a review - Acta Technica Corviniensis

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ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERING ISSN: 2067-3809 [CD-Rom, online] copyright © UNIVERSITY POLITEHNICA TIMISOARA, FACULTY OF ENGINEERING HUNEDOARA, 5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIA http://acta.fih.upt.ro ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERING ISSN: 2067-3809 [CD-Rom, online] copyright © UNIVERSITY POLITEHNICA TIMISOARA, FACULTY OF ENGINEERING HUNEDOARA, 5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIA http://acta.fih.upt.ro © copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA
1. Mohammed Ali I. AL-HASHIMI, 2. Manar M. AL-SAFAR REMOVAL OF CADMIUM FROM SYNTHETIC WATER BY USING AGRICULTURAL WASTES 1-2. ENVIRONMENTAL & SANITARY ENGINEERING BRANCH, UNIVERSITY OF TECHNOLOGY, BUILDING & CONSTRUCTION ENGINEERING DEPARTMENT, BAGHDAD, IRAQ ABSTRACT: Heavy metals are among the most toxic contaminants of surface water. The main sources of toxic metals are industrial wastes from processes such as electroplating, metal finishing, chemical manufacturing, and nuclear fuel processing. Since most of heavy metals are non degradable into nontoxic metals end products, these concentration must be reduced to acceptable levels before discharged them into environment. The goal of this research Examine the ability of different media to reduce the concentration of cadmium ions in aqueous solution. The application of lowcost adsorbents obtained from plant wastes as a replacement for costly conventional methods of removing cadmium ions from waste water has been <strong>review</strong>ed. Langmuir and Freundlich adsorption isotherms were applicable to the absorption process and their constants were evaluated. The single component adsorption of heavy metal ions named Cadmium (II) onto powdered activated carbon (PAC), karab, rice husks and corncobs from water aqueous solution has been investigated in batch. The multiple correlations simulated the experimental data of the batch tests, and regression equations were found for (PAC), karab, rice husks and corncobs with correlation coefficient for each media: 0.984, 0.946, 0.951, 0.932, respectively. In batch tests the effects of pH of solution, dosage adsorbent, contact time, initial concentration, mixing (stirring) speed and particle size diameter were studied. The optimum values of pH of solution was 5.5, for dosage adsorbent was 1g sorbent/100ml of Cd(II), for contact time was 30min, for initial concentration was 125 mg/L and for mixing (stirring) speed was 100 rpm. In continuous fixed bed tests, the effects of flow rate, and bed height of Cd (II) uptake onto rice husks studied. Different flow rates were used (1,3,5,7) L/hr. Different bed height (10, 20 and 30) cm was used. The removal of Cd (II) increased as the bed height increased and decreased as the flow increased. KEYWORDS: Cadmium, Adsorption, Isotherm INTRODUCTION Cadmium is highly toxic non-essential metal which accumulates in the kidneys of mammals and can cause kidney dysfunction [Alloway and Ayres, 1997]. Cadmium may interfere with the metallothionein's ability to regulate zinc and copper concentrations in the body. Epidemiological studies have revealed that Cd 2+ may contribute to some forms of cancer in humans and low exposures may result in kidney damage [Terry and Stone, 2002]. Cadmium is widely distributed in the environment of Iraq as a result of the use of galvanizing, pigments, stabilizers, thermoplastics, batteries and alloys. Moreover, the absence of the direct control from environmental protection agencies on above industries has increased the size of this problem. Cadmium is responsible for serious damage to the health of humans: The most severe from Cd (II) toxicity in humans is "itai- itai", a disease characterized by excruciating pain in the bone [Sulaymon, et al., 2010]. The harmful effects of cadmium include a number of acute and chronic disorders, such as renal damage, emphysema, hypertension, and testicular etrophy [Tilaki, et al., 2004]. Cadmium toxicity contributes to a large number of health conditions, including the major killer diseases such as heart disease, cancer and diabetes. Cadmium concentrates in the kidney, liver and various other organs and is considered more toxic than either lead or mercury. It is toxic at levels one tenth that of lead, mercury, aluminum, or nickel [Sayed, et al., 2010]. The term “biosorption” is used to describe metabolism independent binding of heavy metals and/or radionuclides to nonliving adsorbents. The discovery and development of biosorption phenomena provide a basis for a whole new technology aimed at removal of heavy metallic species from dilute solutions in the range of 1 to 100 mg/L [Chong and Volesky, 1995]. There are various methods to treat the metal contaminated effluent such as precipitation, reverse osmosis, ion exchange, coagulation, and adsorption. But the selection of the treatment methods differ with respect to costs, complexity and efficiency. Among these technologies adsorption is a userfriendly technique for the removal of heavy metal. This process-seems to be most versatile and effective method for removal of heavy metal if combined with © copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 131
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ROLE OF METAMODELING Detailed resea
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economy, packaging and knock limita
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satisfy constraints. This technique
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metamodel driven conceptual design
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Figure 5 presents the cross-recepta
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RESULTS AND DISCUSSION. Electrochem
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REFERENCES [1.] Velisek, J.; Cejpek
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October 2008 (6.200 BAR) Figure 1.
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Figure 5. High pressure connection
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Figure 5. Diagram illustrating the
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CONCLUSIONS Based on the discussed
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REFERENCES [1] Budzik G., Kozik B.,
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