Adsorption of Nickel and Zinc by Residual Soils
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American Journal of Environmental Sciences Original Research Paper Adsorption of Nickel and Zinc by Residual Soils Nur ‘Aishah Zarime, W.Y. Wan Zuhairi and Sivarama Krishna Geology Programme, School of Environmental Sciences and Natural Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia Article history Abstract: Soil has long been utilized as low cost liner material to prevent Received 23-04-2014 contamination from leachate to groundwater media. To find a suitable soil Revised 26-06-2014 material for this purpose is a great challenge. This study describes the potential Accepted 27-11-2014 use of residual soil to functions as engineered clay liner for waste disposal landfill in Malaysia. Three types of residual soils were investigated namely Corresponding Author: Nur ‘Aishah Zarime, marine clays (SBMC1, SBMC2), Residual Granites (BGR, KGR) and residual Geology Programme, School meta-sediments (BBMS1, BBMS2 and PMS). Physical and chemical tests of Environmental Sciences were applied for both granitic soils to determine the physical and chemical and Natural Resources, properties of soil materials. Physical and chemical tests involved grain size Faculty of Science and distribution, Atterberg limits, compaction, pH, organic content, specific Technology, Universiti gravity, Cation Exchange Capacity (CEC) and Specific Surface Area (SSA) as Kebangsaan Malaysia, 43600 well as Batch Equilibrium Test for adsorption of heavy metals. The best Bangi, Selangor, Malaysia potential soil materials for clay liner is the materials that have high pH value, Email: [email protected] high organic matter, high liquid and plastics limits, high CEC and SSA values. The best material also highly dominated with clay (in this case PKMC, SBMC1 and SBMC 2). Result show the range of pH values are from 6.95-8.36, range of organic content are from 4.35-6.41%, the specific conductivity values range from 2.13-2.34 and for liquid limit and plastic limit range are from 56.40-84 and 26.86-59.35% respectively; which is high to very high plasticity. Residual soils as low-cost adsorbent materials were also used for removal of Nickel (Ni) and Zinc (Zn) from aqueous solutions. Batch test was used and the effect of heavy metal concentration was studied. Results were analyzed using adsorption isotherm models (i.e., Linear, Langmuir and Freundlich). Based on the correlation coefficient (r2 values), most of residual soils fitted nicely to Linear, Langmuir and Freundlich models. For Ni, most soils fitted to Langmuir models except for meta-sediment while for Zn fitted to Linear model. Marine clay has the highest adsorption coefficient ranged between KL = 0.2380-0.9655 L kg −1 followed by granite and meta-sediment KL = 0.0031-0.0168 L kg −1 and KL = 0.0016-0.0075 L kg −1 respectively. While for Zn, marine clay also has the best adsorption coefficient ranged between Kd = 0.0453-0.1249 L kg −1, followed by granite and meta-sediment ranged between Kd = 0.0027-0.0028 L kg −1 and Kd = 0.0012-0.0016 L kg −1. The selectivity sequence KL for Ni is SBMC2> SBMC1 > PKMC> BGR> PMS> KGR> BBMS2> BBMS1 while for Zn, the selectivity sequence of Kd is SBMC2> SBMC1> PKMC> BBMS1> BBMS2> PMS>BGR> KGR. The study concludes that marine clay is the best material for landfill clay liner due to suitable physical-chemical characteristics and also appeared to be the best natural adsorbent of Ni and Zn of metal concentration in solution. Keywords: Residual Soils, Heavy Metals, Physical-Chemicals Properties, Adsorption Isotherm Introduction disposal site with specific pollution control is designed to minimize pollution. However, Malaysia’s landfills are Solid wastes are part of environmental pollution’s still using the oldest and very common way of disposing contributor. Landfill; which is an engineered waste which is open dumping due to the increase of pollutions. © 2014 The Nur ‘Aishah Zarime, W.Y. Wan Zuhairi and Sivarama Krishna. This open access article is distributed under a Creative Commons Attribution (CC-BY) 3.0 license Saidi Neila et al . / American Journal of Environmental Sciences 2014, 10 (6): 523.529 DOI: 10.3844/ajessp.2014.523.529 Its occur when solid phase (waste), liquid phase Sorption Test (leachate) and gas phase form due to biological, physical, chemical and other influent factors of waste Samples were tested using Batch equilibrium test (Sabahi et al ., 2009). Leachate can percolate through the where this test provides a quick method of estimating the base of landfill, enter the groundwater systems and contaminant retention capacity of any liner material change the quality of groundwater (Taha et al ., 2011). (Zuhairi and Samsudin, 2007). This test used to study the Engineered clay liners are utilized to Malaysia sanitary behavior of natural soil (adsorbent) through a different landfill by using the compacted clay to prevent the initial concentration factor. seepage and remove heavy metals commonly found in Preparation landfill leachate. Many metals ions are essentials as trace elements but in higher concentration it’s become toxic. After collecting soil samples, samples were air-dried Heavy metals are difficult to remove from environment and passed through 63µm sieve. To prepare the Ni and Zn unlike other pollutant that chemically or biologically metal, stock solutions were made using their nitrates and degraded (Komy et al ., 2013). Therefore, conventional were further diluted with 10 different concentration 20, −1 clay liners are design with the focus on minimizes the 40, 60, 80, 100, 150, 200, 250, 300 and 400 mg L under permeation of leachate through liner. Residual soils are room temperature and controlled with pH 5-6 by adding chosen to be clay liner as abundance and availability of HNO3 and NaOH. Nitrate salts were chosen because this residual soil will make them economically feasible nitrate has poor ability to complex with metallic cations (Rosli et al ., 2008). Soil structures and the various size (Zuhairi et al ., 2008). To perform this test, 4 g of soil fractions have their own ability to absorb and transfer to sample (adsorbent) with 40 mL of metal aqueous solutions the environment (Huang et al ., 2014). The capacity of (1:10 ratio soil/solution) were added in centrifuge tubes. natural soil to adsorb heavy metals has been study and Samples were shaken 100 RPM under room temperature published by many researchers (Antoniadis et al ., 2007; (27±1°C) for 24 h for attained the equilibrium. After Zuhairi et al ., 2008). Mobility of heavy metals in soils shaking, samples were centrifuged at 1500 RPM for 10 can be describe by distribution coefficient (Kd) where minutes and were filtered using 45 µm nitrocellulose Kd is one of the input parameters in contaminant membranes. The pH of this solution also measured using transport modeling to model the contaminant flow in pH meter (Hanna Instrument 2211). Solutions were groundwater (Zuhairi and Samsudin, 2007). Kd analyzed using Couple Plasma Mass Spectroscopy (Perkin parameter shows the absorption or attenuation of Elmer Model OPTIMA 3000 with auto sampler). contaminant. The objectives of this study are to investigate the attenuation capability of natural geologic Data Evaluation material based on chemical-physical and adsorption Adsorption isotherms are mathematical models where properties and proposed the best materials that function they describe the distribution of adsorbate among liquid as engineered clay liner for landfill application. and solid phases, based on assumptions that are related to the heterogeneity, homogeneity of solid surface, the Material and Methods type of coverage and the possibility of interaction Material between the adsorbate species (Babazadeh et al ., 2011). The equilibrium adsorption isotherm is importance in the In the present study, eight samples were collected from design of adsorption system (Parida et al ., 2012). Selangor area in Malaysia and they consist of three types of residual soils which were; granitic residual soils from Adsorption Isotherm Broga (BGR) and Kajang (KGR), meta-sediment residual Adsorption data were analyzed using Linear, soils from Puchong (PMS) and two samples from Bukit Langmuir and Freundlich isotherm models. The Badong (BBMS 1 and BBMS 2) and marine clay from concentration of heavy metals adsorbed by soils, qe can Port Klang (PKMC) and two samples from Sungai Besar be calculated by using following formula Equation 1: (SBMC 1 and SBMC 2). All samples were air-dried and sieved into 0.125 mm and 63 µm for soil tested. − (Co Cf ) V qe = (1) Physical-Chemical Characteristics W Physical-chemical tests were conducted according to British Standard Method, BS1377 (1990) and Geotechnical Where: Research Centre, Montreal, Canada (1985). Physical Co and Cf = Initial concentration and equilibrium properties test consist of particle size distribution, Atterberg concentration of metal solution respectively Limits, specific gravity and compaction while chemical (mg/L) properties test consist of soil pH, organic matter, Specific V = Volume of solution added (mL) Surface Area (SSA) and Cation Exchange Capacity (CEC). W = Mass of air-dried soil (g) 524 Saidi Neila et al . / American Journal of Environmental Sciences 2014, 10 (6): 523.529 DOI: 10.3844/ajessp.2014.523.529 Langmuir isotherm model is valid for mono-layer 1/n = Freundlich sorption exponent adsorption onto a surface with a finite number of identical Ce = The metal concentration in final contact sites and also considered several assumptions like the concentration (mg/L) localized adsorption, similar energies on the surface of active sites where there is no interaction between adsorbed Results molecules and the surface of heterogeneous catalytic reactions (Parida et al ., 2012; Tang et al ., 2012). Soil Characterization Langmuir models represented in following equations (Galedar and Younesi, 2013) Equation 2: The characteristics of each soil are tabulated in Table 1 and 2. Based on particle size distribution granitic residual = KL. Am . C e soils have high percentage of sand ranged from 46-63%, qe (2) followed by meta-sediment residual soil which have ranged 1+ KL .