Investigation of recovery potentials of textile industry wastewater with innovative approaches

In recent years, factors such as population growth, the expansion of agricultural activities, urbanization, and accelerated industrialization, combined with global climate change, have led to the rapid depletion of potable and usable water resources. This situation increasingly hinders access to necessary water supplies, resulting in significant challenges in securing clean water. The difficulty in accessing clean and usable water not only gives rise to economic and social issues but also raises critical environmental and public health concerns. Additionally, water scarcity negatively impacts industrial efficiency, thereby endangering human comfort. For these reasons, sustainable management of water resources, more efficient water usage, and the recycling of treated wastewater are becoming increasingly critical topics. Water not only meets the basic needs of living organisms but is also an integral part of many industrial processes. In particular, in sectors such as the textile industry, water plays a critical role at almost every stage, leading to the generation of large volumes of wastewater. Effective management, treatment, and reuse of wastewater resulting from such industrial activities are of great importance, both economically and for the sustainable use of water. In this study, the recovery potential of wastewater generated in the textile industry was investigated using innovative treatment methods. The potential for reusing the recovered wastewater in textile production processes and other areas was also evaluated. For these purposes, the production processes of a textile factory, the water cycle within these processes, and the performance of the existing wastewater treatment plant were examined in detail as a case study. On-site observations were made, and interviews were conducted with relevant personnel regarding the current or potential issues of the factory's existing wastewater treatment plant. Based on the characterization of the raw wastewater, improvement studies for the existing biological treatment plant were conducted, and the approximate costs of these studies were calculated. As part of the improvement efforts, potential scenarios were developed to address nutrient deficiencies using animal (chicken-pigeon manure) and synthetic fertilizers (diammonium phosphate (DAP), DAP + urea mixture). The results of these studies identified the DAP + urea mixture as the most cost-effective and efficient option for compensating for nutrient deficiencies in the existing biological wastewater treatment plant. In the second phase of the study, designs were developed for the combined use of newer/innovative treatment systems to enhance the quality of the effluent from the existing biological wastewater treatment plant. In this context, the addition of a membrane bioreactor (MBR) system to the existing aeration basin was examined in detail, including costs (MBR design steps, parameters to consider during design, and all necessary equipment and instrumentation systems). The MBR design studies estimated a capital cost of approximately €227,312.94 under current conditions. In the final phase of this study, a reverse osmosis (RO) system was designed for the recovery of wastewater following the MBR treatment. The Water Application Value Engine (WAVE) projection sofware was used in the design of the RO system. For the economic analysis of the RO system, market research was conducted (offers were obtained from membrane manufacturers), and all required equipment, instrumentation, and fittings for the system were identified. The design, considering the necessary parameters for using the treated water as process water within the plant after treatment in the MBR + RO system, was conducted such that 70% of the 600 m³/day feed water would be recovered using single-stage, two-pass membranes. The cost of the reverse osmosis system, designed within a 40-foot container, was estimated at €113,670.61. Therefore, the total cost for wastewater recovery (MBR + RO) was found to be €340,983.55. As a result, the treatment systems designed for the examined facility indicate that the recovered water can be used in place of well water as process water within the system. Furthermore, based on the findings of this study, it can be stated that the facility's water footprint can be reduced, and compliance with the emerging Zero Liquid Discharge (ZLD) concept can be achieved.