Industrial water management. A review of water consumption and the available wastewater technologies in five water intensive industries

The concept of water being a never-ending resource with a limitless renewable capacity belongs to the past. Summing up the fresh water on the Earth's surface and the economically attractive ground water reserves gives a mere 1% of water available to quench the thirst of an insatiable human population. The 2012 World WaterAssessment Programme of the United Nations indicates that by 2025, 2/3 of the water population could face water stress, and the latest data about global water consumption do not seem to disprove this statement. Although industrial water consumption varies widely between countries, especially between developed and developing countries, on a global scale, industries are responsible for approximately 20% of the world’s freshwater withdrawals. Water fulfils several important roles and functions in industries, but a considerable portion of this precious resource ends up as wastewater. Recycling and reusing wastewater lessen the stress imposed on fresh water reserves particularly in developing countries, where industrial consumption is skyrocketing. Ranade, et al., (2014) argue that the future competitiveness of water intensive industries is related to how effectively industrial wastewater is treated, recycled, and reused. This paper studies the production process with a particular focus on the water flows in 5 industrial sectors: large thermal plants, oil and gas extraction, pulp and paper, textile, and automotive manufacturing. The conclusion suggests that in Europe, textile mills are by far the thirstiest industries among the 5 analysed. This result is in line with the AquaFit4Use publication of the European Union (2010), which places textile just below agriculture in terms of water consumption. In addition to providing a general overview of the process, whenever a production step consume a significant amount of water or discharge a highly polluted load, the step is carefully described, and existing technologies adopted to treat the wastewater are presented.