PHYSICO-CHEMICAL PROPERTIES ON RAIN WATER

Description

ABSTRACT

This study was carried out to determine the physico-chemical properties of rain water from four different industrial sites in Lagos State Nigeria. Rain water samples were collected from four locations (viz Ikeja, Oshodi, Odongunyan, and Imota) of Lagos Metropolis, during the months of May, July and September 2009 and the rainwater samples were taken to the laboratory and analyzed. The first three locations were industrial layouts while the last one was a rural, non-industrialized community on the outskirt of Lagos. The result of analyses on the rainwater samples indicated that at the four locations (i.e Ikeja, Oshodi, Odongunyan, and Imota) the average values were: color ( 7.0, 9.0, 6.7 and 5.0 Hazen units); turbidity (0.2, 0.25,0.18 and 0.16 NTU); chloride (15,13.3, 14.3 and 11.1 mg/l); total hardness (21.3, 20.0, 20.0, 15.1 mg/l) respectively. The PH values of the samples show that rain water from the three industrial locations showed slight acidity (ie P^H< 6.5), particularly for the month of May 2009, which for the year under consideration marked the onset of the rainy season after a spell of dryness. This shows that it is possible to have acidic rain in these locations and thus suggestive of immediate corrective actions.

 

CHAPTER ONE

INTRODUCTION

1.1 Background of the study

Rainwater is an important source of fresh water especially for those who live in rural areas, where water use is limited due to scarcity or where surface and underground water quality is poor. In many areas, rainwater is still considered as a safe and suitable source of potable water, and it is commonly used as such (Vikaskumaret al, 2007). Developments in science and technology have brought improved standard of living, but have also unwittingly introduced some pollution into our environment. Substances are regarded as pollutants if they are present in concentration toxic to man, animals or plants, have an odor or in some other ways that irritate our senses (Wooven, 1974). These include emissions and effluent outflow from factories, refineries, waste treatment plant, oil or gases of varying quality and quantity directly into the atmosphere. As noted by Ayodele and Abubakar (1998) the concentrations of pollutants correlated with the industrial activities of metropolis.These chemicals are mostly odorless, colorless and tasteless and most importantly, are health hazards. The massive increase in chemical utilization due to recent development in science and technology has greatly increased different contaminant present in water generally, regardless of its source. In an industrial area, there is possibility of acidic rain.

Acid rain is formed through a complex process of chemical reaction involving air pollution (Kemp, 1971). The most important pollutants that contribute to the formation of acid rain are nitrogen oxide and sulphur-dioxide, which react with moisture in the atmosphere, to form nitric and sulphuric acid. The sulphur and nitrogen compounds that contribute to acid rain primarily come from man made source, such as industries, utilities, automobiles, and other form of transportation and industrial process, such as melting. Acid rain has recently become a serious environmental problem in many industrialized countries including Japan, in Europe and in the northeast areas of the United States and Canada (Adachi, et al 1990).

Many researchers including Evans et al (2006), Yasunori and Akira (1981), Nicole and Mason (2001) and Susumu et al 2001) have considered the effect of acid rain on human health. These acid pollutants can be deposited in a dry form through dust. Pollutant that contributes to acid rain may be carried hundred of miles before being deposited on the earth. Because of this, it is sometimes difficult to determine the specific sources of these acid rain pollutants.

Lagos remains Nigeria’s most industrialized city. Many of the factories in Lagos freely release their effluents and emissions to the environment. In the neighborhoods of these industrial centers, some forms of farming activities take place. The farmers and horticulturists in the areas depend on rainfall and the water harvested by the usual methods of rainwater harvesting (RWH). Earlier studies by Uzomah and Sangodoyin and Ojoloet al reported a higher than normal levels of sulphites and nitrites in the rainwater samples from some of these industrial areas. Beside farming and horticultural activities, the quality of rainwater has the potential to affect aquaculture (Adewoluet al 2009). There is a need therefore, to investigate the effects of these pollutants on the rainfall occurring in the vicinity of these industries. Such study may form the basis for the recommendation of remedial actions. In this study, rainwater samples from Oshodi Industrial Area, Odongunyan Industrial Complex of Lagos state was collected in order to check for the physical and chemical properties.

1.2 Statement of the problem and justification

Rain water contamination has become one of the main environmental issues and a challenge to the world population especially in arid and semi-arid areas. The occurrence of contaminants in rain water that is either from natural origin or anthropogenic activities is said to be influenced by changes in season (Likambo, 2014). Harvey (2011) reveals water and sanitation accounts for 80% of all illness in developing countries. The levels of physico-chemical parameters of rain water above the WHO (2010) permissible guidelines have resulted to health problems among the water users especially in rural areas of the developing countries where a significant number of serious human health problems have been reported to have occurred as a result of contamination of rain water (WHO, 2008) yet the rain water contamination is ignored based on the general belief that it is  self-purifying and thus safe (Sinaet al., 2009) with minimum treatment (Oruonyeet al., 2009) hence termed as clean and safe for drinking. Nigeria being a water scarce country, rain water use is encouraged (GoN, 2007) although some of the sources have been reported to contain some contaminants such as fluoride and nitrate in levels above the nationally and internationally permissible standards (Gichuki & Gichumbi, 2012) and this has greatly contributed to rising cases of health problems like dental fluorosis and blue baby syndrome (WHO, 2008).

There is also no comprehensive study that has been carried out on the levels of physico-chemical parameters of rain water in this location despite the contribution by the residents that the water tastes salty hence this motivates the researcher to investigate the levels physico-chemical parameters of rain water in the area as there is minimal literature on this area currently available.

1.3 Research questions

The study was guided by the following questions;

1. What are the levels of physico-chemical parameters of rain water?
2. What is the effect of seasonal variation on the levels of physico-chemical parameters of rain water?
3. How do the levels of physico-chemical parameters of rain water compare with WHO standards?

1.4 Main objective

The main objective of the study was to determine the water quality properties of rain water. The specific objectives are;

1. To determine the levels of the physico-chemical parameters of rain water during the dry and wet season.
2. To compare the levels of physico-chemical parameters of rain water during dry and wet season.
3. To compare the levels of physico-chemical parameters of rain water with the WHO standards.

1.5 Research hypotheses

1. There is a significant variation in the mean levels of physico-chemical parameters of rain water during the dry and wet season.
2. The mean levels of physico-chemical parameters of rain water during the dry and wet season are significantly different from the WHO standards.

1.6 Significance of the study

This study was to enable the residents of Lagos state Location to be aware of the levels of the physico-chemical parameters of rain water as this would control the risks of their exposure to the hazardous characteristics in the water. It is also useful to the government of Lagos state in order to sensitize the community against consumption of the contaminated water and create awareness to the community on safe usage of the rain water as some of the contaminants exceed the WHO (2010) permissible guidelines. This is also to enhance safe water supply coverage in the area by the County government and the non-governmental organizations.

CHAPTER FIVE
CONCLUSION AND RECOMMENDATIONS
5.1 Conclusion
This study considered the physico-chemical properties of rain water from four different industrial sites in Lagos State Nigeria. Rain water samples were collected from four locations (viz Ikeja, Oshodi, Odongunyan, and Imota) of Lagos Metropolis, during the months of May, July and September 2009. The analysis carried out on the four samples of rainwater showed that only the samples from Imota, for the period conformed to W.H.O standard. The other three locations (i.e. Ikeja, Oshodi, and Odongunyan) which were industrial areas in Lagos State did not conform to W.H.O standard in terms of PH, chloride, total alkanility, and salinity. This shows that the rainwater from the industrial areas was contaminated by the emission of the industries and possibly emissions from automobiles.

 

  5.2       Recommendations
The following recommendations were made in the course and after the study;

i.  The concentrations of some parameters of rain water in the study area were found to be significant, an indication of unclean water in the area..

ii.  There is need to prevent rain water contamination especially when water become contaminated by the run off.

iii.  There is need for the government to provide safe piped water in the area for the safety of the residents as the levels of the physico-chemical parameters of rain water in the area were found to be significantly different from the WHO standards. The government should ensure that the water in the study area meet the required standards for human consumption.

 

5.3 Area for further study
Further research is required in the following areas in Oshodi Industrial area, Lagos state;

i.  More research to be done on the health implications of rain water contamination on the inhabitants of Oshodi Industrial area, Lagos state.

ii.  Analysis of microbiological factors that affect the rain water quality in the area.

iii. Research to be done on the physico-chemical parameters of rain water in other locations in Lagos state.