k. 04 A SD9800005 INVESTIGATION OF THE ELEMENTAL CONTENTS OF SOME ENVIRONMENTAL SAMPLES FROM THE BLUE NfLE AND WHITE NILE AROUND KHARTOUM AREA By Kama! Khalifa Taha A thesis submitted in fulfillment of the degree of Masters of Science in the University of Khartoum Department of Chemistry Faculty of Education October, 1997 29-37 TO THE SOUL OF MY FATHER TO MY MOTHER ACKNOWLEDGEMENT i ABSTRACT ii Chapter one Introduction 1 1.1. General introduction 1 1.2. Literature review 3 1.2.1. Trace and macro elements 3 1.2.2. Soil analysis 3 1.2.3. Sediment analysis 5 1.2.4. Plant analysis 7 1.2.5. Fish analysis 8 1.2.6. Water analysis 9 1.2.7. Environmental Analysis 11 1.3. Analytical methods 13 1.3.1. Atomic Absorption Spectrometry 13 1.3.2. Flame Photometry for determination of sodium and potassium 14 1.3.3. X-ray Fluorescence Spectroscopy 17 1.3.4. Colorimetry 19 1.3.5. Ultra Violet Spectrometry 21 Chapter two Experimental 23 2.1. Sample collection 23 2.1.1. Area of collection 23 2.1.2 Sampling 23 2.1.2.1. Water samples 23 2.1.2.2. Sediments 1 23 2.1.2.3. Plants 24 2.1.2.4. Soil 24 2.1.1.5. Fish 24 2.2.2. Soil pH determination 26 2.3. Analysis 26 2.3.1. X-ray Fluorescence Spectroscopy 26 2.3.1.1. Procedure 26 2.3.1.1.1. Solid samples 26 2.3.1.2. Water samples 28 2.3.1.2.1. Reagents 28 2.3..1.2..2. Procedure 28 2.3.2. Atomic Absorption Spectroscopy 29 2.3.2.1. Sapmle preparation for AAS 29 2.3.2.1.1. Soil and Sediments 29 2.3.2.1.2. Plants and fish 29 2.3.2.2. Standard preparation 30 2.3.2.3. Measurement 30 2.3.3. Colorimetry for total phosphorus determination 30 2.3.3.1. Reagents 30 2.3.3.2. Measurements 31 2.3.4. Flame Photometry for the determination of potassium and sodium.... 3 2 2.3.4.1. Reagents , 32 2.3.4.2. Measurements 32 2.3.5. Ultra Violet for the determination of iron 34 2.3.5.1 Reagents 34 2.3.5.2. Procedure 34 Chapter Three 38 3.1. Measurements 38 3.1.1. XRF measurement 38 3.1.2. AAS measurement 39 3.1.3. Flame Photometry 43 3.1.4. Colorimetry 43 3.1.5. Ultra Violet Spectromerry 43 3.2. Analysis 44 3.2.1. Soil analysis 44 3.2.2. Sediment analysis 53 3.2.3. Plant analysis , 63 3.2.4. Fish analysis 71 3.2.5. Water analysis 76 Conclusion 82 References 84 ACKNOWLEDGEMENT Praise be to Allah, He by His Grace deeds of righteousness are completed. I would like to express my sincere thanks and gratitude to my Supervisor Dr. Ali Hamoud Ali for his fine and dedicated supervision of this thesis. My thanks are also conveyed to my Co-supervisor Dr. Mohammed Ahamed Hassan Eltayeb, for his utmost help and encouragement through out the course of this work. My thanks are also due to the Atomic Energy Commission (Sudan) for making their facilities available for me at all stages of this work. My thanks are conveyed to the Chemistry Department at the Faculty of Education U. of K. and also to the Physics Department, Faculty of Science, U. of K. My thanks, at last, to my friends Dafalla A. Hassan, Mohamed A. Elmalih and Yassir A. Abdu who stood behind me to finish this work ABSTRACT This work was performed to evaluate the environmental pollution at the Blue Nile (BN) and White Nile (WN) around Khartoum state. Samples of soil, sediments, plants, fish and water were collected from the studied area and analyzed. The concentrations of some elements (K, Ca, Ti, Mn, Fe, Cr, Co, Cu, Ni, Sr, Rb, Na, P, Zn, Br, Y, Zr and Pb) were determined using the following analytical methods; atomic absorption spectroscopy (AAS), X-ray fluorescence (XRF), flame photometry, colorimetry and ultra violet spectrometry (UV). The data obtained was compared with the data from literature The data was statistically analyzed to compare the results obtained by the different methods. The results of most elements determined by more than one method were significantly similar. The statistical analysis together with the chemical analysis revealed that the soil and sediments of the BN and WN are significantly different. The extent of pollution was determined by calculating the enrichment factors. The enrichment factors in sediments were calculated using both Fe and Ti as reference elements where values were almost equal. Some elements were slightly enriched at some sites but not to a degree to indicate a serious pollution. The accumulation of elements in plants as a clue for pollution was also calculated. Some elements; P,Cu and Zn were accumulated. The elemental concentrations in fish and water were not that high but water was still higher than the WHO recommended concentrations. 11 Introduction 1.1. General introduction: The place where we live and interact with the different living organisms and non- living things can be defined as the environment, the components of which are : i - The lithosphere (rocks and soil) is the reservoir of salts necessary for plants and animals in limited amounts. ii - The hydrosphere i.e. the water, fresh or saline has a vital role in dissolving these salts and transporting them. iii - The biosphere or plants and animals. The former consumes these salts in making food, so salts which are dissolved in water are uptaken by plants which are eaten by animals. iv - The atmosphere or the air we breath, holds all the volatile substances and gases that result from the combustion of fuel or reactions in the environment. These environment components exist in a natural sort of balance but when human beings interfere this balanced system can be disturbed. Many interactions affect the environment to a great extent resulting in exposing the life of man to risk of pollution. Anthropogenic activities as a result of industry and urbanization affect the environment. Hutton et cr/.(l) estimated the quantities of trace elements inputs to the land in the UK as a result of human activities that include use of articles containing the element, iron and steel production, fuel consumption, cement industry, phosphate, municipal waste disposal, sewage and sewage sludge disposal in tons per year, Cd (899), Pb (48361), Hg (113) and As( 1530). In Khartoum state the main Nile and its two main branches the Blue and White Niles are the main sources of water used for drinking, cooking, industry, irrigation and many other usages. The silt carried by the water is either laid out at the banks or settled at the bottom as sediments. The salts poured into this water or at the shores can reach man through the different food chains i.e. via meat, milk, cereals, vegetables or water. Local people have the habbit of pouring wastes without pretreatment, these wastes in addition to those resulting from traffic, fertilizers and pesticide use, car wash and sewage all ad^ to the hazards of pollution in the environment. In this study samples of water, plants, sediments, soil and fish were collected from stations at the Blue Nile (BN) and White Nile(WN) within the boundaries of Khartoum state in order to assess the impact of human activities that add to the hazards of pollution in the environment. These locations include a power station, industrial area, river transportation, brick burning place (clinks), traffic affected locations and waste dumping areas. The objectives of this study are: 1 - Establishment of background baseline data for pollution levels. 2 - Assessment of the anthropogenic activities that affect the environment components under study. 3-The impact of such activities as waste dumping, sewage discharge, traffic, car wash and fertilizers on the biota living on the aquatic ecosystem. 1.2. Literature review 1.2.1. Trace and macro Elements Trace analysis may be quantitatively defined as determination of constituents making less than 0.01 % of a sample. Some of these trace elements are essential for living organisms which need them in very small amounts. When they exceed the need of the organism they become toxic and hence hazardious. The lower limit of a trace concentration is zero, but practically the lower limit is set by the sensitivity of the available analytical methods and in general is pushed downwards with the progress of ana1ysis(2) while macro elements constitute more than 90 % of the dry weight of the sample. These trace elements are essential for the growth of plants so they can reach man directly through eating plants or indirectly by meat or milk. They can also reach him through water or air. The samples under study include soil, plants, sediments, fish and water. Some of the previous data and literature are given below. 1.2.2. Soil Analysis Soil is the sink of salts and therefore one of the sources of nutrients to plants. In so being it is related to food chains and highly affects the health of man. Yousif et alQ) investigated soils from central Sudan using XRF. He determined the concentration of K, Ca, Mn, Cr, Fe, Ti, Ni, Cu, Zn, Rb, Sr, Y and Zr. Irene et al.w also used XRF for the determination of V, Cr, Ni, Cu, Zn and As in soil using Ga as an internal standard. They corrected for the overlap between V and Ti, where the Ka lines of V superimpose on KP lines of Ti.