Removal of Heavy Metals Using Bentonite Clay and Inorganic Coagulants
The cost-effective removal of heavy metals from aqueous solution is a major challenge for the scientific community. Heavy metal reduction from aqueous solution using bentonite clay, inorganic coagulants, and their mixture is a cost-effective technique. Th
- PDF / 353,616 Bytes
- 23 Pages / 439.37 x 666.142 pts Page_size
- 6 Downloads / 252 Views
Abstract
The cost-effective removal of heavy metals from aqueous solution is a major challenge for the scientific community. Heavy metal reduction from aqueous solution using bentonite clay, inorganic coagulants, and their mixture is a costeffective technique. They are easily available and cheaper compared to the activated carbon, which is widely used but an expensive adsorbent. Bentonite is a clay mineral composed of very fine particles with high opening volume and high specific active site. Thus, it has a significantly high absorption capacity. The metal ion properties, adsorbent dosage, initial concentration, and operating conditions (temperature, pH, contacting time, etc.) are the major parameters for the effective application of raw and modified bentonite. Coagulation is also a traditional technique to minimize metal ions from the bulk solution. Excessive use of inorganic coagulants may result in corrosion and erosion effect on the equipment and excessive generation of sludge volume during coagulation process. Effectiveness of bentonite clay can be enhanced by mixing inorganic coagulants such as sodium carbonate, sulfates and chlorides of aluminum, iron, etc. These coagulants are mixed with the bentonite clay in an optimum ratio to reduce the turbidity and COD of solution. This chapter includes a detailed review of recent work on heavy metal reduction in aqueous system using bentonite clay, inorganic coagulants, and their mixtures.
A. K. Thakur · R. Kumar · P. Chaudhari Department of Chemical Engineering, University of Petroleum and Energy Studies, Dehradun, Uttarakhand, India R. Shankar (*) Department of Chemical Engineering, Madan Mohan Malaviya University of Technology, Gorakhpur, Uttar Pradesh, India e-mail: [email protected] # Springer Nature Singapore Pte Ltd. 2021 M. P. Shah (ed.), Removal of Emerging Contaminants Through Microbial Processes, https://doi.org/10.1007/978-981-15-5901-3_3
47
48
A. K. Thakur et al.
Keywords
Heavy metals · Bentonite clay · Adsorption · Low-cost adsorbents · Inorganic coagulants
1
Introduction
Elements with density above 5 g/cm3 are categorized as the heavy metals. These pollutions are major components of wastewater system. Wastewater emanating from mining, textiles, tannery, fertilizers, pesticides, metal refining, and smelting processes is a major source of these types of unwanted metal contaminants. Generally, metal pollutants in the aqueous phase are found in the ionic form. Metal pollutants such as lead, cadmium, cobalt, zinc, nickel, arsenic, chromium, mercury, and iron are detrimental to living organisms including human and aquatic animals. Many of these metallic ions are highly toxic, carcinogenic, and non-biodegradable that can cause liver damage, brain damage, and other health difficulties when deposited in internal organs beyond the standard limits. Therefore, the discharge of heavy metalenriched effluent in the water reservoir is a major concern for the scientific community (Xu et al. 2009; Zou et al. 2013; Vodyanitskii 2014). There are several techniques, applie
Data Loading...
