The Impact of Natural Organic Matter on Adsorptive Treatment of Metal Contaminants in Water
Project Description:
Heavy metals such as Cd, Cu, Pb, Zn, Hg, Cr etc. can have adverse effects on aquatic life, human health and the environment. For example, copper at levels below 3 µg/L can have serious effects on Salmonid species.1,2 As such, several techniques like ion exchange, chemical precipitation, membrane processes and adsorption have been studied for heavy metal remediation.3,4 Adsorption has proven to be an efficient technique as it doesn’t present limitations with sensitive operation conditions and costly disposal that other techniques present. Adsorption is however limited by the initial metal concentration and several water chemistry parameters.3,5 Aside from that, the presence of natural organic matter (NOM) in wastewater and stormwater effluents is known to affect the speciation of metals which could impact their removal by adsorption.1,5–7 Adsorption has also been studied for the removal of NOM. In a study by Tanju et al., the researchers found that NOM adsorption on granular activated carbon is influenced by the carbon pore size and surface acidity as well as the NOM size and chemical composition.8 This shows that understanding the relationship between metals, NOM and adsorbents is crucial to evaluating the efficiency of an adsorbent for a target metal.
Research has revealed the importance of the surface characteristics and chemical compositions of the adsorbent in evaluating the overall efficiency of an adsorbent. Yet, there is still a lack of understanding regarding the underlying mechanism of contaminant uptake by adsorption.8–11 In an effort to fill these knowledge gaps, this research seeks to answer four questions: 1) What are the types of metal and organic matter interactions occurring in wastewater effluents and stormwater runoff? 2) What are the specific macromolecules that these metals interact with? 3) What are the underlying mechanisms by which commercially available adsorbents remove target metals? and 4) How do these metal interactions with organic matter impact the efficiency of the adsorption processes? The preliminary work, which is the focus of this presentation, has examined the removal of copper by activated carbon in the presence and absence of natural organic matter. The results from batch adsorption tests indicate that copper removal is somewhat improved in the presence of natural organic matter, but the extent cannot be confirmed with certainty due to the limited access to analytical techniques. NOM adsorption results from ultraviolet-visible spectroscopy analysis show that there is a substantial improvement in removal in the presence of Cu. NOM adsorption was modeled by a Freundlich isotherm.
(1) Nason Jeffrey A.; Bloomquist Don J.; Sprick Matthew S. Factors Influencing Dissolved Copper Concentrations in Oregon Highway Storm Water Runoff. Journal of Environmental Engineering 2012, 138 (7), 734–742. https://doi.org/10.1061/(ASCE)EE.1943-7870.0000537.
(2) Sandahl, J. F.; Baldwin, D. H.; Jenkins, J. J.; Scholz, N. L. A Sensory System at the Interface between Urban Stormwater Runoff and Salmon Survival. Environ. Sci. Technol. 2007, 41 (8), 2998–3004. https://doi.org/10.1021/es062287r.
(3) Renu; Agarwal, M.; Singh, K. Heavy Metal Removal from Wastewater Using Various Adsorbents: A Review. Journal of Water Reuse and Desalination 2016, 7 (4), 387–419. https://doi.org/10.2166/wrd.2016.104.
(4) Fu, F.; Wang, Q. Removal of Heavy Metal Ions from Wastewaters: A Review. Journal of Environmental Management 2011, 92 (3), 407–418. https://doi.org/10.1016/j.jenvman.2010.11.011.
(5) Ernst Clayton; Katz Lynn; Barrett Michael. Removal of Dissolved Copper and Zinc from Highway Runoff via Adsorption. Journal of Sustainable Water in the Built Environment 2016, 2 (1), 04015007. https://doi.org/10.1061/JSWBAY.0000803.
(6) Zhao, C.; Wang, C.-C.; Li, J.-Q.; Wang, P.; Ou, J.-Q.; Cui, J.-R. Interactions between Copper(II) and DOM in the Urban Stormwater Runoff: Modeling and Characterizations. Environmental Technology 2018, 39 (1), 120–129. https://doi.org/10.1080/09593330.2017.1296893.
(7) Dean Christopher M.; Sansalone John J.; Cartledge Frank K.; Pardue John H. Influence of Hydrology on Rainfall-Runoff Metal Element Speciation. Journal of Environmental Engineering 2005, 131 (4), 632–642. https://doi.org/10.1061/(ASCE)0733-9372(2005)131:4(632).
(8) Karanfil, T.; Kitis, M.; Kilduff, J. E.; Wigton, A. Role of Granular Activated Carbon Surface Chemistry on the Adsorption of Organic Compounds. 2. Natural Organic Matter. Environ. Sci. Technol. 1999, 33 (18), 3225–3233. https://doi.org/10.1021/es9810179.
(9) Gabaldón, C.; Marzal, P.; Ferrer, J.; Seco, A. Single and Competitive Adsorption of Cd and Zn onto a Granular Activated Carbon. Water Research 1996, 30 (12), 3050–3060. https://doi.org/10.1016/S0043-1354(96)00165-0.
(10) Yin, C. Y.; Aroua, M. K.; Daud, W. M. A. W. Review of Modifications of Activated Carbon for Enhancing Contaminant Uptakes from Aqueous Solutions. Separation and Purification Technology 2007, 52 (3), 403–415. https://doi.org/10.1016/j.seppur.2006.06.009.
(11) Kang, K. C.; Kim, S. S.; Choi, J. W.; Kwon, S. H. Sorption of Cu2+ and Cd2+ onto Acid- and Base-Pretreated Granular Activated Carbon and Activated Carbon Fiber Samples. Journal of Industrial and Engineering Chemistry 2008, 14 (1), 131–135. https://doi.org/10.1016/j.jiec.2007.08.007.
This project presenter is available for live video chat on Sept. 1, 2020 from 1:00 - 2:45 p.m. PDT.
Project Type:
Student
Project Presenter(s):
Laurinda Nyarko (nyarkol@oregonstate.edu)
Project Communication Piece(s):
Project ID:
2.13