ANALYSIS OF USED PRIMARY DRY CELL BATTERY AND ITS IMPLICATION ON HUMAN HEALTH AND THE ENVIRONMENT

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1 ANALYSIS OF USED PRIMARY DRY CELL BATTERY AND ITS IMPLICATION ON HUMAN HEALTH AND THE ENVIRONMENT SAMUEL-OKEY, FATUMA COMFORT Integrated Science Department, Federal College of Education, Zaria Kaduna State. Abstract Samples of five different brands of used dry cell batteries which include everpro, ace, bbc, Panasonic and tiger were collected and analysed for metals present and determining the solubility of the electrolyte as well as the ph. Samples were analysed using X-ray fluorescence (XRF). The results indicated that the different brands analysed contained reasonable amount of metals with all of them containing manganese, iron and zinc. Everpro, BBC and Tiger brands contain strontium. Ace, Panasonic and Tiger brands contain chromium. Ace brand has in addition Nickel while Panasonic has lead amongst other metals. The solubility test shows that some amount of the metals dissolves which implies leaching of these metals in the environment. Keywords: Dry Cell, Battery, Electrolyte, Environment, Solubility, Heavy Metal. INTRODUCTION A dry cell battery is a galvanic electrochemical cell with a low moisture electrolyte. These batteries regardless of their size have the same component, which includes a rod at the center called the cathode which is generally made of metal or graphite. The cathode is surrounded by an electrolyte paste, which contains manganese dioxide and either potassium hydroxide or ammonium chloride depending on the type of battery and other heavy metals which might include mercury, lead, cadmium, nickel e.t.c. these heavy metals are hazardous to human health and may contaminate the environment when the used batteries are not properly disposed (Waring, 1998), (Smith, 2005). There are essentially two types of dry cell batteries which include the primary cell and secondary cell which its common uses is in appliances like cameras, cellular phones, camcorders, computers, e.t.c. the major difference between the two is that the primary batteries are nonrechargeable, while the secondary batteries are rechargeable (Martin, 2002). The primary cell comprises of alkaline and acidic version of the battery, the alkaline aside the graphite rod and zinc case has the electrolyte paste consisting of potassium hydroxide and manganese dioxide while the acidic version has ammonium chloride and manganese dioxide and other heavy metals (Cross, 1997) The use of primary dry cell batteries (non-rechargeable batteries) is on the increase in These batteries range from the relatively large flashlight batteries to the miniaturized version used for wrist watches or calculators. More households have used these batteries because of the poor power supply. A common example of these appliances is the flashlight which now comes in

2 different shapes and sizes of which the populace cannot do without as a result of the poor state of electricity in the country. Other appliances include radios, toys, hearing aids, cameras, e.t.c. In developed countries, batteries are collected through household battery collection programs. They are either disposed of in hazardous waste landfills or are recycled, however these programs are not available in It has been reported that in the United State about three billion batteries are sold annually averaging about 32 per family (EPA, 2000). It is assume that it will be more in Nigeria since it is still a developing country. Used dry cell batteries in Nigeria are usually thrown into the dustbin or refuse dump are hazardous to the environment and human health. When these dry cell batteries are not properly discarded, the casing disintegrates and heavy metals contained within it have the potential to contaminate surface and ground water and accumulate in wildlife and humans. In the same way when a dry cell battery is incinerated, certain metals are released into the air or concentrated in ash produce by the combustion process. Other hazards of improper disposal of these batteries include exposure of the environment and water to lead and acid as well as explosion during incineration (Hurd, et al, 2000). Material and Methods Sample Collection Five different brands of dry cell battery sample were collected from waste bins in Ahmadu Bello University Zaria environment. The batteries were used and disposed. The brands include; Tiger (TG), BBC (BB), Panasonic (PN), Ace (AC) and Everpro (EP). Sample Preparation The casing of the batteries were broken to get out the electrolyte contained in it. The electrolyte in each of the brands was black in colour. Samples were kept in air-tight container for elemental analysis. X-Ray Fluorescence (XRF) Analysis The X-Ray fluorescence (XRF) method of analysis was used to qualitatively and quantitatively determine the elements present in the sample Solubility Test Solubility test was used to determine the extent to which the metals dissolve in water i.e. how much leach into the soil and water bodies. For this, 1g of each sample was weighed into a 60cm 3 bottle containing 30cm 3 of distilled water. The solution was shaken thoroughly using an end-over shaker for 3hr and allowed to settle for about 12hr. it was thereafter filtered, the residue was dried and quantitative analysis using the XRF was carried out for the residue. ph of the filtrate was taken.

3 Result and Discussion Metal Composition of Used Battery Electrolyte The results of the metal composition are given in table 1. The result showed that each brand of battery has some reasonable amount of heavy metals in ti. The concentration in the electrolyte is more than that in the residue confirming that part of it has leached into the water bodies. It was also observed that the concentration of zinc is very low as against what it should be because battery manufacturer are claiming to have replace the heavy metals with more important metals like zinc. All the brands analysed contained manganese with AC having the highest concentration of 40% while TG has the least of 17.2%. The five brands all contained zinc and iron. BB, EV and TG brands contained strontium. AC, PN and TG contained chromium in the crude electrolyte which was not present in the residue electrolyte implying that it has completely leached into the water. AC has nickel amongst other metals while PN has lead. Table 1 Results of metal composition of electrolyte Crude electrolyte Residue electrolyte Mn Fe Zn Sr Cr Pb Ni Mn Fe Zn Sr Cr Pb Ni AC X 0.31 X X X X 0.02 BB X X X X X X EV X X X X X X PN X X X X 0.21 X TG X X X X X Solubility of Dry Cell Electrolyte Table 2 below shows that about half of the electrolyte dissolved. The implication of this is that when these batteries are disposed improperly, the casing disintegrates and about half of the electrolyte leached into the water bodies which are taken by both humans and animals.

4 Table 2 Results Solubility Test of Electrolyte Sample % soluble fraction Standard deviation AC ±0.10 BB ±0.01 EV ±0.03 PN ±0.02 TG ±0.04 Acidity Test The results for the ph determination of the filtrate are given in table 3. It shows that the filtrate of the electrolyte are acidic. Thus, constituting a great danger to humans and the soil as well. Table 3 ph Values of Filtrate Sample ph values Standard deviation AC 6.24 ±0.14 BB 6.45 ±0.05 EV 6.31 ±0.08 PN 6.52 ±0.10 TG 6.61 ±0.07 Conclusion The dry cell batteries have some concentration of heavy metals in them and these metals have effects on humans when accumulated in the body system and result in diseases with adverse effects. To reduce the danger poses by these used batteries to the environment and human life the following should be considered: 1. The used batteries should be collected and taken to proper site for disposal so as to stop indiscriminate disposal. 2. More rechargeable batteries should be produced or alternatively more appliances that use rechargeable batteries be produced. 3. Government and scientist should propose a method for recycling these batteries. 4. The power sector should be improved because most appliances that use these batteries are electricity dependent. Recommendation

5 Indiscriminate disposal of dry cell battery should be stooped as a matter of urgency and government concern organization should set up programs for their proper disposal and recycling. References Cross, H.U., (1997). The battery book. The Technical Press Ltd London, pp 1-2. Environmental protection agency (2000) Hurd, D.J., Muchnick, D.M., Schedler, M.F., and Mele, T., (2000). Recycling of consumer dry cell batteries. McGraw-Hill. Martin, L.F., (2002). Dry Cell Batteries Chemistry and Design. Noyes data cooperation London. pp Smith, S.P., (2005). The Electrical Equipment of Automobiles. Chapman and Hall Ltd London, pp Waring, S.S. (1998). The Dry Battery, John Wiley & Sons Inc New York pp

Dry Cell Batteries and the Environment

Dry Cell Batteries and the Environment Household batteries can be either single-use or rechargeable dry cell batteries. These batteries are used for power tools, cameras, two-way radios, flashlights, hearing