IndexAbstractIntroductionSituation in Tamil NaduUnavoidable food waste towards defluoridationCharred pomegranate seedsPhyllanthus Emblica seedsConclusionAbstractAir, water and food are the three basic needs for the survival of humanity. The earth's surface is enclosed by two-thirds of the water. But the availability of quality fresh water is one of the most critical environmental issues. Pollutants are the main factor of water pollution. Fluorine is the thirteenth richest element present in the earth's crust. Fluoride is considered a “double-edged sword” because its deficiency leads to dental caries while an excessive amount leads to dental and skeletal fluorosis. Adsorption is considered an efficient process to defluoridate water. On the other hand, food waste is on the rise. Every year around 1.3 billion tonnes of food are lost or wasted, which is almost a third of the food produced worldwide for human consumption. The main purpose of this chapter is to bring to light society's inevitable food waste so that it can be used as an adsorbent. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essayKeywords: deflouridation, adsorbent, fluoride, food waste, food wasteIntroduction"Not all waste is wasteIt can also be transformed into a treasure...." Water is the most abundant and is an essential component of our system life support. Water is present in every cell of our body, in various tissues and compartments. Therefore, the nutritional recommendation for water is higher during the growth period. Water acts as a solvent, reaction medium, reactant and reaction product. Water is necessary for cellular homeostasis because it transports nutrients to cells and removes waste from cells. It is the medium in which all transport systems function, allowing exchanges between cells, interstitial fluid and capillaries. Water quality is affected by various pollutants. Furthermore, long-term discharge of industrial effluents, domestic sewage, use of fertilizers and pesticides, and waste landfills cause groundwater pollution and create health problems. Food waste is defined as waste generated during meal preparation and any uneaten food. It also includes food that is thrown away, unused or partially used. Does not include packaging materials. Food waste can exclude meat, for example vegetable peelings, fruit scraps, tea bags, coffee grounds, egg shells, etc. Alternatively, food waste can include meat and therefore include cooked foods, meat, fish, bones, etc. The types of food waste can be summarized as avoidable, potentially avoidable and unavoidable food waste. 60% is avoidable food waste (for example: dish residues, leftovers, expired fruit and vegetables, expired perishable products, etc.). 20% is potentially avoidable food waste (e.g.: bread crusts, potato peels, etc.). 20% is unavoidable food waste (e.g. general waste, banana peels, chicken bones, etc.). This food waste can be reduced, reused and recycled. The literature review shows that unavoidable food waste also has health benefits and functional properties. So this inevitable food waste can be used effectively. One of the properties of some unavoidable food waste is their ability to fluoridate. Fluoride is considered a natural contaminant of groundwater resources globally. Fluorine is the 17th most elementabundant in the earth's crust. It is a gas and is never found in a free state in nature. Fluoride is essential for the normal mineralization of bones and the formation of tooth enamel. Fluoride is often considered a “double-edged sword” because deficient fluoride intake leads to dental caries while excessive consumption leads to dental and skeletal fluorosis. According to the World Health Organization, the maximum acceptable limit of fluoride concentration in drinking water is 1.5 mg/l. The maximum limit for fluoride in drinking water intended for human consumption is 1.0 mg/l. According to the National Program for Prevention and Control of Fluorosis, high fluoride levels have been reported in 230 districts of 20 states (after the bifurcation of Andhra Pradesh in 2014). Fluoride enters the human body mainly through drinking water and partly also through food. It is absorbed through the gastrointestinal and respiratory tract; it is distributed through the blood and deposited in the bones and teeth. Acute toxicity occurs after ingestion of certain fluoride compounds for a short period of time which then leads to poisoning. Symptoms include nausea, vomiting, hypersalivation, abdominal pain and diarrhea. In severe or fatal cases, these symptoms are followed by seizures, cardiac arrhythmias, and coma. Other symptoms are collapse with paleness, weakness, shallow breathing, faint heart sounds, wet and cold skin, cyanosis, dilated pupils, hypocalcemia and hyperkalemia, and within two to four hours even death. Other possible effects include muscle paralysis, carpopedal spasms, and extremity spasms. Chronic exposure causes dental and skeletal fluorosis. Dental fluorosis is characterized by discoloration, mottling of the teeth, opaque, lackluster white patches in the enamel, which can stain from yellow to dark brown and, in severe forms, cause marked pitting and brittle teeth. Prolonged exposure to fluoride causes brittle bones with low tensile strength known as skeletal fluorosis. Fluoride toxicity at high levels leads to thyroid changes, growth retardation, renal changes, and even urolithiasis. Like lead, even a small amount of fluoride accumulation harms children's brains and development. It also produces abnormal behavior in animals and also reduces the IQ of humans. Situation in Tamil Nadu Among the drinking water samples tested for fluoride, 14% were shown to have levels above 3 ppm/l and 86% had fluoride levels above 1.5 ppm/l, which were higher than permitted levels. In Tamilnadu, water samples collected from districts like Dharmapuri, Krishnagiri and Dindigul yielded fluoride content above 1.5 mg/l. Defluoridation methods are divided into three basic types of modes of action. Chemical reaction with fluorine - Nalgonda Technique Absorption process - e.g. Charcoal prepared from bones, activated charcoal, activated magnesia, tamarind gel, serpentine, activated alumina, plant material, burnt clay. Ion exchange process: anion/cation exchange resins. Inevitable food waste towards defluoridation. A biosorbent was prepared by loading Al/Fe oxide onto tea waste. It has been tested against fluoridated drinking water. It was found that the combination of Tea and Al or Tea-Al and Fe could effectively reduce the fluoride concentration below 1.5 mg/l in drinking water and also reduce the residual concentrations of Al and Fe in drinking water. after Tea-Al- Fe treatment was below WHO standards at pH values ​​between 5 and 10. The maximum fluoride adsorption capacities for the original tea biosorbents, Tea-Fe, Tea-Al and Tea-Al- Fe were 3.83, 10.47, 13.79, and 18.52 mg/g, respectively. Ganvirand his collaborators studied the effect of rice husk ash on removing fluoride from drinking water. Rice husk ash, which is an abundantly available material, was prepared by burning rice/rice husk. Adsorption experiments were conducted using 0.1 g of adsorbent concentration per liter of fluoride-containing water in a range of 10–60 mg/L at pH 7. All experiments were conducted at 27°C for 1 hour. The ash adsorption capacities of modified rice husk and defluoridation column study were found to be 15.08 and 9.5 mg/g. It was concluded that the removal of fluoride depends on a strong pH value. Potato peel in combination with rice husk ash was used as an adsorbent for the removal of As and F from contaminated water. It was found that the maximum adsorption capacity of As and F− adsorbents was 2.17 μg g−1 and 2.91 mg g−1, respectively. Fluorine removal was observed between pH 7 and 9. Therefore it was concluded that in fluoride contaminated water streams these adsorbents can be used to filter out both arsenic and fluoride. fluoride removal. It was tested in three variants: 100% corn cob activated carbon and 50% rice husk + 50% corn cob activated carbon. The adsorption capacities were found to be 7.9, 5.0, and 5.2 mg/g. In the batch test, the maximum adsorption capacity for rice husk and corn cob activated carbon was 7.9 and 5.8 mg/g, and a removal efficiency of 91% and 89%. In batch mode, the ability of corn husk fly ash to remove fluoride from water was tested. The maximum fluoride removal was 86% in an ideal condition. This maximum evacuation was observed with a stirring speed of 250 rpm at pH 2, 2.0 g/50 mL dosage and an equilibration time of 120 minutes. Christina and Viswanathan studied saponified orange peel residue (SOPR) and immobilized Fe3O4 nanoparticles SOPR (FNPSOPR) for the efficient removal of fluoride from water. The maximum adsorption capacity of FNPSOPR was found to be 80.33 mg/g at a sorbent concentration of 0.25 gL−1. Nasr and his colleagues looked at cuttlefish bone as an adsorbent material (available in Tunisia) for water defluoridation. It was concluded that cuttlefish bone has excellent efficiency for fluoride removal. Therefore cuttlefish bone has an 80% efficiency in removing fluoride from water. It was obtained at pH 7.2, contact time of 1 hour, adsorbent dose of 15 g/L and initial fluoride concentration of 5 mg/L. The study shows that sawdust from Indian rosewood (Dalbergia sissoo), wheat straw (Triticum spp.) and sugarcane bagasse resulted in better removal of fluoride in water. The material was dried in an oven at 105 ◦C for 24 hours and then sieved into the size range of 20 to 50 ASTM mesh. Fluoride concentration was significantly reduced from 3.14 to 1.31, 1.59, and 1.71 mg L-1 for sugarcane bagasse, sawdust, and wheat straw, respectively. Coir ash was prepared by drying the coir in a muffle furnace at 423 K for one and a half hours then it was washed with distilled water and dried in the sun. The dried fiber was then dried in an oven at 353 K overnight. It was sieved with 150 mm mesh. It was then impregnated with aluminum (AICFA) to remove fluoride from drinking water. The effect of the adsorbent to remove fluoride from groundwater was conducted without adjusting the pH of the experimental samples at the rate of 0.5 g/L AICFA under experimental conditionsidentical to the equilibrium batch adsorption study. Reduced fluoride level from 6.01 ± 0.11 to < 0.96 mg/L.rch on eggshell powder as adsorbent for removal of fluoride from aqueous solution was conducted using batch technique. Maximum fluoride uptake was achieved at pH 2.0-6.0. A defluoridation of approximately 94% was achieved with an initial metal ion concentration of 5 mg/l with an optimal dose of 2.4 g/100 ml and an optimal time of 120 minutes. Using shrimp shell waste, the initial fluoride concentration of 8 mg/L was removed by approximately 80% at pH 11 within 15 minutes of contact time and the adsorbate dose of 8 mg/L. The research also shows that the F removal rate increased with increasing adsorbent dose from 3.2 g/L to 64 g/L, but there was no difference between 48 g/L and 64 g/L. Banana peel, peanut shell and sweet lemon peel have been used as an adsorbent to remove fluoride from industrial wastewater. It was found that the efficiency of banana peel, peanut shell and sweet lemon peel for defluoridation was 94.34, 89.9 and 59.59%, respectively. The collected banana peel was washed with deionized water and dried in a hot air oven at 50°C for 12 hours. The dried peels were cut into small pieces and dried again in a hot air oven maintaining a temperature of 60°C for 24 hours. In the column study, a removal rate of 86.5% was observed. Java plum (S. cumini) seed adsorbent was prepared by drying the seeds in sunlight for 2 days and then dried in a hot air oven in the range of 80 to 100°C for 36 hours. This experiment was conducted in a reactor column of SS tubes. The reactor is filled with a weighted amount of Java plum seed adsorbent having a particle size of 2-4 mm as a fixed bed adsorbent. The bed was supported by the cotton wool and closed by rubber, to prevent the flow of the adsorbent along with the effluent. The experimental results were encouraging and indicate that Java plum seeds can be used as a biosorbent to remove fluoride in a fixed-bed adsorption process. The optimal dose for the batch system was 3.9 g/50 ml. Charred Pomegranate Seeds Pomegranate seeds have been dried, charred and ground to a fine size. It was found that adsorbents with a particle size of 55 µm, at the optimal dosage of 0.75 g, at pH 5.5 and with a contact time of 75 minutes can act as good adsorbents. They also studied the adsorption for a different solution having initial fluoride concentrations of 2, 4, 6, 8, and 10 mg/L. And it was found that when the fluorine concentration is 2 mg/l the efficiency of the adsorbent is 88%, but when the fluorine concentration increases up to 10 mg/l the efficiency is reduced to 47% . The collected lemon peels were sun-dried for 5-6 days followed by oven drying at 80±5˚C for 24 hours, powdering and then thermal activation (carbonization) at 500±5˚C in a muffle furnace for 1 hour. The obtained ash was washed with distilled water until the pH was 7-7.8 and dried in an oven at 100±5°C for 24 hours. Nearly 83% defluoridation was achieved at pH 4.0 in 100 minutes of contact time at a rotation speed of 125 rpm. Tamarind seeds are considered household waste. Studies revealed that maximum defluoridation was achieved at pH 7, and the defluoridation capabilities decreased with increasing temperature and particle size. It was concluded that for the treatment of 10 liters of drinking water per day for three members of a family with one.