Rochem Separation Systems, Inc. Disc Tube Module Technology - Abstract

The Rochem Separation Systems, Inc. (Rochem) Disc TubeTM Module (DTM) technology is an innovative membrane separation process. It is designed to treat liquid waste that is higher in dissolved solids content, turbidity, and contaminant levels than waste treated by conventional membrane separation processes. According to the technology developer, Rochem, the innovative DTM design reduces the potential for membrane fouling and scaling, which allows it to be the primary treatment for liquid wastes such as landfill leachate. The DTM technology was evaluated by Science Applications International Corporation (SAIC) under the Superfund Innovative Technology Evaluation (SITE) Program at the Central Landfill Superfund Site in Johnston, Rhode Island. The DTM technology treated leachate contaminated with chlorobenzene and 1,2-dichlorobenzene at average concentrations of 21 and 16 milligrams per liter (mg/L), respectively, and lower levels of 1,4dichlorobenzene at 0.7 mg/L; toluene at 1.8 mg/L; xylenes at 1.3 mg/L; and ethylbenzene 0.79 mg/L. Total organic carbon (TOC) was present in the leachate at an average concentration of 460 mg/L, and total dissolved solids (TDS) were present at an average concentration of 4,900 mg/L. Metals were also present at average concentrations such as 1.4 mg/L for barium, 130 mg/L for calcium, 48 mg/L for iron, and 21 mg/L for manganese. The purpose of this SITE Demonstration was to assess the DTM technology’s effectiveness in removing organic and inorganic contaminants from the landfill leachate and in resisting scaling and fouling of the membranes. Overall, the DTM technology was very effective in removing contaminants from the landfill leachate. Mean contaminant rejections were greater than 96.7% for TOC and 99.4% for TDS, both exceeding the developer’s claims of 92% for TOC and 99% for TDS. The overall mean rejection for total metals was greater than 99.2%, exceeding the developer’s claim of 99%. The overall mean rejection for target VOCs was greater than 92.3% which exceeded the developer’s claim of 90% for VOCs. In addition, the DTM process achieved a treated water recovery rate of approximately 75%. The developer’s claim was 75%. DTM operational parameters, such as permeate (treated water) flow rate and module pressure drop, and system permeate quality, indicate that there was a decrease in technology performance over the course of the Demonstration. The Rochem DTM technology was evaluated based on seven criteria used for decision-making in the Superfund Feasibility Study (FS) process. Results of the evaluation are summarized in Table 1.