The management of agro-pastoral waste remains a major concern in countries with high agricultural potential such as Côte d’Ivoire, due to the pollution of environmental components resulting from its poor management. This work aims to identify the different types of agro-pastoral waste generated in the departments of Soubré, Issia, Sassandra and Daloa. It also aims to provide information on the quantities of residues available and to identify the management method for this waste. To do this, some fields of observations were made to identify the different types of waste then based on agricultural statistical data from the Ministry. The quantities of agro-pastoral residues were estimated. A survey was also conducted from a survey sheet of agropastoral residue holders to identify the management method. It appears that in these localities, we find as crop residues, rice straw and husk, stalks, cobs and pobs of maize and cassava, bunches and palm shells, cocoa fibers and pods, shells of coffes. Livestock waste is made up of slurry, liquid manure, manure, bones, feathers and droppings and comes from animals such as cattle, sheep, goats, pigs and poultry. The quantities of crop residues estimated are 236,123.3 t/year in Daloa, 255,000 t/year in Issia, 290,000 t/year in Soubré and 198,221.4 t/year in Sassndra. Livestock waste is 728.8 t/year in Daloa, 3,606.1 t/year in Issia, 2,442.6 t/year in Soubré and 873.4 t/year in Sassndra. In these localities, 85% of planters abandon their residues in the fields, 12% of planters incinerate them in the open air and 3% compost them.
Rice husking residues constitute real bioresources which the development could contribute to improving the living conditions of populations and reducing pressure on forest resources. This study examined the management of rice husking residues in the Lôh-Djiboua region. The survey and field observation carried out showed that the Lôh Djiboua region produces an average of 21,262.4 tonnes of rice per year, including 8,711.9 tonnes in Divo, 9,625.5 tonnes in Lakota and 2,925 tonnes in Guitry. The main residues from husking rice are husks and bran. The average annual bale quantities recorded are 2744.3 ± 446.2 tonnes at Divo, 3032.1 ± 1550.7 tonnes at Lakota and 921.4 ± 249.6 tonnes at Guitry. The average annual bran masses are 304.9 ± 49.6 tonnes, 336.89 ± 172.3 tonnes and between 102.4 ± 27.7 tonnes respectively at Divo, Lakota and Guitry. Rice husking residues produced in the mills are collected by households (0 to 18.9%), pig farmers (8.1 to 27.8%), poultry farmers (45.9 to 55.5%), farmers (16.7 to 28.1%) and fish farmers (2.7 to 3.1%). These use them as fuel in households, as feed and bedding in poultry and pig farming, as feed in fish farming and as fertilizer after calcination in agriculture. There is a low rate of use of rice husking residues as fuel in households in the studied areas (1 to 4%).
The present research work is situated within the framework of the valorization of the plantain through the development of an effective process of extraction, prevention of browning, microbial stabilization, characterization of the pulp juice of ripe plantain at stage 8 and the valorization of the residues resulting from the extraction. Three juice extraction processes were evaluated. The first two processes are based on the use of hot and cold water; the third was carried out with pectinase. The latter process improves the yield (65.4%) while the other hot and cold water extraction processes give respective yields of 60.55 and 61.06%. The reducing sugar contents were 8.65 ± 0.03 mg/100ml for the juice extracted with pectinase, 3.00 ± 0.06 mg/100ml for the juice extracted with hot and cold water. The total sugar contents correspond to the following values: 51.33 ± 0.19 mg/ml for the juice extracted with hot water 54.20 ± 0.08 mg/100ml for the juice extracted with cold water and 55.57 ± 0.92 mg/100ml for that extracted with pectinase. The juice extracted with pectinase is the most energetic with 227.27 Kcal/100mL, followed by the juice extracted by maceration and that extracted by infusion, with 226.47 and 208.48 Kcal/100mL respectively. With an antioxidant activity of 5.89±0.00 (µmol eq. Trolox), the ripe plantain pulp juice has a total polyphenol content of 6.57±0.00 g/L eq. Acid. Gallic acid and total flavonoids of 0.227±0.00 g/L eq. Querc. For the overall assessment of the juices by the panel, the juice extracted with pectinase is preferred to the others.
A series of sand filters in the shape of a “U” are an inexpensive option to to the treatment of nitrogen pollution. This filter system was contained three compartments. Each compartment was contained two columns, a filter column and a settling one. The size of filter media decreased successively in the direction of water flow. This disposition of layering increases solids absorption et adsorption. However, the filter sand depth and media grain size can impact their treatment efficiency. Thus, the effect of sand filter depth and media grain size upon treatment kinetic was studied. To do this, three (3) sand depth (60, 70 et 90 cm) was studied. The results show that the filter bed depth of 90 cm was the most efficient for nitrogen removal. However, the coarse shales provide a good reduction of ammonium and Total Kjeldahl nitrogen in the filtrates compared to the other media grain size. Shale medium and lagoon sand are efficient in the nitrate removal and chemical oxygen demand. The results obtained show that the filter of 90 cm of mean shale and with lagoon sand is an efficient technology for treating nitrogen urban wastewater.
The objective of this study was to know the effect of particle size of the laterite contained in reactors filled with laterite and sand on the removal of the physicochemical parameters of a well water. Three reactors filled from the bottom to the top with 10 cm of granitic gravel, 50 cm of sand, 10 cm of standing water and 30 cm of different particles sizes of laterite (granular, very coarse and medium) were used. The depths of the sand and the standing water were fixed according to a previous study. pH, conductivity, turbidity, suspended solids, ammonium, nitrate, lead and total iron were analyzed according to standard norms. The results showed that pH increased with decreasing particle size while conductivity decreased. With regard to suspended solids and turbidity, the removal was (98.9%) and of the same order in all the reactors. Removal efficiency of ammonium ranged from 97.67% to 98.1% in the reactors. The reactors also removed nitrate, total iron and lead. In addition, the concentrations of nitrate, total iron and lead decreased with increasing particle size. However, the reactor filled with medium laterite and sand was the most efficient.
The kaolinite-coating laterite (B catalysts) was used for the efficient degradation of methylene blue (MB) from aqueous solution. Heterogeneous Fenton catalytic oxidation experiments of B catalyst were investigated by changing the effective factors such as amount of laterite and amount of kaolinite. To that end, four (4) types of B catalysts were made: (i) B0 catalyst (50% kaolinite + 50% uncalcined laterite); B1 catalyst (50% kaolinite + 50% laterite calcined at 600°C), B2 catalyst (30% kaolinite + 70 % laterite calcined at 600° C) and B3 catalyst (100 % kaolinite + Iron solution from laterite). The result showed that B2 catalyst exhibits the highest performance with a MB degradation percentage (77%) after 100 min. For analyzing the performance of B2 catalyst, the effects of B2 catalyst amount, pH, and hydrogen peroxide (H2O2) were also studied at 100 min. Kinetic studies were also carried out in this experiment. The results indicated that more than 90% of decolorization was achieved with 60g of B2 catalyst at pH acidic (2 to 3). Moreover, higher MB degradation (≤ 90%) was reported at the presence of H2O2 and B2 catalyst in the reactor. However, only 14% of MB was adsorbed in the presence of H2O2 and without B2 catalyst. On the other hand, it was observed that second- order kinetics (R2>0.90) was well fitted in the MB degradation process. Considering the above, kaolinite-coating laterite (B2 catalyst) could be used as efficient, cheap, and eco-friendly catalytic oxidation material for the degradation of MB in aqueous solution.
Plant density may have an influence on constructed wetlands (CWs) operation. In this study, the effect of plant density on the efficiency of vertical-flow CWs planted with Panicum maximum treating domestic wastewater was investigated. Two beds were planted with P. maximum at 10 plants/m2 (low density) and two others at 20 plants/m2 (high density). Two unplanted beds were used as control. During six months, domestic (0.05m3) raw wastewater was applied on each bed intermittently. Wastewater samples were taken once a week into the influent and the filtrate of each bed and preserved at 4°C until analysis. The results showed that pollutants were significantly more removed in the planted beds than in the controls. But, the plant densities used were not significantly impact the treatment efficiency. However, the bed planted at low density was clearly distinguished as the one that provided the higher pollutants removal rates (TSS = 91.8%, DCO = 91.6%, P = 69%, PO43- = 74.9%, NTK = 86.5%, NH4+ = 86.5%, Escherichia coli = 87.1%, Clostridium perfringens = 96.7%).
Sanitation and health of populations regarding malaria and diarrhea syndromes were studied in precarious neighborhoods of Abobo (Abidjan, Côte d’Ivoire). Globally, 587 concessions were sampled with 14 232 people. Human excreta are essentially disposed in autonomous sanitation systems (8-88%). The grouping of neighborhoods according to their sanitation gave three entities: (Anonkoua and Abobo PK-18) (Sagbé, Avocatier, M'Ponon and Jean-Tahi) and (Abobo-Baoulé). People have access to the drinking water from SODECI for various usages depending on the use and the season. Drinking water from SODECI is the only one used in the dry season, but it’s partially substituted by rainwater during the rainy season for bath, clothes washing and dishes. However, it is exclusively used for drinking regardless of the season. The classification of precarious neighborhoods based on water use gives five groups: (Anonkoua, Avocatier) (Sagbé, Abobo PK-18), (Jean-Tahi) (M'Ponon) and (Abobo-Baoulé). Population health in these areas is worrying with 47% of patients (35% of malaria syndrome cases and 12% of diarrhea syndrome cases). The young population ([0-8 years [) is the most affected, with 25% of malaria syndrome cases and 34% of diarrhea syndrome cases.
Pesticides used for intensive agricultural production threaten natural resources and human health. The aim of this study is to analyze the use of pesticides in the Marahou
Four biosand filters were used for treatment of Banco river source water to investigate the effects of sand depth (30, 50, 70 and 90 cm) on the removal of suspended solids, nitrogen and oxidized forms of the chemical demand oxygen and their effect on the pH. The results showed that the filter of 90 cm of sand was the most efficient. However, the purification yields between filters 50, 70 and 90 cm of sand showed no significant difference, and the treated water met the drinking water standards of the world health organization. Therefore, sand depth between 50 and 90 cm can be used in biosand filter to treat water.
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