ROTARY FILTER FINES TESTING FOR SMALL COLUMN ION EXCHANGE

Herman, D.

Savannah River Site (S.C.)

关键词: Sludges;    Membranes;    Filtration;    Testing;    Titanates;   

DOI  :  10.2172/1022759
RP-ID  :  SRNL-STI-2011-00396
RP-ID  :  DE-AC09-08SR22470
RP-ID  :  1022759

美国|英语

来源: UNT Digital Library

【 摘 要 】

SRNL was requested to quantify the amount of 'fines passage' through the 0.5 micron membranes currently used for the rotary microfilter (RMF). Testing was also completed to determine if there is any additional benefit to utilizing a 0.1 micron filter to reduce the amount of fines that could pass through the filter. Quantifying of the amount of fines that passed through the two sets of membranes that were tested was accomplished by analyzing the filtrate by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) for titanium. Even with preparations to isolate the titanium, all samples returned results of less than the instrument's detection limit of 0.184 mg/L. Test results show that the 0.5 micron filters produced a significantly higher flux while showing a negligible difference in filtrate clarity measured by turbidity. The first targeted deployment of the RMF is with the Small Column Ion Exchange (SCIX) at the Savannah River Site (SRS). SCIX uses crystalline silicotitanate (CST) to sorb cesium to decontaminate a clarified salt solution. The passage of fine particles through the filter membranes in sufficient quantities has the potential to impact the downstream facilities. To determine the amount of fines passage, a contract was established with SpinTek Filtration to operate a 3-disk pilot scale unit with prototypic filter disk and various feeds and two different filter disk membranes. SpinTek evaluated a set of the baseline 0.5 micron filter disks as well as a set of 0.1 micron filter disks to determine the amount of fine particles that would pass the membrane and to determine the flux each set produced. The membrane on both disk sets is manufactured by the Pall Corporation (PMM 050). Each set of disks was run with three feed combinations: prototypically ground CST, CST plus monosodium titanate (MST), and CST, MST, plus Sludge Batch 6 (SB6) simulant. Throughout the testing, samples of the filtrate were collected, measured for turbidity, and sent back to SRNL for analysis to quantify the amount of fines that passed through the membrane. It should be noted that even though ground CST was tested, it will be transferred to the Defense Waste Processing Facility (DWPF) feed tank and is not expected to require filtration.