MBUYA ILUNGA Bienvenu*1, TSHIBANDA NTAKAMUTSHI Patrick2, MUHUNGU TSHUYI Symphorien1, KAWAMA NGOIE Francis1, KASONGO KALENGA Gigi2, NKULU WA NGOIE Guy3

The current technological and economic constraints impose the development of efficient and ecofriendly processes for the simultaneous treatment of sulphide and oxidized ores. This work investigated the simultaneous extraction of copper and cobalt from the ternary chalcopyrite-magnetite-heterogenite system (CuFeS2-Fe3O4-Co2O3) without the addition of oxidizing and reducing reagents. The redox pair (Fe3+/Fe2+), called loop Fe3+-Fe2+, created and maintained in the reaction medium served to make this simultaneous leaching possible. The following parameters were considered: acidity (75, 204, 332 and 460 g/L), temperature an (25, 40, 60 and 80°C), and mass of iron oxide (8, 16, 24, 32 g). The copper and cobalt solubilization yields obtained were 89.93% and 95.72% at 32 g and 80 ° C. The results showed that solubilization of cobalt was not influenced by temperature. Télécharger l'article

PWEMA KIAMFU Victor1*, MBOMBA BEKELI Nseu1, KIKALA AMI Erick2, LUSASI SWANA Willy1, MICHA Jean-Claude3

Use of The Fry of Schilbe mystus (Linnaeus, 1758) (Siluriformes: Schilbeidae) In Biological Control of Mosquito Larvae.

To fight malaria, which accounts for about 90% of deaths in the world, World Health Organisation (WHO) has developed a global strategy to eradicate or to reduce this disease based on prevention, diagnosis and control of the vector. This study is initiated to test the consumption of mosquitoes larvae by the fry of Shilbe mystus as a mean in the biological control of this vector. After acclimation to the laboratory, Shilbe mystus fry caught in the Congo River at Kinkole were feed with mosquito larvae, maggots and earthworms. Shilbe mystus acclimatizes well in the laboratory in tanks without ventilation and lends itself well to manipulations. They feed on the larvae of mosquitoes and even in the presence of maggots and earthworms; this fish selects first mosquito larvae and then worms and maggots. They can therefore be used in biological control of this vector after tests in vivo. Télécharger l'article

MALUEKI TOKO Erikson*1, MBUMBA BANDI Michel2, NTENDI MASAMBA Albert2, MAYIMONA NSANSIDavid2, LUNDOLOKA MAFUTA Guyguy2, SOKE MBANGA Maurice2

Interspecific Competition between Strangler Ficus and Host Plants in Kinshasa’s Botanical Garden, D.R. Congo
A study on epiphytes was conducted at the Botanical Garden of Kinshasa from July 22, 2012 to July 22, 2013. The methodological approach consisted in carrying out the floristic surveys by inventorying the species composing vegetation of the Botanical Garden of Kinshasa, followed by determination of characteristics of stranglers ficus in interspecific competition with woody species and host palms within this ex situ protected area. It shows that on 306 feet of woody and palm counted in 28 species, 85 (27.77%) bear feet of epiphytes of the genus Ficus. In addition, on 94 feet serving as hosts, 23 (24.46%) are strangled by three species of the Ficus genus including Ficus polita, Ficus lyrata, and an undetermined species. Télécharger l'article

LASSA KANDA Lemmy1, KIKUFI BATOBA Anthony1, ILUMBE BAYEU Guy1, BILOSO MOYENE Appolinaire2, MASENS DA MUSA1, HABARI MULAWA Jean-Pierre1, LUKOKI LUYEYE Felicien1*

Floristic, Ecological and Phytogeographic Study of Useful Plants Species of Kimvula Territory, R.D. Congo.
This study was conducted in in the Kimvula territory and the main aim was to carry an inventory of useful plants used in that territory. The floristico-ecological and phytogeographic method was used. Examination of this inventory helped to establish a floristic list of 353 useful species belonging to 248 genera and 90 families, of which Fabaceae are the most predominant with 39 species, (11,05%). This florule is composed mainly of woody plants; mainly the phanerophyte species, mesophyllous, sarcochores, generally of savanna and belonging to the Guineo-Congolian and pantropical element. Télécharger l'article

KISANGALA MUKE Modeste1*, KAMOSI ZOLA1, KAFUTI SEDEKE1

Assessment of the State of Deforestation of the Mayombe Forest by Remote Sensing from 1990 To 2015 (Kongo Central, D.R. Congo).
The majority of forests in the Democratic Republic of Congo are undergoing more or less severe deforestation and degradation, with negative impacts not only on the ecosystems and lifestyles of local populations, but also on the humanity as a whole because of global climate change and loss of biodiversity. Located in west of the Democratic Republic of Congo in Kongo Central Province, the Mayombe forest is one of those forests in the Democratic Republic of Congo mainly affected by deforestation. This research aims at remotely estimate deforestation in the Mayombe region for the period of 1990 to 2015 from multi-satellite data.
We used Landsat TM images (Thematic Mapper, Enhanced Thematic Mapper) and OLI (Operational Land Imager) with a spatial resolution of 30 m taken in 1990, 2000, 2010 and 2015. The diachronic comparison method and the matrix of confusion were used to validate the results of the classification, the transition matrix was used to perceive the rate of change. All these aspects of mapping were coupled by those of structural indices space in order to quantify any variations in land use and to determine the type of changes made in each land-use class. The results showed that the forest is under heavy human pressure, it has changed a lot in 25 years noticeable by deforestation and degradation of the vegetation cover. The average rate of deforestation is 15.5% for a decade in the studied area. Télécharger l'article

AZANGIDI MAPWANA1, KIDIKWADI TANGO*1, LUTETE LANDU2, BELESI KATULA1, LUBINI AYINGWEA1

Determination of Organic Pollution Indicators in Lukaya River, Kinshasa, Democratic Republic of Congo.
This paper focused on the regression of vegetation cover in a few natural forest patches in Kinshasa. It is mainly based on the use of satellite imagery taken at different periods associated with field surveys to assess the changes in vegetation cover in different sites under study as well as causes arising from it. It aims to evaluate, characterize and map what was and what still remain of old forest patches; green and rich in plant and even animal species in order to hasten their recovery. The method is based on the detection of change on high-resolution images acquired at different dates over the same territory and to compare the results in order to extract change. The study allowed getting a picture that reflects the trends of the reality on the study sites. The results show that the decline in vegetation of selected natural sites is very real and has been of the order of 22.56 ha between 2000 and 2017, which corresponds to a deforestation of 41% of the area concerned. A few natural sites that carry a covered with trees or shrub are converted or transformed into dwelling land on which various buildings are built. However, the use of geomatics, including remote sensing and GIS tools turns valuable and well suited for space-time analysis of changes in different areas and particularly in environmental resources management. Télécharger l'article

MUSANGA MATONDO Jean*1, THAMBWE MUNGELA Thryphon2, ISULU MBUNGWAL Guelor1, MAYAYA KADISHI Emile3, LANDA Alain1

Determination of Organic Pollution Indicators in Lukaya River, Kinshasa, Democratic Republic of Congo.
This study was conducted under the ecological conditions of Kinshasa. It analyzes the waters of Lukaya river and its tributaries in the section crossing the town of Kinshasa; from the point of water catchment by the Régideso station upstream of the tributary Bumuna. The physico-chemical and chemical analysis were done in order to measure the concentrations of parameters indicators of organic pollution in Lukaya River and its tributaries in order to calculate the organic pollution index and evaluate the contribution of pollutants to the tributaries. The results revealed that the waters of the Lukaya River and its tributaries are weakly mineralized. The electrical conductivity of waters varies with the inflow of tributaries. Minocongo's poultry activities tend to increase the pH and nitrate concentrations of waters. Organic pollution index indicates zero pollution of the River’s waters and its tributaries. Télécharger l'article