China
Africa
Explore chapters and articles related to this topic
Recovery Processes and Utilisation of Valuable Materials from Acid Mine Drainage
Published in Geoffrey S. Simate, Sehliselo Ndlovu, Acid Mine Drainage, 2021
The second proposed integrated process by Simate and Ndlovu (2014) is shown in Figure 9.8. In this process the AMD is fed to the first part of the process in which the CH-collector (e.g., amino bisphosphonate adsorbent) adsorbs some of the heavy metals directly from the wastewater. The resulting solution is then passed through a vacuum evaporator where the water component is vaporised thus producing re-usable water while sulphuric acid remains in solution. A vacuum evaporator is used because it has the advantage of producing a large separation factor in the sulphuric acid/water system (Nleya et al., 2016). The remaining solution from the vacuum evaporator that contains dilute sulphuric acid and some remaining heavy metals such as ferrous iron is fed to a fuel cell that produces electricity, iron oxide and metal-barren dilute sulphuric acid.
Surface Phenomena
Published in Pramod K. Naik, Vacuum, 2018
Vacuum evaporation is the process in which the liquid is made to evaporate at a lower temperature than normal when the pressure above the liquid surface is reduced below the vapour pressure of the liquid. This process is employed particularly for the storage of food products for longer periods without degeneration because the water can be effectively removed at much lower temperatures as the boiling point of water is reduced at low pressure. In the vacuum distillation process, this method is used as the more volatile liquid can be removed fast by vacuum evaporation. The vacuum freeze drying process is used to preserve perishable items. In this process, the items such as blood plasma are frozen and
Water Reuse and Recycling
Published in Maulin P. Shah, Removal of Refractory Pollutants from Wastewater Treatment Plants, 2021
Khushboo Dasauni, Divya, Tapan K. Nailwal
The thermal desalination process is most suitable for water and process streams with a high dissolved salt content. In this case, the applied pressure required by the equivalent membrane system will be too high. If possible, the use of low-cost energy sources, such as those available from thermal power plants, is advantageous in reducing energy costs. Another option is to use a low-temperature, high-efficiency vacuum evaporation system, which can operate using waste heat and low electrical energy (Al-Karaghouli et al., 2013).
Cesium Formate as a Dense Medium Liquid for Laboratory Coal Washability Testing
Published in International Journal of Coal Preparation and Utilization, 2020
Alan Pickup, Merrick Mahoney, John Kelly
The recovery of the dilute cesium formate in the rinsing can potentially be carried out using three techniques. Distillation – evaporation at elevated temperatures.Vacuum Evaporator – this involves reducing the pressure above the liquid to less than its vapor pressure allowing it to be boiled off at lower temperatures.Reverse Osmosis – recovery through semi-permeable membranes.