CHAPTER ONEINTRODUCTIONDue to the rapid urbanization and industrialization the municipality water and industrial effluent water are contaminated with the presence of organic compounds as well as inorganic compounds. Organic compounds originate from domestic sewage, urban run-off, industrial effluents and agriculture wastewater. These organic compounds are released as industrial effluent from palm oil refineries, pulp and paper mills, chemical spills, pharmaceuticals, and agricultural pesticides. Organic pollutants are present in the waste water as pesticides, fertilizers, hydrocarbons, phenols, plasticizers, biphenyls, detergents, oils, greases, pharmaceuticals, proteins and carbohydrates [Ali et al., 2012; Berrios, 2012; Crini, 2005]. Wastewater with organic pollutants contains large quantities of suspended solids which reduce the photosynthesis due to light availability to photosynthetic organisms and on settling out alter the characteristics of the river bed. During the decomposition process of these organic compounds the dissolved oxygen in the water may be consumed at a greater rate so that it can be replenished, also causing oxygen depletion and having several consequences for the water stream [Ali et al., 2012].Toxic organic pollutants cause several problems to our environment. These are most common pollutants of great concern because of their toxicity, persistence, long-range transportability and bioaccumulation in animals [Burkhard and Lukasewycz, 2008; Ali et al., 2012], and travel long distances and persists in living organisms. Pollutants are carbon-based chemical compounds and mixtures that include industrial chemicals such as heavy metals, dyes, and phenolic compounds.In Organic pollutants, the phenolic compound is one of the major pollutants present in wastewater. The commercial production of a wide variety of resins occur by phenol as a source material. The phenolic resins, which are used as construction materials for automobiles and appliances, epoxy resins and adhesives, and polyamide for various applications. Phenolic compounds containing waste water comes from certain industries, like high-temperature coal conversion, petroleum refining, resin, and plastics, etc. Such aromatic hydroxyl compounds are considered as priority pollutants since they are harmful to organisms especially human as well as aquatic life, at low concentrations also it can be toxic when elevated present levels and are known or suspected to be carcinogens [Ozkaya, 2006].Due to these unacceptable effects of the phenolic compound in water the World Health Organization (WHO) has set an upper permissible limit of 1mg/l to regulate the phenol concentration in drinking water [WHO report, 2010]. To deal with the problem, we need to treat the wastewater and reuse it instead of leaving that as such. Dyes consider as another type of organic pollutants. The textile, pulp, and paper industries are reported to utilize large quantities of a number of dyes; these pollutants may be found in wastewaters of many industries generating considerable amounts of colored wastewaters, toxic and even carcinogenic, posing a serious hazard to aquatic living organisms [Roozbeh et al., 2013]. Dyes are one of the problematic groups; they are emitted into wastewater from various industries, mainly from the dye manufacturing and textile finishing and also from food colouring, cosmetics, papers and carpet industries. It is well known that the dye effluents from dyestuff manufacturing and textile industries may exhibit toxic effects on microbial populations. It can be toxic and carcinogenic to the mammalian animal. Most dyes used in textile industries are stable to light and are not bio-degradable. Furthermore, they are resistant to aerobic digestion [Ardejani et al., 2007].Dyes are a group of complex materials which enter the environment due to various processes like dynamic and completion in textile industry. Concerning usage, they are divided into different types of watt, reactive, direct, cationic, and disperse (Al Momani, 2002; Xu, 2004). High production and use of dyes generates coloured wastewater and pollute the environment. Textile, paper and food industries, tanneries, electroplating factories discharge colored wastewater (Mckay, et,al. 1998). Dye being one of the recalcitrant, persist for long distances in flowing water, retards photosynthesis, inhibit growth of aquatic biota by blocking out sunlight and utilizing dissolved oxygen. Some dyes may cause allergic dermatitis, skin irritation, cancer and mutation in man. Dyes also prevent light penetration and reduce photosynthesis activities of water streams and disturb aquatic equilibrium. Methylene blue (MB) is the most common among all other dyes of its category. It is generally used in dying textile specially cotton and silk and in some medical treatments’. Through MB is not strongly hazardous it can cause some harmful effects. It can cause eye injury for both human and animals. On inhalation, it can give rise to short periods of rapid or difficult breathing while ingestion through the mouth produces a burning sensation and may cause nausea, vomiting, profuse sweating, diarrhea, gastritis, mental confusion and methemoglobineamia. Acute exposure to MB can cause increased heart rate, vomiting, Heinz body formation, cyanosis, jaundice, quadriplegia and tissue necrosis in humans. Textile industries produce wastewater with different chemical quality and quantity due to diversity of consumed dyes and production method. In these industries, a huge amount of coloreful wastewater is produce that is usally poisonous, resistant to biodegradation and sustainable in environment; thus, common biological methods aren’t effective for removing almost all synthetic dyes due to complex chain structure and dye sustainable nature (Ledakowiez, 2001; Dincer, 2007). Studies has shown that textile wastewater has low BOD/COD ratio (0.1) which is resulted from non-biodegradability of dyes ( Chao, 2002). Discharge of colorful wastewater resulted from textile industries to receiving waters will result in reduced penetration of sunlight, occurrence of eutrophication and interference with receiving water ecology; in addition to decrease photosynthesis of aquatic plants and algae in aqueous environment, it damages environment ( Arsian, 200o; sauer, 2002; Nilson, 2006). To remove dyes from wastewater, physical, chemical, biological or compound methods can be used. Since dyes are susceptible bio-degradation, physical and chemical methods like flocculation-coagulation, surface absorption, chemical oxidation and membrane process are used (Lopez 2004; Tang 2004). Out of various activities in textile industry, they discharge a large variety of dyes and chemicals addition that makes the environmental challenge for textile industry not only liquid waste but also in its chemical composition. Main pollution in textile wastewater came from dyeing and finishing processes. These processes require the input of a wide range of chemicals and dyestuff, which is generally are organic compound of complex structure. Because all of them are not contained in the final product, become waste and it affect the aquatic ecosystem in number of ways such as depleting the dissolved oxygen content or settlement of suspended substances aerobic as well as anaerobic condition. The major pollutants in textile waste are high suspended solid, COD, heat, color, acidity and other soluble substances, most dyes used in textile industries are stable to light and not biologically degradable. Furthermore, they are resistant to aerobic digestion. Many reseachers have studied the applicability of low cost alternative materials like saw dust, coir pith, olive stone, pine bark, coconut shell, tropical grass almond shells e.t.c as carbonaceous precusors from the removal of dyes from wastewater ( Arivoli, et al. 2007; sekar, et, al. 1995;Selvani, et al. 2000). A synthetic dye in wastewater cannot be efficiently decolorized by traditional methods. This is because of the high cost and disposal problems for treating dye wastewater at large scale industries. As earlier stated; adsorption is the most effective method of dyes removal technique using low cost adsorptions as it will be received in next section. Adsorption is well known equilibrium separation process for water decontamination applications. Adsorption has been found to be superior to other techniques for water reuse in terms of initial cost, flexibility and simplicity and simplicity of design and use of separation as review. A researcher studies the adsorption of Congo red on Neem leaf litter showed the highest adsorption capacities compared to any other adsorbents. It was observed that the adsorbent is effective for the removal of anionic dyes in a wastewater treatment process.The present study undertaken to evaluate the efficiency of unactivated carbon from cassava fiber as an adsorbent for the removal of methylene blue dye from aqueous solution.1.2 Problem Statement (harmful effluents) expenseA lot of research has been reported for adsorption of dye using activated carbon from various low cost materials. Usually, activated carbon prepared from teak leaf, maize corn, baboon tree bark, coir pith, & sun flower stalks. In industries such as rubber, plastics, printing leather etc., there is a waste strem (mostly aqueous solution). The waste generation in this case is inevitable but the problem now is how to depose off this waste without altering the normal condition. This research aims at making wastewater treatment more economical and environmental friendly by using manihot esculanta as adsorbent. This study showHow to reduce the cost of this treatment processThe possibility to determine the maximum adsorptive capacityTo determine the contact timeHow reliable is this adsorbent compared to other adsorbent in use.
1.3 Justification of StudyThe study makes availability of cheap and compitative and it also brings about low cost or cheaper to reduces expensive or increase profit.1.4 Research Aim and ObjectivesThe main aim of this work is to investigate the modeling process in the adsorption of methylene blue using unactivated carbon from cassava fiber.The objectives of the study are as followsTo determine the modeling of particles size of cassava fiber on the adsorptionTo determine the factor that affect cassava fiberTo determine the timeTo determine the properties of the adsorbent1.5 Scope of StudyThis study is to investigate the modeling of kinetic batch adsorption of methylene blue using unactivated carbon from cassava fiber.