Rapid small-scale column test

Crittenden J.C., P.S. Reddy, H. Arora, J. Trynoski, D.W. Hand, D.L. Perram, and R.S. Summers (1991). Predicting GAC performance with rapid small-scale column tests. Journal of the American Water Works Association 83(l) 77-87. 

Westerhoff, P., Highfield, D., Badruzzaman, M. and Yoon, Y. (2005) Rapid small-scale column tests for arsenate removal in iron oxide packed bed columns. Journal of Environmental Engineering, 131(2), 262-71. 

Knappe, D. R. U., et al. (1997). Effect of preloading on rapid small-scale column test predictions of atrazine removal by GAC adsorbers. Water Res. 31, 11, 2899-2909. 

There is a range of predictive tools in use for the optimization of GAC [13]. Two of the most widely used are the short bed adsorber test (SBA), which has, a similar basis to the HSDM, requiring similar laboratory data input, and the rapid small-scale column test (RSSCT), which relies on the scaling down of the conditions in the full-scale plant to laboratory scale. Detailed information is available in the literature [1, 10, 13, 14], a short description is given below ... 

Crittenden et al. [48,49] developed a standardized test scenario based on down-scaling a full-scale adsorption filter, called the rapid small-scale column test (RSSCT). By down-scaling the process, it could be ensured that the kinetics in the small-scale tests are equal to those in a large-scale Alter. 

The process variables known to influence arsenic capacity and column performance of alumina, GFH, and other adsorbents are as follows adsorbent, adsorbent particle size, flow rate, EBCT, and water quality parameters including arsenic concentration, As(III)/(V) speciation, pH, silica, phosphate, fluoride, hardness, and sulfate concentrations. Even with a complete water analysis, it is prudent to perform pilot studies with competitive adsorbents on the water to be treated because of the numerous factors that influence arsenic adsorption. Equilibrium isotherms and rapid small-scale column tests (RSSCTs) are typically run prior to the pilot study (7). 

A rapid small-scale column test protocol for bench-scale evaluation of alumina adsorbents was recently developed at the University of Houston (7). The RSSCT allows for faster evaluation of arsenic adsorbents using bench-scale column tests with actual or synthetic groundwaters. The RSSCT protocol uses low-pressure (<5 psig) glass minicolumns containing 4.0 mL of 60 X 100 mesh adsorbent. Compared with the standard (28 X 48 mesh) adsorbents currently used in pilot-scale and minicolumn tests, the RSSCT allows the use of faster flow rates so that the column runs can be completed in one-fourth to one-tenth the time required for the standard tests. 

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