We use cookies to enhance your experience. By continuing to browse this site you agree to our use of cookies. More info.
In a recent study published in the journal Materials, researchers from Poland analyzed the flocculation properties of starch, chitosan, and oxidized derivatives used in water treatment.
Study: The Use of Chitosan and Starch-Based Flocculants for Filter Backwash Water Treatment . Image Credit: Nazriamani/Shutterstock.com
Water purification is an essential step in the production process of safe drinking water and is currently identified as a critical scientific issue. Filtration is the most common process in traditional water treatment systems, but it produces a large amount of filter backwash water (FBW) with colloidal contaminants that are washed out of the filter bed. To reduce wastewater production, FBW is generally treated using a technological process that uses coagulation and flocculation.
Coagulation is a phenomenon in which colloid particles are deposited due to the addition of electrolytes, such as aluminum or iron compounds, and the process of forming larger agglomerates is known as flocculation. They are used in wastewater treatment by developing well-defined aggregates that can rapidly settle out of the water, and these techniques effectively remove fine particles suspended in the liquid.
ATR-FTIR spectra for chitosan (blue) and DCT (red). Image credit: Maćczak, P et al., Materials
In a recent study, researchers synthesized polysaccharide-based flocculants such as dialdehyde chitosan (DCT) and dialdehyde starch (DST) and tested their flocculation properties. The starch and chitosan derivatives were produced using periodate, and the obtained derivatives were characterized by various tests.
The materials used in the current study were chitosan, starch from corn, acetic acid, acetone, and sodium periodate. A water treatment plant (WTP) in Kutno, Poland, was used to collect water samples. Oxidized polysaccharides having hydrolyzed polyaluminum chloride were used as a primary coagulant.
For the study, researchers selected eight commonly used polyacrylamide flocculants with different structures. Oxidation with sodium periodate produced the dialdehyde derivatives of starch (DST) and chitosan (DCT) (NaIO4); DST and DCT were used for filter backwash water treatment.
Additionally, thermogravimetric analysis (TGA), digital jar test, scanning electron microscope (SEM) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis were conducted. The microorganisms' biochemical oxygen demand (BOD) was measured using the respirometric method to determine microbes' metabolic activity.
SEM images of chitosan (a), dialdehyde chitosan (b), corn starch (c), dialdehyde starch, (d) at different magnification. Image credit: Maćczak, P et al., Materials
FTIR spectroscopy confirmed that the structural changes in the samples were caused by the oxidation of chitosan and corn starch.
The SEM image of native chitosan showed irregularly shaped aggregates (20 to 200 µm) and similarities with the shape of thick, elongated sticks. Further, the oxidation of chitosan resulted in significant morphological changes, with objects of smaller size appearing in the DCT image.
It was also observed that oxidation of the polysaccharides caused morphological changes and variations in their physicochemical properties, improved reactivity, and solubility, and decreased macromolecule order and thermal stability.
TGA results indicated that fragmentation, accompanied by the release of low-molecular-weight products, was more efficient in DCT and DST than in unoxidized chitosan (CT) and starch (ST). Moreover, thermal crosslinking was ineffective in DST, where 100% weight loss occurred because of incomplete decomposition. The BOD test indicated that oxygen demand increased over 11 and 8 times after 14 days of test for chitosan and DCT, respectively.
The turbidity and iron removal efficiency results based on synthetic flocculant dose showed that all polymers tested by researchers in the first jar test series had iron concentrations and turbidity reductions of over 90%. Additionally, the findings show that functional groups perform an important role in the flocculation mechanism.
Chitosan produced optimum results due to reactive amine groups in macromolecules and its capability of binding metal ions. Moreover, the presence of amino groups in chitosan gives it cationic properties, which support electrostatic interactions of the removed pollutants.
Furthermore, complex iron ions and other positively charged impurities reacted with the remaining acetylamino in CT and produced aldehyde groups in DCT and DST. The formation of hydrogen bonds by hydroxyls in chitosan also affects the aggregation process. Additionally, in the case of polysaccharides, specific chemical reactions between the reactive groups of the polymer and the contaminant particle may also have affected the process.
Jar test with chitozan-based flocculant in polymer dose (a) 0.1, (b) 0.2, (c) 0.3, (d) 0.5, (e) 1.0, (f) 0.2 mg/L + 1 mg Al3+/L of PAX XL10 coagulant, respectively. Image credit: Maćczak, P et al., Materials
Researchers of the current study demonstrated the successful replacement of commercial flocculants based on synthetic polymers with starch, chitosan, and dialdehyde derivatives. The research also indicated the optimal CT, DCT, ST, and DST doses that can be used for wastewater treatment. Moreover, unmodified chitosan was identified as the most effective flocculant as it removed turbidity and iron ions to the same level as commercial polyacrylamide flocculants.
The flocculants suggested by researchers are inexpensive and can be effectively used in water treatment. Hence, polysaccharide-based flocculants in the filtration of FBW have significant potential in wastewater treatment.
Maćczak, P.; Kaczmarek, H.; Ziegler-Borowska, M.; Węgrzynowska-Drzymalska, K. The Use of Chitosan and Starch-Based Flocculants for Filter Backwash Water Treatment. Materials 2022, 15, 1056. https://www.mdpi.com/1996-1944/15/3/1056
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.
Chinmay Saraf is a science writer based in Indore, India. His academic background is in mechanical engineering, and he has extensive experience in fused deposition-based additive manufacturing. His research focuses on post-processing methods for fused deposition modeling to improve mechanical and electrical properties of 3D printed parts. He has also worked on composite 3D printing, bioprinting, and food printing technologies. Chinmay holds an M.Tech. in computer-aided design and computer-aided manufacturing and is passionate about 3D printing, new product development, material science, and sustainability. He also has a keen interest in "Frugal Designs" to improve the existing engineering systems.
Please use one of the following formats to cite this article in your essay, paper or report:
Saraf, Chinmay. (2022, February 02). Filter Backwash Water Treatment with Starch, Chitosan, and Oxidized Derivatives as Flocculants. AZoM. Retrieved on October 14, 2022 from https://www.azom.com/news.aspx?newsID=58097.
Saraf, Chinmay. "Filter Backwash Water Treatment with Starch, Chitosan, and Oxidized Derivatives as Flocculants". AZoM. 14 October 2022. <https://www.azom.com/news.aspx?newsID=58097>.
Saraf, Chinmay. "Filter Backwash Water Treatment with Starch, Chitosan, and Oxidized Derivatives as Flocculants". AZoM. https://www.azom.com/news.aspx?newsID=58097. (accessed October 14, 2022).
Saraf, Chinmay. 2022. Filter Backwash Water Treatment with Starch, Chitosan, and Oxidized Derivatives as Flocculants. AZoM, viewed 14 October 2022, https://www.azom.com/news.aspx?newsID=58097.
Do you have a review, update or anything you would like to add to this news story?
In this interview, Arnaud Delobel, the R&D and Innovation Director at Quality Assistance talks to AZoM about the emerging field of gene therapy with adeno-associated viruses (AAV).
AZoM speaks with Sung Hoon Kang from Johns Hopkins University about his research into a novel reusable shock-absorbing material that is lighter and tougher than metal.
AZoM spoke with staff scientist for application development, Dr. Chengge Jiao of Thermo Fisher Scientific, about the use of a focused ion beam without gallium to move towards damage-free TEM specimen preparation.
This product profile from ABB features the TALYS ADP300, a dual-channel wet process analyzer.
ROHAFORM® is a lightweight flame retardant particle foam for industries with stringent fire, smoke and toxicity (FST) level requirements.
The Intelligent Passive Road Sensors (IRS) can accurately detect road temperature, water film height, ice percentage and much more.
This article provides an end-of-life assessment of lithium-ion batteries, focusing on the recycling of an ever-growing amount of spent Li-Ion batteries in order to work toward a sustainable and circular approach to battery use and reuse.
Corrosion is the degradation of an alloy caused by its exposure to the environment. Corrosion deterioration of metallic alloys exposed to the atmosphere or other adverse conditions is prevented using a variety of techniques.
Due to the ever-increasing demand for energy, the demand for nuclear fuel has also increased, which has further created a significant increase in the requirement for post-irradiation examination (PIE) techniques.
AZoM.com - An AZoNetwork Site
Owned and operated by AZoNetwork, © 2000-2022