It is difficult to point out technological challenges faced by industrial wastewater treatment because there isn’t really one specific challenge; issues basically vary greatly and are some are complex and local.
One of the biggest problems is that many of the reuse solutions are still so costly that costs outweigh the benefits. Due to water still being generally available and fairly cheap in most countries, discharge is still possible and will only change when current solutions become more cost-effective.
Consistently adding tighter water quality requirements and more stringent wastewater discharge controls are some of the general challenges faced. While costs remain high, technologies that can reduce costs of things like disposal of high-strength final waste and specific ion removal versus non-specific technologies such as membranes are vital.
Unintended effects include the fact that nutrient removal is a problematic challenge which drives more plants to add massive amounts of chemicals to polish their effluents; another problem is that multiple systems now require additional upkeep.
Another problem created by wastewater plant operators in their attempt to keep prices down while maintaining a complicated system is that biological phosphorus removal followed by anaerobic digestion results in the release of phosphorus back into the plant. Fortunately, when these biological techniques are replaced by chemical stabilisation methods, it will result in the phosphorus being permanently tied up until it leaves the system. A process known as integrated fixed-film activated sludge effectively removes nutrients, total nitrogen and total phosphorus.
Water professionals need to constantly engage with suppliers as to any new technology and the costs thereof, and to compare it with current solutions to see which is best suited all round. Dialogue leads to stronger networks, and stronger networks will lead to better solutions all round; improved operating expenses for the company and healthier solutions for the environment and the future of water for all.