted biochar properties and selected responses are the yield, carbon, oxygen, silica, and potassium content. The optimized parameters obtained are 409 °C, 15 °C/min, 120 min with responses of 38.2% yield, 73.37% carbon, 25.48% oxygen, 0.39% potassium and 0.44% silica. Thermal properties of the palm kernel shell biochar affected by the pyrolysis factors such as temperature, heating rate and residence time have also been discussed. In conclusion, this study supports and encourages the use of palm waste, which is abundant in Malaysia, as a supplementary cementitious material to promote sustainable growth in construction.

Matched MeSH terms: Oxygen
A family of three with haemoglobin Cheverly: low oxygen saturation in stable patients

Chow LC, Puah SH, Tiong XT, Aloysious NS, Leong TS, Chew LP

J R Coll Physicians Edinb, 2021 Sep;51(3):253-256.
PMID: 34528613 DOI: 10.4997/JRCPE.2021.309

Haemoglobin (Hb) Cheverly is a rare, low oxygen affinity haemoglobinopathy. It is a result of point mutation at the 45 codon of the beta globin genes that leads to substitution of phenylalanine by serine. It is characterised by spuriously low peripheral oxygen saturation with normal arterial oxygen saturation. We describe a family of three with Hb Cheverly in Sarawak General Hospital, Malaysia. It was discovered through incidental finding during hospital admission for unrelated complaints. Laboratory testing revealed abnormal haemoglobin detected at the C window of the high performance liquid chromatography. Subsequent DNA analysis detected replacement of thymidine by cytosine at the beta globin genes. Hb Cheverly may or may not have clinical significance as most of the patients live a normal life; however, it is crucial for us to make early diagnosis to prevent unnecessary extensive investigations for hypoxaemia detected via pulse oximetry, especially in the midst of COVID-19 pandemic.

Matched MeSH terms: Oxygen
Humic acid recovery from stabilized leachate: Characterization and interference with chemical oxygen demand-colour removal

Ahmed Z, Yusoff MS, Kamal NHM, Aziz HA

Waste Manag Res, 2023 Oct;41(10):1584-1593.
PMID: 37154233 DOI: 10.1177/0734242X231160687

Heterogeneous combinations of organic compounds (humic acid (HA) and fulvic acid) are the prime factor for the high concentration of colour and chemical oxygen demand (COD) in semi-aerobic stabilized landfill leachate. These organics are less biodegradable and cause a severe threat to environmental elements. Microfiltration and centrifugation processes were applied in this study to investigate the HA removal from stabilized leachate samples and its corresponding interference with COD and colour. The three-stage extraction process recovered a maximum of 1412 ± 2.5 mg/L (Pulau Burung landfill site (PBLS) leachate), 1510 ± 1.5 mg/L (Alor Pongsu landfill site (APLS leachate) at pH 1.5 and 1371 ± 2.5 mg/L (PBLS) and 1451 ± 1.5 mg/L (APLS) of HA (about 42% of the total COD concentration) at pH 2.5, which eventually indicates the process efficiency. Comparative characteristics analysis of recovered HA by scanning electron microscopy, energy-dispersive X-ray, X-ray photoelectron spectroscopy, and Fourier transform infrared significantly indicate the existence of identical elements in the recovered HA compared with the previous studies. The higher reduction (around 37%) in ultraviolet (UV) absorbance values (UV254 and UV280) in the final effluent indicates the elimination of aromaticity and conjugated double-bond compounds from leachate. Moreover, 36 and 39% COD and 39 and 44% colour removal exhibit substantial interference.

Matched MeSH terms: Biological Oxygen Demand Analysis
Fulltext Data Descriptor: Daily observations of stable isotope ratios of rainfall in the tropics

Munksgaard NC, Kurita N, Sánchez-Murillo R, Ahmed N, Araguas L, Balachew DL, et al.

Sci Rep, 2019 10 08;9(1):14419.
PMID: 31595004 DOI: 10.1038/s41598-019-50973-9

We present precipitation isotope data (δ2H and δ18O values) from 19 stations across the tropics collected from 2012 to 2017 under the Coordinated Research Project F31004 sponsored by the International Atomic Energy Agency. Rainfall samples were collected daily and analysed for stable isotopic ratios of oxygen and hydrogen by participating laboratories following a common analytical framework. We also calculated daily mean stratiform rainfall area fractions around each station over an area of 5° x 5° longitude/latitude based on TRMM/GPM satellite data. Isotope time series, along with information on rainfall amount and stratiform/convective proportions provide a valuable tool for rainfall characterisation and to improve the ability of isotope-enabled Global Circulation Models to predict variability and availability of inputs to fresh water resources across the tropics.

Matched MeSH terms: Oxygen; Oxygen Isotopes
Insight into potential mechanisms of hypobaric hypoxia-induced learning and memory deficit - Lessons from rat studies

Qaid E, Zakaria R, Sulaiman SF, Yusof NM, Shafin N, Othman Z, et al.

Hum Exp Toxicol, 2017 Dec;36(12):1315-1325.
PMID: 28111974 DOI: 10.1177/0960327116689714

Impairment of memory is one of the most frequently reported symptoms during sudden hypoxia exposure in human. Cortical atrophy has been linked to the impaired memory function and is suggested to occur with chronic high-altitude exposure. However, the precise molecular mechanism(s) of hypoxia-induced memory impairment remains an enigma. In this work, we review hypoxia-induced learning and memory deficit in human and rat studies. Based on data from rat studies using different protocols of continuous hypoxia, we try to elicit potential mechanisms of hypobaric hypoxia-induced memory deficit.

Matched MeSH terms: Oxygen*
Fulltext Titanium dioxide dental implants surfaces related oxidative stress in bone remodeling: a systematic review

Abdulhameed EA, Al-Rawi NH, Omar M, Khalifa N, Samsudin ABR

PeerJ, 2022;10:e12951.
PMID: 35261818 DOI: 10.7717/peerj.12951

BACKGROUND: Titanium dioxide dental implants have a controversial effect on reactive oxygen species (ROS) production. ROS is necessary for cellular signal transmission and proper metabolism, but also has the ability to cause cell death as well as DNA, RNA, and proteins damage by excessive oxidative stress. This study aimed to systematically review the effect of titanium dioxide dental implant-induced oxidative stress and its role on the osteogenesis-angiogenesis coupling in bone remodeling.
METHODS: This systematic review was performed conforming to preferred reporting items for systematic review and meta-analysis (PRISMA) model. Four different databases (PubMed, Science Direct, Scopus and Medline databases) as well as manual searching were adopted. Relevant studies from January 2000 till September 2021 were retrieved. Critical Appraisal Skills Programme (CASP) was used to assess the quality of the selected studies.
RESULTS: Out of 755 articles, only 14 which met the eligibility criteria were included. Six studies found that titanium dioxide nanotube (TNT) reduced oxidative stress and promoted osteoblastic activity through its effect on Wnt, mitogen-activated protein kinase (MAPK) and forkhead box protein O1 (FoxO1) signaling pathways. On the other hand, three studies confirmed that titanium dioxide nanoparticles (TiO2NPs) induce oxidative stress, reduce ostegenesis and impair antioxidant defense system as a significant negative correlation was found between decreased SIR3 protein level and increased superoxide (O2 •-). Moreover, five studies proved that titanium implant alloy enhances the generation of ROS and induces cytotoxicity of osteoblast cells via its effect on NOX pathway.
CONCLUSION: TiO2NPs stimulate a wide array of oxidative stress related pathways. Scientific evidence are in favor to support the use of TiO2 nanotube-coated titanium implants to reduce oxidative stress and promote osteogenesis in bone remodeling. To validate the cellular and molecular cross talk in bone remodeling of the present review, well-controlled clinical trials with a large sample size are required.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Early Oxygen Therapy may be Beneficial to Patients with COVID-19 and Underlying Pulmonary Diseases

Kow CS, Ramachandram DS, Hasan SS

J Asthma, 2023 Feb;60(2):422-423.
PMID: 35315746 DOI: 10.1080/02770903.2022.2056701
Matched MeSH terms: Oxygen; Oxygen Inhalation Therapy
Recent strategies to improve boron dipyrromethene (BODIPY) for photodynamic cancer therapy: an updated review

Kue CS, Ng SY, Voon SH, Kamkaew A, Chung LY, Kiew LV, et al.

Photochem Photobiol Sci, 2018 Nov 01;17(11):1691-1708.
PMID: 29845993 DOI: 10.1039/c8pp00113h

BODIPYs are photosensitizers activatable by light to generate highly reactive singlet oxygen (1O2) from molecular oxygen, leading to tissue damage in the photoirradiated region. Despite their extraordinary photophysical characteristics, they are not featured in clinical photodynamic therapy. This review discusses the recent advances in the design and/or modifications of BODIPYs since 2013, to improve their potential in photodynamic cancer therapy and related areas.

Matched MeSH terms: Oxygen; Singlet Oxygen
Tea Polyphenols Inhibit the Activity and Toxicity of Staphylococcus aureus by Destroying Cell Membranes and Accumulating Reactive Oxygen Species

Zhong W, Tang M, Xie Y, Huang X, Liu Y

Foodborne Pathog Dis, 2023 Jul;20(7):294-302.
PMID: 37347934 DOI: 10.1089/fpd.2022.0085

Staphylococcus aureus can cause bacterial food intoxication and seriously affect human health. Tea polyphenols (TP) are a kind of natural, safe, and broad-spectrum bacteriostatic substances, with a wide range of bacteriostatic effects. In the study, we explored the possible bacteriostatic mode of TP. The minimum inhibitory concentration of TP against S. aureus was 64 μg/mL. Protein, DNA, and K+ leak experiments, fluorescence microscopy, and transmission electron microscopy suggested that TP disrupt cell membranes, leading to intracellular component loss. By studying the effect of TP on the toxicity of S. aureus, it was found that the expression levels of two toxin genes, coa and spa, were downregulated by 2.37 and 32.6, respectively. Furthermore, after treatment with TP, a large number of reactive oxygen species (ROS) were propagated and released, leading to oxidative stress in cells. We speculated that the bacteriostatic mechanism of TP may be through the destruction of the cell membrane and ROS-mediated oxidative stress. Meanwhile, the hemolysis activity proved the safety of TP. Our results suggested that TP may be a potential antimicrobial agent for food.

Matched MeSH terms: Reactive Oxygen Species/metabolism; Reactive Oxygen Species/pharmacology
Fulltext Evaluation of auditory system in obstructive sleep apnea patients

Lim CC, Ahmad TEBTN, Sawali HB, Afandi ANB, Paniselvam V, Bernard MW, et al.

Eur Arch Otorhinolaryngol, 2023 May;280(5):2201-2207.
PMID: 36350365 DOI: 10.1007/s00405-022-07711-1

OBJECTIVES: Obstructive sleep apnea (OSA) has been associated with auditory dysfunction both to the cochlear and higher auditory pathways. However, available literatures presented conflicting results. We aimed to study the impact of OSA severity and their polysomnography parameters on hearing function.
MATERIALS AND METHODS: A total of 44 patients were included after evaluation for sleep disorders and were divided into four groups in accordance with apnea-hypopnea index (AHI). Pure tone audiometry (PTA), distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) were compared in commensurate with the severity of AHI. Polysomnography oximetry parameters of oxygen desaturation index, mean SPO2, minimum SPO2 and percent SPO2

Matched MeSH terms: Oxygen
Influence of exercise intensity and hypoxic exposure on physiological, perceptual and biomechanical responses to treadmill running

Li Tee CC, Chong MC, Sundar V, Chok CL, Md Razali MR, Yeo WK, et al.

Eur J Sport Sci, 2023 Aug;23(8):1581-1590.
PMID: 35912915 DOI: 10.1080/17461391.2022.2109066

Acute physiological, perceptual and biomechanical consequences of manipulating both exercise intensity and hypoxic exposure during treadmill running were determined. On separate days, eleven trained individuals ran for 45 s (separated by 135 s of rest) on an instrumented treadmill at seven running speeds (8, 10, 12, 14, 16, 18 and 20 km.h-1) in normoxia (NM, FiO2 = 20.9%), moderate hypoxia (MH, FiO2 = 16.1%), high hypoxia (HH, FiO2 = 14.1%) and severe hypoxia (SH, FiO2 = 13.0%). Running mechanics were collected over 20 consecutive steps (i.e. after running ∼25 s), with concurrent assessment of physiological (heart rate and arterial oxygen saturation) and perceptual (overall perceived discomfort, difficulty breathing and leg discomfort) responses. Two-way repeated-measures ANOVA (seven speeds × four conditions) were used. There was a speed × condition interaction for heart rate (p = 0.045, ηp2 = 0.22), with lower values in NM, MH and HH compared to SH at 8 km.h-1 (125 ± 12, 125 ± 11, 128 ± 12 vs 132 ± 10 b.min-1). Overall perceived discomfort (8 and 16 km.h-1; p = 0.019 and p = 0.007, ηp2 = 0.21, respectively) and perceived difficulty breathing (all speeds; p = 0.023, ηp2 = 0.37) were greater in SH compared to MH, whereas leg discomfort was not influenced by hypoxic exposure. Minimal difference was observed in the twelve kinetics/kinematics variables with hypoxia (p > 0.122; ηp2 = 0.19). Running at slower speeds in combination with severe hypoxia elevates physiological and perceptual responses without a corresponding increase in ground reaction forces.Highlights The extent to which manipulating hypoxia severity (between normoxia and severe hypoxia) and running speed (from 8 to 20 km.h-1) influence acute physiological and perceptual responses, as well as kinetic and kinematic adjustments during treadmill running was determined.Running at slower speeds in combination with severe hypoxia elevates heart rate, while this effect was not apparent at faster speeds.Arterial oxygen saturation was increasingly lower as running speed and hypoxic severity increased.Overall perceived discomfort (8 and 16 km.h-1) and perceived difficulty breathing (all speeds) were lower in moderate hypoxia than in severe hypoxia, whereas leg discomfort remained unchanged with hypoxic exposure.

Matched MeSH terms: Oxygen Consumption
High cell density fed-batch fermentations for lipase production: feeding strategies and oxygen transfer

Salehmin MN, Annuar MS, Chisti Y

Bioprocess Biosyst Eng, 2013 Nov;36(11):1527-43.
PMID: 23539203 DOI: 10.1007/s00449-013-0943-1

This review is focused on the production of microbial lipases by high cell density fermentation. Lipases are among the most widely used of the enzyme catalysts. Although lipases are produced by animals and plants, industrial lipases are sourced almost exclusively from microorganisms. Many of the commercial lipases are produced using recombinant species. Microbial lipases are mostly produced by batch and fed-batch fermentation. Lipases are generally secreted by the cell into the extracellular environment. Thus, a crude preparation of lipases can be obtained by removing the microbial cells from the fermentation broth. This crude cell-free broth may be further concentrated and used as is, or lipases may be purified from it to various levels. For many large volume applications, lipases must be produced at extremely low cost. High cell density fermentation is a promising method for low-cost production: it allows a high concentration of the biomass and the enzyme to be attained rapidly and this eases the downstream recovery of the enzyme. High density fermentation enhances enzyme productivity compared with the traditional submerged culture batch fermentation. In production of enzymes, a high cell density is generally achieved through fed-batch operation, not through perfusion culture which is cumbersome. The feeding strategies used in fed-batch fermentations for producing lipases and the implications of these strategies are discussed. Most lipase-producing microbial fermentations require oxygen. Oxygen transfer in such fermentations is discussed.

Matched MeSH terms: Oxygen/metabolism*
Biological treatment of produced water in a sequencing batch reactor by a consortium of isolated halophilic microorganisms

Pendashteh AR, Fakhru'l-Razi A, Chuah TG, Radiah AB, Madaeni SS, Zurina ZA

Environ Technol, 2010 Oct;31(11):1229-39.
PMID: 21046953 DOI: 10.1080/09593331003646612

Produced water or oilfield wastewater is the largest volume ofa waste stream associated with oil and gas production. The aim of this study was to investigate the biological pretreatment of synthetic and real produced water in a sequencing batch reactor (SBR) to remove hydrocarbon compounds. The SBR was inoculated with isolated tropical halophilic microorganisms capable of degrading crude oil. A total sequence of 24 h (60 min filling phase; 21 h aeration; 60 min settling and 60 min decant phase) was employed and studied. Synthetic produced water was treated with various organic loading rates (OLR) (0.9 kg COD m(-3) d(-1), 1.8 kg COD m(-3) d(-1) and 3.6 kg COD m(-3) d(-1)) and different total dissolved solids (TDS) concentration (35,000 mg L(-1), 100,000 mg L(-1), 150,000 mg L(-1), 200,000 mg L(-1) and 250,000 mg L(-1)). It was found that with an OLR of 0.9 kg COD m(-3) d(-1) and 1.8 kg COD m(-3) d(-1), average oil and grease (O&G) concentrations in the effluent were 7 mg L(-1) and 12 mg L(-1), respectively. At TDS concentration of 35,000 mg L(-1) and at an OLR of 1.8 kg COD m(-3)d(-1), COD and O&G removal efficiencies were more than 90%. However, with increase in salt content to 250,000 mg L(-1), COD and O&G removal efficiencies decreased to 74% and 63%, respectively. The results of biological treatment of real produced water showed that the removal rates of the main pollutants of wastewater, such as COD, TOC and O&G, were above 81%, 83%, and 85%, respectively.

Matched MeSH terms: Oxygen/metabolism*
Phytometabolites Targeting the Warburg Effect in Cancer Cells: A Mechanistic Review

Hasanpourghadi M, Looi CY, Pandurangan AK, Sethi G, Wong WF, Mustafa MR

Curr Drug Targets, 2017;18(9):1086-1094.
PMID: 27033190 DOI: 10.2174/1389450117666160401124842

Phytometabolites are functional elements derived from plants and most of them exhibit therapeutic characteristics such as anti-cancer, anti-inflammatory and anti-oxidant effects. Phytometabolites exert their anti-cancer effect by targeting multiple signaling pathways. One of the remarkable phenomena targeted by phytometabolites is the Warburg effect. The Warburg effect describes the observation that cancer cells exhibit an increased rate of glycolysis and aberrant redox activity compared to normal cells. This phenomenon promotes further cancer development and progression. Recent observations revealed that some phytometabolites could target metabolic-related enzymes (e.g. Hexokinase, Pyruvate kinase M2, HIF-1) in cancer cells, with little or no harm to normal cells. Since hyper-proliferation of cancer cells is fueled by higher cellular metabolism, phytometabolites targeting these metabolic pathways can create synergistic crosstalk with induced apoptotic pathways and sensitize cancer cells to chemotherapeutic agents. In this review, we discuss phytometabolites that target the Warburg effect and the underlying molecular mechanism that leads to tumor growth suppression.

Matched MeSH terms: Oxygen/metabolism*
The oxygen consumption of Plasmodium berghei in the presence of normal rat serum, immune rat serum and chloroquine sulfate

Desowitz RS

Med J Malaya, 1965 Sep;20(1):52-3.
PMID: 4221414
Matched MeSH terms: Oxygen Consumption*
The evaluation of spatial variation of water quality in Sungai Setiu Basin, Terengganu

Izyan Munirah M. Zaideen, Suhaimi Suratman, Norhayati Mohd Tahir

Sains Malaysiana, 2017;46:1513-1520.

This study investigates the spatial variation of water quality parameters in Sungai Setiu Basin at ten different locations from March 2010 to February 2011. The water quality was assessed using the Water Quality Index by Malaysian Department of Environment (DOE-WQI) and classified according to the Malaysia Interim National Water Quality Standard (INWQS). Six water quality parameters embedded in the DOE-WQI were dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, ammoniacal nitrogen (AN) and total suspended solid (TSS). In addition, this study also examined the changes in water quality over the past 10 years by comparing the present water quality to the previous works. The overall mean WQI value obtained was 84.0 which indicate that the Sungai Setiu basin is in clean condition and all measured water quality parameters gave value within the permissible limits of the INWQS classification except for pH which fall in Class III. It can be concluded that water quality in Sungai Setiu does not varies greatly over a decade. Hence continuous monitoring is needed to improve the water quality and minimize water pollution.

Matched MeSH terms: Oxygen; Biological Oxygen Demand Analysis
Optimal aeration area of cathode electrode in the batch type of microbial fuel cells with non-woven interface

Wang CT, Ubando AT, Wan ML, Ong Tang RC

Chemosphere, 2023 Oct;337:139257.
PMID: 37343634 DOI: 10.1016/j.chemosphere.2023.139257

Microbial fuel cells (MFCs) are based on the biochemical reaction of microorganisms to decompose organic wastewater for converting chemical energy into power energy. MFCs are considered an environmentally friendly technology that is gaining popularity due to their simultaneous digestion and energy production abilities. To enhance its real application in wastewater treatment, this study proposes to use a non-woven material for replacing the usage of expensive membranes in MFCs. In addition, the study aims to consider a series of different aeration areas of cathode electrodes for finding an optional design. Results have shown that the adoption of non-woven with 0.45 μm can effectively prohibit the diffusion of oxygen into the anode chamber. Moreover, the non-woven material played an important role as an interface between the anode and cathode, enhancing the MFC performance. The usage of suitable non-woven material can replace the role of the membrane when applied in real wastewater applications. The results have shown that the case study where a combination of a 50% aeration area of the cathode electrodes with 25% exposure of the cathode plate in the air yielded relatively better aeration in terms of a higher current density of 250 mA/m2, higher power density of 220 mW/m2, and higher open voltage circuit of 0.4 V, compared to other case studies considered. These results indicate the optimal aeration configuration for MFCs applied in commercial wastewater treatment in the future.

Matched MeSH terms: Oxygen/chemistry
Fulltext Optimal reduction of chemical oxygen demand and NH3-N from landfill leachate using a strongly resistant novel Bacillus salmalaya strain

Dadrasnia A, Azirun MS, Ismail SB

BMC Biotechnol, 2017 Nov 28;17(1):85.
PMID: 29179747 DOI: 10.1186/s12896-017-0395-9

BACKGROUND: When the unavoidable waste generation is considered as damaging to our environment, it becomes crucial to develop a sustainable technology to remediate the pollutant source towards an environmental protection and safety. The development of a bioengineering technology for highly efficient pollutant removal is this regard. Given the high ammonia nitrogen content and chemical oxygen demand of landfill leachate, Bacillus salmalaya strain 139SI, a novel resident strain microbe that can survive in high ammonia nitrogen concentrations, was investigated for the bioremoval of ammonia nitrogen from landfill leachate. The treatability of landfill leachate was evaluated under different treatment parameters, such as temperature, inoculum dosage, and pH.
RESULTS: Results demonstrated that bioaugmentation with the novel strain can potentially improve the biodegradability of landfill leachate. B. salmalaya strain 139SI showed high potential to enhance biological treatment given its maximum NH3-N and COD removal efficiencies. The response surface plot pattern indicated that within 11 days and under optimum conditions (10% v/v inoculant, pH 6, and 35 °C), B. salmalaya strain139SI removed 78% of ammonia nitrogen. At the end of the study, biological and chemical oxygen demands remarkably decreased by 88% and 91.4%, respectively. Scanning electron microscopy images revealed that ammonia ions covered the cell surface of B. salmalaya strain139SI.
CONCLUSIONS: Therefore, novel resistant Bacillus salmalaya strain139SI significantly reduces the chemical oxygen demand and NH3-N content of landfill leachate. Leachate treatment by B. salmalaya strain 139SI within 11 days.

Matched MeSH terms: Oxygen/analysis; Oxygen/metabolism; Biological Oxygen Demand Analysis*

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