Quality and treatment of waste water from concrete plants: a case study

The objective of this study was to evaluate the quality of waste water from a concrete plant that was treated with chemical coagulants combined with Moringa oleifera. In the treatment system employed at the plant, waste-water samples were collected at three different points at the beginning and end of each production week throughout the 1 month production life cycle. The monitored parameters included turbidity, pH, alkalinity and hardness. Samples were collected from an intermediate chamber of the treatment system and treated with coagulants in the laboratory. The results indicated that the quality of the waste water exceeded the established limits for the supply of non-potable water, especially for turbidity. The introduction of the coagulation process significantly improved the quality of the waste water or recycled water (significance of 5%) and 99·94% of the turbidity was removed, which enabled the reuse of water for washing vehicles, producing concrete and flushing toilets.