Sustainable Water Engineering: Theory and Practice

4 Fundamentals of Treatment and Process Design, and Sustainability

Every community produces both liquid and solid wastes. The liquid waste is essentially the water after it has been fouled due to the generation of a variety of wastes. If untreated wastewater is discharged into the environment this can lead to malodorous gases. Furthermore, untreated wastewater usually contains many pathogenic micro-organisms. Wastewater also consists of nutrients, which can enhance growth of aquatic plants. For these reasons, wastewater treatment and disposal is desirable and necessary in an industrialized society.

Wastewater engineering is that branch of engineering in which the fundamental principles of science and engineering are applied to control water pollution problems. The ultimate goal, namely, wastewater management, is to protect the environment.

A variety of technologies address the challenge of the UN target that aims to provide safe drinking water and hygienic sanitation to all people on the Earth by the year 2025 but these solutions do not provide an integral solution and lead to problems like eutrophication, water shortages, heavy metals in sludge, loss of fertility, scarcity of nutrients and bio-magnification due to traces of medicine and chemicals in the water and disruption of the nitrogen/phosphorus cycle. Sustainable solutions should therefore balance the use of different resources, including their environmental, economical, and social-cultural aspects (van der Vleuten-Balkema, ...