Two distribution systems, one treating water by ozonation and another nanofiltration in parallel with lime softening, were monitored for bacterial growth. Both systems kept disinfectant residuals such as chlorine chloramine their respective systems. Bacterial growth was assessed heterotrophic plate counts (HPC) on R2A agar. In the fed ozonated water, HPCs correlated (R2 = 0.96) using an exponential model assimilable organic carbon (AOC) at each sampling site. Also, it observed that caused a...

Research Article| November 01 2006 Effect of surface roughness on fouling RO and NF membranes during filtration a high organic surficial groundwater Colin Hobbs; Hobbs 1Civil Environmental Engineering Department, University Central Florida, PO Box 162450Orlando, FL 32816-2450, USA Tel.: (407) 660-2552 Fax: 875-1161; E-mail: hobbscm@cdm.com Search for other works by this author on: This Site PubMed Google Scholar James Taylor; Taylor Seungkwan Hong 2Civil Korea University, 1, 5-ka, Anam-dong,...

The use of membrane processes for controlling trihalomethanes (THMs) was investigated Florida groundwater sources and one surface water source. All the were used public supply had excessive THMs (>300 μg/L) in finished water. performance projected cost system using are reported this article.

The implementation of groundwater conservation measures has forced utilities with a historical reliance on sources to consider alternative augment their supplies or eliminate dependence. Switching from traditional source water, however, can cause unacceptable changes in water quality that result destabilization and the release chemical biological films interior surfaces existing distribution systems. Data two‐year study were used identify significant parameters develop predictive nonlinear...

Effects of water chemistry, temperature, pipe material, and hydraulic conditions on total chlorine dissipation were investigated using laboratory‐ pilot‐scale experiments. Chlorine demand in the bulk phase depends bulk‐phase constant ( k b ) generally increased with increasing dissolved organic carbon. A 10°C rise temperature resulted a threefold increase . Pipe material significantly influenced rates following order: galvanized iron > unlined cast polyvinyl chloride (PVC) lined iron....

Allocating and managing resources have always been important cornerstones of institutional leadership. Institutional include financial, physical human components. Even in the best times, it is a challenge to do this effectively. In times diminished shrinking resources, distributing these precious commodities across institutions most equitable productive manner fraught with complications. As higher education funding streams expand present more options, they also create new challenges. Leaders...

Corrosion indices have a historical as well practical relevance in drinking water treatment. The development of reliable indicators corrosion related problems, like red water, is an ongoing process the industry. Due to complexity interaction among physical, chemical, and biological reactions taking place within typical distribution system, mechanistic models are difficult formulate. Even if such model was available, fitting it actual field conditions would still be empirical process. give...

Utilities must understand the issues involved when multiple source waters are blended, particularly effect on distribution system water quality. This article describes a multiobjective technique that can help evaluate blends to identify acceptable quality for simultaneous control of lead, copper, iron, and monochloramine levels in systems. Blends three waters—groundwater, surface water, desalinated water—were evaluated. Modeling results indicated different pipe materials often have...

The authors investigated the rejection of six synthetic organic chemicals (SOCs) in a potable water source by nanofiltration membrane softening process. Each SOC was studied separately for one month—which subdivided into four recovery periods. largest‐molecular‐weight compounds (chlordane, heptachlor, methoxychlor, and alachlor) were completely rejected membrane. Ethylene dibromide, lowest‐molecular‐weight compound studied, not membrane, whereas dibromochloropropane partially rejected. Mass...

The cost and effectiveness of trihalomethane (THM) control potable water production by a membrane process were investigated during one‐year project at Flagler Beach, Fla., where the feedwater was highly organic groundwater. Results study showed that system could formation THMs for an extended period, producing finished exceeded quality quantity requirements. Construction operating costs plant Beach would be about same as conventional softening plant—but superior quality. observed to less...

Total lead release in the presence of free chlorine and chloramine residuals was investigated drinking waters produced from ground, surface, desalinated, blended water sources. For desalinated finished waters, more total released than chlorine; for groundwater surface water, however, no statistical differences were found. Finished oxidation‐reduction potential (ORP) differed by residual type but equivalent source not affected addition 100 mg/L sulfates or chlorides. ORP measurement...

The removal of micro-organisms by membrane systems was investigated using single-element membranes and five species in a plant setting at East St. Louis, MO. Single-element included cellulose acetate ultrafilter (UF), polysulfone microfilter (MF), (CA) nanofilter (NF), two composite thin-film (CTF) nanofilters. Micro-organism challenge studies were conducted raw, alum coagulated-settled, finished water. Model consisted Clostridium perfringens (strain 26) spores (~1-5 μ m) for bacteria...

A nanofiltration membrane pilot plant was operated for one year at the Daytona Beach, Fla., Brennan water treatment plant. During that year, evaluated disinfection by‐product control and production. This article discusses selection of membranes quality they produced, along with cost estimates a 10‐mgd groundwater