VUNI SIMBU Alexis *, LIKINDA BONONGA Hubert, KISANGALA MUKE Modeste, ALONI KOMANDAJules, N’ZAU UMBA-di- MBUDI Clément

Analysis of the Domestic Wastewater and Rainwater Drainage System in the Industrial/ Municipal District of Limete, Kinshasa

In the city of Kinshasa, a large part of the population does not have access to basic sanitation services. This lack of sanitation is reflected in particular by overexposure of the population to various waterborne diseases such as cholera, diarrhea, typhoid fever, malaria and many other opportunistic infections, yet preventable. In short, the urban space of Kinshasa is increasingly exposed to insalubrity, a poor quality of life, which makes it difficult to find sustainable solutions for the population. The problem concern evacuation of rainwater and wastewater which is mainly linked to the deterioration and/ or the non-maintenance of the existing sanitation installations to the insufficiency of these following an uncontrolled urbanization, all aggravated by unorthodox or even non-existent management of solid, liquid and gaseous waste The main cause is a fast expansion of the city without a strict sanitation plan, especially without a sewage system. Télécharger l'article

LUNDOLOKA MAFUTA Guyguy1, MBUMBA BANDI Michel1,2*, FATIMA BINTI RAMAZANI Julie1, MBIKAYI BIAYI Gabin2, BRIKI MAYO Moïse3

Socioeconomic and environmental aspects of the manufacture of charcoal at Kinsaku Muanda, Madimba, Kongo Central, D. R. Congo.

A study was carried out in the province of Kongo Central at Kinsaku Muanda to analyze the socioeconomic and environmental aspects of charcoal making. The survey was carried out from March 2 to May 2, 2018 among 75 charcoal manufacturers. The data were processed on the basis of averages using Excel 2010 software. The result of this study showed that charcoal making is exclusively men activity, the majority of them exploit wood in family concessions during fallows or forest galleries and wooded savannas so that they produce more than 5 bags of charcoal of about 25 to 50 kg per oven and for which the price of a bag varies between 5,000 and 20,000 Fc. The products are sold locally in the village and in markets in Kinshasa. But, the activity of making charcoal is not very profitable economically. Several tree species are used for the manufacture of charcoal among which: mango (Mangifera indica L.), safou (Dacryodes edulis), avocado (Persea americana), black wood (Milletia laurentii), etc. Moreover, it emerges from this study that environmental consequences linked to the production of charcoal are not well perceived by the respondents. They are more concerned with money than with the ecosystem’s conservation. According to the respondents, the two major problems they face are the scarcity of forest species and the low demand for charcoal. The majority of respondents mentioned reforestation as a local strategy for the sustainable management of ecosystems. Télécharger l'article

MUSEME NYOLENGE Noël-Anselme1, MVAKA MVANDA Jean Robert3, MATITI Guelord1, ISA MANIKISA4, KALALA BOLOKANGO Gaétan1, 2*

Exploitation of Natural Resources in the Forest Ecosystems of the Hinterland of the City of Bandundu: Status and Prospects.

Central Africa, and in particular the Democratic Republic of Congo (DRC), in all its ecological and socio-economic diversity, is one of the countries where forest ecosystems (as a reservoir of biodiversity and supplier of forest products) are expected to take a predominant part in the process of its sustainable development.

In Bandundu and its hinterland, forests are under increasing pressure and continue to deteriorate as a result of their overexploitation in order to meet the basic needs of a mostly poor and especially unemployed population.

To mitigate this threat, which could jeopardize the future of these fragile ecosystems, this study is based on the exploitation of the related forests, to establish the current situation, to identify future prospects and to suggest some corresponding sustainable management orientations.

To achieve this, in addition to documentation, direct field observations and interviews with stakeholders, the interview technique was used to collect data subject to relative frequency analyzes. The resulting results show a progressive degradation of forests due to increasing human pressure linked to population growth. Télécharger l'article

MUKANU KASIALA Arsène* et MITI TSETA Felicien

Estimation of the Potential Erosion in the N’djili River (Kinshasa) Watershed by Integration of the Wischmeier Equation in the Geographic Information System and Remote Sensing.

This study was conducted in the watershed of N’djili river, in order to identify and quantify the risks of water erosion for a sustainable land management. Specifically, it’s important to rate the major factors and potential erosion using the Universal Soil Loss Equation (USLE), coupled with GIS and remote sensing on this watershed.

The calculated results indicate the order of magnitude of parameters which generate the rain erosivity varying from 124 to 151 MJ.mm/ha/h/year while soil erodibility rises to 0.2. In some parts of the land, topographic factor reach the value of 30.89. Following cultural practices in bands, the cropping factor can reach the maximum value of 1 unit while conservative factor ranges from 0.25 to 0.45.

As far as the potential erosion is concerned, calculated soil loss spread from 2 to about 180t/ ha/year. Data analysis show that over 99 % of the watershed surface is near the threshold of soil loss in the intertropical region estimated as 20 t/ha/ year. However, it appears that 1 % of the watershed area is gullied on uncovered surface or on urbanization area. It is certain that through this study, some control methods could be considered in order to assume soil conservation. Télécharger l'article

NYOLO LONEMA Jean-Marie1, KOY KASONGO Ruben 2*, MAWA TUZINGILA Romulus3, BIEY MAKALY Emmanuel1

Bioremediation of Tank Bottom Sludge from Petroleum Refinery.

Arenosols cover extensive areas of oil exploitation in the coastal basin of the Democratic Republic of Congo (DRC). These soils are thus subject to continous pollution by oil waste products. An experiment in station and in vitro was carried out to study the possibility of depollution of polluted sites in the Moanda region (PERENCO-SOCIR) by bio-and phytoeremediation. Hence, a combination of micro-organisms from polluted sites was used to degrade ex-situ, the ex-reservoir sludges taking into account the optimal conditions of their life in the soil which serves as diluent. The first order kinetic constant was calculated and an interesting value of 0.034/day for a substrate/microorganism ratio of 5.0 in bioreactors was found. Bacteria Bacillus cereus, Enterobacter cloacae, Escherichia coli, Pseudomonas putida as well as fungi Trichophyton sp. and Fusarium solani were effective in large concentrations of hydrocarbons in the soil. Leguminous plants (Acacia auriculiformis) have been shown to be of confirmed interest in both bioaugmentation and phytodegradation of pollutants. Télécharger l'article

KOY KASONGO Ruben 1*, KANYANKOGOTE MPAGAZEHE Prosper1, DISA DISA Pascal2, BAERT Geert3, VAN RANST Eric4

Improving the Charge Properties of Highly Weathered Soils of the Kinshasa’s Hinterland by Using Pink Dolostone from Kimpese and Local Coffee Waste.

The Arenosols of Kinshasa’s hinterland are characterized by a low chemical fertility, an acid reaction and a mineralogical composition limited to quartz, kaolinite and some residual oxides of Al and Ti. The effects of pink dolostone from Kimpese (PDK) and coffee waste (CW) application on the charge properties of the Batéké soils were studied in vitro using a completely randomized experimental design. Different amounts of 6.4 g CW. (kg sol)-1 and 1748 mg PDK. (kg sol)-1, corresponding to 20.0 t.ha-1 of CW and 5.46 t.ha-1of finely grounded PDK were mixed with topsoil (0-25 cm), and incubated and leached for 3, 6, 9, and 12 months. The use of CW and PDK as amendments resulted in a significant (p<0.05) increase in chemical soil fertility indicators (pH, available phosphorus, sum of basic cations, organic carbon and total nitrogen content and base saturation. The study revealed that CW is an excellent organic manure and NPK nutriment provider for crops. Studying the charge properties of the Batéké soils, it was found that the application of CW and PDK to soil, (i) significantly increased the soil pH (pH0.002), (ii) decreased the point of zero charge (pH0), (iii) substantially increased the negative charge components, CECT and CECB, with concomitant decrease of the positive charge component (AEC). Furthermore, a strong exponential correlation was found (R2 = 0.94; y = 0.97 e-0.63x) between the negative charge CECT and the difference (pH0 – pHsol), indicating that the Gouy-Chapman model is likely an alternative option for sustainable management of the Kinshasa’s hinterland soils. The PDK and the CW materials have thus, all requirements to improve significantly the charge properties of the highly weathered Batéké soils. Télécharger l'article

MFELE NTSA Jeanine, KAZADI KASHISHI Théodore, NTUMBA KANKOLONGO Josephine, TABA KALULU Muzele, TSHIONGO MUAMBA Christian*

Malaria is one of the most frequent infectious diseases in the world with an annual mortality rate of more than one million people per year. The parasite responsible, Plasmodium, is becoming increasingly resistant to the drugs currently in use. Thus, Strophanthus hispidus DC, a medicinal plant widely used in traditional medicine in West Africa and in the Democratic Republic of Congo, was chosen to evaluate the anti-malarial activity of different extracts from the bark of its roots on malaria-infected blood using the microplate method. In vitro evaluation of the antiplasmodial activity of crude extracts (petroleum ether, dichloromethane, ethyl acetate, ethanolic, aqueous and methanolic) showed good antiplasmodial activity, with IC50 of 6.25 μg/mL, 6.01 μg/mL, 3.10 μg/mL, 3.12 μg/mL, 3.02 μg/mL and 0.39 μg/mL, respectively. This activity could be due to the presence of secondary metabolites found in various extracts including polyphenols and flavonoids. The dichloromethane and ethyl acetate extracts were separated by thin layer chromatography, each of which yielded two fractions that also showed very good antimalarial activities with IC50 values of 0.78 μg/mL, 1.02 μg/mL, 1.56 μg/mL, 12.20 μg/mL for the dichloromethane 1, dichloromethane 2, ethyl acetate 1 and ethyl acetate 2 fractions respectively. These results justify the traditional use of S. hispidus DC. against malaria. Télécharger l'article

BEYA KAMBA Jean-Marie *, LUSINDE WA LUSANGI KABEMBA Fabrice

Challenges and Issues Facing Electricity Industry in the Democratic Republic of Congo in the Covid-19 Era.

The COVID-19 and the resulting global economic recession deeply affect the Congolese economy and negatively impact all productive sectors including the electricity sector. The recovery economic policy requires implementing innovative financing mechanisms and strategies to recapitalize as quickly as possible the electricity power industry, as it plays a key role in the DRC’s economic growth and industrial expansion, including a special effort in funding training of thousands of highly skilled engineers and technicians which the country needs for its effective development. Télécharger l'article