Background of the Study
At present age there is a rapid increase of contaminants in the environment, but one of the major global concerns is the heavy metal concentrations in the environment as a result of man’s activities and since the biosphere is a closed system this heavy metals remains on earth and continuously increase as the human population increase. The acute and chronic effects of these heavy metals especially lead have been a worldwide concern.
In fact in April 2000 the use of leaded gasoline was phased out in Metro Manila, such movement was partly due to the implementation of Clean Air Act of 1999 as well as the environmental concern of previous president Fidel V. Ramos. Add an intro here about the presence and sources of lead and correlate it with the possibility of contaminating waters. Conventional methods for metal removal in water include chemical precipitation, lime coagulation, ion exchange, reverse osmosis and solvent extraction.
Although this methods for the removal of heavy metals from wastewaters, however, are often cost prohibitive having inadequate efficiencies at low metal concentrations, particularly in the range of 1 to 100 mg/L. Some of these methods, furthermore, generate toxic sludge, the disposal of which is a burden on the techno-economic feasibility of treatment procedures. The search for new technologies involving the removal of toxic metals from wastewaters has directed attention to biosorption, based on metal binding capacities of various biological materials.
Biosorption can be defined as the ability of biological materials to accumulate heavy metals from wastewater through metabolically mediated or physico-chemical pathways of uptake. Biosorption for the removal of heavy metal ions may provide an attractive alternative to physico-chemical methods. The major advantages of biosorption over conventional treatment methods include low cost, high efficiency of metal removal from dilute solution, minimization of chemical and/or biological sludge, no additional nutrient requirement, and regeneration of biosorbent and the possibility of metal recovery.
In this present study, Musa sapientum L. peels, which are available in large quantities or from business operations may have potential to be used as low cost de-leading agent, as they represent unused resources, widely available and are environmentally friendly. 1. 2 Significance of the Study The researcher aims to generate a low-cost de-leading agent that may be beneficial to the following: Readers –Generating awareness of the readers about the prevalence and increasing concern for heavy metal contamination of Philippine waters.
Researchers – To help them in developing an inexpensive and effective biosorbent that is easily available in large quantities in the Philippines and feasible economically for lead contaminated water. Policy Makers – They would be able to create policies about waste water treatments in factories and as well as those who are engaged in the treatment facility of water consumed by the public like MAYNILAD.
Statement of the Problems
Conventional methods of removing lead from the environment are said to be cost-prohibitive and generate toxic sludge. In this study the researches sought answers to the following problems:
- Can the peels of Musa sapientum (L. ) (Fam. Musaceae) reduce the level of lead ions from contaminated water.
- What is the optimum pH of the solution for banana peels to exhibit maximum Biosorption capacity?
- What is the effect of contact time on the Biosorption capacity of banana peels?
- What is the effect of initial metal concentration of lead in the solution to the amount of lead adsorbed by the banana peels?
Objectives of the study
The general objective of this study is: . To determine the potential biosorbent capacity of the peels of Musa sapientum (L. ) (Fam. Musaceae).
The specific objectives of this study are:
- Determine if banana peels can reduce the level of lead ions from contaminated water
- Determine the optimum pH by which banana peels exhibit maximum biosorption capacity
- Determine the optimum contact time and the effect of contact time on biosorption capacity of banana peels
- Determine the effect of initial lead concentration on amount of lead adsorbed by the banana peels
- Ho 1: The fruit peels of Musa sapientum (L. ) (Fam. Musaceae) can reduce the level of lead ions in contaminated water.
- Ha 1: The fruit peels of Musa sapientum (L. ) (Fam. Musaceae) cannot reduce the level of lead ions in contaminated water.
- Ho 2: Maximum lead ion removal by banana peel is at pH 3.
- Ha 2: Maximum lead ion removal by banana peel is not at pH 3.
- Ho 3: There is no direct relationship between contact time and biosorption capacity of bananapeels, up to a certain extent. Biosorption kinetics does not follow a pseudo-second-order model.
- Ha 3: There is a direct relationship between contact time and biosorption capacity of bananapeels, up to a certain extent. Biosorption kinetics follows a pseudo-second-order model.
- Ho 4: There is no direct relationship between initial concentration of chromium in the solution and amount of chromium adsorbed by the banana peels, as best described by Langmuir isotherm model.
- Ha 3: There is a direct relationship between initial concentration of chromium in the solution and amount of chromium adsorbed by the banana peels, as best described by Langmuir isotherm model.
Scope and Delimitations Samples were collected in a street vendor along U. N. Avenue. The specific research was conducted at EAC School of Pharmacy 7th floor E7- laboratory room, and use of instruments such as Flame Atomic Absorption Spectrophotometer was performed in De La Salle University-Taft, Manila. The study evaluates the biosorbent effect of Musa sapientum L. (Banana peel) for Lead-contaminated water solution. The study focused on Lead-contaminated water solution only. The study did not focus on the lead content of banana peels per se.
Review of Related Literature
Lead in the Environment
Lead is a gray, soft, and malleable metal that exists naturally as a mixture of three isotopes. It serves as one of the most important heavy metal contaminants . According to the WHO, Lead poisoning is one of the most significant environmental health threats that children face. Exposure to even low levels of lead may lead to impairment of childhood cognitive function and abnormal infant behavior. It was reported that 21% of 2861 children living in the rural Philippines had elevated levels of lead in whole blood.
Lead is a classified as possible human carcinogen by the International Agency for Research on Cancer and also listed by the United States-Environmental Protection Agency as one of priority contaminants. Removal of Lead from wastewater before they are released is of high importance, due to its detrimental health effects for humans.
Biosorption as a solution
Biosorption serves as a potential cost-effective alternative in the removal of heavy metals in water through adsorption. Most biosorption related studies focused on several fungal strains and several species of marine algae.
Biosorption is a physic-chemical adsorption whereby metal ions become attached to the biomass surface It can be defined as the ability of biological materials to accumulate heavy metals from wastewater through metabolically mediated or physico-chemical pathways of uptake . The major advantages of biosorption over conventional treatment methods include low cost, high efficiency of metal removal from dilute solution, minimization of chemical and/or biological sludge, no additional nutrient requirement, and regeneration of biosorbent and the possibility of metal recovery.
Potential use of Banana
Peels Banana (Musa sp. ) peel is an abundant and low cost agricultural waste residue and is easily available in large quantities. Achak et al.  investigated the efficiency of banana peel as a biosorbent for removal of phenolic compounds from Olive mill wastewater. Thirumavalavan et al.  and Li et al.  was demonstrated to convert solid fruit peel residue into an effective adsorbent for the adsorption of metal ions and compared the activity with activated carbon.
Lemon peel, orange peel, and banana peel as adsorbents for the removal of various metal ions such as Cu(II), Ni(II), Zn(II), Pb(II), and Cd(II). Musa sapientum peels were analyzed for minerals, nutritional and anti-nutritional contents. The result of mineral content analysis indicates the presence of potassium, calcium, sodium, iron, manganese, bromide, rubidium, strontium, zirconium, and niobium. Protein, crude lipid, carbohydrate and crude fiber were also indicated. The peels of Musa sapientum, if exploited and processed properly, could be a high-quality and cheap source of carbohydrates and minerals for livestock.
The Musa sapientum peels, which is usually ignored and treated as waste could be domesticated for proper utilization and use. Morphological Properties of Banana Musa sapientum which is commonly called banana is a herbaceous plant of the family Musaceae. The banana plant is the largest herbaceous flowering plant. The main or upright stem is actually a pseudostem, growing from a corm, to a height of 6 to 7. 6 meters. Leaves are spirally arranged, as long as 2. 7 meters and 60 cm wide, fragile and easily torn by wind, with the familiar frond look.
Each pseudostem produces a single bunch of bananas; the pseudostem dies after fruiting, as offshoots usually develop from the base of the plant. Each pseudostem produces a single inflorescence, the banana heart, containing many bracts between rows of flowers. The banana fruits develop from the heart, in a hanging cluster made up of tiers (hands), up to 20 fruit to a tier. According to the study conducted by Anhwange et al. , shows the concentration of potassium to be highest (78. 10mg/g).
The concentration (mg/100g) of calcium, sodium, iron, and manganese were 19. 0, 24. 30, 0. 61 and 76. 20 respectively. The appreciable high content of potassium signifies that if the peel is taken, it will help in the regulation of body fluids and maintained normal blood pressure.
Materials and Methods
Modify the procedures in chapter 3 I already changed the objectives and hypothesis.
Collection of Plant Material
Banana peels (Musa sapientum L), biomass will be collected from the local market. The biomass will be dried in sun for fifteen days. The buds will be removed and further dried in sun for another fifteen days.
This biomass will be washed with tap water to remove any dust or foreign particles attached to biomass and thoroughly rinsed with distilled water. The washed biomass will be dried at 50°C and ground to powder using mortar and pestle. Grinded biomass will be further thoroughly washed with distilled water till the color of washing water clear. The powdered biomass will be dried in oven at 50°C to a constant weight. The biosorbent will be again ground to powder and screened using a sieve of mesh size 80 to an approximate size of 1. 5-2 millimeter.
Stock solution of lead (1000mg/L) will be prepared by dissolving the desired quantity of hydrated lead acetate [Pb(CH3COO)2·3H2O] in distilled water. Other concentrations will be obtained by proper dilution of stock solution. The chemicals used will be of analytical reagent grade.
Determination of Biosorption Capacity
Biosorption studies will be carried out by batch process. Biomass will be added to conical flasks containing a known amount of metal solution of desired concentration. The mixture will be agitated using Burell Wrist Action Shaker model 75 for 3 hours, time more than sufficient to reach equilibrium.
The pH of the solutions will be adjusted by adding 0. 1 N NaOH or 0. 1N HNO3. The biomass will then removed by filtration using a vacuum filter (pore size of 45 micrometers) and the filtrates will be analyzed for residual lead concentration by atomic adsorption spectrophotometry (Perkin-Elmer model) with an air-acetylene flame. All experiments will be performed in triplicate and mean values were presented with a maximum deviation of 5% in all cases. Blank samples were run under similar experimental conditions but in the absence of the biosorbent.
Determination of the optimum pH of the solution Batch experiments will be carried out by contacting 0. 1 g banana peel and 100 mL of lead acetate solution with a concentration of 50 mg/L placed in conical flasks and subjected to agitation using a shaker for 3 hours at room temperature (28°C). The solution pH values ranged from pH 1 to pH 6.
Kinetic of adsorption
Kinetic studies will be carried out in a conical flask with constant agitation of 0. 1 g banana peels in 100 mL of lead acetate solution with a concentration of 50 mg/L at room temperature (28°C).
Samples will be taken at predetermined time intervals (0, 5, 10, 15, 20, 25, 30, 60, 90, 120, 150, 180 minutes) using 25mL transfer pipets and filtered immediately through vacuum filtration. A pH value of 4 will maintained throughout the experiment by adding 0. 1N NaOH or 0. 1N HNO3.
A constant mass of 0. 1 g of banana peel material will be added to conical flasks containing 100mL of metal solution. The lead acetate concentrations were varied in the range of 25-100 mg/L. Contact time of 3 hours will allotted with constant agitation, at room temperature (28°C).
A pH value of pH 3, 4, or 5 will be maintained throughout the experiment by adding 0. 1N NaOH or 0. 1N HNO3. The amount of metal ion that will be taken up by the banana peel per gram of biomass will be calculated using the expression adapted from: qe=(V(Ci–Ce))/m (3) While, the efficiency of banana peel biosorption will be determined using the equation from : %E=((Ci–Ce)/Ci) x 100 (3) Where: qe = equilibrium lead ion capacity (mg/g) E = biosorption efficiency V = suspension volume (L) m = mass of banana material (g) Ce = lead ion concentration at equilibrium (mg/L) Ci = initial lead ion concentration (mg/L).
The root mean squared error (RMSE) will be calculated to determine the model fit. The squared difference between the experimental metal uptake (q) and the corresponding model predictions for the uptake (qm) will be summed up. This sum will be divided by the number of data points (p) for each data set to calculate the mean square error. The RMSE will obtained by taking the square root of that term. The RMSE may be considered as the average deviation between the predicted and actual uptake of the metal ion. The equation for RMSE, will beadapted from.