Abstract
The immense health problems caused by the extremes of Mo concentration in drinking water are raising a major issue of concern. This is because of the variation in Mo concentration in water. Research has shown that low and high concentrations of Mo have immense effects on the health of people, animals, plants, and bacteria. Rapid population growth and industrial activities have greatly increased the demand for high-quality groundwater and surface water in the world. Though, there is no significant seasonal effect depicted from the high and low concentrations of molybdenum in different areas; the issue cannot be taken for granted. The concept of molybdenum in groundwater is very vital and worth of research; this will help in giving precise information on the behavior of molybdenum in carbonated aquifers (Campillo, Et al, 2002).
Due to the lack of adequate studies on molybdenum in groundwater; the results of this research will serve as a scientific basis for future investigations on the occurrence and flow of groundwaters that are high concentrations of molybdenum. The research findings can provide a scientific and technical base to future development programs including agriculture, energy, settlement, and urbanization. The scientific community, the public, entrepreneurs, regional and federal governments, and WHO can benefit from the research outcomes. The concept of molybdenum in groundwater is so vital and it’s worth of research in order to give a solution to high-quality water (Bostick, et al, 2003).
Background information
Motivation
As it has been revealed, Molybdenum is a very essential catalyst for enzyme actions in many metabolic activities in the human body; which is widely through aldehyde-oxidase and xanthine-oxidase. Mo is also very important in plants and bacteria in which it is involved various biological activities in such organisms; making it of more interest as such organisms are very essential in human activities. On this basis, therefore, the study of Molybdenum becomes very vital since it’s a key component of life and the entire process which enhances life continuation. Nevertheless, overconsumption of the recommended amount of Molybdenum is very harmful to both animals and plants in the ecosystem. In this regard, therefore, both extremes of Molybdenum concentration are harmful to the health of living organisms. Considering all the above processes involving molybdenum, a sense of motivation towards the study of Mo arises; thus making it important for being studied on (Campillo, Et al, 2002). For instance, the following table represents normal Mo contents as per various human body organs as postulated by Randahl et al, (1998).
- Liver 3.2
- Kidney 1.6
- Spleen 0.2
- Lung 0.15
- Brain 0.14
- Muscle 0.14
On the other hand, Mo content in plant tissues should be maintained lower than 2mg kg-1; as any Mo content in plants above this value would be regarded as toxic as suggested by Kabata et al, (1984). On this regard therefore, the various levels of Mo (mg/kg) in tissue of ripe leaves from various plants are presented in the table below as put forth by Kabatas et al, (1984).
- Essential content 0.1 – 0.3
- Sufficient/Normal content 0.2 – 1
- Exceeding or Toxic contents 10 – 50
Generally, Mo is very vital for a range of biological functions in animals, plants and microorganisms; in which it is an essential constituent of enzymes that catalyze redox reactions (Stiefel, 1996). Molybdenum interacts with copper and sulphate in organisms and the complex interactions between these compounds can lead to problems in biological systems which relate to both molybdenum deficiency and excess. Molybdenum is important in plant growth and is added to some fertilizers in trace amounts to enhance crop production. It also has a role in nitrogen fixation (Bostick et al., 2003). However, excessive molybdenum concentrations have been linked to abnormal plant growth (Waterson, 1984). Molybdenum availability to plants from soils is known to be pH-dependent, being greatest in alkaline soils (National Research Council, 1980).
It is important to note that, Molybdenum has a particularly large health impact on ruminant animals. For instance Mo deficiency in goats has been linked to reduced fertility and increased mortality (Expert Group on Vitamins and Minerals, 2003). High dietary molybdenum intakes inhibit the uptake of copper and lead to copper-deficiency disorders (Suttle, 1991; Shen et al., 2006). Comparatively, the signs of excess molybdenum in animals are related to those for copper deficiency like anaemia, anorexia, diarrhea, joint abnormalities, and hair discoloration.
Similarly, Shen et al. (2006) described symptoms of a similar condition of Mo deficiency known as ‘shakeback’ disease in yaks from the Qing Hai-Tibetan Plateau. Such symptoms included emaciation, unsteadiness, shivering backs and reduced appetite (though not hair discoloration). Many of the symptoms were consistent with molybdenum-induced copper deficiency. A critical minimum Cu/Mo ratio in ruminants has been taken at around 2:1 (Suttle, 1991). More so, animal studies using rabbits and mice have also linked high intakes of dietary Mo with weight loss, anorexia, premature deaths and reduced fertility (Expert Group on Vitamins and Minerals, 2003). The toxic effects were seen with administration of Mo (VI) but not Mo (III) (as molybdenite).
In humans, molybdenum has an important function in the activity of xantine oxidase, sulphite oxidase and aldehyde oxidase (Momcilovic, 1999; Expert Group on Vitamins and Minerals, 2003). Molybdenum is said to have beneficial effects for patients with sulphite sensitivity and asthmatics. It has also been claimed to reduce the incidence of dental caries. Though data documenting molybdenum toxicity in humans are limited, it has been reported that: water-soluble molybdenum compounds are taken up readily through the lungs and digestive tract. On this basis therefore, the physical and chemical state of molybdenum, the route of exposure, and factors such as dietary copper and sulphur concentrations all likely affect toxicity. As it has been revealed, the effects of acute molybdenum toxicity in humans include diarrhoea, anaemia and gout. Chronic occupational exposure has been linked to weakness, fatigue, lack of appetite, anorexia, joint pain and tremor.
Cases of pneumoconiosis have also been reported (Expert Group on Vitamins and Minerals, 2003) though no currently available data on molybdenum carcinogenicity. Despite the above observations, recognized cases of molybdenum toxicity in humans are rare. WHO first promulgated a guideline value for molybdenum in drinking water in 1993 (WHO, 1993). The value introduced was 70 μg L–1 on the basis of limited toxicological studies on Mo in drinking water in humans. This value has been upheld in the WHO (2004) guidelines.
Concentrations of Mo in ground-water
Perhaps, the solubility of Mo varies significantly with different in different locations and in different compounds. Certainly, the solubility of Mo is very low in acid soils while being very high in alkaline soils. In this regard therefore, the concentration of Mo is higher in acidic soils than as it is in acidic soils. It is of great importance to note that, this concept forms a basis for further study in order to determine the precise concentration of Mo in different elements. In these acidic soils, the average amount of dissolved Mo has been found to range between 0.2 to 1.0 mg/kg.
On this regard, the expected concentration of molybdenum in carbonate aquifers is certainly higher than 70g L-1. Basically, various studies conducted on different regions have proofed a difference in molybdenum concentration ranging from 0.03 g L-1 to above 70g L-1. Perhaps, WHO stipulates a molybdenum concentration of 70g L-1. Molybdenum occurs as a major constituent in the sulphide minerals molybdenite (MoS2), wulfenite (PbMoO4) and powellite (Ca (Mo, W) O4). Sulfurized organic matter in the sedimentary rocks is a powerful trap for Mo and its long-term sequestration. Mo is distributed in the environment as a result of industrial or agricultural contamination leading to the variations in its concentration in the ground water.
Sources of Mo in ground-water
As it has been revealed, Mo is easily absorbed in iron oxides as well as to aluminum oxides (e.g. hydrous ferric oxide) at low or neutral pH (Koback and Runnells, 1980; Dzombak and Morel, 1990; Morrison and Spangler, 1992; Goldberg et al., 1996). However, Mo is also strongly adsorbed to manganese oxides and some clay minerals under acidic conditions in which its absorption to carbonate minerals is insignificant (Goldberg et al., 1996). Under reducing conditions, Mo immobilization has been attributed to the reduction of Mo (Mo (V) to Mo (IV) and precipitation of MoS2; thus enhancing its release from its compounds (Amrhein et al., 1993). Perhaps, stream sediments can have very variable Mo concentrations; despite of it being as low as 10 mg kg-1. Randahl et al (1997) reported that the largest concentration of molybdenum had been found in asphalt and crude oil contents; whereby in crude oil, it constituted of 17 mg Mo/kg (Yen, 1975).
As it has been revealed, Mo is found in various concentrations in the crust, as well as rocks, sediments and soils from Britain and elsewhere as shown in the following table.
*10–90th percentiles; #median value
Further, Nicoli et al. (1989) present Mo concentration data for ground waters from Argentina that range from 23 nmol/kg up to 188,000 nmol/kg which have a mean value of 2,033 nmol/kg.
Perhaps, Liming of acid soils increases the bio-accessibility of molybdenum. As an approximation it can be stated that the molybdenum content in crops can increase two to three times if the soil is limed from pH5 to pH6. If the lime addition is increased to pH7, the molybdenum content in the growth is increased several times (Swedish Environmental Protection Agency, 1997). At high lime additions the solubility can, however, decrease because of adsorption to calcium carbonate. Use of molybdenum salts is preferred to liming of soils where pH increase to raise the bio-accessibility of molybdenum is not wanted (Kabata et al, 1984).
Generally, it has been revealed by Walterson (1993) that, there is a transfer of molybdenum to the external environment through, mainly, wear of railroad rails. At some steelworks the metal contents in leach and groundwater beneath the slag tips have also been measured in the field. One example of results from measurements in the field is Contents of molybdenum in leach/groundwater samples beneath slag tip in May 1990 was under the detection limit while in 1993 and in leach liquor was 210 μg/l (Elander & Fällman, 1993). Further, it has been revealed that; stream sediments can have very variable molybdenum concentrations although concentrations are usually less than 10 mg kg–1.
Mobilization of Mo from sources
According to Campillo, Et al (2002) Mo trafficking for FeMo-co fusion entails the particular donation of Mo from NifQ to NifEN/NifH. However, hereditary and biochemical verification shows that excess molybdate can form a replacement for NifQ, in which this protein is of crucial role once the amounts of Mo obtainable for FeMo-co fusion are small. Perhaps, the recognition of NifQ as a physiological Mo giver suggests that, a putative NifEN/NifH complex capacitate be the molybdenum receiver on the course of FeMo-co biosynthesis. The chemical processes that is basic for this process is that; no NifQ relocates the entire [Mo–3Fe–4S] and thus, cluster remains to be elucidated.
Mineralogical studies and geochemical laboratory investigation have for long been used to determine the reactions and processes controlling the release of Mo from its sources. More specifically, release of Mo from the matrix (limestone) into the solutions such as the stability and solubility of Mo minerals like CaMoO4 (Powellite), Fe2 (MoO4) 3(Ferrimolybdate), PbMoO4 (Wulfenite) and other related minerals and materials like pyrite, Hydrous Ferric Oxides (HFO), Celestine, Organic Matter and Clays in groundwater. Temporal analysis of water samples would help characterizing the chemistry and seasonal variability of the ambient aquifer. This research will also include characterizing permeability, transmissivity, effective volume, saturated thickness and the boundary condition of the limestone aquifers by examination of the lithology logs, pumping tests and other related available data and information (Campillo, Et al, 2002).
Processes transplanting Mo in ground-water
Basically, Mo is a soluble metal which dissolves easily in water and other liquid waste. Based on this, Mo is able to be diffused into different environments including ground water. In addition, increased industrial activities have been a major cause of increased levels of Mo in groundwater; this is through distribution of sewage, ore transportation and disposal of other industrial waste. These processes are a major cause of increased Mo concentration in groundwater. Importantly, the permeability and solubility of carbonated aquifers also contribute to the high concentration of Mo in groundwater (Bostick, et al, 2003).
Investigation of the Mo found in ZVI barrier revealed that; the breakthrough related to the precipitation of calcite, Fe oxide and S minerals in pore spaces which reduced the permeability of the reactive barrier and led progressively to flow via preferential flow paths and ultimately to complete bypass of the ZVI horizon. Significant factors that appear to give rise to increased molybdenum concentrations in ground waters therefore appear to include the creation of reducing conditions, relative abundance and instability of molybdenum-rich minerals (e.g. iron oxides, sulphide minerals) in the aquifer, and groundwater residence time (Campillo, Et al, 2002). In general, Mo is expected to occur as the stable molybdenate oxyanion (MoO42-) in oxidizing terrestrial waters and be removed from solution in reducing systems (Brookins, 1988; Emerson and Huested, 1991).
Aims and objectives of the study
Due to lack of studies on molybdenum in groundwater the results of this research will serve as scientific basis to future investigations on the occurrence and flow of ground waters that are high concentrations of molybdenum. Further, the research findings can provide scientific and technical base to future development programs including agriculture, energy, settlement and urbanization. The scientific community, the public, entrepreneurs, regional and federal governments and WHO can benefit from the research outcomes (Bostick, et al, 2003).
This research aims to be an integrated approach employing hydro geological, geochemical and mineralogical techniques to assess the behavior of molybdenum in ground waters in the carbonate aquifers. Concentration of Molybdenum in ground waters is often insignificant but depending on the aquifer matrix, litho logy of surrounding environment and the anthropological contaminations (these are related to urban, commercial, industrial, mining and governmental activities), it may be very high locally and exceed the WHO guidelines of 70g/l. Therefore, geochemical processes controlling molybdenum leaching from contamination sources into groundwater is very important and need to be researched by geochemical techniques including (1) analysis of total metals and whole-rock specimens and (2) use of Sobek humidity cells and recirculation leach columns (Bostick, et al, 2003).
Literature Review
Mo is distributed in the environment as a result of industrial or agricultural contamination. It is an ingredient used in steel alloys and welding rods and is used as an additive in lubricants, as a corrosion inhibitor and in the manufacture of tungsten, pigments and ceramics (Morrison et al. 2006). Mo can also be distributed in the environment as a result of fossil-fuel combustion, leaching from fly ash and mobilization from mine wastes (Morrison and Spangler, 1992; Zhang and Reardon, 2003). It is also used in agricultural activities to counteract molybdenum deficiency in crops (WHO, 2004). In abandoned mines, often reclamation is designed to reduce the acidity and to reestablish the vegetation to minimize erosion. However, maximum concentration of Mo in groundwater can be increased following reclamation practices (Kaback, 1980).
Molybdenum is therefore often concentrated in sulphide-rich ore zones, and is commonly associated with high concentrations of uranium, antimony, arsenic, vanadium, barium, copper, lead and zinc (Erickson, 2000). Sulfurized organic matter in the sedimentary rocks is a powerful trap for Mo and its long-term sequestration. Compared to other trace elements used as redox proxies, molybdenum (Mo) shows the highest degree of enrichment (relative to crustal values) in the reducing sediments (Crusius et al., 1996, Tribovilard et al., 2004). Thus, Mo concentrations in sediments and sedimentary rocks deposited in anoxic settings preserve useful information about the local redox conditions at the time of sedimentation (Goldberg, Et al. 1996).
Molybdenum concentrations in water are controlled to a significant extent by redoxconditions and pH. In oxic waters at pH>5, Mo occurs principally as the molybdate oxyanion (MoO42-). This means that Mo can be present as a stable soluble species under the conditions of a large group of natural waters. Sorption reactions also have a strong control on the mobility of Mo. Mo adsorbs easily to iron oxides as well as to aluminum oxides (e.g. hydrous ferric oxide) at low or neutral pH (Koback and Runnells, 1980; Dzombak and Morel, 1990; Morrison and Spangler, 1992;Goldberg et al. , 1996). It is also strongly adsorbed to manganese oxides and some clay minerals under acidic conditions. Sorption to carbonate minerals is insignificant (Goldberg et al. , 1996).
Under reducing conditions, Mo immobilization has been attributed to the reduction of Mo (Mo (V) to Mo (IV) and precipitation of MoS2 (e.g. Amrhein et al. , 1993). This can be described by the following half-reaction:
MoO42- + 2e- + 2HS- MoS2 + 4H2O.
However, the kinetics of MoS2 precipitation are slow and the mineral is rarely seen in natural systems (Erickson and Helz, 2000; Bostick et al. , 2003). Mo more likely co-precipitates with FeS or FeS2 under such reducing sulphidic environments (Helz et al. , 2004). This gives rise to the often high concentrations of Mo found in sulphide minerals. Helz et al. (1996) suggested that available HS- ions under S-reducing conditions could transform conservative dissolved molybdate to reactive thiomolybdate species which are more susceptible to scavenging by Fe-rich particles and S-rich organic matters (Vorlicek et al., 2004). In sulphidic solutions, molybdate can undergo sulphidation in a series of steps, leading to monothio-, dithio- and trithio- to tetrathiomolybdate. Though thermodynamically unstable, these intermediate (Mo (VI)) thiomolybdates could become dominant in sulphide rich environments (Erickson and Helz, 2000). Lyons et al. (2003) suggested that organic matter could play an important role in thiomolybdate formation.
Under reducing conditions, molybdate (MoO42-) and tetrathiomolybdate (MoS42-) have also been observed to adsorb onto synthetic pyrite (Bostick et al. , 2003). Adsorption of MoO4 2- to pyrite was noted to be greatest at low to neutral pH, although MoS42- sorption remained strong even at high pH. Bostick et al. (2003) suggested that molybdate sorption to pyrite was reversible while the sorption of tetrathiomolybdate likely forms strong inner-sphere complexes and is therefore less mobile. They also concluded that thiomolybdate species could controls the concentrations of molybdenum in reduced sulphidic sediments. Vorlicek et al. (2004) concluded that Mo-Fe-S cubical structures on pyrite, observed by x-ray spectroscopy, must involve reduction of Mo (VI) in order to stabilize. They suggested that zero-valent sulphur was an important factor in reducing Mo. Figure 1 summarizes the probable model for Mo scavenging from a coastal anaerobic basin (Morin, 1997).
In the sulfide zone, MoO42- begins to convert to thiomolybdate as aHS- approaches the switch point, subsequently; thiomolybdates can be scavenged by fe-bearing fluvial or Aeolian detritus. Additionally, sulfidized organic particles can capture Mo as organic oxythiomolybdates. The sedimentary products of these processes are represented here as Mo-S-Fe cubane-like compounds petrinlike organic Thiomolybdates because such materials are known to possess interaction distances. The cubane from may exist as a surface phase on fe sulfide minerals. Compounds of the kinds depicted are versatile redox agents and from readily in the laboratory by obiotic pathway. Their oxidation states in sediments may be poised by local conditions (Morrison, 1992).
As it has been revealed, concentrations of molybdenum in a sand column with acetate as a reducing agent increased modestly to 1.8 g L-1 as a result of reduction of iron-manganese oxides, but decreased further along the column as a result of sulphate reduction and the co-precipitation of molybdenum with FeS (Schlieker et al., 2001). This spatial variation in dissolved Mo concentrations has also been observed in aquifers. Smedley and Edmunds (2002) investigated the concentration of molybdenum in ground waters from the East Midlands Triassic Sandstone aquifer (Tribovillard, Et al, 2004).
The aquifer outcrops in central Nottinghamshire but is confined in east Nottinghamshire and Lincolnshire by poorly-permeable marls and mudstones of the Mercia Mudstone Group. They (2002) found that molybdenum concentrations were low in oxic, unconfined ground waters in Nottinghamshire but increased progressively downgradient (up to 3.5 g L-1) in the confined, reducing part of the aquifer further eastwards. This research led to the conclusion that probably reductive dissolution of iron oxides; manganese oxides were the cause of low abundance in the aquifer. Concentrations of molybdenum in old, deep, saline ground waters further down the groundwater flow gradient in Lincolnshire were lower (<2 g L-1) as a result of incorporation into precipitating sulphide (FeS) (Yao, 1999).
Morrison et al. (2006) reported high concentrations of molybdenum and uranium, mobilized by oxidation reactions at a uranium tailings site in Colorado, USA. They observed the unexpectedly early breakthrough of molybdenum from a permeable reactive barrier composed of zerovalent iron (ZVI) installed to treat the uranium-molybdenum-rich waters. Influent molybdenum concentrations were around 4.8 mg L-1. The ZVI in the barrier and initially reduced the dissolved molybdenum concentrations in the effluent to around 0.1 mg L-1, although after 250 days, concentrations increased to as much as four times the influent concentration because of desorption of molybdenum (Bostick, et al, 2003).
Methods and Procedures
All methods used in this data collection involves standard and consistent with general geological procedures. Adequate chemical and physical processes will be undertaken in the endeavors of deriving sufficient information about groundwater that have high concentration of molybdenum. There will be a series of field and laboratory operations which will ensure collection of sufficient data that will help in providing viable information for present and future research. The deployment of modern technology will also be adequately utilized to ensure that monitoring of the processes is undertaken efficiently and effectively (Campillo, Et al, 2002).
Facilities
A number of techniques and equipments will be used in the elucidation and identification of the linderoles as well as the derivatives and intermediates produced in the chemical procedures. Highly specialized equipments will be needed in order to guarantee results. In this case, the need to mobilize funds and resources to acquire these facilities is inevitable. This will include data collection facilities as well as equipments for storing and analyzing data. This may be within the organization or from external sources. In addition, various specialist and staff will be needed in the operation, retrieval of data as well as in the process of analyzing the collected data (Goldberg, Et al. 1996).
Chemical procedures will be undertaken in the laboratory in collaboration with geological specialist. The guidelines of the professor will also be of great help to the success of the whole process. Consultation on chemical and physical procedures will be highly prioritized. In this case, adequate consultation from the university library will be made due to its richness in a wide range of chemistry materials. By so doing, any problem or challenge in undertaking the operations will be addressed thus helping in yielding a successful research (Erickson, 2000).
The general methodology consists of the following components
Data collection
The process of data collection will be effectively coordinated to ensure production of results from the process. The incorporation of efficient and competent staff will be of great consideration to avoid delays and mistakes. As it had been outlined the collection of data will also be reinforced by the use of modern technology; whereby sophisticated facilities will be used to ensure collection of precise information. On this aspect, both primary and secondary data will be essential in coming up with viable information that can be used in making conclusions (Goldberg, Et al. 1996).
Firstly, the use of topographical maps will be of great importance. This is because they will help in giving precise locations which will help in answering questions on geological differences. The topography of an area is directly correlated with the ground water, thus the need to utilize topographical maps. Previous data on geological, geophysical and geochemical maps is of great importance to the collection of data. In this aspect, this data will be used in making comparisons with current data as well as giving vital ideas which help in speculating about the outcomes of the study (Erickson, 2000).
Rainfall data from metrological departments will also be utilized in these procedures. This is based on the fact that, groundwater if a product of rain and also the topography. This information will help in speeding up the data collection process since the existing data will serve the purpose of fresh data which would have otherwise been collected. On the other hand, the ASR Data will be incorporated in the study; this will lead to a very fast and efficient process. This is widely due to the application of sophisticated facilities by the ASR in the storing and retrieval of data (Erickson, 2000).
Importantly, data from the borehole inventory will be optimally utilized in investigating about groundwater which has high concentration of molybdenum. This is due to their expertise and experience in the borehole operations thus help in giving crucial information about the orientation of different locations. In the process of data collection, this study will analyze the information about the current wells production. Basically, information about existing wells production will tell more about the chemical composition of the rocks and that of ground water. Finally, the process of data collection will incorporate the utilization of data on limestone. Characteristics like the degree of transmissivity, permeability, saturation, effective volume, and aquifer boundary will be realized (Goldberg, Et al. 1996).
Field works
Various field works for groundwater chemistry studies which include sampling from drilling cores and water wells will be conducted. In addition, there will be examination of lithologic logs to determine the length of core available for the study area. Other fieldwork activities like taking about 10-15 samples from each well to provide an unbiased general chemistry will also be performed. In addition, water sampling to measure field parameters like pH, Eh, DO (dissolve oxygen), conductivity and temperature (Erickson, 2000).
Laboratory works
Most of the research will be undertaken in the laboratory and will include: Selecting duplicate samples randomly for approximately 10% of the samples to detect precision and accuracy of analytical results. Secondly, chemical and mineralogical analysis (ICP-AES) for major and minor elements and ICP-MS for trace elements, thin sections for petrography and mineralogy studies (Kaback, 1980).
Data processing
A number of procedures will be undertaken so as to ensure that the data is efficiently and effectively processed. Firstly, replacing censored data (some of data are generally out of detection limit of laboratory; this type of data is commonly called censored data). Secondly, calculating enrichment factor for Mo and other trace elements should also be performed. Further, Calculating OM (organic matter) in limestone to obtain Mo enrichment vs. OM will be keenly undertaken. Data processing also involves the establishment of a histogram, P-P plot and Q-Q plot for each elements and calculating correlation matrix for the elements. Finally, factor analysis (Principle component analysis) is used for the identification of hydro geochemical processes responsible for variance of concentrations of the elements (Kaback, 1980).
Determining the contamination sources and leaching rates into the groundwater by static and kinetic tests and etc.Determining sources of Mo in groundwater (Quantified Role of Pyrite, Hydrous Ferric Oxides (HFO), Celestine and other related minerals depending on abundance in limestone, Organic Matter and Clays)
Component Stages of the Project
This is a three year project which will commence in 2010 and be terminated in the year 2013. The different activities and phases of the projected have been keenly spread out in the three years. This will ensure sufficient time allocation for each activity which will ensure perfection and production of good results. This type of research is time intensive and it’s on that basis that the project is scheduled to take that amount of time. Each of the different faces is very complex in its own kind thus calling for adequate allocation of time (Morin, 1997).
This research on the characteristics of molybdenum in underground water is very essential and requires sufficiency of time and resources. As it has been described before, the collection, recording and analysis of data is time intensive. In general, all the aspects of the research need maximum attention and consideration in order to help yield viable results. Despite that, the results of the final analysis and evaluation are most crucial; the role of all the other stages of the research cannot be undermined. The outline of the different faces and time schedule is as follows (Kaback, 1980).
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