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The world is today faced by myriad challenges raging from environmental problems to depletion of key resources that are very vital for the growth of the world economy. Toxic heavy metals found in the air, soil and water are one of the significant pollutants affecting the global environment. Toxic metals exist naturally in the ecosystem, and their composition and concentration vary considerably in different geographical locations. Human activities are one of the factors responsible for the increase in metal concentration in the environment. For instance, activities such as the purification of metals, the smelting of copper and production nuclear energy, have significant ramifications on the balance of some heavy metals in the environment. The alteration of heavy metals concentration, therefore, obliterates the ecosystem. This is because such metals are non-degradable and toxic. Hence, they affect the aquatic life and other life forms.
The European community has managed to identify some of the most harmful elements to the environment. “These elements include arsenic, cadmium, cobalt, chromium, copper, mercury, manganese, nickel, lead, tin, and thallium” (Norse, 2005). Elements like copper, manganese and nickel are quite important to the human health if consumed in low quantities. Nonetheless, some elements are extremely toxic, and if consumed can interfere with the normal body functions. Besides this, they can also affect an individual’s bones and teeth. Consequently, the concentration of these elements should be closely examined in various environments to determine their level of contamination.
The aquatic environment is important for the survival of various living things that inhabit it, and human beings are also directly or indirectly affected by the nature of the aquatic environment. This is because the aquatic environment acts as a key source of food that many people depend on for their livelihood. Moreover, it acts as a recreational facility for tourists. Besides this, some species of birds mainly rely on the aquatic environment because it provides them with food, and they also use it for breeding purposes. Apart from the above mentioned elements, the pollution of the aquatic environment also stems from contaminated domestic and factory water discharge. Direct dumping of solid materials that are non biodegradable also contributes to pollution of this environment. All these pollutants have serious ecological impact. This is because they interfere with the quality of water, plants and the aquatic organisms.
Laboratory Analysis of the Chemical Samples Derived from an Aquatic Environment
This paper discusses chemical data that was derived from an environmental laboratory analysis, which was designed for chemistry students. Therefore, the purpose of this experiment is to analyze samples, which were collected from an aquatic environment. The analysis of the chemical data derived from the samples will be instrumental in determining whether that environment is polluted or not.
According to the study guidelines, the students were instructed to collect samples from a particular aquatic environment. After collecting the samples, students were to prepare them for laboratory analysis. With regard to this chemical analysis, two analysis instruments, ICP-AES, ICP-MS, were chosen because they can facilitate accurate identification of the level of concentration of various elements.
The analysis was designed for the examination of a wide range of elements. The wide scope of analysis was recommended because it would reveal several pollutants that are caused by various elements. In this case, the sources of pollution will be determined through examining the level of concentration of each element in the samples collected. Apart from this, the geographical and historical aspects of these elements will also be used to reveal their level of pollution.
The above table indicates the average concentration of some elements, which include lead, Cadmium, Strontium, Copper, Nickel and Chromium in Biota from the three sites. It clearly shows that the concentration of these elements in site two and three are higher than those in site one and four. The difference in Biota concentration is mainly attributed to two factors. First, the Biota in both sites two and three are smaller in size than the Biota in site one and four. It is, therefore, evident that the Biota with relatively small sizes tend to accumulate high levels of metals than the big ones.
The second factor that accounts for the variation in metal concentration in the Biota is related to the areas inhabited by these organisms. For instance, small amounts of Biota were located in the sediments found between small plants, while the big Biota was located in water. It can be concluded that the Biota, which live in the sediments between plants exhibit high concentration of elements. This occurs because they inhabit the same environment with the organic materials. As will be revealed later in this report, the concentration of elements in water is compared to the concentrations in the sediments.
The above table indicates the ratio of the concentration of Ni: Co found in Biota situated in water and sediments collected from there different sites. It also shows that Biota and sediment contain the same ratio of Ni: Co, which is 0.1. Nonetheless, both filtered and unfiltered water contain different ratios of Ni: Co, which in this case is 1.1. According to this table, sediments gathered from the Eastern Cape had Ni: Co concentrations whose ratios were less than 1.1. This occurred due to the urban wastes such as sewage discharge. The ratio of 2.1 for Ni: Co is regarded as a normal ratio, and it indicates that there is little or no urban run off or sewage input. This may imply that water does not necessarily reveal the actual concentration of metals in a given environment. Therefore, it is not recommended to use water samples in examining the concentration of heavy metals, and also in analyzing the extent of pollution in a given environment.
This table presents the average concentrations of some heavy elements in filtered and unfiltered water from the three sites. It indicates that the concentrations of the metals are higher in filtered water than in unfiltered water. This implies that the filtered water samples were contaminated during the filtering process. The contamination may have also occurred as a result of using plastic syringe filters. This is because plastics contain some organic matters, which may have affected the samples, hence, increasing the level of concentration of the elements. Another possible cause of the contamination was probably the use of dirty syringes and the filters for filtering the water samples. Therefore, it is recommended to re-filter the samples in the laboratory using better techniques. Another viable alternative in this process is to apply chemical techniques instead of the normal filtration methods such as precipitation.
This table indicates the concentration of copper in sediments derived from the three sites. Generally, the concentration of Cu in sediments is higher than in Biota located in the same site. This means that Biota does not accumulate as much Cu as sediments.
In the first site as indicated in the above graph, the concentration of Cd is high both at the bottom and at the core. However, between these two locations, the concentration is approximately 50% lower. According to the information obtained from this location, in the past this city was hit by a Tornado, and the whole city was ravaged. Therefore, it was probably contaminated by the industrial wastes that came from the ravaged structures and sewage installations. This is likely to have occurred if the structures were built on limestone foundations that increased the Cd concentration. At present, this area is crowded with boats and fishing activities are also prevalent. Therefore, it can be assumed that this area is polluted. As a result of this, it is not surprising to identify high concentration of Cd at the top of the core.
In site two indicated above, the graph shows a high concentration of Cd at the top of the core, which is about 1659 ng/ml, and at the bottom ( 90 cm depth) which is about 208 ng/ml. According to the history of this site, the high concentration of Cd at the bottom could be attributed to the fact that sixty years ago there was the Perth's main airport in this suburb. The industrial sources of the Cd must have originated from people’s activities and the equipment they used. Moreover, it clearly shows that the data came from the core, and it presents the data for the sixty years. In addition, the high concentration of Cd at the top of the core is attributed many factors. For example, the suburb is near a railway station, and there is also a path that is shared by both cyclist and pedestrians. Besides this, there is a small yacht club and a golf course.
As shown in graph seven the concentrations of Cd in site three is relatively lower than that is in sites one and two, but it is still higher than the natural concentration of Cd in the sediment. However, the graph does not show a significant change of the concentration over time. This implies that that there were no considerable factors to increase or decrease the concentration of Cd. Thus, the high concentration of Cd in this area may have been caused by toxic gases and emitted by vehicles. This is because the location is near a highway that has a bridge.
Table seven shows the average concentration of Zinc (mg/ml) in sediments collected from sites one, two, and three. In site one and two where we have sand sediments, the concentration of Zinc is lower than that in site three where the sediment is muddy. The concentration level can be estimated by analyzing the relationship between metal concentration and the size of sediment particles. This is because the concentration of Zinc in marine sediments increases with decreasing size of the sediment particles. Since the normal concentration of Zinc in sediments is 200 mg/kg = 0.0002 mg/ml, the concentrations of zinc in forested sites are considered to be toxic concentrations. The highest concentration of Zinc in site three can be due to the fact that the dissolved Zinc in water settles in sediments due to the low speed of the water movement.
Future Survey Recommendations
Future analysis of this nature can be improved by the following recommendations. According to the results indicated in the above discussion, it is evident that sediments and Biota are potential sources of toxic metals in the environment. However, water does not reveal environmental pollution compared to sediment and Biota. Therefore, it is not recommended to conduct future analysis using water samples because it does not provide reliable data.
When gathering samples, it is advisable to use boats because they facilitate movement in water. Hence, a researcher can easily access and collect a variety of samples from different locations in the same field of study.
For the core samples, it would be easier to use an electronic technique rather than a manual method to access the depth point. Apart from this, the core should be long to enhance the presentation of more data on how human activities culminate into high levels of pollution. Another noteworthy recommendation is that, the core should be taken from the same location where the sediment was collected. This is important in the sense that it enhances accuracy during data analysis.
Last but more importantly, it is better to collect mussel samples from sediments rather than from water. Since different sizes of mussels revealed different metal concentrations, it is, therefore, better to record the weight of the mussels’ tissues, and then compare the analyzed data of the mussels that have the same weight.