Determination of Organic Matter and Trace Metals Elements (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) in the Soils of the Banks of Watercourses in Brazzaville City (Republic of Congo)
This work focused on determining the physico-chemical characteristics (pH, carbon and nitrogen) and trace metal elements (TMEs) content (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) of soils in the Brazzaville city. Soil samples were taken from a depth of 0 to 20 cm using a hand auger on both banks of five tributaries of the Congo River (Djoué, Mfilou, Mfoa, Tsiémé, Djiri) that flow through the city of Brazzaville. 90 sampling points were defined, with 3 points 250 m apart on the banks and located, for each river, at three sites: upstream, midstream and downstream. Finally, 15 composite samples representative of the study area were taken. The average pH values of the water varied between 6.5 and 7.5. These pH values show that the soils studied are neutral. Total carbon content varied between 0.7% (Djiri) and 1.6% (Djoué). Total nitrogen content ranged from 0.08% (Djiri) to 0.12% (Djoué). TMEs contents varied from 0.5 to 1.8 mg/kg for Sb, from 0.5 to 2.5 mg/kg for As, from 0.1 to 0.18 mg/kg for Cd, from 4.2 to 11.3 mg/kg for Cr, from 0.07 to 0.27 mg/kg for Hg, from 0.7 to 2.4 mg/kg for Ni, from 0 to 158 mg/kg for Pb and from 16 to 105 mg/kg for Zn. The lowest TMEs levels were observed in the soils of the Djiri river, while the highest levels were observed in the soils of the Djoué and Tsiémé rivers. The ANOVA and Bonferroni test did not show significant differences in the means of the parameters measured (p > 0.05). The TMEs levels were below the accepted standards (NF U44-041), with the exception of Pb, which had high levels downstream of the Djoué. According to the pollution index values calculated using soil TME content, the soils on the banks of the Djoué river are considered polluted, while those on the banks of the Tsiémé river are moderately polluted, those on the banks of the Mfoa and Mfilou rivers are slightly polluted, and the soils on the banks of Djiri river are unpolluted.
References
[1]
Hellou, M., Nguyen, T.D. and Dupont, P. (2012) Phénomènes de transport de polluants dans les sols urbains. European Journal of Environmental and Civil Engineering, 16, 650-668. https://doi.org/10.1080/19648189.2012.667673
[2]
Kheddaoui, G. and Adilia, F. (2023) Analyse et caractérisation physico-chimique de quelques sols d’Ouled Addi. Wilaya de M’Sila. Mémoire de l’Université de Mohamed Boudiaf-M’Sila (Algérie), 89 p.
[3]
Gobat, M., Aragnom, M. and Matthey, W. (2010) Le Sol Vivant. Bases des pédologie, biologie des sols. 3éme édition, Presse Polytechnique et Universitaire Romandes, 817 p.
[4]
Jolivet, C., Arrouays, D., Boulonne, L., Ratié, C. and Saby, N. (2006) Le Réseau de Mesures de la Qualité des Sols de France (RMQS). Etude et Gestion des Sols, 13, 149-164.
[5]
Ndiaye, O., Tamsir Diop, A., Elie Akpo, L. and Diène, M. (2014) Dynamique de la teneur en carbone et en azote des sols dans les systèmes d’exploitation du Ferlo: Cas du CRZ de Dahra. Journal of Applied Biosciences, 83, 7554-7569. https://doi.org/10.4314/jab.v83i1.5
[6]
Nzila, J.D., Watha-Ndoudy, N., Kaya-Mabiala, D., Mboungou-Nsompi, P., Louembe, D., Kimpouni, V. and Samba Kimbata, M.J. (2020) Current Dynamics of Hydric Erosion in the Kingouari, Mfilou and Djoué Watersheds in the Southwestern Part of Brazzaville City (Congo). Earth Sciences, 9, 201-209. https://doi.org/10.11648/j.earth.20200905.16
[7]
Nazarpour, A., Watts, M.J., Madhani, A. and Elahi, S. (2019) Source, Spatial Distribution and Pollution Assessment of Pb, Zn, Cu, and Pb, Isotopes in Urban Soils of Ahvaz City, a Semi-Arid Metropolis in Southwest Iran. Scientific Reports, 9, Article No. 5349. https://doi.org/10.1038/s41598-019-41787-w
[8]
Osujieke Nweze, D., Imadojemu Ezemon, P., Okon Akpan, M. and Obinna Marcellinus Okeke, O.M. (2018) Profile Distribution of Physical and Chemical Soil Properties in Izombe, Rainforest Zone of Nigeria. Bulgarian Journal of Soil Science, 3, 90-103.
[9]
Pourtier, R. (2021) Congo, un fleuve à la puissance contrariée. CNRS Éditions, 300 p.
[10]
Mambou, J. and Elenga, H. (2023) Erosions, Inondations et Mauvais Drainage des Eaux Pluviales à Brazzaville: Quelles Solutions dans le Cadre d’un Réaménagement Durable de la Ville à l’Horizon 2030? EuropeanScientificJournal, ESJ, 19, 205. https://doi.org/10.19044/esj.2023.v19n20p205
[11]
Toli, G. (2020) Aperçu sur le climat urbain de Brazzaville entre la fin du XXe siècle et le début du XXIe siècle. Hal Open Sciences, ffhal-03000336, 16 p.
[12]
RGPH. (2023) Résultats préliminaires du 5e recensement général de la population et de l’habitation. Institut National de Statistiques (INS), 51 p.
[13]
Schwartz, D. (1987) Les podzols tropicaux sur sables batéké en R.P. du Congo: Description, caractérisation, genèse. 25-36.
[14]
WRB (2022) World Reference Base for Soil Resources. International Soil Classification System for Naming Soils and Creating Legends for Soil Maps. 4th Edition, International Union of Soil Sciences (IUSS), 234 p.
[15]
Callec, Y., Bauer, H., Paquet, F., Prognon, F., Issautier, B., Schroetter, J.-M., Thiéblemont, D., Boudzoumou, F., Guillocheau, F., Kebi-Tsoumou, S., Dah Tolingbonon, R.H. and Nganga Lumuamu, F. (2015) Notice Explicative de la carte géologique de la République du Congo à 1/100 000. Feuille Brazzaville. BRGM.
[16]
NF ISO 14235 (1998) Qualité du sol—Dosage du carbone organique par oxydation sulfochromique. 9 p.
[17]
Walkley, A. and Black, I.A. (1934) An Examination of the Degtjareff Method for Determining Soil Organic Matter and a Proposed Modification of the Chromic Acid Titration Method. Soil Science, 34, 29-38. https://doi.org/10.1097/00010694-193401000-00003
[18]
Baize, D. (2018) Guide des analyses en pédologie. 3e édition revue et augmentée, Éditions Quæ, 339 p.
[19]
Kjeldahl, J. (1883) A New Method for the Determination of Nitrogen in Organic Matter. Zeitschrift für AnalytischeChemie, 22, 366-382. https://doi.org/10.1007/BF01338151
[20]
NF ISO 11261 (1995) Qualité du sol—Dosage de l’azote total—Méthode de Kjeldahl modifiée. 8 p.
[21]
Boyer, J. (1982) Les sols ferralitiques: Facteurs de fertilité et utilisation des sols. Tome X. Initiation-Documentations Techniques, 52, ORSTOM, 384 p.
[22]
Kaboré, S.S. (2001) Évaluation d’un écosystème pastoral sahélien: Apport de la géomatique (Oursi-Burkina Faso). Thèse de PhD, Université de Sherbrooke, 148 p.
[23]
Nzila, J.D., Yallo Mouhamed, S., Watha-Ndoudy, N., Nguila-Ntsoko, D.P., Gakosso, N.V., Banzouzi Ntondélé, C., Kampé, J.P., Louembé, D. and Kimpouni, V. (2018) Spatial Distribution of Metallic Trace Elements in the Soils of Mayanga Market Garden Sites in Brazzaville (Congo). Journal of Applied Biosciences, 132, 13413-13423.
[24]
Kang, Z., Wang, S., Qin, J., Wu, R. and Li, H. (2020) Pollution Characteristics and Ecological Risk Assessment of Heavy Metals in Paddy Fields of Fujian Province, China. Scientific Reports, 10, Article No. 12244.
[25]
Yallo Mouhamed, S. (2024) Étude agroécologique des sites maraîchers du sud de Brazzaville (Congo): Propriétés physicochimiques des sols et teneurs minérales des cultures. Thèse de Doctorat de l’Université Marien Ngouabi, 203 p.
[26]
Amlinger F., Pollak M. and Favoino E. (2004) Heavy Metals and Organic Compounds from Wastes Used as Organic Fertilisers. ENV.A.2./ETU/2001/0024. Final Report. http://ec.europa.eu/environment/waste/compost/pdf/hm_finalreport.pdf
[27]
Salomon, M.B., Digue, T.M., Ngoussou, M., Constant, A.N., Richard, M.F. and Mianpereum, T. (2024) Assessment of Soil Pollution by Heavy Metals at the Daniela Oil Site in the Bongor Basin of Southern Chad. Open Journal of Soil Science, 14, 778-790. https://doi.org/10.4236/ojss.2024.1412038
[28]
Sanchez, P.A., Palm, C.A. and Boul, S.W. (2003) Fertility Capability Classification: A Tool to Help Assess Soil Quality in the Tropics. Geoderma, 114, 157-185. https://doi.org/10.1016/S0016-7061(03)00040-5
[29]
Onyenechere, E.C., Uwazie, U.I., Elenwo, E.I and Chizoruo, F.I. (2022) The Urban Informal Sector’s Activities and Its Influence on Soil and Water Quality of Some Southern Nigerian Cities. Scientific African, 15, e01077. https://doi.org/10.1016/j.sciaf.2021.e01077
[30]
Bardoul, E.C., Martin, T., Grace Mazel, I.F.O. and Promesse, M.N. (2023) Speciation and Pollution Assessment of Chromium and Zinc in Landfill Soils of Brazzaville: Physico-Chemical Analyses and Heavy Metal Contamination. International Journal of Science and Research (IJSR), 12, 731-739. https://doi.org/10.21275/SR23824181941
[31]
Engambé, C.B., Tchoumou, M., Ifo, G.M., Louzayadio Mvouezolo, F.R., Ngoro-Elenga, F., Atipo Ngopo, F. and Moussoki Nsona, P. (2023) Evaluation of Contamination by Heavy Metals in Soils Collected from Four Public Landfills in Brazzaville, Republic of Congo. International Journal of Innovation and Applied Studies, 41, 71-78. http://www.ijias.issr-journals.org/
[32]
El Oumlouki, K., Moussadek, R., Zouahri, A., Dakak, H., Chati, M. and El Amrani, M. (2014) Étude de la qualité physico-chimique des eaux et des sols de la région Souss Massa, (Cas de périmètre Issen), Maroc [Study of Physic-Chemical Quality of Water and Soil in the Region Souss Massa (Case Perimeter Issen), Morocco]. Journal of Materials and Environmental Science, 5, 2365-2374.
[33]
Landon, J.R. (1991) Booker Tropical Soil Manual: A Handbook for Soil Survey and Agricultural Land Evaluation in the Tropics and Subtropics. Pbk. ed., Longman Scientific & Technical.
[34]
Tessens, E. and Gourdin, J. (1993) Critères d’interprétation des analyses pédologiques. Programme de Pédologie. Laboratoire de Chimie Agricole. Département des études du Milieu et des Systèmes de production. Fiche de labo, No. 19, ISABU, Bujumbura, 36 p.
[35]
EUROCONSULT (1996) Agricultural Compendium: for Rural Development in the Tropics and Subtropics. EUROCONSULT, Elsevier, 778 p.
[36]
Kushwaha, C.P., Tripathi, S.K. and Singh, K.P., (2001) Soil Organic Matter and Water-Stable Aggregates under Different Tillage and Residue Conditions in a Tropical Dryland Agroecosystem. Applied Soil Ecology, 16, 229-241.
[37]
Nobile, C.M., Bravin, M.N., Tillard, E., Becquer, T. and Paillat, J.M. (2018) Phosphorus Sorption Capacity and Availability along a Toposequence of Agricultural Soils: Effects of Soil Type and a Decade of Fertilizer Applications. Soil Use and Management, 34, 461-471.
[38]
Sawadogo, J., Coulibaly, P.J.A., Traoré, B., Bassole, M.S.D., Kabore, A. and Legma, J.B. (2021) Amélioration des propriétés physico-chimiques et microbiologiques des sols par des fertilisants biologiques sous cultures de la tomate en zone Soudano-Sahélienne. Afrique Science, 19, 189-202.
[39]
Yallo Mouhamed, S., Watha-Ndoudy, N., Goma, I.M.C., Mboukou-Kimbatsa, Mbou Malonga, M.D., Nzila, J.D., Makouanzi Ekomono, C.G., Kimpouni, L.M.V. and Loumeto, J.J. (2022) Pratiques culturales et caractérisation physicochimique des sols sous maraîchage à Brazzaville (Congo). International Journal of Biological and Chemical Sciences, 16, 2978-2991. https://doi.org/10.4314/ijbcs.v16i6.40
[40]
Nijimbere, S., Kaboneka, S., Ndihokubwayo, S., Irakoze, W. and Ndikumana, J. (2020) Caractérisation physico-chimique des sols d’une exploitation agricole du Mumirwa en commune Rumonge (Burundi). Revue de l’Université du Burundi Série-Sciences Exactes et Naturelles, 29, 34-44. https://www.researchgate.net/publication/348541492
[41]
NF U44-041 (1985) Produits utilisés en agriculture. Boues des ouvrages de traitement des eaux. Dénominations et spécifications.
[42]
Godin, P. (1983) Les sources de pollution des sols: Essai de quantification des risques dus aux éléments traces. Science du Sol, 2, 73-87.
[43]
Baize, D. (1996) Détection des contaminations modérées en «métaux lourds» dans les sols agricoles. Intérêt et limites de la norme AFNOR U 44-041. /f Symposium international environnement et nouvelles technologies—«Protection des Sols» Bordeaux.
[44]
Tankari Dan-Badjo, A., Guero, Y., Dan Lamso, N., Tidjani, A.D., Ambouta, K.J.M., Feidt, C., Sterckeman, T. and Echevarria, G. (2013) Evaluation de la contamination des sols par les éléments traces métalliques dans les zones urbaines et périurbaines de la ville de Niamey (Niger). Revue des BioRessources, 3, 82-95.
[45]
Diop, T., Diarra, A., Diallo, M.A., Dione, M.M. and Diop, A. (2022) Impact d’une décharge urbaine sur la contamination métallique des sols: Cas de la décharge de Mbeubeuss (Dakar) International Journal of Biological and Chemical Sciences, 16, 2992-3002.
[46]
Bouras, S., Maatoug, M., Hellal, B. and Ayad, N. (2010) Quantification de la pollution des sols par le plomb et le zinc émis par le trafic routier (Cas de la ville de Sidi Bel Abbes, Algérie occidentale). Les technologies de laboratoire, 5, 11-17.
[47]
Iyabo Biou, C., Hedible, S.C., Codjo Landeou, R. and Boko, M. (2019) Impact des décharges sauvages des déchets solides sur les sols à Cotonou. European Scientific Journal, 15, 94-104.
[48]
Gizanga, R., Bonya, J. and Milau, F. (2022) Évaluation de la concentration en éléments traces métalliques (ETM) dans les sols des décharges publiques de la ville de Kinshasa en République Démocratique du Congo. Afrique Science, 21, 11-19.
[49]
Adeyi, A.A. and Babalola, B.A. (2017) Lead and Cadmium Levels in Residential Soils of Lagos and Ibadan, Nigeria. Journal of Health and Pollution, 7, 42-55.
[50]
Mbianda Nfong-Ya, O.L., Nzila, J.D., Louzayadio Mvouezolo, R.F., Bonazaba Milandou, L.J.C., Nguelet-Moukaha, I., Wando, G.P., Ouamba, J.M. and Aina, M.P. (2024) Water, Sanitation, Waste Management, and Professional Activities in Relation to Diseases with Neighboring Citizens of Congo Rivers in the Brazzaville Agglomeration (Republic of Congo). European Scientific Journal, ESJ, 20, 60-79.
[51]
Bardoul, E.C., Martin, T., Ifo, G.M., Promesse, M.N. (2016) Détermination du degré de contamination du site de la décharge, non contrôlée, de la ville de Tanger par quelques métaux lourds. Journal of Materials and Environmental Science, 7, 541-546. http://www.jmaterenvironsci.com/
[52]
Zhang, X., Yang, H. and Cui, Z. (2018) Evaluation and Analysis of Soil Migration and Distribution Characteristics of Heavy Metals in Iron Tailings. Journal of Cleaner Production, 172, 475-480. https://doi.org/10.1016/j.jclepro.2017.09.277
[53]
Tack, F.M.G. (2010) Trace Elements: General Soil Chemistry, Principles and Processes. In: Hooda, P.S., Ed., Traces Elements in Soil, Blackwell Publishing Ltd., 9-37.
[54]
Schneider, A.R. (2016) Comportement et mobilité des éléments traces métalliques dans les sols environnants une usine de seconde fusion du plomb: Approche expérimentale et modélisation. Thèse de Doctorat de l’Université Reims Champagne-Ardennes, 234 p.
[55]
Brady, N.C. and Weil, R.R. (1996) The Nature and Properties of Soils. 11th Edition, Prentice-Hall International, Inc., 740 p.
