scholarly journals Assessment of the breakthrough of micropollutants in full-scale granular activated carbon adsorbers by rapid small-scale column tests and a novel pilot-scale sampling approach

2020 ◽  
Vol 6 (10) ◽  
pp. 2742-2751 ◽  
Author(s):  
Tony Merle ◽  
Detlef R. U. Knappe ◽  
Wouter Pronk ◽  
Bernadette Vogler ◽  
Juliane Hollender ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Service Life ◽  
Granular Activated Carbon ◽  
Pilot Scale ◽  
Full Scale ◽  
Small Scale ◽  
Column Tests ◽  
Sampling Approach

This study aimed to compare three approaches for predicting the service life of full-scale GAC adsorbers for the removal of micropollutants.

Improved removal of arsenic from groundwater using pre-corroded steel and iron tailored granular activated carbon

2010 ◽  
Vol 61 (2) ◽  
pp. 441-453 ◽  
Author(s):  
J. Zou ◽  
F. S. Cannon ◽  
W. Chen ◽  
B. A. Dempsey
Keyword(s):  
Activated Carbon ◽  
Granular Activated Carbon ◽  
Small Scale ◽  
Iron Release ◽  
Iron Corrosion ◽  
Column Tests ◽  
Reducing Conditions ◽  
Perforated Sheets ◽  
Removal Of Arsenic ◽  
Corrosion Of Steel

The authors have combined corrosion of steel fittings or perforated sheets with granular activated carbon (GAC) that had been pre-treated with Fe(III)-citrate, to produce an innovative and low-maintenance technique for removing arsenic from groundwater. Removal of arsenic was measured using two GAC column configurations: rapid small scale column tests (RSSCT's) and mini-column tests. Independent variables included pH, pre-corrosion procedure, and idling of the column (i.e. intentionally stopping flow for defined times in order to create reducing conditions). Use of corroded steel plus pre-treated GAC removed arsenic to below 10 μg/L for up to 248,000 bed volumes (BV) at pH 6, compared to 7,000 BVs for pre-treated GAC without pre-corroded steel. Performance was not as good at pH 6.5 or 7.5. Idling the system recovered the iron corrosion ability by reducing the passive Fe(III) layer on pre-corroded steel surface, as a result the BVs to arsenic breakthrough was doubled. But idling also caused brief periods of arsenic and iron release after restart, due to reductive dissolution of arsenic-containing ferric oxides. GAC was also effective as filtration media for removal of iron (hydr)oxide particles (and associated arsenic) that was released from the pre-corroded iron.

scholarly journals Machine Learning Models to Predict Early Breakthrough of Recalcitrant Organic Micropollutants in Granular Activated Carbon Treatment of Water

2021 ◽  
Author(s):  
Yoko Koyama
Keyword(s):  
Machine Learning ◽  
Activated Carbon ◽  
Organic Compounds ◽  
Granular Activated Carbon ◽  
Breakthrough Curves ◽  
Full Scale ◽  
Small Scale ◽  
Data Sets ◽  
Organic Micropollutants ◽  
Water Matrix

Granular activated carbon (GAC) adsorption is frequently considered to control recalcitrant organic micropollutants (MPs) in both drinking water and wastewater. To predict full-scale GAC adsorber performance, bench- and/or pilot- scale studies are widely used. These studies have generated a wealth of MP breakthrough curves. The overarching aim of this research was to develop machine learning (ML) models from these data to predict MP breakthrough from adsorbent, adsorbate, and background water matrix properties. These models provide a simple and fast tool to predict GAC performance. To develop information for model calibration, MP breakthrough curves were collected from the peer-reviewed literature, research reports, and engineering reports. These data sets, which included results from rapid small-scale column tests (RSSCTs) and pilot/full-scale adsorbers, were analyzed to determine the bed volumes of water that could be treated until MP breakthrough reached ten percent of the influent MP concentration (BV10). The data set encompassed 43 MPs (including neutral and ionizable organic compounds), 3 GAC types by base material (18 unique GAC products), and 38 water matrices, including groundwater, surface water, and treated wastewater. Approximately 400 data sets were split into training, validation, and test sets. Seventeen candidate features, such as MP properties (Abraham parameters), background water matrix characteristics, and GAC properties, were explored in ML models to predict log-10-transformed BV10 (logBV10). BV10 values obtained from the resulting predictive model were highly correlated with experimentally determined BV10 values (coefficient of determination ~0.89 for logBV10 prediction), and the most effective model predicted BV10 with an absolute mean error of ~ 0.11 log units. Key drivers influencing BV10 prediction included the MP’s partitioning coefficient between air and hexadecane (Abraham parameter L); dissolved organic matter concentration in background water matrix; and the adsorbent’s point of zero charge (pzc). The model can be used to estimate GAC bed life and select effective GACs for the removal of MPs such as per- and polyfluoroalkyl substances (PFASs), pesticides, pharmaceuticals, and volatile organic compounds (VOCs) in a wide range of water types.

Removal of algal taste and odour compounds by granular and biological activated carbon in full-scale water treatment plants

2018 ◽  
Vol 18 (5) ◽  
pp. 1531-1544 ◽  
Author(s):  
Aisha Faruqi ◽  
Milann Henderson ◽  
Rita K. Henderson ◽  
Richard Stuetz ◽  
Brendan Gladman ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Algal Blooms ◽  
Pilot Scale ◽  
Full Scale ◽  
Biologically Active ◽  
Removal Rates ◽  
Biological Activated Carbon ◽  
Treatment Processes ◽  
Water Treatment Plants ◽  
Service Life Modelling

Abstract The occurrence and severity of cyanobacterial and algal blooms in water supplies has been increasing due to the effects of eutrophication and climate change, resulting in more frequent taste and odour (T&O) events. Conventional treatment processes have been found to be inefficient in removing the two most commonly detected algal T&O compounds, geosmin and 2-methylisoborneol (MIB), though granular activated carbon (GAC) and biological activated carbon (BAC) contactors have achieved high T&O removal rates. Literature on the performance of GAC and BAC for T&O removal in full-scale treatment plants, however, is limited. This review collates and assesses pilot-scale and full-scale studies which focus on removal of geosmin and MIB, with the aim of understanding the factors which influence T&O removal and determining knowledge gaps in the use of GAC and BAC. Age and empty bed contact time (EBCT) were found to have a significant impact on GAC performance, with removal efficiency decreasing with increased age and increasing with longer EBCTs. BAC contactors have achieved higher removal rates than non-biologically active GAC contactors and were not impacted by age, EBCT and/or carbon type. From these observations, implementation of BAC for T&O removal would be favourable; however, further investigations are required to understand full-scale performance of BAC and service life modelling.

scholarly journals The Bacterial Communities of Full-Scale Biologically Active, Granular Activated Carbon Filters Are Stable and Diverse and Potentially Contain Novel Ammonia-Oxidizing Microorganisms

2015 ◽  
Vol 81 (19) ◽  
pp. 6864-6872 ◽  
Author(s):  
Timothy M. LaPara ◽  
Katheryn Hope Wilkinson ◽  
Jacqueline M. Strait ◽  
Raymond M. Hozalski ◽  
Michael J. Sadowksy ◽  
...  
Keyword(s):  
Activated Carbon ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Bacterial Communities ◽  
Granular Activated Carbon ◽  
Full Scale ◽  
Biologically Active ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Content Type

ABSTRACTThe bacterial community composition of the full-scale biologically active, granular activated carbon (BAC) filters operated at the St. Paul Regional Water Services (SPRWS) was investigated using Illumina MiSeq analysis of PCR-amplified 16S rRNA gene fragments. These bacterial communities were consistently diverse (Shannon index, >4.4; richness estimates, >1,500 unique operational taxonomic units [OTUs]) throughout the duration of the 12-month study period. In addition, only modest shifts in the quantities of individual bacterial populations were observed; of the 15 most prominent OTUs, the most highly variable population (aVariovoraxsp.) modulated less than 13-fold over time and less than 8-fold from filter to filter. The most prominent population in the profiles was aNitrospirasp., representing 13 to 21% of the community. Interestingly, very few of the known ammonia-oxidizing bacteria (AOB; <0.07%) and no ammonia-oxidizingArchaeawere detected in the profiles. Quantitative PCR ofamoAgenes, however, suggested that AOB were prominent in the bacterial communities (amoA/16S rRNA gene ratio, 1 to 10%). We conclude, therefore, that the BAC filters at the SPRWS potentially contained significant numbers of unidentified and novel ammonia-oxidizing microorganisms that possessamoAgenes similar to those of previously described AOB.

scholarly journals Effects of Backwashing on Granular Activated Carbon with Ammonium Removal Potential in a Full-Scale Drinking Water Purification Plant

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1830 ◽  
Author(s):  
Jia Niu ◽  
Ikuro Kasuga ◽  
Futoshi Kurisu ◽  
Hiroaki Furumai
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Purification ◽  
Granular Activated Carbon ◽  
Full Scale ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonium Removal ◽  
Before And After ◽  
Drinking Water Purification ◽  
Purification Plant

Granular activated carbon (GAC) has been widely introduced to advanced drinking water purification plants to remove organic matter and ammonium. Backwashing, which is the routine practice for GAC maintenance, is an important operational factor influencing the performance of GAC and its microbial biomass. In this study, the effects of backwashing on the ammonium removal potential of GAC were evaluated. In addition, abundances of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) on GAC were analyzed. GAC samples before and after backwashing were collected from a full-scale drinking water purification plant. Samplings were conducted before and after implementation of prechlorination of raw water. The results showed that the ammonium removal potential of the GAC increased by 12% after backwashing before prechlorination (p < 0.01). After implementing the prechlorination, the ammonium removal potential of the GAC decreased by 12% even after backwashing (p < 0.01). The AOA was predominant on the GAC in the two samplings. Regardless of prechlorination, the amounts of the AOA and the AOB remained at the same level before and after backwashing. Analysis of the backwashing water indicated that the amounts of the AOA and AOB washed out from the GAC were negligible (0.08%–0.26%) compared with their original amounts on the GAC. These results revealed the marginal role of backwashing on the biomass of ammonia oxidizers on GAC. However, the results also revealed that backwashing could have a negative impact on the ammonium removal potential of GAC during prechlorination.

Sign in / Sign up

Export Citation Format

Share Document