Zeolite Application in Wastewater Treatment

Abstract

As a scarce natural resource, the preservation of water quality is of fundamental importance to guarantee its availability for future generations. Due to the increasing industrial activity, effluents are generated with a series of chemical compounds, such as nitrogenous, phosphoric, and organic compounds, heavy metals, and dyes which, if improperly disposed of, contribute to contamination, followed by significant environmental impacts, in addition to the damage to human health. The adsorption technique is an effective approach for removing contaminants from effluents, showing high versatility, due to the use of various materials as adsorbents. Belonging to a wide variety of materials, zeolites reveal to be a promising adsorbent. Zeolites are minerals found in nature or which can be synthesized from industrial residues, standing out in the treatment of contaminated effluents. Zeolite removal efficiency depends on the contaminant to be removed and can reach up to 96% for heavy metals, 90% for phosphoric compounds, 96% for dyes, 80% for nitrogen compounds, and 89% for organics. Aiming at the identification of the more relevant findings and research gaps to advance the use of zeolites in the large-scale treatment of industrial effluents, a review on the recent application of zeolites is needed. This paper presents a global view of zeolites, and a review is conducted on several recent studies using zeolites as adsorbents for the contaminants considered, indicating the main characteristics of the various adsorption systems, demonstrating the particularities of each process, and aiming to reveal useful information to provide future research, in addition to identifying points that need further investigation.

Porous organic polymers as a promising platform for efficient capture of heavy metal pollutants in wastewater

“…Zeolites can become fouled with organic matter or other substances leading to a reduction of their effectiveness; moreover, their effectiveness can be affected by changes in pH and the production of synthetic zeolites can have an environmental impact due to the release of greenhouse gases. 14…”

Stabilization of Zeolite and Bentonite with Sewage Sludge Ash

“…There is a significant number of studies on wastewater and water treatment sludge from bentonite and bentonite-based materials [18]. On the other hand, the usability of zeolite in water treatment is being investigated by researchers [19]. Cieślik et al [20] conducted a comprehensive literature review of sewage sludge management methods and applications.…”

Sol–gel synthesis of alumina gel@zeolite X nanocomposites for high performance water defluoridation: batch and column adsorption study

“…It is worth mentioning that zeolite without any modification show nominal adsorption efficiency within the range 25-50 mg/g towards the removal of heavy metals. 20 Therefore, prior modification using different materials is needed towards water decontamination applications. In a recent time, Angaru et al have reported the removal of industrial effluents using sodium alginate (SA) and carboxymethylcellulose (CMC) entrapped with bimetallic magnetic (nano zero valent iron and nickel) fly ash zeolite (ZFN) with composition of SA : CMC : ZFN as 1 : 1 : 1 (weight ratio).…”