The large amount of sago waste produced by sago processing industries can cause serious environmental problems. When dried, these residues usually have a high starch content (around 58%) and have many potential applications. In this study, the drying of sago waste using a fluidized bed dryer (FBD), which offers more advantages than other drying methods, is analyzed via computational fluid dynamics (CFD) modeling. A two-dimensional (2D) FBD model is also developed and a mesh independency test is conducted immediately afterwards. A fine mesh is selected for the CFD model and a simulation is conducted using ANSYS Fluent 17.1 software (Ansys Inc., version 17.1, Canonsburg, PA, USA). The governing and discretized algebraic equations are solved by applying the phase-coupled semi-implicit method for pressure-linked equations. Both the Eulerian-Eulerian multiphase model approach and the turbulence model are applied in the simulation due to the turbulent flow in the dryer. A velocity of 1.30 m/s and temperature of 50 • C are selected as boundary conditions based on the optimum parameter values from previous experiments. The final moisture content that we aim to achieve is 10% or a moisture ratio of 0.25 in sago waste for the purpose of animal feed, so as to prevent bacterial growth and for packaging purposes based on common industrial practice. Both the drying rate and fluidization profile are examined at air velocities of 0.6, 1.0, 1.3, 1.8, and 2.2 m/s. Based on the results, the velocity range of 1.0 m/s to 2.2 m/s is deemed suitable for the fluidization and drying of sago waste with a particle size of 2000 µm for a drying simulation of 1 h. The drying rate is further examined at air temperatures of 50 • C, 60 • C, 70 • C, and 80 • C, whereas the fluidization profile is examined at particle sizes of 200, 500, 1000, and 2000 µm. The results reveal excellent fluidization at a particle size range of 500 µm to 2000 µm and a velocity of 1.3 m/s. Energies 2018, 11, 2383 2 of 13 9.2% hemicellulose, and 4% lignin [3] and have many potential functions, such as in the manufacturing of textile printing materials [4]. Several studies have investigated other usages of sago waste, including their adsorption of lead and copper [5] as well as their use in the production of bioethanol [6].Sago waste is usually mixed with wastewater and either discharged into streams or deposited in factory compounds. Each tone of extracted sago starch produces and dumps approximately one tone of sago waste into the nearby rivers. Data from the Malaysian Department of Statistics reveal that the country produced approximately 52,000 tons of sago starch in 2011. Nearly the same amount of sago waste was dumped in nearby rivers [7], thereby causing serious environmental problems such as water pollution. The high demand for biological oxygen (approximately 5820 mg/L) and chemical oxygen (approximately 10,220 mg/L) [1] in wastewater affects the marine life and water quality via microbiological degradation and by consuming the dissolved oxygen in the water. Som...

Water is an important factor of life for all living organisms and it is now deteriorated very rapidly due to industrial effluents, municipal and agriculture waste leaching down the groundwater. The percolation of water through the deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates increases the mineral contents. So, the presence of high mineral contents creates water hardness. Water hardness is mainly occurring by the existence of calcium and magnesium, their high concentration in water makes water hard which cause several hazardous impacts on human life. Therefore, certain concentration standard limits have been fixed by different organizations. According to WHO 500 mg/l is allowable limit for water hardness. So regular use of high concentration of Calcium and magnesium ions above standard limits is causing real problems for human beings and environment. In daily routine life different harmful incidence occurs due to hard water. To overcome this problem water softening is a technique that serves the removal of cations which are most likely the hardness factors are calcium and magnesium. Water softening is the most useful technique to remove hardness. Therefore, a water softener is developed for domestic purpose. As the development of an optimum water softener was very essential for domestic use. The water softener can have performed efficiently with a hardness range of 1000-1200 mg/l and TDS may be up to 1500mg/l. The water softener plant is also cost efficient that have almost one-time production cost and very low maintenance and running cost. After the manufacturing of water softening plant hardness, pH, DO, TDS and EC is calculated to check its efficiency. The hardness, TDS and conductivity reduces after passing the sample water through the sample, DO was increased to little extent and pH was remained in a specific range.