15 research outputs found
The Territory Governance and The Public Services Delivery in The Periurban Commune of Maluku in Kinshasa (The Democratic Republic of Congo)
Les territoires périurbains apparaissent comme des espaces spécifiques en Afrique centrale notamment du fait de leur caractère hybride et complexe. La spécificité de ces espaces pousse à s’interroger sur le mode de gouvernance qui s’y installe particulièrement dans la mesure où l’Etat s’y caractérise souvent par une « présence-absence » qui en facilite l’intervention d’autres individus et/ou groupes. La thèse des services publics des territoires périurbains a eu le mérite d’avoir mis en exergue la manière dont l’Etat, en ce compris les acteurs locaux investis ou pas de l’autorité publique, produisent le territoire à travers leurs pratiques, leurs comportements et les actes qu’ils posent tous les jours. Envisagé comme espace de projection de la ville de Kinshasa pendant l’époque coloniale et même post-coloniale, le territoire périurbain de Maluku a vite déçu notamment suite à la rapide faillite des entreprises, dont principalement Sosider, qui y avaient été établis au début des années 1970. La faillite de ces entreprises a immédiatement entraîné celle des services publics qui leur avaient été corollaires, justifiant ainsi le retrait de l’Etat d’un domaine qui lui est pourtant régalien. Les acteurs locaux en reprendront cependant les commandes en inventant des mécanismes de délivrance des services publics, domaine dans lequel ils opèreront de manière assez souveraine. Ces acteurs, à un moment donné de l’histoire sociale de la cité de Maluku, ont ainsi marqué de leur empreinte le territoire qui a pris la forme et la structure que nous lui attribuons aujourd’hui.Plateforme Afrique centrale-Thématique de la périurbanisatio
The problem of bushmeat: Example of a contribution of environmental criminology to questions of health, sustainable management of wildlife resources and governance in the DRC.
peer reviewedL’urbanisation croissante liée à une démographie galopante a fait exploser la demande en viande de brousse en milieu urbain. Ce qui était un moyen de subsistance traditionnel, local enraciné dans la culture des communautés forestières et rurales est devenu un grand marché informel qui alimente les grands centres urbains et a déjà entraîné la perte de deux tiers de la faune des grandes forêt tropicales. Il se développe un ensemble de pratiques illégales de braconnages, de corruption, etc. qui inscrivent cette consommation dans le trafic d’espèces protégées ou de prélèvement dans des zones protégées faisant l'objet notamment d'un trafic transfrontalier ou vers les pays occidentaux. Par ailleurs l’absence de gestion de ce marché et la vacuité du cadre législatif contribuent à faire peser une menace sanitaire et nutritionnelle sur les populations. L’ampleur actuelle de ce marché informel de la viande de brousse justifie incontestablement son étude sous l’angle criminologique, Les questions de gouvernance, les impacts actuels et à venir sur la biodiversité et sur la santé justifient de s’inquiéter des aspects illégaux, de la fragilité du cadre législatif et des moyens possibles de mise en œuvre d’une régulation et d’une gestion durable de ce marché
Structure-Surface Activity Relationships Of Uronic Acid-Derivative Surfactants From Renewable Resources Applications
Introduction and Background: Uronic acid-derivative surfactants are amphiphilic compounds with growing interests owing to their potential applications in various areas [1]. This class of carbohydrate-based surfactants can be easily prepared from renewable raw materials in a wide range of structure by modular synthesis thanks to the presence of one carboxylic and numerous hydroxyl groups. The polar head group configurations according to the stereochemistry of OH
groups, and geometry (cyclic or not), the hydrophobic tail (number and length of alkyl chain), and the type of linker (ester, acetal and amide, etc) are among the main variables in their structural entities. Therefore, the investigation of their structure-surface activity relationships appears valuable for increasing backgrounds, and achieving a rational design for selecting the best structures to be used in different industrial fields [2].
Methodology: A few analogous of glucuronic acid-derivative surfactants have been synthesized by chemical or enzymatic routes. After purification, their structure has been confirmed by various spectroscopic techniques (RMN, MS, IR). Surface tensions of true aqueous solution have been then measured in dynamic and static modes using a series of complementary techniques. Critical micelle concentrations, minimum molecular areas, and maximum surface excesses have also been determined.
Results and Discussion: Glucuronic acid derivative surfactants under investigation vary in the polar head group configuration including cyclic or non-cyclic structure and α or β anomeric form, in the hydrophobic tail regarding to the chain length (C8 to C14), the presence of a double bond, as well as an OH group at the terminal carbon, and in the type of linker, ester in C6 or acetal in C1. Results showed that all of these structural attributes affect both dynamic and equilibrium surface properties of glucuronic acid -based surfactants.
Conclusion: A set of synthetic glucuronic acid-based surfactants varying in the polar head group, hydrophobic tail, and linker allow us to generate various surface-active properties at the air-water interface, and to increase the knowledge on relationships between their structure and surface-active properties.
[1] Laurent, P.; Razafindralambo, H.; Wathelet, B.; Blecker, C.; Wathelet, J.-P.; Paquot, M., Synthesis and Surface-Active
Properties of Uronic Amide Derivatives, Surfactants from Renewable Organic Raw Materials. Journal of Surfactants and
Detergents 2010, in press.
[2] Razafindralambo, H.; Blecker, C.; Mezdour, S.; Deroanne, C.; Crowet, J.; Brasseur, R.; Lins, L.; Paquot, M., Impacts
of the Carbonyl Group Location of Ester Bond on Interfacial Properties of Sugar-Based Surfactants: Experimental and
Computational Evidences. The Journal of Physical Chemistry B 2009, 113 (26), 8872-8877.
Acknowledgment: This work was supported by Belgian Walloon Region within DGTRE research project of excellence
(TECHNOSE).TECHNOS
Citizen sensing of solid waste disposals: crowdsourcing as tool supporting waste management in a developing country
Large sub-Saharan African cities are characterized by serious and persistent environmental problem of Solid Waste Management (SWM). The city of Kinshasa, in Democratic Republic of the Congo has a long lasting and major concern of SWM. More worryingly, with rapid population growth and urbanization, waste generation, both domestic and industrial, is expected to rise with great potential of health and environmental problems. Therefore, with an objective of bringing a possible solution that reduces the increasing problem of SWM, we explore in the present study the use of crowdsourcing as a possible mechanism to identify, localize, characterize solid waste landfills. The proposed approach allows (i) creating a spatial and temporal database through a participatory process to support data collection and information generation, and (ii) visualizing the spatial and temporal distribution of observations through an interactive map. Our database holds 187 observations of solid waste disposals across Kinshasa within two years with estimated volume of solid waste accounts of 587'920 m3. These observations include 61 public disposals (e.g., transit center), and 151 wild dumps, of which, 174 active and 3 inactive disposals. The approach developed in this study is a proof-of- concept and a successful implementation was achieved. Our conception and results provide new tool and mechanism to collect data and generate useful information on solid waste landfills in the city of Kinshasa that was not available before. The results of this study indicate that crowdsourcing can be a valuable mechanism to involve citizens in collecting data on solid waste landfills in the city of Kinshasa, which can be applied in similar urban cities
Evaluation of heavy metal content and potential ecological risks in soil samples from wild solid waste dumpsites in developing country under tropical conditions
Solid waste management constitutes a major concern and unresolved problem in most parts of the world, particularly in developing countries where solid waste is disposed in unregulated dumpsites in the public spaces. This practice can lead to contamination of environmental compartments such as soil, surface and groundwater which could negatively impact human health. In this study, surface soil samples were collected from 15 selected solid waste dumpsites in Kinshasa City (Democratic Republic of the Congo) to examine the heavy metal content and potential environmental risks. The results highlighted a high concentration of metals in soil samples compared to local background values and international threshold. The average concentration of metals in all soil samples followed generally the order: Zn>Pb > Cu >Cr> Co> Cd> As> Hg. The calculated pollution indexes including Geo-accumulation, Enrichment Factor, Contamination degree and Potential Ecological Risk, revealed polymetallic contamination dominated by several of these metals in which Zn, Cu, Pb and Hg were of greatest concern indicating high environmental risks. This work showed that illegal wild landfills represent a real danger for the environment and human health. Due to the toxicity of heavy metals, the measures to establish a monitoring program that address uncontrolled landfills and solid waste management and disposal are recommended to reduce the load of contaminants in soils which can reach surface and groundwater. On the other hand, the use of manures from these dumpsites for agricultural purposes should be discouraged because they may be easily absorbed at alarming levels by vegetables
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Putting conservation efforts in Central Africa on the right track for interventions that last
Interventions in Africa designed to stop biodiversity decline have often failed because they were based on a top-down approach to management and focused on enforcing restrictive rules and imposing bans. They were equally misaligned with the values and needs of local actors. This paper presents an African perspective on the discourse regarding the bushmeat crisis and shows that bushmeat in Africa goes beyond being a source of livelihood, having a multifaceted use that must be considered when designing interventions. We show that current conservation initiatives often do not address the right issues, by neglecting nonmonetary dimensions of bushmeat use, inadequately planning interventions, failing to align wildlife laws with realities on the ground, and carrying out ineffective law enforcement characterized by poor governance and corruption. We recommend a revision of current legal frameworks to enhance local ownership, tenure rights, and the sustainable economic empowerment of local communities to reduce hunting. We also call for development of regionally led innovative programs that invest in nature-based solutions and payments for environmental services. Finally, we identify where more research is needed to understand why wildlife use in Africa is overlooked in national development policies and not considered in national accounting
Leachates draining from controlled municipal solid waste landfill: Detailed geochemical characterization and toxicity tests
Management of municipal solid wastes in many countries consists of waste disposal into landfill without treatment or selective collection of solid waste fractions including plastics, paper, glass, metals, electronic waste, and organic fraction leading to the unsolved problem of contamination of numerous ecosystems such as air, soil, surface, and ground water. Knowledge of leachate composition is critical in risk assessment of long-term impact of landfills on human health and the environment as well as for prevention of negative outcomes. The research presented in this paper investigates the seasonal variation of draining leachate composition and resulting toxicity as well as the contamination status of soil/sediment from lagoon basins receiving leachates from landfill in Mpasa, a suburb of Kinshasa in the Democratic Republic of the Congo. Samples were collected during the dry and rainy seasons and analyzed for pH, electrical conductivity, dissolved oxygen, soluble ions, toxic metals, and were then subjected to toxicity tests. Results highlight the significant seasonal difference in leachate physicochemical composition. Affected soil/sediment showed higher values for toxic metals than leachates, indicating the possibility of using lagoon system for the purification of landfill leachates, especially for organic matter and heavy metal sedimentation. However, the ecotoxicity tests demonstrated that leachates are still a significant source of toxicity for terrestrial and benthic organisms. Therefore, landfill leachates should not be discarded into the environment (soil or surface water) without prior treatment. Interest in the use of macrophytes in lagoon system is growing and toxic metal retention in lagoon basin receiving systems needs to be fully investigated in the future. This study presents useful tools for evaluating landfill leachate quality and risk in lagoon systems which can be applied to similar environmental compartments
Seasonal variability of water quality by physicochemical indexes and traceable metals in suburban area in Kikwit, Democratic Republic of the Congo
Water resource contamination is still a major concern in several regions of developing countries especially in sub-Saharan countries in which polluted waters pose serious risks to human health and the environment. The seasonal variation of the physicochemical parameters including pH, temperature (T), electrical conductivity (EC), dissolved oxygen (O2), dissolved organic carbon (DOC), total organic carbon (TOC), and trace metals were assessed in water samples collected from wells (n=3) and two rivers which were the River Lukemi (RLK, n=3) and River Luini (RLN, n=2) located in the City of Kikwit (Province of Kwilu, Democratic Republic of the Congo). Samples were collected during the dry and wet seasons. The concentration of trace metals (Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Ag, Cd, Sn, Sb, and Pb) in water was measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and soluble ions (Na+, K+, NH4+, SO42-, NO3-, and Cl-) analysis was performed using Ion Chromatography.
The results indicate the seasonal difference in the physicochemical composition of water e.g., the pH was lower in the wet compared to the dry season. pH values during the wet season ranged from 4.12 to 5.60 in wells and from 5.55 to 6.31 in rivers while the dry season values ranged from 6.27 to 6.98 in wells and from 7.09 to 7.44 in rivers. The concentrations of soluble ions and other physicochemical parameters (O2, DOC and TOC) also varied with the seasons, being higher in the wet and lower in the dry season. With the exception of Mn, the average concentrations of other trace metals measured in water samples from wells and rivers met the World Health Organization (WHO) guidelines for drinking/domestic water quality. Mn concentration in water samples analysed ranged between 634 to 812 and 1352–1741 µg L−1 during the dry and wet seasons, respectively. These results imply that the high concentration of Mn in the water samples may be explained by the geological origin and result of natural weathering processes. In general, according to the parameters analysed, the water samples taken from the sites studied in both seasons appear to meet drinking water standards according to the WHO guidelines but with the two exceptions of the pH and Mn.
This study is important for the present situation and can be applied in similar environmental compartments in the future to assess the availability of safe drinking water in developing countries