Industrial Wastewater Treatment - Trends and Perspectives

abstrakt

en

Water, energy, raw materials – key elements for every industrial activity. However, they are not available in unlimited amounts and the savings are discussed worldwide. Besides, there are negative environmental impacts related to their massive use due to increasing industrial production. This forces governments to motivate industry to implement saving measures and industry might by motivated by increasing cost of either water or energy or raw materials. Industrial wastewater treatment may be considered as a contributor to recovery of water with sometimes with benefit of raw materials recovery. Moreover, depending on the treatment process, it can utilize frequently present low potential waste heat, which further increases efficiency of the primary energy source. Recently, the concept of zero liquid discharge (ZLD), or alternatively minimum liquid discharge (MLD), was introduced. The primary goal is waste reduction; however, recovery of water and the other positive impacts are not less important. It basically consists of three steps: pre-treatment (chemical and mechanical treatment), concentration (split into clean water and concentrated wastewater by filtration) and final treatment of concentrated wastewater (usually by evaporation and crystallization). High investment cost and sometimes also operation cost of ZLD/MLD technology prevents it from more frequent application. The other reason might be lower awareness of the technologies between potential users. The objective of researchers should be an improvement of the individual steps as well as the whole process towards lower investment and/or operational costs. Moreover, optimal integration into the existing primary process is also very important. Some recent examples of ZLD/MLD technologies application in biogas plants, industrial laundries and wineries, which the authors have been dealing with, will be introduced. Water is valuable, and water management in plants with high consumption should pay more attention. It can be positive in terms environment but also in terms of cost if designed and integrated properly. The presented examples demonstrate that there is a great potential for application of ZLD/MLD technologies to maximize water use efficiency and possibly raw materials recovery and waste heat utilization.

Water, energy, raw materials – key elements for every industrial activity. However, they are not available in unlimited amounts and the savings are discussed worldwide. Besides, there are negative environmental impacts related to their massive use due to increasing industrial production. This forces governments to motivate industry to implement saving measures and industry might by motivated by increasing cost of either water or energy or raw materials. Industrial wastewater treatment may be considered as a contributor to recovery of water with sometimes with benefit of raw materials recovery. Moreover, depending on the treatment process, it can utilize frequently present low potential waste heat, which further increases efficiency of the primary energy source. Recently, the concept of zero liquid discharge (ZLD), or alternatively minimum liquid discharge (MLD), was introduced. The primary goal is waste reduction; however, recovery of water and the other positive impacts are not less important. It basically consists of three steps: pre-treatment (chemical and mechanical treatment), concentration (split into clean water and concentrated wastewater by filtration) and final treatment of concentrated wastewater (usually by evaporation and crystallization). High investment cost and sometimes also operation cost of ZLD/MLD technology prevents it from more frequent application. The other reason might be lower awareness of the technologies between potential users. The objective of researchers should be an improvement of the individual steps as well as the whole process towards lower investment and/or operational costs. Moreover, optimal integration into the existing primary process is also very important. Some recent examples of ZLD/MLD technologies application in biogas plants, industrial laundries and wineries, which the authors have been dealing with, will be introduced. Water is valuable, and water management in plants with high consumption should pay more attention. It can be positive in terms environment but also in terms of cost if designed and integrated properly. The presented examples demonstrate that there is a great potential for application of ZLD/MLD technologies to maximize water use efficiency and possibly raw materials recovery and waste heat utilization.

Wastewater Treatment; Industry; Zero Liquid Discharge; Recycling; Secondary Raw Materials; Evaporation; Waste Heat

06.02.2022

University of Thessaly

Volos, Greece

2653-8911

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