This study is designed to investigate the suitability of selected Nigeria clay deposit for clay based ceramic water filters (CWFs). Clay samples were taken from five randomly selected locations in Nigeria Namely: Okpella (Edo 1) and Ojirami (Edo 2) in Edo; Ikere in Ekiti state; FUTA in Ondo state and Onibode in Ogun to determine their suitability for clay based ceramic water filters (CWFs). Experimental analysis for linear shrinkage, water absorption, bulk density, compressive strength X-ray diffraction (XRD) and X-ray Fluorescence (XRF) was carried out on each of the clay samples. Test results reveal that all the clays contain high contents of alumina (Al 2O 3) and silica (SiO 2) with minor contents of P 2O 5, Fe 2O 3, MgO, K 2O, MnO and TiO 2. The average crystal sizes of the clay were between 15 and 27 nm. Lattice structure indicates that the sample is Monoclinic and Anorthic. Ceramic water filters (CWFs) were made from a mixture of clay and sawdust at different volume ratios, and processed into test samples. Water absorption, linear shrinkage and compressive strength of the clay based ceramic filters (CWFs), reveal that as the volume ratio of sawdust increases these properties decrease. Flow rate analysis indicates that Edo and Ekiti ceramic water filters (CWFs) have higher flow rates. The research indicates that Edo and Ekiti Clay with specification of some industrial clays shows that the samples can be recommended for use in clay based ceramic water filters production.
The complex nature of clay makes its study and findings an ever fresh area of interest especially to the world of science. Clay and its minerals have played major roles in anthropogenic activities. The low cost of clay and its relative abundance in nature, high sorptive/electric charge properties, plus ion exchange ability and compatibility with several materials, give it a wide range of application [
The basic rocks from which clays are formed are complex alumina silicates that exist in various proportions and contain varied amounts of impurities of iron, organic matters and residual minerals [
Clay based ceramic water filters (CWFs) are usually produced by mixing of clay, sawdust (woodchips) and water [
The samples were taken from five randomly selected locations in Nigeria Namely: Okpella (Edo1) and Ojirami (Edo2) in Edo; Ikere in Ekiti state; FUTA in Ondo state and Onibode in Ogun.
The collected samples were dried in open air, after which, the samples were manually crushed into thin particles using a mortar and pestle, and then levitated using the water extraction method. The clay samples were mixed with distilled water and thoroughly stirred and allowed to hydrate for several hours and latter decanted this process is repeated until purer clay is obtained. The samples were sun dried and subsequently dried in a laboratory oven at 110˚C for 24 hours. The resulting dried clay samples were pulverized and sieve with a digital octagon sieve shaker BS/ISO 3310 to an average particle size of 150 µm, and label as processed clay (PC), and sent for analysis.
The clay samples were mixed with sawdust in five (5) different ratios into homogenous paste using an electronic mill, with water as the binding agent. The resulting mixture (clay, sawdust and water) was form into 3 geo- metrical shapes; cylindrical, flat and cubes slabs; it was there after dried in an oven (temperature of 105˚C, humidity of 40%) for 24 hours. After drying, the samples were sintered in a muffle furnace. The firing involved pre-heating of the sample to 450˚C - 500˚C (to burn off the sawdust), followed by heating to the sintering temperature of 850˚C for six hours in the same muffle furnace.
Clay sample were made into flat bars of 12 cm × 3 cm × 1 cm was dried at room temperature for 14 days, after which the final length was measured. Total percentage shrinkage was determined using the formula;
Flat bar of clay samples were first weighed using an electronic weighing balance, soaked in a bowl of water for 24 hours. Each was then removed from water, allowed to drip and the remaining was gently wiped to ensure that no water was attached to the surface and was re-weighed again. The difference in weight was then used in computing the percentage water absorption applying the formula below:
The compressive strength was determined using the Instron Universal Tester Model No: 3069, with a compressive load rate of 70 N/min.
The quantitative analysis of chemical components of both processed and unprocessed clay was done using EDX 3600B Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer.
The X-ray diffraction (XRD) was monitored using X-ray diffractometer GBC EMMA, CuKα radiation using an acceleration voltage of 25 kV and current of 400 µA. The diffraction angle was scanned from 10˚ to 65˚ 2θ, at a rate of 4.00˚/min.
Prior to the water flow experiments, the CWFs were saturated by complete submersion in a vat containing distilled water. The ceramic pot was first placed into a plastic receptacle that was fitted with a large plastic funnel. The filter and receptacle-funnel were suspended above an empty collection bucket. A known volume of distilled water was poured into the CWF, and the volume of the water that flowed into the collection bucket was measured. The flow rates were obtained by measuring the volume of water discharged from the CWFs as a function of time.
X-Ray Diffraction Analysis the clay samples are shown in
Mineralogical compositions as determined by X-ray diffraction in
Property | Edo1 | Ekiti | Edo2 | Ondo | Ogun |
---|---|---|---|---|---|
Average Crystal Size (nm) | 19.95 | 27.84 | 26.57 | 15.88 | 18.78 |
Lattice Structure | Monoclinic | Monoclinic | Monoclinic | Anorthic | Anorthic |
free silica or quartz (SiO2), illite {KAl2 (Si3,Al)O10(OH)2}, The major non-clay mineral constituent in these samples were quartz. The percentage composition of quartz ranges from 9% to 21%. Feldspar’s {(K,Na)AlSi3O8}, composition in sample d, was however lower than that of other clays used in the research. According to Brown et al. [
Generally, the XRD result revealed a high degree of crystalinity in all the samples. Careful investigation has reveals that all samples were composed essentially of SiO2, Al2O3, and to very limited extent of K2O and Fe2O3. Some other oxides were also present but in very negligible proportions. All the samples showed Kaolinite Al2Si2O5(OH)4 as the predominant mineral content with main reflections of silicon oxide and kaolinite.
The X-ray Fluorescence (XRF) results showed in
The ratio of clay-sawdust are shown in
Water absorption and Liner shrinkage results shown in
Linear shrinkage shown in
Compressive strength result are shown in
Locations | Al2O3 | SiO2 | P2O5 | SO3 | K2O | CaO | MnO | Fe2O3 | Others |
---|---|---|---|---|---|---|---|---|---|
Edo1 | 37.392 | 53.683 | 0.191 | 0.403 | 1.246 | 0.271 | 0.056 | 4.939 | 1.819 |
Ekiti | 49.661 | 42.321 | 0.013 | 0.015 | 1.31 | 0.053 | 0.014 | 5.112 | 1.501 |
Edo2 | 38.436 | 51.338 | 0.184 | 0.451 | 2.093 | 0.284 | 0.093 | 6.472 | 0.649 |
Ondo | 42.303 | 50.074 | 0.149 | 0.578 | 1.582 | 0.052 | 0.026 | 4.586 | 0.650 |
Ogun | 42.604 | 48.341 | 0.184 | 1.067 | 1.466 | 0.061 | 0.027 | 5.64 | 0.610 |
Locations | Clay: Sawdust (%) | ||||
---|---|---|---|---|---|
Edo1 | Ekiti | Edo2 | Ogun | Ondo | 100:0 |
Ed1(a) | Ek (a) | Ed2 (a) | Og (a) | Od (a) | 70:30 |
Ed1(b) | Ek (b) | Ed2 (b) | Og (b) | Od (b) | 65:35 |
Ed1(c) | Ek (c) | Ed2 (c) | Og (c) | Od (c) | 55:45 |
Ed1(d) | Ek (d) | Ed2 (d) | Og (d) | Od (d) | 50:50 |
Ed1(e) | Ek (e) | Ed2 (e) | Og (e) | Od (e) | 40:60 |
From
Locations | Edo1 | Ed1(a) | Ed1(b) | Ed1(c) | Ed1(d) | Ed1(e) |
---|---|---|---|---|---|---|
Water Absorption (%) | 20.23 | 39.36 | 40.12 | 41.18 | 53.81 | 71.93 |
Liner Shrinkage (%) | 7.3 | 7.37 | 7.24 | 7.2 | 7.18 | 7.08 |
Flow rate (L/hr) | 0.0 | 0.025 | 0.045 | 0.076 | 0.15 | 0.18 |
Compressive strength (Mpa) | 11.46 | 10.46 | 9.28 | 6.82 | 4.51 | 2.32 |
Locations | Edo2 | Ed2(a) | Ed2(b) | Ed2(c) | Ed2(d) | Ed2(e) |
---|---|---|---|---|---|---|
Water Absorption (%) | 23.1 | 29.49 | 32.02 | 34.13 | 34.45 | 42.66 |
Liner Shrinkage (%) | 7.72 | 7.43 | 7.17 | 6.93 | 6.73 | 6.6 |
Flow rate (L/hr) | 0.0 | 0.032 | 0.071 | 0.084 | 0.091 | 0.098 |
Compressive strength (Mpa) | 13.7 | 11.15 | 9.75 | 6.02 | 4.46 | 3.11 |
Locations | Ondo | Od(a) | Od(b) | Od(c) | Od(d) | Od(e) |
---|---|---|---|---|---|---|
Water Absorption (%) | 40.95 | 58.14 | 63.22 | 69 | 72.78 | 98.06 |
Liner Shrinkage (%) | 6.6 | 6.28 | 6.17 | 5.89 | 5.82 | 5.65 |
Flow rate (L/hr) | 0.0 | 0.06 | 0.078 | 0.089 | 0.098 | 0.1 |
Compressive strength (Mpa) | 13.41 | 10.97 | 9.31 | 5.68 | 3.46 | 2.3 |
Locations | Ekiti | Ek(a) | Ek(b) | Ek(c) | Ek(d) | Ek(e) |
---|---|---|---|---|---|---|
Water Absorption (%) | 32.78 | 49.8 | 51.21 | 54.63 | 55.18 | 68.65 |
Liner Shrinkage (%) | 8.24 | 8.21 | 8.14 | 8.13 | 8.08 | 7.42 |
Flow rate (L/hr) | 0.0 | 0.02 | 0.05 | 0.09 | 0.12 | 0.17 |
Compressive strength (Mpa) | 12.23 | 10.21 | 7.96 | 6.54 | 4.31 | 2.11 |
Locations | Ogun | Og(a) | Og(b) | Og(c) | Og(d) | Og(e) |
---|---|---|---|---|---|---|
Water Absorption (%) | 31.7 | 48.09 | 54.24 | 75.73 | 86.02 | 96.54 |
Liner Shrinkage (%) | 6.24 | 6.12 | 5.85 | 5.61 | 5.53 | 5.2 |
Flow rate (L/hr) | 0.0 | 0.008 | 0.034 | 0.06 | 0.062 | 0.076 |
Compressive strength (Mpa) | 12.84 | 10.85 | 9.34 | 6.09 | 3.91 | 2.76 |
Selected Nigeria clay deposit from Edo, Ogun and Ekiti states for clay based ceramic water filters (CWFs) has been characterized. Results obtained suggest that the sample contains high contents of alumina (Al2O3) and silica (SiO2) with minor contents of P2O5, Fe2O3, MgO, K2O, MnO and TiO2. Water absorption, linear shrinkage and compressive strength of the clay based ceramic filters reveal that as the volume ratio of sawdust increases these properties decrease. Flow rate indicates that Ondo and Ekiti blended clays have higher flow rates, while Ogun clay has poor flow rate. A comparison of all clay used in the research indicates that Ondo and Ekiti clay with specification of some industrial clays shows that the samples can be recommended for use in ceramic filter production
The contributions and assistance of the Managing Director EMDI, Engr (Dr.) Olusunle, and staff of EMDI especially, Mr. Patrick Ehi Imoisili, Miss Theresa Ezenwafor, Mr. Monday Eshiett and Mr. Femi Osho are greatly appreciated.
Smart AdeleyeOlubayode,Olufiropo SamsonAwokola,Enoch OlugbengaDare,Olubayo TimothyOlateju,11, (2016) Suitability of Some Selected Clay Deposit from Edo, Ogun, Ondo and Ekiti State of Nigeria for Ceramic Water Filters Production. Journal of Minerals and Materials Characterization and Engineering,04,26-32. doi: 10.4236/jmmce.2016.41003