Producing Ceramic Water Purifiers Made Of Iraqi Bentonite Type (Bpl1)

: In this study, ceramic purifier (CP) was produced from a mixture of Iraqi raw materials. This ceramic mixture was prepared using Bentonite as a Clay, Porcelanite as a Silica, and Limestone as a flux. The produced ceramic filter was formed by semi-dry compressing method and was fired at 1200 C˚. Physical properties of the produced CP were measured. A hydraulic test rig was constructed to study the hydraulic conductivity of the produced CP. The average hydraulic conductivity of the produced CP was 55 times that of commercial types of ceramic filters. The mineral composition of the produced ceramics was found by X-Ray tests. Tests results showed that all of the produced ceramics filters composed mainly of low Cristobalte and Tridoymite in addition to some of other minerals. Both of the raw and the water purified by produced ceramic were tested for a number of water quality parameters. that the ceramic disc purifier could remove, as an average percentages of removal, 99.98 % of turbidity, 78.86 % of the electrical conductivity , 81.61 % of the total dissolved solids, 73.45 % of Ca ++ , 49.69 % of Na + , 55.63 % of NO 3 - , 37.54 % of HCO 3. The results showed that CP has excellent adsorption ability for solutes of seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn, at concentrations of 1 mg / l each and 10 mg/l each. The adsorption capacities of each filter to adsorb seven heavy metals were computed according to Langmuir model and Freundlich models. The results showed variety in adsorption capacities for each heavy metal .


Introduction:
Water filtration means removing undesirable contaminates such as suspended solids, dissolved salts, microorganism, and other chemical substances from contaminated water.Filtration is done by passing water through a medium that allows only water with a quality that meets water standards of a specific purpose to pass through.Water filtration is a very important subject due to lack of water in some regions that require circulation and reuse of water.
Ceramic is produc by firing materials or mixture of materials of inorganic and non-metallic materials.Its properties can be controlled by developing technology to meet certain purposes.The pore size of the ceramic material can be made homogeneous and small within the range of microfiltration, which is excellent to remove most of the suspended solids and bacteria.Some of particles smaller than the ceramic pore size could be adsorbed by ceramic.CP can withstand solutions of high temperatures and a wide range of acidity that other microfiltration media can't withstand.CP can be operated with a proper maintenance or stored for a long time without losing its filtration efficiency.CP can be used easly and they have no side effects, they are environmentally friendly.
Generally, this research aims to study the hydraulic performance and adsorption propert of the CP made of local materials.

Laboratory Work
Laboratory work of this study includes preparing raw materials, producing the ceramic, and the necessary test to get the physical and purification properties of the ceramic product.

Preparing Raw Materials And Producing Cp
The ceramic raw materials that are used in this study are: Bentonite, Porcelanite, and Limestone.They were provided by General Company of Geological Surveying and Mineralization.Table 1 showes the chemical analysis of raw materials.Bentonite is one of the clay minerals in Iraq [ 1].It is composed of the following minerals: Montmorillonite, with 80%Alumino-Calcium Silicates [ 2].It consists of one sheet of Alumino-Silicates with varying water content and a little of Alkalis Mg 2 Al 10 Si 24 O 60 (OH) 12 Ca, [ 2].Due to its structure it has high ion exchange capacity, 80-150meq/gm, [ 3], as reported in [ 1].Porcelanite is a siliceous rock.These rocks are found in Iraq in Akashatat the western desert.It is largely composed of sponge spicules and some other siliceous microfossils (Diatoms and Radiolarian), as well as silicified foraminifera and non-plankton, [ 4].It is composed of the following minerals: Cristobalite, Tridymite, and Calcite, [ 2].Limestone is a white rock found at Kerbela and the western desert in Iraq.It is mainly composed of Alcalsiet, CaCO 3 , [2].Raw materials were milled and sieved to be uniformly graded material to get porous ceramic, [ 5] as reported in [ 6].Generally, Clay plus Silica and fluxes are used to produce ceramic.Bentonite, as a clay, Porcelanite as a Silica, and Limestone as a flux were used in this study.The creamic mixtures were used depending on the weight of the component used to the total weight of the mix used to produce the ceramic samples.Bentoniet formed the large ratio in the ceramic mixture contains comparable to the other component.
Mixtures were prepared by semi dried compressing method with 10%by weight of water content [ 7].CP samples were manufactured in this study as cylindrical disc tablets of a diameter of 50 mm and thickness of 10 mm, using semi drypressing method, Fig. 1.
Carbonate steel mold was manufactured to produce the ceramic discs as shown in Fig. 2. The mold should be cleaned and lubricated by thin oil (glycerin) before each pressing, [ 6].Some of the prepared wet mixture was placed in the mold and pressed with an electrical hydraulic jack at 250kg/cm 2 , Drying the sample at 105 C ˚ for 24hr, .

PHYSICAL TESTS
Tests were carried out to examine the physical properties of the produced ceramic discs.The physical properties which may affect the durability and hydraulic conductivity of ceramic are the apparent density, and porosity.

Density and Porosity Tests
Apparent density means dry density.It affects the compressive and tensile strength of ceramic.It also gives the indication to the porosity of ceramic.Apparent density of ceramic body depends on firing program, size graduation, applied pressure and water content during shaping process, [ 8].Porosity refers to the percentage of pore space in a material.An open pore is a cavity or channel that communicates with the surface of the particle.The apparent density, apparent and true porosity of ceramic discs were measured according to ASTM-C 373 standards, [ 9].

Hydraulic Conductivity Test
The hydraulic conductivity(HC) of a porous medium defines its ability to transmit water.It can be defined as the rat of flow per unit area of porous medium, which is perpendicular to the direction of flow, under unit hydraulic gradient.It has units of velocity(cm/sec, cm/min, m/hr, and m/day), [ 10]: (1) where: HC=hydraulic conductivity, cm/sec, cm/min, m/hr, and m/day, q= rat of water flow per unit cross sectional area,m 3 /m 2 /hr, and i h = hydraulic gradient.That is, [ 10]: where: loss in hydraulic head through flow path,m, and length of flow path, m.The hydraulic conductivity is calculated by constant head method by applying the following equation, [ 10] : Where: A c = cross section area of ceramic sample, m 2 , h = constant head exerted by water level, m, L=length of sample, m, Q= water discharge passed CP at time t, m 3 , and t=time at which water discharge Q passed through CP .Constant head method was employed to measure K of the whole ceramic disc production using distilled water.Equipment was designed to be used for measuring hydraulic conductivity Fig. 4 shows the general view of the hydraulic conductivity equipment that was constructed to be used to measure K described by equation 3. Fig. 5 shows a schematic diagram of the equipment.The equipment consists of a plastic or glass tube with a 52 mm diameter and 150 mm height in which the ceramic disc was fixed inside it and sealed with silicon to prevent water from passing through the open between tube and ceramic disc.The tube placed between two galvanized steel covers containing valves for inlet and outlet water.Control of the head of water above the filter was arranged using a loop system.The equipment set-up for hydraulic conductivity Investigations is detailed below: The reservoir which provided the head above the filter disc consisted of an opaque polyethylene cylinder of 250 mm in diameter and a height of 250 mm.The cylinder containing 50 mm tube inside it to keep the water in the reservoir at a constant head, which is called, overflow tube.The overflow water from the overflow tube is discharged to other reservoir, which is inlet reservoir.Influent flow to the head reservoir was drawn from an inlet reservoir using a pump.This maintains slow flow rates whilst not physically contacting the influent water.Thus head was controlled at a constant level, allowing water loss from the system as it filtered through the ceramic.The test collection placed at an aluminum frame in order to raise the head reservoir to the desired head.Fig. 6 shows the test set up view and Fig. 7 shows a schematic diagram of the test set up.Each test of HC of the ceramic disc test was carried out with one replication.Computing the average saturated hydraulic conductivity HC a for each disc.Computing the standard hydraulic conductivity, HC s, for each disc according to equation, [ 11]:   The required amount of metal salt was dissolved into one liter of distilledwater and stirred .Mass of metal salt was calculated as follows: 500 ppm =500 mg/l.To make one liter of metal salt solute, 500 mg metal is needed, 0.50g of metal.That means, [13]: (5) where The Langmuir Isotherm One particular mathematical form of an isotherm which is often found to fit experimental data is the so-called Langmuir isotherm [14], which was derived in 1916 by Irving Langmuir [15].
The Langmuir equation applicable to adsorption is described as [13]: Where: Ce= the equilibrium concentration of the adsorbate(mg/L) in solution.
qe =the amount of adsorbate adsorbed per unit mass of adsorbent at equilibrium(mg/g).
Q o and b = Langmuir constants related to the adsorption capacity an energy of adsorption, respectively.When Ce/qe is plotted versus Ce, the slope is equal to 1/Q o and the intercept is equal to 1/Q o b [16] The Freundlich Isotherm Non-ideal systems can sometimes be fitted to an empirical dsorption isotherm developed by the German physical chemist Herbert Max Finlay Freundlich(1880-1941), [ 15] .The Freundlich equation applicable to adsorption is described as, [17]: Log qe =log Kf +1/n log Ce (8) Where: Ce = the equilibrium concentration of the adsorbate(mg/L) in solution.qe = the amount of adsorbate adsorbed per unit mass of adsorbent at equilibrium(mg/g).
Kf and n =constants incorporating all factors affecting the adsorption.

Results and Discussion:
This paragraph presents the laboratory experiments results that were carried out to examine the physical properties, hydraulic performance, and adsorability of the produced ceramic discs.

Physical Properties
Six tests were carried out to specify the physical properties of the produced CP discs.The results of physical properties tests are listed in Table 2.

Hydraulic Conductivity Test
Hydraulic conductivity test was carried out on CP, including three replications, to evaluate its hydraulic performance.
The tests were carried following the constant head method which was viewed previously.The results showed that the average hydraulic conductivity was 0.0023 m/hr, which is 56.5 times maximum hydraulic conductivity of the commercially available ceramic filters which is about 0.00004 m/hr, [ 6].

Mineralogical Test
Mineralogical test was carried on the produced ceramic purifier according to the procedure explained befor.The resulting minerals were found by measuring their reflecting angles and their intensities as shown in Fig. 8 ).It could be seen that the three has of silica (SiO 2 ), Beta Quartz, Tridoymite, and Low Cristobalite,had appeared in this ceramic filter due to the same reasons mentioned before.
While Al +3 appeared in Anorthite and Plagioclase syn in addition to some impurity with Na + .
Protoenstatite (MgSiO 3 ) had appeared due to existing of some impurity of Mg +2 in the initial composition of minerals with plenty of silica in all used minerals, and it is stable phase of Magnesium Silicate which formed at high temperatures, [ 19] as reported in [ 6].

Heavy Metals Adsorption Tests
Two adsorption tests, including two replication, were carried out to examine the adsorption of heavy metals properties of the produced CP disc.One, including one replication, were carried out on a per prepared solution of 1mg/l of each of seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn.Other one test, including one replication, were carried out on per prepared solution of 10mg/l of each of these seven heavy metals.According to Iraqi Specifications No 417 [ 20], limits of these heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Znin drinking waterare listed inTable 2. Average results of test that were carried out to examine heavy metals adsorption properties of the produced CP discs using a per prepared solution of 1mg/l of each of the used seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn, are shown in Fig. 9. Generally, the results showed that CP adsorbed most of the heavy metals ions.The removal varies between (99.60 -100%) of the initial concentration.10 showed the average results of test that were carried out to examine heavy metals adsorption properties of the produced CF discs using a per prepared solution of 10mg/l of each of the used seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn.Generally, the results showed that all the ceramic filters adsorbed most of the heavy metals ions.Fig. 10 showes the variation in percentages of adsorption of the heavy metals with 10 mg/l concentrain of each of the produced ceramic.The adsorption varies between 96.32 and 100% of the initial concentration of each metal.Adsorption Capacity Adsorption capacities of CP, was measured according to the procedure mentioned befor.The polluted water with seven heavy metals (Mn, Fe, Pb, Cd, Co, Cu, and Zn), at (20, 40, 60, and

Conclusion:
The following could concluded frome this research: 1. Ceramic water purifier can be produced by using Iraqi Bentonite.
)where:HC a =average saturated hydraulic onductivity, m/hr,µ= viscosity of water at any temperature,Pa.s,and µ 20 =viscosity of water at 20˚C,Pa.s.
the produced ceramic discs were done by the x-ray reflection device at Baghdad University College of Science Geological Department x-ray laboratory, [12].The samples were tested in Philips X-Ray Powder Diffractometer Vertical Gionometer PW 1050/10.Adsorption TestAdsorption test was carried for each produced ceramic disc.The test was carried out passing polluted water through the ceramic disc and measuring the concentration of pollution before and after passing.The polluted water was prepared at laboratory.500 mg/l standard stock solutions of Pb(II), Co(II),Fe(II), Mn(II), Cd(II), Zn(II)and Cu(II)were prepared as follows:

: 6 )
Ma=mass of metal salt, g, MW =molecular weight of the metal salt,g, and AW = atomic weight of metal in salt, g.Make up solutions of Pb(II), Co(II), Fe(II), Mn(II), Cd(II), Zn(II), and Cu(II) at different concentratio1,10, 20, 40, 60, and 80 mg/l of each of these ions by diluting 0.2 , 2, 4, 8, 12, 16, and 20 ml of the 500 mg/l standard solution to100 ml, with distilled water[ 6].Adsorptiontest was carried out at room temperature.The test was carried out for all filters together at one time.The final concentrations of metal ions in the solution were determined by atomic absorption spectrometer, AAS, for residual metal content.The percentage adsorption was calculated as follows,[13]:(where: Ap=percentage of adsorption, %.Co =initial concentration of metal ion in the queous phase, mg/l, Ce = final concentration of metal ion in the aqueous phase, mg/l.

Fig 9 :
Fig 9: % of removal of heavy metals at concentration 1mg/l.

Fig 10 :
Fig 10: % of removal of heavy metals at concentration 10mg/l.
Fig.10showed the average results of test that were carried out to examine heavy metals adsorption properties of the produced CF discs using a per prepared solution of 10mg/l of each of the used seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn.Generally, the results showed that all the ceramic filters adsorbed most of the heavy metals ions.Fig.10showes the variation in percentages of adsorption of the heavy metals with 10 mg/l concentrain of each of the produced ceramic.The adsorption varies between 96.32 and 100% of the initial concentration of each metal.Adsorption Capacity Adsorption capacities of CP, was measured according to the procedure mentioned befor.The polluted water with seven heavy metals (Mn, Fe, Pb, Cd, Co, Cu, and Zn), at(20, 40, 60, and 80 mg/l) of each metal.The remaining

2 . 5 .
The average hydraulic conductivity of CP is 0.0023 m/hr.3. The ceramic product composites of Tridoymite and Low Cristobalite, which have adsorption properties.4. The CP could adsorb seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn, frome their solutions at 1.0 mg/l, and 10.0 mg/l concentrations.Asorption capacity of CP seven heavy metals, Mn, Fe, Pb, Cd, Co, Cu and Zn according to Freundlich model are: Pb>Cd>Cu>Zn>Mn>Co>Fe, and maximum capacity was for Pb (3.694 mg/g), and minimum was for Fe (1.517 mg/g).While according to Langmuir model were: Fe>Co>Mn>Zn>Pb>Cd>Cu, and maximum capacity was for Fe (1.337 mg/g), and minimum was for Cu (0.394 mg/g).

.
This means it has very good purification properties especially in removing turbidity, EC, TDS, hardness (Ca ++ ), Na + , and NO 3 due to forming Tridoymite in its final mineralogy.