Evaluation of Dispersion of Lead-Bearing Mine Wastes in Kabwe District, Zambia

Dispersion of lead (Pb) in mine wastes was simulated for reproducing Pb contamination of soil in Kabwe District, Zambia. Local weather data of year 2019 were monitored in situ and used for the simulations. The plume model, weak puff model, and no puff model were adopted for calculation of Pb dispersion under different wind conditions. The results showed that Pb dispersion from the Kabwe mine was directly affected by wind directions and speeds in the dry season, although it was not appreciably affected in the rainy season. This may be because the source strength is lower in the rainy season due to higher water content of the surface. This indicates that Pb dispersion patterns depend on the season. In addition, the distribution of the amount of deposited Pb-bearing soils around the mine corresponded to the distribution of Pb contents in soils. These results suggest that Pb contamination in soils primarily results from dispersion of fine mine wastes.

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Diurnal, Seasonal and Annual Variation of Microwave Radio Refractivity Gradient over Akure, South West Nigeria

Physical Science International Journal ◽

10.9734/psij/2019/v23i430161 ◽

2019 ◽

pp. 1-11

Author(s):

Adekunle Titus Adediji ◽

Joseph Babatunde Dada ◽

Moses Oludare Ajewole

Keyword(s):

Rainy Season ◽

Annual Variation ◽

Ground Surface ◽

Local Effect ◽

Dry Season ◽

Radio Link ◽

Wet Season ◽

Annual Variations ◽

Microwave Radio

In this study, four years in-situ measurements of atmospheric parameters (pressure, temperature and relative humidity) were carried out. The measurement was by placing an automatic weather station at five different heights: ground surface, 50, 100, 150 and 200 m respectively on a 220 m Nigeria Television Authority TV tower in Akure, South Western Nigeria. The four years Data collected (January 2007 to December 2009 and January to December 2011) were used to compute radio refractivity and its gradient. The local effect of a location/ region cannot but looked into when designing effective radio link, hence the diurnal, seasonal and annual variations of the radio refractivity gradient were studied. Results showed that refractivity gradient steadily increases inthe hour of 8:30 and 9:30 to 18:00 during dry season throughout the years investigated, and decreases two hours in the rainy season than the dry season. The record shows that at 50 m altitude, the maximum and minimum values are 158 N-unit/km around 14:30 and - 286 N-unit/km around 13:30 to 14:00 hrs, LT during the dry and rainy season respectively. Seasonally, refractivity gradient is steeper with greater variability in the dry season months than in the wet season months.

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The invertebrate colonization during decomposition of Eichhornia azurea kunth in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir (São Paulo, Brazil)

Brazilian Journal of Biology ◽

10.1590/s1519-69842002000200014 ◽

2002 ◽

Vol 62 (2) ◽

pp. 293-310 ◽

Cited By ~ 21

Author(s):

N. de L. STRIPARI ◽

R. HENRY

Keyword(s):

Decomposition Rate ◽

Rainy Season ◽

Dry Season ◽

Material Loss ◽

Litter Bags ◽

Eichhornia Azurea ◽

Mouth Zone ◽

Dry Seasons ◽

Invertebrate Colonization

The invertebrate colonization during decomposition of Eichhornia azurea was observed in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir in two periods of the year. The litter bags method was used for measuring the decomposition rate as well as to evaluate the invertebrates colonization. Forty-two litter bags, measuring 15 × 20 cm in size and 2 mm mesh net, were incubated "in situ". Six litter bags (three for colonization and three for decomposition measurements) were removed after the 1st, 3rd, 7th, 14th, 28th, 56th and 72nd days of incubation. After each day, the material was carefully cleaned for detritus removal and invertebrate sampling. The biological material was fixed with 4% formaline and then sorted and identified. The remaining plant material was dried in an oven (at 60ºC) and weighed. A fast material loss occurred during the first 24 hours and the decomposition rate was higher during the rainy season than in the dry season. A peak on invertebrate density (110 ind.g.DW--1) on the remaining detritus of Eichhornia azurea was recorded in the 56th day of dry season, when the polyphenol concentration of plant detritus was 0.57 UDO.g.DW--1. In the rainy season, higher density was found in the 28th day of incubation, when the polyphenol concentration was 4.36 UDO.g.DW--1. Apparently, the reduction in the polyphenol concentration was followed by an increase in invertebrate densities. The majority of the species observed in the detritus belongs to the collector group that was dominant after the 7th and 14th days in the rainy and dry seasons, respectively.

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Seasonal morphological variability in an in situ Cyanobacteria monoculture: example from a persistent Cylindrospermopsis bloom in Lake Catemaco, Veracruz, Mexico

Journal of Limnology ◽

10.4081/jlimnol.2016.1190 ◽

2016 ◽

Vol 75 (s1) ◽

Cited By ~ 4

Author(s):

Owen Lind ◽

Laura Dávalos-Lind ◽

Carlos López ◽

Martin López ◽

Juli Dyble Bressie

Keyword(s):

Rainy Season ◽

Morphological Variability ◽

Morphological Diversity ◽

Dry Season ◽

Transient Condition ◽

Dry Seasons ◽

Trichome Morphology ◽

Determining Factor

The phrase cyanobacteria bloom implies a transient condition in which one to few species dominates communities. In this paper we describe a condition in which the bloom is of multi-year duration consisting of different morphologies of a single cyanobacteria species. Lake Catemaco, Veracruz, México maintained a year-round massive (108 trichomes L-1) population of potentially toxin-producing cyanobacteria, Cylindrospermopsis spp. The trichomes are present as straight and coiled morphotypes. The relative trichome morphology abundance varied with rainy (June – October) and dry seasons (November – May), but total trichome abundance did not vary. Coiled trichomes and heterocytes (occurring only on coiled trichomes) were significantly more abundant, both absolutely and relatively, during the dry season. Both coiled trichome and heterocyte mean volumes were significantly smaller during the rainy season than during the dry season. Biovolumes were largest in January when water temperature was 5º C cooler suggesting buoyancy as a morphology-determining factor. However, with a more than three-fold lower TIN concentration during the dry season, we hypothesized that the coiled morphotype became abundant primarily because it formed heterocytes, which the straight morphotype did not. Spatial trichome and heterocyte abundance differences were small among the 15 lake sites (average CV for all dates = 20%). However, there was a pattern of increased heterocyte and coiled trichome abundance from lake inflow, as a nitrogen source, to outflow during the rainy season. The total volume of heterocytes per litre of lake water increased progressively four-fold from a minimum early in the rainy season to a maximum at the end of the dry season. Morphological diversity, as seen in Lake Catemaco, can partially compensate for the lack of species diversity in determination of community structure.

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Kondisi Gradien Temperatur terhadap Proses Pengenceran Smog Fotokimia di Cekungan Bandung

Jurnal Teknologi Lingkungan ◽

10.29122/jtl.v21i2.3977 ◽

2020 ◽

Vol 21 (2) ◽

pp. 219-226

Author(s):

Sumaryati Sumaryati ◽

Asri Indrawati ◽

Dyah Aries Tanti

Keyword(s):

Air Pollution ◽

Rainy Season ◽

Inversion Layer ◽

Dry Season ◽

Photochemical Smog ◽

Temperature Changes ◽

Basin Topography ◽

Using Data ◽

Dry And Rainy Seasons

ABSTRACTBig cities with valley or basin topography such as Bandung, generally have problems with air pollution due to the inversion layer and photochemical smog formations. The inversion conditions cause photochemical smog settling so that the air looks dark on the surface. This study was conducted to analyze the character of inversion events in Bandung due to vertical temperature changes. The inversion layer is obtained from the TAPM (The Air Pollution Model) model and in situ measurement of vertical temperatures by flying a temperature sensor to get the temperature profile. The TAPM running model is carried out in July and December following the dry and rainy seasons. In situ temperature observations are carried out in September 2018 using a drone according to the dry season and data corresponding to the rainy season using data from previous research with a radiosonde balloon. The running model results show that the inversion layer in the rainy season is stronger and more persistent than in the dry season. The inversion layer at night until morning occurs at the surface level, then the inversion layer rises, and finally, the inversion layer breaks up around 10:00 in July and around 12:00 in December. Validation with in situ measurements shows similarity in the pattern. The inversion event correlates with the subsidence and dilution of smog and photochemical smog pollutants from the edge of the Bandung Basin area.Keywords: basin, urban, photochemical smog, inversionABSTRAKKota besar dengan topografi berbentuk lembah atau cekungan seperti Bandung, umumnya memiliki masalah dengan polusi udara karena adanya pembentukkan lapisan inversi dan smog fotokimia. Kondisi inversi menyebabkan terjadinya pengendapan smog fotokimia, sehingga udara terlihat gelap pada permukaan. Penelitian ini dilakukan untuk menganalisis karakter kejadian inversi di Cekungan Bandung akibat dari perubahan temperatur vertikal. Lapisan inversi diperoleh dari model TAPM (Model Polusi Udara) dan pengukuran in situ temperatur vertikal dengan menerbangkan sensor suhu untuk mendapatkan profil suhu. Running model TAPM dilakukan pada bulan Juli dan bulan Desember berkesesuaian dengan musim kemarau dan hujan, sedangkan pengamatan temperatur in situ dilakukan pada bulan September 2018 dengan menggunakan wahana drone yang berkesesuaian dengan musim kemarau, serta untuk data yang berkesesuaian dengan musim hujan menggunakan data hasil penelitian sebelumnya dengan wahana balon radiosonde. Hasil running model menunjukkan, lapisan inversi pada musim hujan lebih kuat dan lebih persisten dari pada musim kemarau. Lapisan inversi pada malam sampai pagi hari terjadi pada level permukaan, kemudian lapisan inversi ini naik dan akhirnya lapisan inversi pecah sekitar pukul 10:00 pada bulan Juli dan sekitar pukul 12:00 pada bulan Desember. Validasi dengan pengukuran in situ menunjukkan kemiripan pola. Kejadian inversi berkorelasi dengan pengendapan dan pengenceran polutan smog dan smog fotokimia dari pinggir Cekungan Bandung. Kata kunci: cekungan, urban, smog fotokimia, inversi

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THE DETERMINATION OF ETHYL P-METHOXY CINNAMATE IN KAEMPFERIA GALANGA L. RHIZOME EXTRACT HARVESTED IN RAINY AND DRY SEASONS

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2021.v13s4.43841 ◽

2021 ◽

pp. 132-135

Author(s):

INDAH SUASANI WAHYUNI ◽

IRNA SUFIAWATI ◽

WIPAWEE NITTAYANANTA ◽

JUTTI LEVITA

Keyword(s):

Water Content ◽

Rainy Season ◽

Ethanol Extract ◽

Standard Addition ◽

Dry Season ◽

Internal Diameter ◽

Kaempferia Galanga ◽

Percentage Yield ◽

Dry Seasons

Objective: Kaempferia galanga L. rhizome (KGR), has been empirically used in Indonesia, particularly by Javanese, to cure inflammation. KGR contains various secondary metabolites which explain its pharmacology activities, among them is ethyl p-methoxycinnamate (EPMC). However, due to the different seasons of our country, the yield of extraction is often unalike. In this work, we determined the percentage of yield (w/w), the water content (thermogravimetric method), and the concentration of EPMC in the Ethanol extract of Kaempferia galanga L. Rhizome (EEKG) harvested from the rainy (EEKG-R) and dry seasons (EEKG-D). Methods: The sun-dried rhizomes were cold macerated for 3x24 h with 70% ethanol, filtered, and the solvent was evaporated at 40-45 °C until a viscous extract was obtained. The determination of EPMC in the extract was carried out using the RP-HPLC standard addition method. Detection was set at 308 nm; injection volume 20 µl; flow rate 1.0 ml/min. The column used is C18 (length 250 mm, internal diameter 4.6 mm, particle size 5 µm). Results: The yield of EEKG-R (harvested in the rainy season) = 14.56% w/w, water content = 4.37%, and the EPMC = 0.01%. Meanwhile the yield of EEKG-D (harvested in the dry season) = 5.79% w/w, water content = 18.76%, and the EPMC = 0.001%. Conclusion: Different climates affect the percentage yield and the quality of the extract. In our work, the EEKG-R (harvested in the rainy season) revealed a better quality compared to that of EEKG-D (harvested in the dry season) This study gives important information to standardize and optimize the harvest time of KG rhizomes for drugs development, which are strongly influenced by seasonal differences.

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Assessing and modeling particulate pollution in the city of Ouagadougou (Burkina Faso)

Journal de Physique de la SOAPHYS ◽

10.46411/jpsoaphys.2020.01.14 ◽

2021 ◽

Vol 2 (1b) ◽

pp. C20A14-1-C20A14-6

Author(s):

Issoufou Ouarma ◽

◽

Bernard Nana ◽

Kayaba Haro ◽

Jean Koulidiati ◽

...

Keyword(s):

Rainy Season ◽

Road Traffic ◽

Threshold Value ◽

Emission Factors ◽

Dry Season ◽

In Situ Measurements ◽

Industrial Plant ◽

Pm2.5 And Pm10 ◽

The City

In the present work, the pollution levels of airborne particles in the city of Ouagadougou have been assessed through two campaigns of in situ measurements of PM2.5 and PM10 concentrations. These measures were performed using a portable device (AEROCET 531S) on roadside sites and on sites located in administrative services, secondary schools and outlying districts. Since in situ measurements don’t give any indication of the pollution that could be due to a new source (industrial plant, road, etc.) and how it is dispersed spatially and temporally, thus pollutant emissions from road traffic and the dispersion of these pollutants are obtained by a modelling chain that couples COPERT IV emission model under Pollemission code with MUNICH dispersion model. As results, the average 24-hour concentrations are 87±16 and 951±266 μg/m3 for the PM2.5 and PM10, respectively, in 2018 dry season. They are 29±5 and 158±43 μg/m3, respectively, in 2018 rainy season and, 22±9 and 187±67 μg/m3 in 2019 rainy season, respectively. These results show that independently of the season (dry or rainy), the PM10 concentrations are high and exceed the World Health Organization Air Quality Guidelines (WHO AQG) and European 24-hour threshold value of 50 μg/m3. Concerning the PM2.5 concentrations in dry season, they are high and exceed the WHO AQG and European 24-hour threshold value of 25 μg/m3. The results obtained concerning the modeling of the dispersion of PM air pollution due to road traffic in the city of Ouagadougou are partially satisfactory. The modeled maximum values of the exhaust emission factors are very high while the modeled concentrations are underestimated compared to the measured concentrations The estimated emission factors range between 0 and 400 g/km/h and between 0 and 303 g/km/h for exhaust PM2.5 and resuspension PM2.5, respectively. They vary between 0 and 2 997 g/km/h for resuspension PM10. Concerning the modelled concentrations, they are between 0 and 238 μg/m3 for PM2.5 and between 0 and 2 072 μg/m3 for PM10. These results can be improved with updated traffic and road characterization data.

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Analyse De L’évolution Saisonnière Des Matières Oxydables Dans Le Secteur Oriental De La Lagune Ebrié (Côte d’Ivoire)

European Scientific Journal ESJ ◽

10.19044/esj.2018.v14n3p221 ◽

2018 ◽

Vol 14 (3) ◽

pp. 221

Author(s):

Irié B.T. Jean-Gaël ◽

Wognin A. Valérie ◽

Kando A. Marie-Laure ◽

Aka Natcha ◽

Aka A. Maurice ◽

...

Keyword(s):

Dissolved Oxygen ◽

Negative Correlation ◽

Rainy Season ◽

Statistical Treatment ◽

Dry Season ◽

Eastern Sector ◽

Hydrological Parameters ◽

Urbanized Areas ◽

Positive Correlations

Faced with the extension of the cities of Grand-Bassam and Abidjan along the Ebrié lagoon and the lack of data on the oxidizable content in the eastern sector of the Ebrié lagoon, this study was initiated. It aims to determine the levels of oxidizable materials in the eastern sector of the Ebrié lagoon. PH, temperature, salinity and dissolved oxygen were determined in situ at thirtyone (31) stations during the dry season and the rainy season. On these same stations, water samples were also taken per season to determine the content of oxidizable matter according to the methods in force. The statistical treatment consisted in knowing the links between the hydrological parameters. The average values of the parameters in the rainy season and in the dry season are 5,98 and 7,28 respectively for the pH, 27,59 °C and 29,6 °C for the temperature, 5,01 and 19,48 for salinity, 6.14 mg/L and 3.78 mg/L for dissolved oxygen, 0.24 mg/L and 0.38 mg/L for ammonium, 0.089 mg/L and 0.036 mg/L for nitrite, 8.18 mg/L and 0.23 mg/L for nitrate, 1.57 mg/L and 1.78 mg/L for orthophosphate, 76.06 mg/L and 56.81 mg/L for COD and 40.23 mg/L and 34.16 mg/L for BOD5. The evolution of oxidizable matter depends on the entry of continental, oceanic and precipitation waters into the lagoon. The high levels of oxidizable materials are observed in large part in the berries. Good positive correlations are observed between COD and DBO5 and between salinity and nitrite. Temperature and salinity have a good negative correlation. Lagoon waters receive more oxidizable materials in highly urbanized areas than in areas with little or no urbanization.

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