scholarly journals A Review on the Application of Isotopic Techniques to Trace Groundwater Pollution Sources within Developing Countries

Water ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 35
Author(s):  
Abdul Aziz Sankoh ◽  
Nana Sarfo Agyemang Derkyi ◽  
Ronnie A. D. Frazer-williams ◽  
Cynthia Laar ◽  
Ishmail Kamara
Keyword(s):  
Developing Countries ◽  
Seawater Intrusion ◽  
Groundwater Pollution ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Animal Manure ◽  
Pollution Sources ◽  
Water Bodies ◽  
Landfill Leachates ◽  
Dual Isotope

Owing to a lack of efficient solid waste management (SWM) systems, groundwater in most developing countries is found to be contaminated and tends to pose significant environmental health risks. This review paper proffers guidelines on the application of isotopic techniques to trace groundwater pollution sources from data spanning from 2010 to 2020 within developing countries. Earlier groundwater studies in those countries were mainly focused on using hydrochemical and geophysical techniques. The limitation of these techniques is that they can only monitor the concentration of pollutants in the water bodies and possible leachate infiltration but cannot determine the specific sources of the pollution. Stable isotopes of δ18O, δ2H and δ13C can confirm leachate migration to water bodies due to methanogenesis. The high tritium in landfill leachates is useful to identify leachate percolation in groundwater. The δ15N technique has been used to distinguish between synthetic and organic nitrogen sources but its application is limited to differentiating between atmospheric vs. inorganic nitrogen sources. The use of a dual isotope of δ15N–NO3− and δ18O–NO3− is beneficial in terms of identifying various sources of nitrogen such as atmospheric and inorganic fertilizers but is yet to be used to differentiate between nitrogen pollution sources from dumpsites, sewage and animal manure. The coupling of the 11B isotope with δ15N–NO3− and δ18O–NO3− and other hydrochemical parameters has proven to be effective in distinguishing between nitrate fertilizer, animal manure, seawater contamination and sewage. Therefore, in areas affected by agricultural activities, landfill leachates, domestic or sewage effluent and seawater intrusion, it is incumbent to couple hydrochemical (Cl−, NO3−, B, DO) and isotope techniques (δ18O, 2H, δ13C, δ18O–NO3−, δ15N–NO3−, δ11B and 3H) to effectively determine pollution sources of groundwater in developing countries. The foregoing review will provide guidelines for studies that may aim to critically distinguish between seawater intrusion, dumpsites, sewage and septic leachates.

scholarly journals Varied Diazotrophies, Morphologies, and Toxicities of Genetically Similar Isolates of Cylindrospermopsis raciborskii(Nostocales, Cyanophyceae) from Northern Australia

2001 ◽  
Vol 67 (4) ◽  
pp. 1839-1845 ◽  
Author(s):  
Martin L. Saker ◽  
Brett A. Neilan
Keyword(s):  
Nitrogen Source ◽  
Growth Rates ◽  
Vegetative Cell ◽  
Nitrogen Sources ◽  
Water Bodies ◽  
Cylindrospermopsis Raciborskii ◽  
Rrna Gene ◽  
Northern Australia ◽  
Fixed Nitrogen ◽  
Freeze Dried

ABSTRACT The potentially toxic freshwater cyanobacteriumCylindrospermopsis raciborskii has become increasingly prevalent in tropical and temperate water bodies worldwide. This paper investigates the effects of different nitrogen sources (NO3 −, NH4 +, and omission of a fixed form of nitrogen) on the growth rates, morphologies, and cylindrospermopsin (CYL) concentrations (expressed as a percentage of the freeze-dried weight) of seven C. raciborskii isolates obtained from a range of water bodies in northern Australia and grown in batch culture. In general, growth rates were lowest in the absence of a fixed-nitrogen source and highest with NH4 + as the nitrogen source. Conversely, the highest concentrations of CYL were recorded in cultures grown in the absence of a fixed-nitrogen source and the lowest were found in cultures supplied with NH4 +. Cultures supplied with NO3 − were intermediate with respect to both CYL concentration and growth rate. Different nitrogen sources resulted in significant differences in the morphology of C. raciborskii trichomes. Most notable were the loss of heterocysts and the tapering of end cells in cultures supplied with NH4 + and the statistically significant increase in vegetative cell length (nitrogen depleted < NO3 − < NH4 +). The morphological changes induced by different nitrogen sources were consistent for all isolates, despite measurable differences in vegetative-cell and heterocyst dimensions among isolates. Such induced morphological variation has implications forCylindrospermopsis taxonomy, given that distinctions between species are based on minor and overlapping differences in cell lengths and widths. The close phylogenetic association among all seven isolates was confirmed by the high level (>99.8%) of similarity of their 16S rRNA gene sequences. Another genetic technique, analysis of the HIP1 octameric-palindrome repeated sequence, showed greater heterogeneity among the isolates and appears to be a useful method for distinguishing among isolates of C. raciborskii.

scholarly journals Energy Calculator for Solar Processing of Biomass with Application to Uganda

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1485 ◽  
Author(s):  
Toby Green ◽  
Opio Innocent Miria ◽  
Rolf Crook ◽  
Andrew Ross
Keyword(s):  
Developing Countries ◽  
Rural Areas ◽  
Energy Demand ◽  
Hydrothermal Carbonization ◽  
Resource Assessment ◽  
Animal Manure ◽  
Integrated System ◽  
Steam Treatment ◽  
Waste Biomass ◽  
Local Supply

Rural areas of developing countries often have poor energy infrastructure and so rely on a very local supply. A local energy supply in rural Uganda frequently has problems such as limited accessibility, unreliability, a high expense, harmful to health and deforestation. By carbonizing waste biomass streams, available to those in rural areas of developing countries through a solar resource, it would be possible to create stable, reliable fuels with more consistent calorific values. An energy demand calculator is reported to assess the different energy demands of various thermochemical processes that can be used to create biofuel. The energy demand calculator then relates the energy required to the area of solar collector required for an integrated system. Pyrolysis was shown to require the least amount of energy to process 1 kg of biomass when compared to steam treatment and hydrothermal carbonization (HTC). This was due to the large amount of water required for steam treatment and HTC. A resource assessment of Uganda is reported, to which the energy demand calculator has been applied. Quantitative data are presented for agricultural residues, forestry residues, animal manure and aquatic weeds found within Uganda. In application to rural areas of Uganda, a linear Fresnel HTC integration shows to be the most practical fit. Integration with a low temperature steam treatment would require more solar input for less carbonization due to the energy required to vaporize liquid water.

Comparison of Organic and Inorganic Nitrogen Sources for Rice 1

1987 ◽  
Vol 79 (5) ◽  
pp. 937-943 ◽  
Author(s):  
M. P. Westcott ◽  
D. S. Mikkelsen
Keyword(s):  
Inorganic Nitrogen ◽  
Nitrogen Sources

scholarly journals Medium Optimization for Spore Production of a Straw-Cellulose Degrading Actinomyces Strain under Solid-State Fermentation Using Response Surface Method

2020 ◽  
Vol 12 (21) ◽  
pp. 8893
Author(s):  
Huanran Liu ◽  
Dan Zhang ◽  
Xia Zhang ◽  
Chuanzhi Zhou ◽  
Pei Zhou ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Spore Production ◽  
Steepest Ascent ◽  
Medium Components ◽  
Burman Design ◽  
Plackett Burman Design ◽  
Central Composite

The strains capable of degrading cellulose have attracted much interest because of their applications in straw resource utilization in solid-state fermentation (SSF). However, achieving high spore production in SSF is rarely reported. The production of spores from Streptomyces griseorubens JSD-1 was investigated in shaker-flask cultivation in this study. The optimal carbon, organic nitrogen and inorganic nitrogen sources were sucrose, yeast extract and urea, respectively. Plackett–Burman design (PBD) was adopted to determine the key medium components, and the concentration levels of three components (urea, NaCl, MgSO4·7H2O) were optimized with the steepest ascent path and central composite design (CCD), achieving 1.72 × 109 CFU/g of spore production. Under the optimal conditions (urea 2.718% w/v, NaCl 0.0697% w/v, MgSO4·7H2O 0.06956% w/v), the practical value of spore production was 1.69 × 109 CFU/g. The determination coefficient (R2) was 0.9498, which ensures an adequate credibility of the model.

EFFECTS OF NITROGEN SOURCES AND ORGANIC MATTER ON NITROGEN FIXATION AND YIELD OF SOYBEANS

1972 ◽  
Vol 52 (6) ◽  
pp. 991-996 ◽  
Author(s):  
H. S. JOHNSON ◽  
D. J. HUME
Keyword(s):  
Organic Matter ◽  
Nitrogen Fixation ◽  
Seed Yield ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Cattle Manure ◽  
Control Treatment ◽  
Available N ◽  
Corn Cobs ◽  
Ground Corn

The effects of two sources of nitrogen and ground corn cobs, applied either alone or in combination, on nitrogen fixation and seed yield of Glycine max (L.) Merr. cult Altona were investigated in an area where control plants fixed only 7.5 kg N2/ha. Treatments were: N, 280 kg N/ha as NH4NO3; organic matter (O.M.), 14 T (dry wt)/ha of ground corn cobs as an organic matter source; N + O.M.; M1; 88 T/ha of liquid cattle manure; M1 + O.M.; M2, 176 T/ha of liquid cattle manure; M2 + O.M.; and C, control. Treatment effects on nitrogen fixation, measured as acetylene reduction rates, and seed yield were related to the levels of available N supplied to the plants. Nitrogen fixation was progressively increased by treatments M1, M2 + O.M., M1 + O.M., and O.M., with the latter two fixing seven times as much nitrogen as the control. Final seed yield, however, was increased by treatments supplying the highest levels of inorganic nitrogen to plants, with N and N + O.M. producing higher yields than the control plots.

THE ISOLATION AND CHARACTERIZATION OF METHANOMONAS METHANOOXIDANS BROWN AND STRAWINSKI

1964 ◽  
Vol 10 (5) ◽  
pp. 791-799 ◽  
Author(s):  
L. R. Brown ◽  
R. J. Strawinski ◽  
C. S. McCleskey
Keyword(s):  
Formic Acid ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Energy Sources ◽  
Resting Cells ◽  
Gram Negative ◽  
Oxidation Of Methane ◽  
Isolation And Characterization ◽  
Trapping Agent

Procedures for the isolation and characterization of Metkanomonas methanooxidans Brown and Strawinski are described. Isolates from varied sources are alike in cellular morphology, inasmuch as they form only microcolonies, and in their dependence on methane or methanol as carbon and energy sources for growth. Both organic and inorganic nitrogen sources are used. The organism is a Gram negative non-sporeforming rod, 1.5 to 3.0 μ by 1.0 μ in size, and motile by means of a single polar flagellum. In growing cultures the oxygen/methane ratio was approximately 1.1 and in resting cells 1.7. The R.Q. for methane with resting cells was 0.43. Resting cells were unable to oxidize organic compounds other than methane, methanol, formaldehyde, and formate. Formic acid was detected in test solutions after cell suspensions had metabolized methane, methanol, and formaldehyde. Using sodium sulphite as trapping agent for formaldehyde, it was found that 60 to 70% of the methane or methanol consumed was converted to formaldehyde. In the presence of iodoacetate, 70% of the methane consumed was present terminally as methanol. Thus it was shown that methanol, formaldehyde, and formic acid are sequential intermediates in the oxidation of methane by these organisms.

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