Critical Analysis


 


This dissertation aims to analyse the Environmental Chemistry of Permeable Pavement Systems in the Field of Irrigation.  In the last few decades people have become increasingly aware of the issues environmental chemistry encompasses and of its remarkable power to treat those issues. Environmental toxicologists and atmospheric and oceanic modelers are discovering crises at a prodigious rate, solutions are being suggested, and governments and international agencies are taking steps to implement them. It is tempting to see these changes as products of modern science, particularly modern chemistry: to believe that science has finally progressed sufficiently to allow humans to run the world properly (Mauskopf 1993). People can claim that man’s ability to model has allowed him to predict a set of photochemical reactions in the upper atmosphere and that his analytical abilities have enabled him to document, with startling sensitivity, that a number of these predictions are accurate. In this perspective environmental chemistry is likely to be seen as an outcome of the accumulation of chemical knowledge, the development of statistical research methods, and much better understandings of transport processes in soils, bodies of water, and the atmosphere (Mauskopf 1993).


Here it will be the product of a mature science where a certain level of knowledge has generated new research possibilities whose exploration leads to a recognition of needs for policy, to policies themselves, and to further research problems. It would seem to follow that there could have been little environmental chemistry prior to that maturity, simply because there would have been no grounds for concern or any sound basis for policy. In such a view, then, environmental chemistry is a product of knowledge and leads to action. In terms of the history of chemistry, the field of what may loosely be called environmental chemistry is rich with important and largely unstudied questions. It is perhaps the key area for understanding the interaction between chemistry on the one hand and society and culture on the other (Mauskopf 1993).


The permeable pavement systems in the field of irrigation is generally a good thing for agriculturist but the chemical problems of permeable pavement particularly on Efflorescence poses a threat. Efflorescence is mostly crystal salts that have hardened, then transferred from the center of the concrete to the surface. Efflorescence occurs after a cementitious product cures or has reached the state desired. It routinely occurs in various construction works, particularly brick, as well as some fire stop mortars. The process involved in such state starts when water moving through a wall or any kind of structure brings salts to the surface that are not bound as part of the cement stone. In some instances efflorescence occurs when water is driven out as a result of the heat of hydration as cement is being formed. Most of the time Efflorescence can be removed using phosphoric acid, if the source of the water penetration or the Efflorescence phenomenon is not addressed properly efflorescence may reappear and cause more damage. Efflorescence can cause increase water deposits that can limit or decrease the flow of water into the agricultural products.  It reduces the chance for the agriculture products to receive water for its daily needs.  Moreover Efflorescence is primarily a salty substance and when it is mixed with agricultural products, it leads to unwanted results. 


            With this regard, this part of the paper will determine the difference of pH and electrical conductivity values of the soil on which tomato and ryegrass were grown, as well as the water from the system and ascertain the suitability of the stored water for irrigation purposes. Aside from this, a comparison of the metal levels in tomato grown with the stored water and that bought from the market will be analysed.


 


Difference of PH between Tomato and Ryegrass


            From the gathered data, the ph of Tomato and Ryegrass were recorded depending on the type of bases. Basically, the data of ph of tomato and ryegrass are from Stone Base


Plastic Base, Dionised Water, Ctrl Stone Base, Ctrl Plastic Base and compose seed. And using the t-test analysis procedure, we will compare if there is a significant difference between ph of Tomato and Ryegrass in consideration to the type of their bases.


 


The Data:


pH


Ryegrass


tomato


Stone Base


7.373


7.253


Plastic Base


7.39


7.22


Deionized Water


7.25


7.13


Ctrl Stone Base


7.4


7.23


Ctrl Plastic Base


7.36


7.11


Seed Compost


6.49


0


 


 


Analysis Result:


 



 


            With this information, the computed two-tailed P value is equal to 0.3360 and by conventional criteria, this difference is considered to be not statistically significant.  Basically, the mean of Tomato minus Ryegrass is equals to -1.22000 with 95% confidence interval from -3.90973 to 1.46973. And the computed t-value is 1.0106 with df = 10 and standard error of difference equal to 1.207.


            As seen in the results we may say that the pH level between tomato and ryegrass in accordance to the type of base has no significant difference.


 


Difference of Electrical Conductivity (EC) between Tomato and Ryegrass


            Similar to the previous analysis, the Electrical Conductivity (EC) of Tomato and Ryegrass were also recorded depending on the type of bases. Basically, the data of EC of tomato and ryegrass are from Stone Base, Plastic Base, Dionised Water, Ctrl Stone Base, Ctrl Plastic Base and compose seed. And through the t-test analysis procedure, we will conduct an analysis of differences between ph of Tomato and Ryegrass in consideration to the type of their bases.


 


The Data:


EC  µs/cm


ryegrass


tomato


Stone Base


728


700


Plastic Base


782.667


597.667


Deionised Water


772


655


Ctrl Stone Base


760


646


Ctrl Plastic Base


987


547


Seed Compost


1570


0


 


 


Analysis Result:


 



            From the gathered data and results of t-test analysis, the computed two-tailed P value is equal to 0.1480 and by conventional criteria, this difference is considered to be not statistically significant.  Basically, the mean of Tomato minus Ryegrass in accordance to their EC is equal to -409.00000 with 95% confidence interval from -1023.88484 to 205.88484. And the computed t-value is 1.7099 with df = 10 and standard error of difference equal to 239.201.


            As revealed by these results we may say that the EC level between tomato and ryegrass in accordance to the type of base has no significant difference.


 


Comparison of the metal levels in tomato in dionised water and that bought from the market


            Again using the t-test analysis, this part of the paper will determine if there is a significant difference between the metal levels in tomato in dionised water and that bought from the market. Here are the data used in the analysis.


 


 


 


The Data:


Treatments


Cd 214.440


Cu 324.752


Fe 238.204


Ni  231.604


Pb 217.000


Zn 213.857


Tomato fruit  from market


0.133


6.767


37.700


5.167


0.000


14.600


Dionised Water


50.400


48.967


48.967


49.967


48.567


46.700


 


Analysis Results:



            From evaluation of values, it shows that the results of analysis indicate significant difference among samples. From the gathered data and results of t-test analysis, the computed two-tailed P value is equal to 0.0014 and again by conventional criteria, this difference is considered to be very statistically significant.  Basically, the mean of Tomato fruit from the market minus Dionised Water in accordance to the metals present is equal to -38.20017 with 95% confidence interval from -53.58966 to -22.81067. And the computed t-value is 6.3808 with df = 5 and standard error of difference equal to 5.987.   As revealed by these results we may say that the metals present in a tomato from dionized water was significantly different from tomato bought in the market.


 


Synthesis


            Basically, heavy metals absorbed by plants and to be consumed by humans were considered harmful. To be absorbed by plants metals need to be in a soluble form i.e. ions/salts. As seen in our study, the content of metals absorbed by a plant e.g. tomato depends on its container and bases.  Basically, once the ions are in the soil they are actively taken up by the plant via the root hair cells or more passively absorbed via diffusion. It seems to depend on the concentration of ions in the plant, in some cases this is 1000′s of times greater than in the soil. The rate at which these metals are taken up is heavily dependent on the pH of the soil, as at certain pH levels these nutrients become ‘locked up’ in solid form and are unavailable to the plants.


            In consideration to these findings, we may say that plants can absorb heavy metals from its bases and store them. That is why heavy metals are so dangerous. They can be spread with the water or through the fish and concentrated in carnivores higher up the food chain. Many materials spayed on crops leave residual quantities in the soil for plants to take up. Not every non-organic crop ever becomes tainted with questionable chemicals but some do but there is no way to tell which ones. The soils pH at 6.5 -7 has shown crop plants absorb less of the metals. Soil nutrients are most available at this pH so the plants will grow well. The best way to avoid worrying might be to create raised beds or convert the roof to support one of the roof top growing systems.


 


Reference:


Mauskopf, SH (ed.) 1993, Chemical sciences in the modern world, University of Pennsylvania Press, Philadelphia.


 


 


 



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