Tuesday 15 April 2014

the effects of practical work and the theoretical work on the academic performance of chemistry students.

CHAPTER ONE
INTRODUCTION
1.0    Introduction
In Nigerian schools, the issue of theoretical method of teaching rather than practical approach has over the years become a subject of concern to many in the educational system.
Today it is usual to see that chemistry which is a practical science subject is taught using lecture method (theoretical work) instead of applying methods such as activity method, demonstration method, etc which emphasizes "learning by doing". This practice has far reaching consequences on student's/learners academic performance, and the nation's development at large. An individual who holds a bachelors degree (BSc) in chemistry from a Nigerian university cannot operate the various analytical instruments such as Gas Chromatography (GC), Atomic Absorption Spectrophotometer (AAS), Infrared Spectrophotometer (IR), etc, let alone to interprete results from chemical analysis using these instruments. In this study, one major purpose is to carryout comparison between practical work and theoretical work as it affects chemistry student's academic performance. 
1.1    Background to the Study 

The performance of chemistry students at the secondary and tertiary levels has been poor and deplorable over the years (Agbadinano, 1987; Jimoh, 2004; Njoku, 2007). Analysis of student's performance in the sciences at SSCE level as noted by Njoku, 2007 revealed that between 1980 and 1991, the annual average pass rate at credit level (grade 1-6) in chemistry was 15.41%, while the absolute failure rate (grade 9) was 61.82%.
Akinyele (1987) remarked that student's poor performance in practical aspect of chemistry examination at the SSCE level contribute to high failure rate of students in chemistry which in turn affect students performance at the tertiary level. 
Researchers conducted by Jimoh (2004) and Njoku (2007) on student's performance in chemistry practical at the SSCE level reveal that student's found questions on quantitative chemical analysis easier than that on quantitative chemical analysis and the theory of practical work in that order.
From these studies, there seem to be no doubt that chemistry students have problems/difficulties with the chemistry practical at SSCE level. The interim joint matriculation board (IJMB, 2006) and Science Teachers Association of Nigeria (STAN, 2007) report reveal that majority of young chemistry graduates could not prepare standard solutions correctly not to talk of conducting weekly practicals for students. This statement clearly shows that student's performance in analytical chemistry at the degree level is not different from what is attainable at the SSCE level. The pertinent questions often asked by chemistry educators is on how alleviate students poor performance in practical chemistry examinations since the quality of chemists could be judged accurately their competence in analytical chemistry.
A critical analysis of chemistry curriculum at the Nigeria Certificate in Education (NCE) and the degree levels show that undergraduates chemistry students are expected to conduct weekly practical usually on four areas. These are quantitative, qualitative, thermo-chemistry and kinetics practicals. In line with the foregoing problems, this study is carried out therefore to show a comparison between practical and theoretical work as it affects chemistry students.
Soil is a complex mixture of organic and inorganic materials. It is the medium for plant growth. Understanding the characteristics of soil, in particular knowing how to maintain good quality soil and how to improve difficult soil is of importance for successful agriculture. It thus has considerable economic significance (Campbell, Reece, Urry, Cain, Wasserman, Minorsky, and Jackson, 2008).
Land fills have been identified as one of the major threat to ground water resources (Fatta, Papadopoulos and Zidou, 1999; USEPA, 1984). Waste placed in landfills or open dumps are subjected to either groundwater underflow or infiltration from precipitation. The dumped solid wastes gradually release its initial interstitial water and some of its decomposition by products gets into water moving through the waste deposit. Such liquid containing innumerable organic and inorganic compounds is called "LEACHATE". This leachate accumulated at the bottom of the landfill and percolates through the soil.
An open dump site is a land disposal site at which solid waste are disposed off in a manner that does not protect the environment, is susceptible to open burning and is exposed to the elements, disease vector and scavengers. These unplanned heaps of uncovered wastes, often burning and surrounded by pool stagnated polluted water, rat and fly infestations with domestic animals roaming freely and families of scavengers picking through the wastes is not only an eye sore but a great environmental hazard (Okonkwo, Okieimen and Olorunfemi, 2010).
The generation of Leachate is caused principally by precipitation percolation through waste deposited in a landfill. Once in contact with decomposing solid waste, the percolating water becomes contaminated and if it then flows out of the waste material it is termed Leachate (Young, 1992). Additional Leachate volume is produced during this decomposition of carbonaceous materials producing a wide range of other materials including Methane, carbon dioxide, and a complex mixture of organic acids, aldehydes, alcohols and simple sugars.
The physical appearance of leachate when it emerges from a typical landfill or open dump site is a strongly-odoured blackish, or yellow-or orange-coloured cloudy liquid. The smell is acidic and offensive and may be very pervasive because of hydrogen, nitrogen and Sulphur rich organic species such as mercaptans (Kjeldsen, Barlaz, Rooker, Baun, Ledin, and Christensen, 1996).
This study is based on the determination of the effects of various concentrations of leachate collected from an open dump site in Warri on the germination of maize seeds. 
In the UK, in the late 1960's Central Government Policy was to ensure new landfill sites were being chosen with permeable underlying geological strata to avoid the build-up of leachate. This policy was dubbed "dilute and disperse". However, following a number of cases where this policy was seen to be failing and an exposee in the "The Sunday Times" of serious environmental damage being caused by inappropriate disposal of industrial wastes, both policy and the law was changed. The deposit of poisonous wastes Act 1972, together with the 1974 Local Government Act, made Local Government responsible for waste disposal and also responsible for environmental standard enforcement for waste disposal. Proposed landfill location also needed to be justified not only by geography but also scientifically. Many European countries decided to select sites in groundwater free clay geographical conditions or to seal each site with an engineered lining. In the wake of European advancement, the United States increased its development of leachate retaining and collection systems. This quickly led from lining in principle, into the use of multiple lining layers in all landfills (Minus those truly inert) (www.leachate.co.uk)
In the recent past, the Gazipur landfill (in Delhi, India) started in the year 1984 and still in use. The waste dumped of this site includes domestic waste, e.g kitchen waste, paper, plastic, glass, clothes, construction and demolition waste consisting of sand bricks, iron scraps, further waste from the adjacent poultry market, fish market, slaughter house, diary form and non-infectious hospital waste is also dumped. The site is non-engineered low lying open dump, looks like a huge help of waste up to a height of 12-20 metres (Aggarwal, Singhmar, Kulshrestha, and Mittal, 2005). This is similar to the Warri open dump site where the leachate was collected.
The impact of landfill leachate on the surface and groundwater has given rise to a number of studies in recent years (Saarela, 2003 Abu-Rukah and Kofahi 2001; Looser et al 1999, Christensen et al, 1998, de Rosa et al, 1996; Flyhammar 1995, Okieimen and Tabeta, 2008).
Urbanization, Industrialization and high rate population growth have therefore led to unprecedented pressure on the environment. It is also true that the level of urbanization on an area profoundly influences the amount, size, nature and complexity of waste generated by men (Tairu, 1980). In 1991, the erstwhile Nigerian Federal Environmental Protection Agency (FEPA) published its standard for the regulation of industrial discharges. This stated that such discharges must be treated and disposed of only into temporary or permanent waste to prevent undesirable effects on the biota, surface, underground water quality and soil characteristic. However, over the years, the published standards did not seem to have reduced the load of untreated waste disposed into the environment in Nigeria (Okonkwo et al, 2010).
1.2    Statement of the Problem
The issue of practical and theoretical work as it affect chemistry students academic performance in Nigeria has been of much concern to all and assundry. The use of theoretical work alone, leads to poor academic performance of students.
The problem is so much that it has lead to the widely acclaimed fallen standard of education, at all levels, in Delta State and Nigeria at large. The quality of education depends on teachers as reflected in the performance of their duties.
In schools today, chemistry is taught mainly employing theoretical approach, this is a problem because this practice produce students/outputs with low quality; for the NCE level, teachers who cannot conduct weekly practicals for their secondary school students.
1.3    Objectives of the Study     
The objectives of this study are;
1.    To compare the academic performance of chemistry students using practical work and theoretical work.
2.    To investigate the contributions of practical work on student's academic achievement and on the nation's economy.
3.    To determine the effects of various concentration of leachate on the germination of maize seeds.
4.    To determine the leachate concentration that can be best recommended to farmers for the germination of seeds.
1.4    Significance of the Study     
This research work will be beneficial to;
1.    To teachers, it will help them appreciate the importance/advantages of the use of practical work.
2.    To students and teachers/lecturers, this work will lead to students being more active in practicals and for teachers to use both practical work and theoretical work side by side to improve on student's academic performance and improving on teacher's professional competence.
3.    Also to students and lecturers in the various institutions, as it will serve as a data base for future research work on leachate.
4.    To farmers, it will enable them know the appropriate concentration of leachate that is favourable to plant growth, hence leachate will serve as a cheap sources of fertilizer to farmers, and thereby improve crops and food production.
5.    To the Government, this work will help government and environmental policy makers to provide laws that can reduce the uncontrolled release of hazardous waste materials to the environment and also to provide engineered landfill sites in various parts of the country to promote a healthy and cleaner environment.


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