Bench‐scale evaluation of GAC for NOM control

Abstract

Although these authors confirm that the RSSCT is able to predict the breakthrough behavior of full‐scale activated carbon columns, they emphasize the importance of obtaining a representative batch water sample for the RSSCT. The Information Collection Rule (ICR) will require that some utilities perform disinfection by‐product (DBP) precursor removal studies. The rapid small‐scale column test (RSSCT), a bench‐scale granular activated carbon (GAC) test designed to reduce time and costs associated with field‐scale studies, has been proposed as an alternative to evaluate GAC performance for the ICR. RSSCT scaling equations maintain similitude with full‐scale GAC systems, and therefore the RSSCT directly assesses the concentration breakthrough in a full‐scale GAC column. A review of past studies shows that the RSSCT has successfully predicted field‐scale performance for the control of natural organic matter and DBP precursors. The results of a current study emphasize the importance of obtaining a representative batch water sample for the RSSCT. A cost analysis based on using GAC to satisfy stage 1 and stage 2 requirements of the Disinfectants/Disinfection Byproducts Rule suggests that minimizing empty bed contact time will reduce capital costs associated with GAC contactors.

Improving GAC performance by optimized coagulation

“…The RSSCT utilizes small GAC particles and short empty-bed contact times (EBCTs), which decrease the run time required to assess the concentration breakthrough profile through a full-scale GAC contactor. A proportional diffusivity design has been found appropriate for NOM and DBP precursor adsorption 29 and is utilized here. Thus the breakthrough profile generated by the RSSCT is directly related to full-scale breakthrough, through a scaling factor determined by the ratio of the particle sizes used.…”

“…The design equations used for the RSSCT are presented elsewhere. 29,30 All RSSCTs in this study were designed to simulate a 15-min full-scale EBCT. A commercially available GAC* with a 12 ˘ 40 US standard mesh size (average particle diameter [APD] = 1.05 mm) was ground using mortar and pestle and sieved to yield a 140 ˘ 230 US standard mesh size (APD = 0.084 mm) for ORW and a 100 ˘ 200 US standard mesh size (APD = 0.11 mm) for SRPW and HLW.…”

Removal of chromium(VI) from water and wastewater by using riverbed sand: Kinetic and equilibrium studies

“…Scrap rubber has been successfully used as an adsorbent for removal of metallic species from wastewater [3]. Removal of metallic species by adsorption on activated carbon has been a popular choice of scientific workers world over [4][5][6][7][8]. Many workers have reported excellent results for the removal of pollutant species by modified activated carbons [9][10][11][12].…”

Modeling Selenite Breakthrough with the Pore Surface Diffusion Model in Iron Coated Granular Activated Carbon Packed Bed Columns

“…They have been applied for adsorption of organic micro-pollutants onto granular activated carbon (Crittenden et al, 1991). Summers et al (1995) confirmed that the RSSCT can predict breakthrough behavior of a full-scale column. The advantages of RSSCTs include short breakthrough times that can be obtained in a fraction of the time of a full-scale system and that only a fraction of the water is required for pilot tests.…”