ABSTRACT
Treatment Plant in Mexico ............................................................... 158 6.3.5 System Design .................................................................................. 158 6.3.6 Results ............................................................................................... 159
6.4 Case Study: Zero Effluent Systems at Formosa Plastics Manufacturing, Texas ............................................................................................................. 160 6.4.1 Complying with ISO 14001 .............................................................. 160 6.4.2 The Quest for Zero Discharge .......................................................... 160 6.4.3 Summary .......................................................................................... 163
6.5 UV Disinfection ............................................................................................ 164 6.5.1 The Move toward UV Disinfection in North America ..................... 164 6.5.2 UV Light and Its Mechanism of Germicidal Action ........................ 165 6.5.3 UV Lamps ........................................................................................ 166
6.5.3.1 Ballasts and Power Supplies to UV Lamps ....................... 167 6.5.4 Open-Channel Modular UV Systems ............................................... 167
6.5.4.1 UV System for Wastewater at LOTT ................................. 168
Industry and communities around the world are increasingly turning to water recycling and reuse for a wide range of purposes. The drivers are varied and include the need to augment limited water supplies, reduce nutrients in treated effluent, maintain ecological balance, and reduce the costs of purchased and treated water, among others. In the industry, another incentive for water reuse is energy efficiency, as part of
6.5.5 Parameters Affecting the UV Disinfection of Wastewater .............. 170 6.5.5.1 UV Transmission or Absorbance ....................................... 170 6.5.5.2 Suspended Solids ............................................................... 171 6.5.5.3 Particle Size Distribution ................................................... 171 6.5.5.4 Flow Rate ........................................................................... 172 6.5.5.5 Iron ..................................................................................... 173 6.5.5.6 Hardness ............................................................................ 173 6.5.5.7 Wastewater Source ............................................................. 174 6.5.5.8 Equipment Maintenance, Lamp Life, and Workers’
Safety ................................................................................. 174 6.5.6 Germicidal Efficiency ....................................................................... 174 6.5.7 Disinfection Standards ..................................................................... 176
6.6 Brine Concentrators for Recycling Wastewater ............................................ 177 6.6.1 Evaporator Basics ............................................................................. 178
6.6.1.1 Controlling the CF ............................................................. 179 6.6.1.2 Falling Film Evaporation ................................................... 180 6.6.1.3 Typical Feed Waters ........................................................... 181
6.6.2 Zero-Discharge Systems Using Brine Concentrators ....................... 181 6.6.3 Alternative Zero-Discharge Methods ............................................... 183
6.6.3.1 Staged Cooling ................................................................... 183 6.6.3.2 HERO Process ................................................................... 183
6.6.4 Economics of Brine Concentrator Systems ...................................... 186 6.7 Progress toward Zero Discharge in Pulp and Paper Process Technologies .... 188
6.7.1 Two Case Studies .............................................................................. 189 6.7.1.1 Louisiana-Pacific Corporation: Conversion to Totally
Chlorine Free Processing ................................................... 189 6.7.1.2 The World’s First Zero Effluent Pulp Mill at Meadow
Lake: The Closed-Loop Concept ....................................... 189 6.7.2 Clarification ...................................................................................... 190 6.7.3 Evaporation ....................................................................................... 190 6.7.4 Concentration .................................................................................... 192 6.7.5 Stripping ........................................................................................... 193 6.7.6 Incineration ....................................................................................... 193
6.8 Successful Implementation of a Zero- Discharge Program ........................... 193 6.8.1 Closing the Loop .............................................................................. 194
6.9 Conclusions ................................................................................................... 195 References .............................................................................................................. 195
the water-energy nexus. Water reuse can be energy intensive depending on the level of treatment required, and a life cycle cost (LCC) analysis is required to compare overall resource costs with the cost of alternative water supplies.
