Recommended architecture for medium-sized WWTP
Water treatment plants with power demand of 125 to 1250 kVA, IEC.

Recommended architecture for large WWTP
Single line diagram: double radial architecture

System Management and Optimization
• System-wide integration (multiple plants)
• Enterprise historian and report generator
• System-wide asset management and reliability programs
• Interface to plant security systems,and design database Intelligent Device Management

Intelligent Device Management
• Health monitoring
• Calibration
• Configuration
• Audit trails

Plant Controls and Monitoring Systems
• Distributed control system / Programmable logical controller (HMIs, controllers, network, etc.)
• Advanced treatment: microfiltration, UV, RO
• Plant historian and report generator
• Electronic documentation
• Integration with other systems and intranet/Internet
• Field bus solutions (HART, Foundation field bus, PROFIBUS, Device Net, etc.)

Electrical & Auxiliaries
• UPS, power conditioning, and distribution
• Motors
• Couplings
• Gear reduction drives
• Backup power generators

Energy Management
• On-Line Plant Modeling Optimization
• Equipment performance Modeling
• Contingency analysis/load Shedding
• Remote breaker control
• Synchronization

Economic Optimization
• Minimizes costs
• Reduces equipment wearand tear
• Balance trade off in time of day pumping strategies
• Energy management
• Optimizes pump and chemical usage

Plant Controls and Monitoring Systems
• Distributed control system / Programmable logical controller (HMIs, controllers, network, etc.)
• Plant historian and report generator
• Electronic documentation
• Integration with other systems and intranet/Internet
• Field bus solutions (HART, Foundation field bus, PROFI-BUS, Device Net, etc.)
• Simulation
• ControlWave RTUs and PLCs

Loop Metrics
• Optimizes the process dynamically throughout full operating range
• Provides real time error distribution analysis

Engineering Services and Lifecycle Support
• Front-end engineering and design capabilities
• Installation, commissioning, and startup services
• Long-term maintenance
• Support, reliability, and maintenance services
• Optimization programs
• Educational services
• Integration services
• Security assessments
• Instrumentation maintenance

Global Performance
• Monitors and benchmarks equipment performance against design specifications

Disinfection - Chlorine, bromine, iodine, and UV radiation.
• Chlorine and bromine are the chemical treatments of choice.
• UV radiation plus hydrogen peroxide is also effective for swimming pools.
• 0.6 mg/L free available residual chlorine recommended.

Control of pH, corrosion, scale.
• pH should be adjusted to above 7.4.
• (Eye irritation occurs below pH 7.4).
• Addition of soda ash (sodium carbonate) raises pH (lowered by chlorine).
• High pH promotes scale formation and can be lowered by addition of fresh water or acids (HClHCl, H2SO4, sodium bisulfate).

Treatment of bathing beaches
• If turnover rates are unsatisfactory for natural waters, disinfection may be necessary.
• Chlorine or other disinfectant can be added in dry or liquid form.
• Natural waters can also be re-circulated, filtered and chlorinated similarly to human-made pools.

Control of bathing beaches
• Control of algae
  • Copper sulfate doses of 5 lb/mg every 2-4 weeks usually controls algal growth.
• Control of aquatic weeds.
  • Lowering of water levels during winter will kill plants.
• Elimination of pathogenic protozoa.
  • CuSO4 and elimination of plants .