A self-contained pH control and monitoring sys- tem for ready mixed operations yields clean water for recycling or permitted discharge to the environment. Fortrans' Model 5000S uses car- bon dioxide gas to neutralize high-pH process water, offering precise alkalinity monitoring and control of water in pits, settling basins and other containment areas, as it lowers total suspended solids.
Designed to (maintain a specified pH level in a body of water usually 100,000 gallons or less, the Model 5000S pH Control and Monitoring System lowers pH to 7.5, whereupon total suspended solids (TSS) typically fall between 10-18 mg/L without filtration—readings that satisfy both pH require- ments and the 30 mg/L TSS most permits demand before water can be released. Treated water then may be used for wetting rock and/or dust control to aid compliance with storm water run-off regula- tions, or it can be recycled to batch concrete and rinse mixer-drum interiors, as well as trucks bodies without staining or scaling their finishes.
The Model 5000S includes a pH monitor and control system housed in a weatherproof facility with lockable doors and adequate space to house the instrumentation and circulation pump. Con- figured for carbon dioxide gas operation, the sys- tem treats approximately 75,000 gallons of water over a 24-hour period. A maximum 20-ft. head pressure allows handling up to 57 gallons per min- ute. Higher-capacity systems up to 200,000 GPD are also available.
Permitting easy hook-up, the manufacturer affirms, are 1.5-in. quick-connect fittings on inlet and return for standard 2- to 20-ft. sections of 1.5- in. flexible hose. Inlet and outlet fittings at the pit or basin are specified accordingly.
Units are shipped fully assembled, requiring only an electrical connection and a supply of car- bon dioxide gas. Further, since the chemical con- troller is preprogrammed to maintain a pH of 7.5, merely attaching hoses and PVC fittings is required upon delivery.
Model 5000S reportedly costs 60 percent to 70 percent less to operate and maintain than an acid- based pH control systems. Also safer than acid- based alternatives, the 5000S does not require a separate tank on account of its novel water circula- tion design. Certified by an independent engineer- ing firm to operate as specified, the Model 5000S is offered with a one-year warranty on all component parts and housing.
The system is also available as a skid-mounted unit containing all instrumentation and compo- nents of Model 5000S. The Model 5000SK Skid- Mounted pH Control System is shipped on a 44- x 47-in. plastic skid fortified with a durable, solid- plastic surface. Its control panel, provided loose with all components installed, is designed to be attached to an interior wall of the control build- ing. Tubing to the sample cell and from the C02 solenoid valve to the Sparger stone-fed assembly must be inserted after receipt of the unit. The sys- tem features a 115V-30Amp breaker box and two ground-fault circuit interrupter (GFCI) receptacles. The system is shipped with a CO2 feed device.
'We are currently using nine of Fortrans' Model 5000 pH Control Systems at our ready mixed con- crete plants,' reports Jeff Lamm, environmental manager for Southern Concrete Materials in Ashe- ville, N.C. 'They enable us not only to control the pH in our [process water], but help us deal with solids build-up as well. Reliable and virtually maintenance-free, they are one of the best meth- ods I have found to deal with high-pH process water—one of the most critical and increasingly regulated issues in our industry.' SCM is eyeing additional Model 5000 systems for its 30-plant network, he adds. — www.fortransinc.com