Water is an essential part of any food manufacturing plant. It is used as an ingredient, coolant, CIP solvent or in many other chemical based reactions in companies. After the completion of manufacturing process, this influent gets converted into wastewater which gets expelled from industry as a byproduct which is also known as effluent. This effluent is defined as a mixture of both toxic and non- toxic materials and it generally contains 99.9% water and 0.1% solids. The main task in treating the wastewater is simply to remove most or all this 0.1% of solids. Effluent cannot just be disposed to the environment because of the harmful material it contains. Therefore, an effluent treatment plant comes into play. This is simply a procedure put in place to purify industrial wastewater to recycle it or dispose of it safely. Different companies have different wastewater composition and require slightly different effluent treatment plant.
A. Characterization of Wastewater
Physical Parameters of the Wastewater
Wastewater has physical characteristics such as temperature, solids, odor, and color. In plumbing work the temperature and type of solids in the wastewater are important considerations. Wastewater at high temperature will affect some piping materials and treatment units such as septic tanks. You may have to consider the use of an arrestor to pre-treat the wastewater.
Chemical Parameters of the Wastewater
Wastewater contains chemicals such as nitrogen, phosphorus, and levels of dissolved oxygen as well as others that may affect its composition and pH rating. Highly acidic or alkaline wastewater is probably trade waste and will require pre-treatment before discharge to the sewer. The chemical properties of wastewater may also affect the pipe material.
Biological Parameters of the Wastewater
This is the presence of microbial pathogens in the wastewater. Consists of microscopic flora and fauna which are pathogenic in nature and can transmit dangerous diseases such as typhoid, cholera and dysentery.
Therefore, ETP is designed to remove the physical, chemical, and biological materials present in the effluent.
B. Components of Effluent Treatment Plant:
Depending on the level of treatment the wastewater requires, an ETP is divided into four different levels each designed to remove a certain type of material in the effluent. There are four levels in wastewater treatment, each level designed in a way that by the time the process is complete, the water to be disposed to the environment is as friendly as possible. These levels are as follows:
This aims at the removal of physical waste present in the effluent. This level involves physical processes such as sedimentation, filtration, aeration, flow equalization, clarification and screening.
Aims at the removal of large solids and organic matter. It involves both physical and chemical processes. The same physical processes mentioned in the first level are utilized. The chemical process involves the addition of certain chemicals to improve the quality of the wastewater. These chemical processes include chemical coagulation, pH control by addition of HCI or sodium carbonate, chemical precipitation, flocculation, and dissolved air flotation.
Involves the removal of biodegradable organic materials and suspended matter. This level uses biological and chemical processes. The chemical processes are similar to level Biological processes involved are the suspended-growth process and the attached-growth/fixed-film process. The two biological processes can be used together or either one can be chosen.
This level entails the removal of suspended and dissolved materials using the physical, chemical and biological process utilized together. The processes are as discussed in previous levels. Effluent treatment plants are a critical part of the manufacturing industries and other wastewater treatment plants. They keep the environment safe from hazardous materials through strict treatment protocols.
Effluent of food wastes are a significant contributor to nutrient and carbonaceous and nitrogenous waste discharge. Treatment of this food processing wastewater is complex and costly because of the contaminant loadings and the variability of the different wastes encountered in a plant. Industries including poultry and meat processing, dairy products and oil production generate high-strength wastes. While common wastewater treatment processes are used, there are constant developments taking place in treatment scheme so that wastewater can be economically converted into nontoxic effluent which can be discharged off into environment. In addition to reducing operating costs, ETPs are also considered environmentally friendly by reducing waste discharges and carbon footprints.