One of the most important factors to know when establishing a wastewater treatment facility in a location is the population data specific to that area.
The area for the project should be selected according to the urban planning of the city it is located in, its geographical structure, infrastructure facilities, and the location and characteristics of the receiving environment. Wastewater treatment plants are divided into two sections: construction and electromechanical, with construction serving for 30-40 years and the electromechanical part for 10-15 years. Generally, wastewater treatment plants are planned in two stages of 15 years each or three stages of 10 years each. One of the most important factors to know when establishing a wastewater treatment plant in a location is the population data for that area. According to Article 6 of the Second Section of the Regulation, "The choice of population estimation method varies according to factors such as the urban plan of the settlement, its economy, tourism potential, and migration in and out. In population estimates, methods such as arithmetic increase, geometric increase, decreasing rapid increase, logistic curve, and similar methods are used. In 'metropolitan areas', since the population approaches saturation value, methods of generally decreasing growth or logistic curve tend to yield more appropriate results. The most suitable method should be chosen by considering past population censuses of the settlement and comparing multiple methods."If there is no wastewater collection system in a region and installation is not possible, on-site treatment systems should be implemented in those areas. In such cases, the provisions of the "Regulation on Pits to be Constructed in Places Where Sewage Construction is Not Possible," published by the Ministry of Health and Social Assistance in the Official Gazette dated March 19, 1971, and numbered 13783, are applicable. The principles to be applied vary depending on whether the equivalent population is below or above 500.According to the Technical Procedures Regulation for Wastewater Treatment Plants,Technical Principles to be Applied in Tourism Areas,
Technical Principles to be Applied in Areas Where Land is Scarce and Valuable,
Technical Principles to be Applied in Areas Where Land is Easily Obtainable,
Technical Principles to be Applied According to Climate Conditions
Four special situations have been identified under these headings. According to each special situation, the treatment te...The establishment and operation of the system show variations. For example, according to Article 18, "Natural treatment systems (anaerobic treatment, stabilization ponds, aerated lagoons, artificial wetlands) that cover larger areas can be used in places where land can be easily obtained (Central Anatolia and Southeastern Anatolia Region)."Turkey is divided into five different regions in terms of wastewater management. The first region includes the Mediterranean and Aegean coasts, the second region consists of the inland areas of the Mediterranean and Aegean Regions and the Thrace part of the Marmara Region, the third region covers the Black Sea coasts, the fourth region includes Central Anatolia and Southeastern Anatolia Regions, and the fifth region is the Eastern Anatolia Region. The recommended treatment methods differ for each region. For instance, it has been determined that septic tanks can be installed in the fifth region, which has a very cold climate and a population below 500; the Mediterranean and Aegean Coasts, being the first region, are classified as the most developed and sensitive area from a tourism perspective.It is essential that the existing Wastewater Treatment Plants are continuously monitored and improved from time to time. This issue is addressed in Article 27 of the Regulation. The necessity of improvement works for existing wastewater treatment plants is stated with objectives such as improving effluent water quality, increasing capacity in pollutant and hydraulic loads, process control and optimization within the facility, and minimizing operating costs. First, the current situation must be established, and needs and future primary goals should be determined. Then, design data such as process and hydraulic calculations related to the wastewater treatment plant are examined, and experimental characterization studies that reveal the current situation can also be conducted if necessary. After evaluations related to the facility are made, experiments are planned to identify factors that limit process efficiency. After this stage, feasible alternatives for improvement are identified. The alternatives may include existing or new technologies. After possible alternatives are selected and implemented in the field, the...The implementation of alternative methods; construction of new treatment units, installation of existing and new equipment, arrangement of process control equipment, revisions related to construction and equipment carried out in parallel at the existing treatment plant, and internal arrangements of the facility are included.The fourth section of the Technical Procedures Regulation for Wastewater Treatment Plants, consisting of a total of 7 sections and annexes, discusses the procedures and requirements of the "Disinfection" process. Disinfection of treated wastewater is mandatory before it is discharged into the receiving environment. Chlorine is the most commonly used disinfectant in wastewater treatment due to its low cost. While chlorine is inexpensive, it also has disadvantages due to the potential for accidents during transportation and application, its toxic effects, the formation of odors and disinfection by-products when it comes into contact with organic substances, and the toxic effects of these by-products in the receiving environment. The regulation specifies the required chlorine dose; initial chlorine demand, the chlorine dose necessary for disinfection of microorganisms, and residual chlorine. The amount of residual chlorine that should remain in the water after a 1-hour contact time should be between 1-2 mg/L.Ozone and UV systems are also disinfection systems. Ozone is produced by ozone generators in the treatment plant and is mixed with wastewater through contact tanks. UV systems, especially used in cases where the treated wastewater is planned to be reused for irrigation purposes, transfer UV light to the cells' proteins and nucleic acids (RNA-DNA). UV light must be absorbed by the organism, as it can only harm the organism in this way. The effectiveness of these disinfection systems varies according to the types of microorganisms. For example, while chlorination and ozonation methods are very effective for bacteria, UV disinfection is not very effective.Another section mentions Deep Sea Discharge Systems, which are designed to utilize the dilution and natural treatment processes of the sea in receiving environments identified through engineering studies as having sufficient treatment capacity, discharging wastewater at certain distances from the shores.It is based on the principle of discharging into the sea through pipes and diffusers at the sea bottom. The pollutants in the wastewater discharged into the sea through a long discharge line are diluted in three different ways as first (initial), second, and third dilution in the discharge environment. Dilution calculations are generally included in the annexes of the regulation. During the treatment of wastewater, large amounts of sludge are produced, and due to their high organic content, this sludge decomposes and causes undesirable odors. The most important chemical parameter to be considered in the final disposal of the sludge after processing is its nutrient (fertilizer) content.Recently, the increase in water usage due to rapid population growth has led to water scarcity. According to the regulation, countries with 1000-2000 m³ of water per capita per year are considered to be under water stress, and our country is one of these countries. Considering that 65-70% of the used water is thought to be used for agricultural and green area irrigation, and 20-25% in industry, the recovery of urban wastewater for agricultural purposes and industrial recovery is of great importance. The technological requirements for wastewater recovery are related to the intended use of the recovered water; if the water is to be used for agricultural or green area irrigation, a well-disinfected biological treatment effluent may be sufficient.The "Technical Procedures Regulation for Wastewater Treatment Plants" dated March 20, 2010, numbered 27527, has come into force to regulate technical procedures and applications and is one of many regulations that will provide advantages not only for us environmental engineers but for every citizen as well.
