Rapid small-scale column testing of granular activated carbon for organic micro-pollutant removal in treated domestic wastewater

2014 ◽  
Vol 70 (7) ◽  
pp. 1271-1278 ◽  
Author(s):  
F. Zietzschmann ◽  
J. Müller ◽  
A. Sperlich ◽  
A. S. Ruhl ◽  
F. Meinel ◽  
...  

This study investigates the applicability of the rapid small-scale column test (RSSCT) concept for testing of granular activated carbon (GAC) for organic micro-pollutants (OMPs) removal from wastewater treatment plant (WWTP) effluent. The chosen experimental setup was checked using pure water, WWTP effluent, different GAC products, and variable hydrodynamic conditions with different flow velocities and differently sized GAC, as well as different empty bed contact times (EBCTs). The setup results in satisfying reproducibility and robustness. RSSCTs in combination with WWTP effluent are effective when comparing the OMP removal potentials of different GAC products and are a useful tool for the estimation of larger filters. Due to the potentially high competition between OMPs and bulk organics, breakthrough curves are likely to have unfavorable shapes when treating WWTP effluent. This effect can be counteracted by extending the EBCT. With respect to the strong competition observed in GAC treatment of WWTP effluent, the small organic acid and neutral substances are retained longer in the RSSCT filters and are likely to cause the majority of the observed adsorption competition with OMPs.

2020 ◽  
Vol 26 (10) ◽  
pp. 66-79
Author(s):  
Marwa M. Ali ◽  
Nawar Omran Ali ◽  
Mahdi Shanshal Jaafar

Greywater is a possible water source that can be improved for meeting the quality required for irrigation. Treatment of greywater can range from uncomplicated coarse filtration to advanced biological treatment. This article presents a simple design of a small scale greywater treatment plant, which is a series of physical and natural processes including screening, aeration, sedimentation, and filtration using granular activated carbon filter and differentiates its performance with sand filter. The performance of these units with the dual filter media of (activated carbon with sand) in treatment of greywater from Iraqi house in Baghdad city during 2019 and that collected from several points including washbasins, kitchen sink, bathrooms, and laundry, was recorded in terms of removal efficiency of particular pollutants like Turbidity 94%, chemical oxygen demand (COD) 93%, and oil 91%. Dual filter was the most effective filter for decreasing these pollutants, while sand indicates the lowest removal efficiency. In general, granular activated carbon media seemed to be the most proper medium to improve greywater quality for reaching the quality of irrigation within the terms of organic matter decrease. Accordingly, this technology may be reliable for greywater treatment in a residential area.


2021 ◽  
Author(s):  
Yoko Koyama

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.


2002 ◽  
Vol 2 (1) ◽  
pp. 233-240 ◽  
Author(s):  
J. Cromphout ◽  
W. Rougge

In Harelbeke a Water Treatment Plant with a capacity of 15,000 m3/day, using Schelde river water has been in operation since April 1995. The treatment process comprises nitrification, dephosphatation by direct filtration, storage into a reservoir, direct filtration, granular activated carbon filtration and disinfection. The design of the three-layer direct filters was based on pilot experiments. The performance of the plant during the five years of operation is discussed. It was found that the removal of atrazin by activated carbon depends on the water temperature.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 337
Author(s):  
Sara Mesa Medina ◽  
Ana Rey ◽  
Carlos Durán-Valle ◽  
Ana Bahamonde ◽  
Marisol Faraldos

Two commercial activated carbon were functionalized with nitric acid, sulfuric acid, and ethylenediamine to induce the modification of their surface functional groups and facilitate the stability of corresponding AC-supported iron catalysts (Fe/AC-f). Synthetized Fe/AC-f catalysts were characterized to determine bulk and surface composition (elemental analysis, emission spectroscopy, XPS), textural (N2 isotherms), and structural characteristics (XRD). All the Fe/AC-f catalysts were evaluated in the degradation of phenol in ultrapure water matrix by catalytic wet peroxide oxidation (CWPO). Complete pollutant removal at short reaction times (30–60 min) and high TOC reduction (XTOC = 80 % at ≤ 120 min) were always achieved at the conditions tested (500 mg·L−1 catalyst loading, 100 mg·L−1 phenol concentration, stoichiometric H2O2 dose, pH 3, 50 °C and 200 rpm), improving the results found with bare activated carbon supports. The lability of the interactions of iron with functionalized carbon support jeopardizes the stability of some catalysts. This fact could be associated to modifications of the induced surface chemistry after functionalization as a consequence of the iron immobilization procedure. The reusability was demonstrated by four consecutive CWPO cycles where the activity decreased from 1st to 3rd, to become recovered in the 4th run. Fe/AC-f catalysts were applied to treat two real water matrices: the effluent of a wastewater treatment plant with a membrane biological reactor (WWTP-MBR) and a landfill leachate, opening the opportunity to extend the use of these Fe/AC-f catalysts for complex wastewater matrices remediation. The degradation of phenol spiked WWTP-MBR effluent by CWPO using Fe/AC-f catalysts revealed pH of the reaction medium as a critical parameter to obtain complete elimination of the pollutant, only reached at pH 3. On the contrary, significant TOC removal, naturally found in complex landfill leachate, was obtained at natural pH 9 and half stoichiometric H2O2 dose. This highlights the importance of the water matrix in the optimization of the CWPO operating conditions.


2010 ◽  
Vol 75 (4) ◽  
pp. 565-573 ◽  
Author(s):  
Mirjana Ninkovic ◽  
Rada Petrovic ◽  
Mila Lausevic

Public water systems use granular activated carbon in order to eliminate pesticides. After saturation, the used activated carbon is regenerated and reused in order to reduce the costs of water production and minimize waste. In this study, the adsorption of 10 different chlorinated pesticides from water using columns packed with commercial virgin and regenerated granular activated carbon was simulated in order to compare their adsorption capacities for different chlorinated pesticides. The breakthrough curves showed that chlorinated pesticides from the group of hexachlorocyclohexane (HCH) were poorly adsorbed, followed by cyclodiens as averagely adsorbed and the derivatives of halogenated aromatic hydrocarbons (DDT) as strongly absorbed. However, the adsorption capacity of regenerated granular activated carbon was considerably lower for tested pesticides compared to the virgin granular carbon. In addition, rinsing of the pesticides after the saturation point is a far more efficient process on regenerated carbon.


1986 ◽  
Vol 18 (1) ◽  
pp. 31-42 ◽  
Author(s):  
E. A. Shpirt ◽  
K. T. Alben

The particle size distribution at different bed depths of a fixed bed of granular activated carbon (GAC) has been monitored during 50 weeks of a pilot column run at the Waterford, New York potable water treatment plant. Initial backwashing resulted in significant stratification of GAC in the column: larger particles (average diameter 1.18 mm) settled in the bottom of the column (105 cm), and smaller particles (average diameter 0.97 mm) were concentrated near the top (24 cm), compared to samples of unstratified virgin Calgon F400 (average diameter 1.09 mm). During column loading and initial backwashing, more fines were created than were present in the virgin GAC (average 6.5% of GAC fines in the > 40 mesh fraction, compared to only 0.3% in the > 40 mesh fraction for virgin Calgon F400). After 50 weeks of service there was an overall trend toward a smaller average particle size (0.9 mm) with development of a more regular pattern of bed stratification (1.08 mm at the bottom and 0.75 mm at the top). These changes are attributed to breaking of large particles (12-20 mesh) and creation of intermediate size particles (20-30 and 30-40 mesh).


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