Optimization of Cadmium Removal from Aqueous Solutions Using Walnut-shell Residues Biochar Supported/unsupported by Nanoscale Zero-valent Iron through Response Surface Methodology

Mahboub Saffari


Using various biochars to remove heavy metals (HMs) from aqueous solutions has been increased in recent years. It is believed that the use of nanocompounds in biochars surface structure may increase the efficiency of contaminants removal. Therefore, this research tries to investigate the efficiency of walnut-shell biochar (WSB) alone or supported by nanoscale zero-valent iron (WSB-nZVI) on cadmium (Cd) removal in aqueous solution controlled by four variables including initial Cd concentration, initial solution pH, contact time, and adsorbent dosage by Box Behnken design under response surface methodology. The results of present study showed that WSB-nZVI has a significant priority on WSB of Cd removal efficiency in aqueous solutions. The existence of functional groups on the surface of WSB via precipitation and adsorption processes, as well as nZVI formed on the WSB-nZVI via generating adsorption and complexation processes, have increased the ability Cd removal than WSB raw adsorbent. The maximum predicted Cd removal efficiency based on the proposed model was 99.72% with desirability of 1, in initial Cd concentration of 70.78 mg L-1, pH of 6.92, adsorbent dose of 0.56 g L-1 and contact time of 40.42 min.


Box Behnken design; Biochar; Heavy metal; Nanocomposite

Full Text:



Awomeso J.A., Taiwo A.M., Gbadebo A.M., Arimoro A.O., 2010. Waste disposal and pollution management in urban areas: a workable remedy for the environment in developing countries. Am J Environ Sci. 6(1), 26-32.

Wang Q., Yang Z., 2016. Industrial water pollution, water environment treatment, and health risks in China. Environ Pollut. 218, 358-365.

Nagajyoti P.C., Lee K.D., Sreekanth T.V.M., 2010. Heavy metals, occurrence and toxicity for plants: a review. Environ Chem Lett. 8(3), 199-216.

Agarwal S., Zaman T., Murat Tuzcu E., Kapadia S.R., 2011. Heavy metals and cardiovascular disease: results from the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Angiology. 62(5), 422-429.

World Health Organization, 2004. Guidelines for drinking-water quality: recommendations (Vol. 1). World Health Organization.

Fu F., Wang Q., 2011. Removal of heavy metal ions from wastewaters: a review. J Environ Manage. 92(3), 407-418.

Babel S., Kurniawan T. A., 2003. Low-cost adsor-bents for heavy metals uptake from contaminated water: a review. J Hazard Mater. 97(1-3), 219-243.

Sud D., Mahajan G., Kaur M.P., 2008. Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions–A review. Bioresour Technol. 99(14), 6017-6027.

Lehmann J., Joseph S. (Eds.)., 2015. Biochar for environmental management: science, technology and implementation. Routledge.

Ahmad M., Lee, S. S., Dou, X., Mohan, D., Sung, J. K., Yang, J. E., Ok, Y. S., 2012. Effects of pyrolysis temperature on soybean stover-and peanut shell-derived biochar properties and TCE adsorption in water. Bioresour Technol. 118, 536-544.

Yao Y., Gao B., Chen J., Zhang M., Inyang M., Li Y., Yang L., 2013. Engineered carbon (biochar) pre-pared by direct pyrolysis of Mg-accumulated tomato tissues: characterization and phosphate removal potential. Bioresour Technol. 138, 8-13.

Zhang M., Gao B., Varnoosfaderani S., Hebard A., Yao Y., Inyang M., 2013. Preparation and characterization of a novel magnetic biochar for arsenic removal. Bioresour Technol. 130, 457-462.

Gan C., Liu Y., Tan X., Wang S., Zeng G., Zheng B., Liu W., 2015. Effect of porous zinc–biochar nanocompos

ites on Cr (vi) adsorption from aqueous solution. RSC Adv. 5(44), 35107-35115.

Zhang M., Gao B., Yao Y., Xue Y., Inyang M., 2012. Synthesis of porous MgO-biochar nanocompo-sites for removal of phosphate and nitrate from aqueous solutions. Chem Eng J. 210, 26-32.

Tan X., Liu Y., Zeng G., Wang X., Hu X., Gu Y., Yang Z., 2015. Application of biochar for the removal of pollutants from aqueous solutions. Chemosphere. 125, 70-85.

Boparai H.K., Joseph M., O’Carroll D.M., 2013. Cadmium (Cd2+) removal by nanozerovalent iron: surface analysis, effects of solution chemistry and surface complexation modeling. Environ Sci Pollut Res. 20(9), 6210-6221.

Rahmani A. R., Ghaffari H.R., Samadi M.T., 2010. Removal of arsenic (III) from contaminated water by synthetic nano size zerovalent iron. World Academy of Science, Engineering and Technology. 62, 1116-1119.

Alidokht L., Khataee A.R., Reyhanitabar A., Oustan S., 2011. Reductive removal of Cr (VI) by starch-stabilized Fe0 nanoparticles in aqueous solution. Desalin. 270(1-3), 105-110.

Esfahani A. R., Firouzi A.F., Sayyad G., Kiasat A., Alidokht L., Khataee A.R., 2014. Pb (II) removal from aqueous solution by polyacrylic acid stabilized zero-valent iron nanoparticles: process optimization using response surface methodology. Res Chem Intermed. 40(1), 431-445.

Phenrat T., Saleh N., Sirk K., Kim H.J., Tilton R.D., Lowry G.V., 2008. Stabilization of aqueous nanoscale zerovalent iron dispersions by anionic polyelectrolytes: adsorbed anionic polyelectrolyte layer properties and their effect on aggregation and sedimentation. J Nanopart Res. 10(5), 795-814.

Khuri A.I., Mukhopadhyay S., 2010. Response surface methodology. Wiley Interdisciplinary Reviews: Comput Stat. 2(2), 128-149.

Singh B., Singh B.P., Cowie A.L., 2010. Characterisation and evaluation of biochars for their application as a soil amendment. Soil Res. 48(7), 516-525.

Quan G., Sun W., Yan J., Lan Y., 2014. Nanoscale zero-valent iron supported on biochar: characterization and reactivity for degradation of acid orange 7 from aqueous solution. Water Air Soil Pollut. 225(11), 2195-2199.

Box G.E., Behnken D.W., 1960. Some new three level designs for the study of quantitative variables. Technometrics. 2(4), 455-475.

Ferreira S.C., Bruns R.E., Ferreira H.S., Matos G.D., David J.M., Brandao G.C., Dos Santos W.N.L., 2007. Box-Behnken design: an alternative for the optimization of analytical methods. Anal Chim Acta. 597(2), 179-186.

Myers R.H., Montgomery D.C., 2002. Response surface methodology: Process and product improvement with designed experiments.

Mukherjee A., Zimmerman A.R., Harris W., 2011. Surface chemistry variations among a series of laboratory-produced biochars. Geoderma. 163(3-4), 247-255.

Sharma Y.C., 2008. Thermodynamics of removal of cadmium by adsorption on indigenous clay. Chem Eng J. 145(1), 64-68.

Zhu S., Ho S.H., Huang X., Wang D., Yang F., Wang L., Ma F., 2017. Magnetic Nanoscale Zerovalent Iron Assisted Biochar: Interfacial Chemical Behaviors and Heavy Metals Remediation Performance. ACS Sustainable Chemistry and Engineering. 5(11), 9673-9682.

Li X.Q., Zhang W.X., 2007. Sequestration of metal cations with zerovalent iron nanoparticles a study with high resolution X-ray photoelectron spectroscopy (HR-XPS). J Phys Chem. 111(19), 6939-6946.

Huang P., Ye Z., Xie W., Chen Q., Li J., Xu Z., Yao M., 2013. Rapid magnetic removal of aqueous heavy metals and their relevant mechanisms using nanoscale zero valent iron (nZVI) particles. Water Res. 47(12), 4050-4058.

Tan X.F., Liu Y.G., Gu Y.L., Xu Y., Zeng G.M., Hu X.J., Li J., 2016. Biochar-based nano-composites for the decontamination of wastewater: a review. Bioresour Technol. 212, 318-333.

Sun J., Lian F., Liu Z., Zhu L., Song Z., 2014. Bio-chars derived from various crop straws: characterization and Cd (II) removal potential. Ecotoxicol Environ Saf. 106, 226-231.

Usman A., Sallam A., Zhang M., Vithanage M., Ahmad M., Al-Farraj A., Al-Wabel M., 2016. Sorption process of date palm biochar for aqueous Cd (II) removal: Efficiency and mechanisms. Water Air Soil Pollut. 227(12), 449-455.

Song Z., Lian F., Yu Z., Zhu L., Xing B., Qiu W., 2014. Synthesis and characterization of a novel MnOx-loaded biochar and its adsorption properties for Cu2+ in aqueous solution. Chem Eng J. 242, 36-42.

Wang H., Gao B., Wang S., Fang J., Xue Y., Yang K., 2015a. Removal of Pb (II), Cu (II), and Cd (II) from aqueous solutions by biochar derived from KMnO4 treated hickory wood. Bioresour Technol. 197, 356-362.

Baig S.A., Zhu J., Muhammad N., Sheng T., Xu X., 2014. Effect of synthesis methods on magnetic Kans grass biochar for enhanced As (III, V) adsorption from aqueous solutions. Biomass Bioenergy. 71, 299-310.

Wang S., Gao B., Zimmerman A.R., Li Y., Ma L., Harris W.G., Migliaccio K.W., 2015b. Removal of arsenic by magnetic biochar prepared from pinewood and natural hematite. Bioresour Technol. 175, 391-395.

Doumer M.E., Rigol A., Vidal M., Mangrich A.S., 2016. Removal of Cd, Cu, Pb, and Zn from aqueous solutions by biochars. Environ Sci Pollut Res. 23(3), 2684-2692.

Rao K.S., Mohapatra M., Anand S., Venkateswarlu P., 2010. Review on cadmium removal from aqueous solutions. Int J EngSci Tech. 2(7), 81-103.

Park D., Lim S.R., Yun Y.S., Park J.M., 2008. De-velopment of a new Cr (VI)-biosorbent from agricultural biowaste. Bioresour Technol. 99(18), 8810-8818.

Javanbakht V., Zilouei H., Karimi K., 2011. Lead biosorption by different morphologies of fungus Mu-corindicus. Int Biodeterior Biodegradation. 65(2), 294-300.

Amini M., Younesi H., Bahramifar N., Lorestani A. A.Z., Ghorbani F., Daneshi A., Sharifzadeh M., 2008. Application of response surface methodology for optimization of lead biosorption in an aqueous solution by Aspergillus niger. J Hazard Mater. 154(1-3), 694-702.

Salmani M.H., Ehrampoush M.H., Sheikhalishahi S., Dehvari M., 2012. Removing copper from contaminated water using activated carbon sorbent by continuous flow. J Community Health Res. 1(1), 11-18.

Rao K.S., Anand S., Rout K., Venkateswarlu P., 2012. Response surface optimization for removal of cadmium from aqueous solution by waste agricultural biosorbentPsidiumguvajava L. leaf powder. Clean Soil Air Water. 40(1), 80-86.


  • There are currently no refbacks.