This work was financially supported by the Natural Science Funds for Distinguished Young Scholar of Guangdong Province, China, No. 2020B151502094; National Natural Science Foundation of China, No. 21777045 and 22106064; Foundation of Shenzhen Science, Technology and Innovation Commission, China, JCYJ20200109141625078; 2019 youth innovation project of Guangdong universities and colleges, China, No. 2019KQNCX133 and a special fund for the science and technology innovation strategy of Guangdong Province (PDJH2021C0033). This work was sponsored by the Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials (No. ZDSYS20200421111401738), Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control (2017B030301012), and State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control. In particular, we acknowledge the technical support from the SUSTech Core Research Facilities.

1. Raw material collection and treatment
<ol>
	<li>Red soil collection
	<ol>
		<li>Collect the red soil. Remove the 30 cm top layer of the soil containing plants and residual organic matter. 
		NOTE: In this experiment, the red soil was collected at the campus of Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong, China (113&#176;59&#39; E, 22&#176;36&#39; N).</li>
	</ol>
	</li>
	<li>Red soil treatment
	<ol>
		<li>Air-dry the collected red soil at room temperature and fil...

<ol>
	<li>Qin, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soil+heavy+metal+pollution+and+food+safety+in+China:+Effects,+sources+and+removing+technology.">Soil heavy metal pollution and food safety in China: Effects, sources and removing technology.</a> Chemosphere. 267, 129205 (2021).</li><li>Xu, D. M., Fu, R. B., Liu, H. Q., Guo, X. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+knowledge+from+heavy+metal+pollution+in+Chinese+smelter+contaminated+soils,+health+risk+implications+and+associated+remediation+progress+in+recent+decades:+A+critical+review.">Current knowledge from heavy metal pollution in Chinese smelter contaminated soils, health risk implications and associated remediation progress in recent decades: A critical review.</a> Journal of Cleaner Production. 286, 124989 (2021).</li><li>Dong, X., Ma, L. Q., Li, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characteristics+and+mechanisms+of+hexavalent+chromium+removal+by+biochar+from+sugar+beet+tailing.">Characteristics and mechanisms of hexavalent chromium removal by biochar from sugar beet tailing.</a> Journal of Hazardous Materials. 190 (1-3), 909-915 (2011).</li><li>El-Mekkawi, D. M., Selim, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Removal+of+Pb2++from+water+by+using+Na-Y+zeolites+prepared+from+Egyptian+kaolins+collected+from+different+sources.">Removal of Pb2+ from water by using Na-Y zeolites prepared from Egyptian kaolins collected from different sources.</a> Journal of Environmental Chemical Engineering. 2 (1), 723-730 (2014).</li><li>Perego, C., Bagatin, R., Tagliabue, M., Vignola, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zeolites+and+related+mesoporous+materials+for+multi-talented+environmental+solutions.">Zeolites and related mesoporous materials for multi-talented environmental solutions.</a> Microporous and Mesoporous Materials. 166, 37-49 (2013).</li><li>Zheng, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Converting+loess+into+zeolite+for+heavy+metal+polluted+soil+remediation+based+on+&amp;#34;soil+for+soil-remediation&amp;#34;+strategy.">Converting loess into zeolite for heavy metal polluted soil remediation based on &amp;#34;soil for soil-remediation&amp;#34; strategy.</a> Journal of Hazardous Materials. 412, 125199 (2021).</li><li>Cheng, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Feasible+low-cost+conversion+of+red+mud+into+magnetically+separated+and+recycled+hybrid+SrFe12O19@NaP1+zeolite+as+a+novel+wastewater+adsorbent.">Feasible low-cost conversion of red mud into magnetically separated and recycled hybrid SrFe12O19@NaP1 zeolite as a novel wastewater adsorbent.</a> Chemical Engineering Journal. 417, 128090 (2021).</li><li>Yang, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remediation+of+Cu-polluted+soil+with+analcime+synthesized+from+engineering+abandoned+soils+through+green+chemistry+approaches.">Remediation of Cu-polluted soil with analcime synthesized from engineering abandoned soils through green chemistry approaches.</a> Journal of Hazardous Materials. 406, 124673 (2021).</li><li>Song, W., Li, G., Grassian, V. H., Larsen, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+improved+materials+for+environmental+applications:+Nanocrystalline+NaY+zeolites.">Development of improved materials for environmental applications: Nanocrystalline NaY zeolites.</a> Environmental Science &amp; Technology. 39 (5), 1214-1220 (2005).</li><li>Cheng, H., Reinhard, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sorption+of+trichloroethylene+in+hydrophobic+micropores+of+dealuminated+Y+zeolites+and+natural+minerals.">Sorption of trichloroethylene in hydrophobic micropores of dealuminated Y zeolites and natural minerals.</a> Environmental Science &amp; Technology. 40 (24), 7694-7701 (2006).</li><li>Rayalu, S. S., Bansiwal, A. K., Meshram, S. U., Labhsetwar, N., Devotta, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fly+ash+based+zeolite+analogues:+Versatile+materials+for+energy+and+environment+conservation.">Fly ash based zeolite analogues: Versatile materials for energy and environment conservation.</a> Catalysis Surveys from Asia. 10 (2), 74-88 (2006).</li><li>Borel, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SDA-free+hydrothermal+synthesis+of+high-silica+ultra-nanosized+zeolite+Y.">SDA-free hydrothermal synthesis of high-silica ultra-nanosized zeolite Y.</a> Crystal Growth &amp; Design. 17 (3), 1173-1179 (2017).</li><li>Jin, Y., Li, L., Liu, Z., Zhu, S., Wang, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+characterization+of+low-cost+zeolite+NaA+from+coal+gangue+by+hydrothermal+method.">Synthesis and characterization of low-cost zeolite NaA from coal gangue by hydrothermal method.</a> Advanced Powder Technology. 32 (3), 791-801 (2021).</li><li>Huiyu, S., Weiming, L., Zheng, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+situation+of+comprehensive+utilization+of+waste+industrial+molecular+sieve+and+agricultural+rice+husk.">Current situation of comprehensive utilization of waste industrial molecular sieve and agricultural rice husk.</a> Liaoning Chemical Industry. 49 (12), 1555 (2020).</li><li>Azizi, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microporous+and+macroporous+materials+state-of-the-art+of+the+technologies+in+zeolitization+of+aluminosilicate+bearing+residues+from+mining+and+metallurgical+industries:+A+comprehensive+review.">Microporous and macroporous materials state-of-the-art of the technologies in zeolitization of aluminosilicate bearing residues from mining and metallurgical industries: A comprehensive review.</a> Microporous and Mesoporous Materials. 318, 111029 (2021).</li><li>Yang, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transferring+waste+red+mud+into+ferric+oxide+decorated+ANA-type+zeolite+for+multiple+heavy+metals+polluted+soil+remediation.">Transferring waste red mud into ferric oxide decorated ANA-type zeolite for multiple heavy metals polluted soil remediation.</a> Journal of Hazardous Materials. 424, 127244 (2022).</li><li>Kirdeciler, S. K., Akata, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One+pot+fusion+route+for+the+synthesis+of+zeolite+4A+using+kaolin).">One pot fusion route for the synthesis of zeolite 4A using kaolin).</a> Advanced Powder Technology. 31 (10), 4336-4343 (2020).</li><li>Rubtsova, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoarchitectural+approach+for+synthesis+of+highly+crystalline+zeolites+with+a+low+Si/Al+ratio+from+natural+clay+nanotubes.">Nanoarchitectural approach for synthesis of highly crystalline zeolites with a low Si/Al ratio from natural clay nanotubes.</a> Microporous and Mesoporous Materials. 330, 111622 (2022).</li><li>Setthaya, N., Chindaprasirt, P., Pimraksa, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+zeolite+nanocrystals+via+hydrothermal+and+solvothermal+synthesis+using+of+rice+husk+ash+and+metakaolin.">Preparation of zeolite nanocrystals via hydrothermal and solvothermal synthesis using of rice husk ash and metakaolin.</a> Materials Science Forum. 872, 242-247 (2016).</li><li>Belviso, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Red+mud+as+aluminium+source+for+the+synthesis+of+magnetic+zeolite.">Red mud as aluminium source for the synthesis of magnetic zeolite.</a> Microporous and Mesoporous Materials. 270, 24-29 (2018).</li><li>Zhao, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Removal+of+ammonium+from+wastewater+by+pure+form+low-silica+zeolite+Y+synthesized+from+halloysite+mineral.">Removal of ammonium from wastewater by pure form low-silica zeolite Y synthesized from halloysite mineral.</a> Separation Science and Technology. 45 (8), 1066-1075 (2010).</li><li>Meng, Q., Chen, H., Lin, J., Lin, Z., Sun, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zeolite+A+synthesized+from+alkaline+assisted+pre-activated+halloysite+for+efficient+heavy+metal+removal+in+polluted+river+water+and+industrial+wastewater.">Zeolite A synthesized from alkaline assisted pre-activated halloysite for efficient heavy metal removal in polluted river water and industrial wastewater.</a> Journal of Environmental Sciences (China). 56, 254-262 (2017).</li><li>Wang, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+substrate-bound+Au+nanowires+via+an+active+surface+growth+mechanism.">Synthesis of substrate-bound Au nanowires via an active surface growth mechanism.</a> Journal of Visualized Experiments. (137), e57808 (2018).</li><li>Asundi, A. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+structure-property+relationships+of+MoO3-promoted+Rh+catalysts+for+syngas+conversion+to+alcohols.">Understanding structure-property relationships of MoO3-promoted Rh catalysts for syngas conversion to alcohols.</a> Journal of the American Chemical Society. 141 (50), 19655-19668 (2019).</li><li>Zhu, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solvent-free+crystallization+of+ZSM-5+zeolite+on+SiC+foam+as+a+monolith+catalyst+for+biofuel+upgrading.">Solvent-free crystallization of ZSM-5 zeolite on SiC foam as a monolith catalyst for biofuel upgrading.</a> Chinese Journal of Catalysis. 41 (7), 1118-1124 (2020).</li><li>Ghrear, T. M. 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Zeolite is typically an aluminosilicate material. In theory, materials that are rich in silicate and aluminate can be chosen as raw materials for zeolite synthesis. The Si/Al ratio of the raw material must be similar to that of the selected type of zeolite to minimize the usage of additional silicon/aluminum sources6,8,16. The Si/Al ratio of FAU-type zeolite is 1.2, and the Si/Al ratio of red soil is 1.3. Therefore, red soil is ...

Heavy metal(loid)s from anthropogenic and natural activities are ubiquitous in the air, water, and soil environment1. They are of high mobility and toxicity, posing a potential health risk to human beings by direct contact or via food chain transportation2. Water is vital for the life of human beings since it is the feedstock of every family. Restoring water health is crucial. Therefore, it is of great importance to decrease the mobility and bioavailability of toxic heavy metal(loid)s in water. To maintain good health in water, water remediation materials, such as biochar, iron-based materials, and zeolite, play an essential role in immobilizing or removing heavy metal(loid)s from aqueous environments3,4,5.
Zeolites are highly crystalline materials with unique pores and channels in their crystal structures. They are composed of TO4 tetrahedra (T is the central atom, usually Si, Al, or P) connected by shared O atoms. The negative surface charge and exchangeable ions in the pores make it a popular adsorbent for ion capture, which has been extensively used in heavy metal-polluted water and soil remediation. Benefiting from their structures, the remediation mechanisms involved in contaminant removal by zeolites mainly include chemical bonding6, surface electrostatic interaction7, and ion exchange8.
Faujasite (FAU)-type zeolite has relatively large pores, with a maximum pore diameter of 11.24 &#197;. It shows high efficiency and broad applications for contaminant removal9,10. In recent years, extensive research has devoted to developing green and low-cost routines for zeolite synthesis, such as using industrial solid wastes11 as raw material to provide silicon and aluminium sources, or adopting directing agent-free recipes12. The reported&#160;alternative industrial solid wastes that can be silicon and aluminum sources include coal gangue13, fly ash11, waste molecular sieves14, mining and metallurgical wastes15, engineering-abandoned soil8, and agricultural soil6, etc.
Herein, red soil, an abundant and easily obtained silicon and aluminum-rich material, was adopted as the raw material, and a facile green chemistry approach was developed for Fe2O3/FAU-type zeolite composite material synthesis (Figure 1). The detailed synthesis parameters have been finely tuned. The as-synthesized material shows high immobilization capacity for heavy metal-contaminated water remediation. The present study should be instructive for related researchers who are interested in this area to use soil as a raw material for eco-material synthesis.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Chemicals</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cadmium nitrate tetrahydrate</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>C102676</td>
			<td>AR, 99%. Make 1,000 ppm&#160; stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Chromium(III) nitrate nonahydrate</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>C116446</td>
			<td>AR, 99%. Make 1,000 ppm&#160; stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Copper sulfate pentahydrate</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>C112396</td>
			<td>AR, 99%. Make 1,000 ppm&#160; stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Lead nitrate</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>L112118</td>
			<td>AR, 99%. Make 1,000 ppm stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Nickel nitrate hexahydrate</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>N108891</td>
			<td>AR, 98%. Make 1,000 ppm&#160; stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Nitric acid</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>N116238</td>
			<td>AR, 69.2%. Used as solvent in ICP-MS test.</td>
		</tr>
		<tr>
			<td>Potassium dichromate</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>P112163</td>
			<td>AR, 99.8%. Make 1,000 ppm&#160; stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Silicon dioxide</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>S116482</td>
			<td>AR, 99%. For synthesis of zeolite.</td>
		</tr>
		<tr>
			<td>Sodium (meta)arsenite</td>
			<td>Sigma-aldrich</td>
			<td>S7400-100G</td>
			<td>AR, 90%. Make 1,000 ppm stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Sodium hydroxide</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>S111502</td>
			<td>Pellets. For the synthesis of zeolite.</td>
		</tr>
		<tr>
			<td>Zinc nitrate hexahydrate</td>
			<td>Shanghai Aladdin Bio-Chem Technology Co., LTD</td>
			<td>Z111703</td>
			<td>AR, 99%. Make 1,000 ppm&#160; stock solution for the test of adsorption performance of zeolite.</td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Air-dry oven</td>
			<td>Shanghai Yiheng Technology Instrument Co.,LTD.</td>
			<td>DHG-9075A</td>
			<td>Used for hydrothermal crystallization and drying of sample</td>
		</tr>
		<tr>
			<td>Analytical balance</td>
			<td>Sartorius Scientific Instruments Co.LTD</td>
			<td>BSA224S-CW</td>
			<td>Used for weighing samples</td>
		</tr>
		<tr>
			<td>Centrifuge tubes</td>
			<td>Nantong Supin Experimental Equipment Co., LTD</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>High speed centrifuge</td>
			<td>Hunan Xiang Yi Laboratory Instrument Development Co.,LTD</td>
			<td>H1850</td>
			<td>Used for separation of solid and liquid samples</td>
		</tr>
		<tr>
			<td>Multipoint magnetic stirrer</td>
			<td>IKA Equipment Co.,LTD.</td>
			<td>RT15</td>
			<td>Used for stirring samples</td>
		</tr>
		<tr>
			<td>Oscillator</td>
			<td>Changzhou Guohua Electric Appliances Co.,LTD.</td>
			<td>SHA-B</td>
			<td>For uniform mixing of samples</td>
		</tr>
		<tr>
			<td>Syringe-driven filter</td>
			<td>Tianjin Jinteng Experimental Equipment Co.,LTD.</td>
			<td></td>
			<td>0.22 &#956;m. For filtration.</td>
		</tr>
		<tr>
			<td>Softwares</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>JADE 6.5</td>
			<td>Materials Data&#38; (MDI)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mercury</td>
			<td>Cambridge Crystallographic Data Centre (CCDC)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Materials Studio</td>
			<td>Accelrys Software Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Websites</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Database of Zeolite Structures: http://www.iza-structure.org/databases/</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>ICSD: https://icsd.products.fiz-karlsruhe.de/en</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

resource recycling of red soil to synthesize fe2o3/fau-type zeolite composite material for heavy metal removal

Heavy metal-polluted water is of great concern to human health and the eco-environment. In situ water remediation techniques enabled by highly efficient adsorption materials are of great importance in these circumstances. Among all the materials used in water remediation, iron-based nanomaterials and porous materials are of great interest, benefiting from their rich redox reactivity and adsorption function. Here, we developed a facile protocol to directly convert the widely spread red soil in south China to fabricate the Fe2O3/faujasite (FAU)-type zeolite composite material. 
The detailed synthesis procedure and synthesis parameters, such as reaction temperature, reaction time, and the Si/Al ratio in the raw materials, have been carefully tuned. The as-synthesized composite materials show good adsorption capacity for typical heavy metal(loid) ions. With 0.001 g/mL Fe2O3/FAU-type zeolite composite material added to different heavy metal(loid)-polluted aqueous solutions (single type of heavy metal(loid) concentration: 1,000 mg/L [ppm]), the adsorption capacity was shown to be 172, 45, 170, 40, 429, 693, 94, and 133 mg/g for Cu (II), Cr (III), Cr (VI), As (III), Cd (II), Pb (II), Zn (II), and Ni (II) removal, respectively, which can be further expanded for heavy metal-polluted water and soil remediation.

Figure 1 illustrates the overall synthesis route of zeolite based on the &#34;soil for soil remediation&#34; strategy6. With a simple organic-free route, red soil can be converted to Fe2O3/FAU-type zeolite composite material without adding any Fe or Al source. The as-synthesized zeolite composite material exhibits excellent removal capacity for heavy metal-polluted water remediation and can be used for soil remediation.
<p class="jove_content...

Watch this Scientific Journal Video about Resource Recycling of Red Soil to Synthesize Fe2O3/FAU-type Zeolite Composite Material for Heavy Metal Removal at JoVE.com

Resource Recycling of Red Soil to Synthesize Fe2O3/FAU-type Zeolite Composite Material for Heavy Metal Removal

This article presents a novel and convenient route to synthesize Fe2O3/faujasite (FAU)-type zeolite composite material from red soil. The detailed synthesis parameters have been finely tuned. The obtained composite material can be used for efficient heavy metal-contaminated water remediation, indicating its potential applications in environmental engineering.

Resource Recycling of Red Soil to Synthesize Fe2O3/FAU-type Zeolite Composite Material for Heavy Metal Removal

Heavy metal-polluted water is of great concern to human health and the eco-environment. In situ water remediation techniques enabled by highly efficient ...

A green chemistry approach has been developed to convert the widely-distributed red soil into the iron oxide FAU zeolite composite material. This material is capable for remove the hair metal irons in water and restore the water health. This protocol demonstrates the strategy to directly use soil as raw material for eco-material sensors, and providing insight into resource utilization of four typical soils based on the elemental cycling philosophy.The present study can be informative for the related researchers who are interested in soil resource utilization. Now that can be material synthesis and water mediation. To begin, remove the 30 centimeter top layer of the soil containing plants and residual organic matter at the collection site, and collect the red soil and air dry it at room temperature.After proper drying, filter the soil through a 30-mesh sieve. Weigh five grams of this pretreated red soil, one gram of silicon dioxide, and 7.63 grams of sodium hydroxide, and add them to a natural agate mortar. Next, grind them for two to three minutes into a fine powder.For alkali-activation, transfer this alkaline mixture into a 100 milliliter Teflon reactor liner without the stainless steel outer covering, and heat it in the 200 degree Celsius oven for one hour. Then add 60 milliliters of deionized water into the Teflon reactor liner containing the activated alkaline mixture. Add a stir bar of the appropriate size and stir the mixture at 600 RPM on the magnetic stirrer for three hours at 25 degrees Celsius.For the crystallization process, transfer the homogenous gel into a 100 milliliter stainless steel autoclave and heat the gel in a 100 degree Celsius oven for 12 hours. Next, wash the obtained zeolite with deionized water several times until the solution pH is close to seven. Use a centrifuge to separate the solid and liquid and collect the solid at the bottom of the 50 milliliter centrifuge tube.Finally, dry the obtained product for eight hours in an 80 degree Celsius oven, followed by grinding it into a fine powder for subsequent characterization. Prepare 50 milliliters of 1000 parts per million aqueous solutions of bivalent copper ion, trivalent chromium ion, hexavalent chromium ion, trivalent arsenic ion, bivalent cadmium ion, bivalent lead ion, bivalent zinc ion, and bivalent nickel ion. And note the pH of each solution.Next, add 50 milligrams of zeolite to each heavy metalloid solution. Finally, adjust the pH of the solution with 0.1 molar hydrochloric acid or 0.1 molar sodium hydroxide, and stir the mixture at 600 revolutions per minute for 48 hours at 25 degrees Celsius. Then, filter the mixed solutions through 0.22 micron membranes.Dilute them to 1000 x by adding 2%nitric acid solution and measure the residual heavy metalloid concentrations with inductively-coupled plasma mass spectrometry with a testing range of 0.001 parts per million to one part per million. The crystal structure of the FAU-type zeolite framework and ferric oxide shows that the FAU zeolite is composed of three-dimensional, 12-membered rings. It belongs to the cubic crystal system.The space group is FD 3M, and the unit cell parameter is 24.3450 angstrom. The powder X-ray defraction pattern of the iron oxide FAU-type zeolite composite material revealed a great match of this sample with the simulated standard materials, suggesting the success of the synthesis. The scanning electron microscopy image clarified that the iron oxide FAU-type zeolite composite material shows needle-like morphology with high purity.Energy dispersive x-ray spectroscopy mapping show that the typical zeolite composition elements like silicon, aluminum, sodium, and oxygen were evenly distributed on the material, and iron was distributed discreetly in the composite material. The absorption capacity of iron oxide FAU-type zeolite composite material for eight typical heavy metal solutions showed a fascinatingly high capacity for bivalent lead ion and bivalent cadmium ion absorption. The most crucial steps concerning valid counted material synthesis include alkali-activation, precursor preparation, and crystallization.This work paves the way for the direct utilization of soil as raw materials for your mentor material synthesis, which can be further expanded to other type of soils for broad environmental engineering applications.

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JoVE Journal

Environment

2.7K vistas.  Southern University of Science and Technology. Se ha desarrollado un enfoque de química verde para convertir el suelo rojo ampliamente distribuido en el material compuesto de zeolita FAU de óxido de hierro. Este material es capaz de eliminar las planchas metálicas del cabello en agua y restaurar la salud del agua. Este protocolo demuestra la estrategia para utilizar directamente el suelo como materia prima para sensores de materiales ecológicos, y proporciona información sobre la utilización de recursos de cuatro suelos típicos bas...