Dey, Ghosh, & Naskar (2013) studied the synthesis of ZSM-5 zeolite in an organic template free under a hydrothermal condition of 150oC for 72 to 96 hours. Kaseelouri-Rigopoulou (2008) studied the synthesis of ZSM-5 from crystalline RHA as an alternative silica source. In addition, Esmaeili and Saremnia (2016) investigated the synthesis of NaA zeolite nanoparticles from Hordeum vulgare L.
Synthesis of Zeolite A and Its Parameters
A 2008 study by Chandrasekhar and Pramada on the synthesis of zeolite A from metakaolin as a source showed that it could take as little as 2 hours for calcination. Izidoro et al., for the synthesis of zeolite A, showed that its calcination process can occur at 550 o c for only one hour using fly ash as a source. All three studies showed that the alkalinity for the synthesis of zeolite A is suitable for a ratio of 1.0:1.0.
As shown in Table 2.5, various studies on the effect of curing time from different sources on the synthesis of zeolite A. The curing time of the synthesis of zeolite A can be observed at 100oC with different times. And in 2013, a study was made with the same temperature of 100oC and the same time of 24 hours with kaolin as a source for the synthesis of zeolite A.
The hydrothermal curing for the synthesis of zeolite A can take place at 100oC from different sources (oil shale, kaolin, rice hulls, synthetic zeolite) and different sources. The hydrothermal curing for the synthesis of zeolite A can take place above 100oC from different agricultural waste sources (barley husk ash, rice husk ash) at different times or time intervals (24 hours; 12 hours) (Esmaeili & Saremnia, 2016; Mukherjee et al., 2018) .
At the same temperature of 110oC, a 2018 study also used agricultural waste RHA at a lower time of 12 hours. Hydrothermal solidification for the synthesis of zeolite A can take place at over 100 oC from different sources of agricultural waste (barley husk ash, rice husk ash) at different times or time spans (24 h; 12 h) (Esmaeili & Saremnia, 2016; Mukherjee). et al., 2018). Durgun et al., 2014) and natural gas dehydration (Shirazian & Ashrafizadeh, 2015). It is also used for water softening opportunities – used as a softener for reverse osmosis brine or simulated seawater (Tokmachev et al., 2008) and also used in the detergent industry to improve calcium and magnesium removal (Bessa et al., 2017 ).
The main feature of zeolite A is the fact that it is now widely used in ion exchange separation, such as in waste water treatment, where zeolite A has been found to have a variety of uses in ion exchange or adsorption of water contaminants such as ammonium ions (Millar et al. al., 2016), lead, copper (Djamel & Samira, 2021) and nickel ions (Hong et al., 2019), as well as malachite green dyes (Abdelrahman, 2018) and oil-water (Mahmodi et al., 2020).
- Desalination Technologies
- Different Studies Employing Electrodialysis in Desalination
- Ion Exchange Membranes Types and Principles
Zheng et al., 2015) and is receiving increasing attention in water resource management as illustrated in Table 2.6. It was discovered that as the number of cell pairs increases, the net power density decreases as the partial pressure drop in the branches becomes dominant (Pawlowski et al., 2014). Good IEMs have high IEC, permselectivity, high conductivity (low resistance), dimensional stability (low membrane swelling and water uptake), as well as high thermal, mechanical and chemical properties (Hosseini et al., 2017; Jiang and Ladewig, 2017; Son et al. al., 2017).
Recently, in addition to the common cations, there are new types of emerging functional cations for AEMs such as metal cation-based group (Hagesteijn et al., 2018). Proton exchange membranes are generally used to conduct protons inside fuel cells (Kim et al., 2015). Water will detach from hydroxide ions and hydrogen ions in the interface of these two layers when force is applied (Pärnamäe et al., 2021).
The major advantage of amphoteric IEMs over the common CEMs is its lower permeability (Wang et al., 2014). Monovalent selective IEMs are another special type of IEMs, they can separate monovalent ions and retain multivalent ions in solutions (Nie et al., 2017; Radmanesh et al., 2019). They can be further classified into monovalent selective CEMS and AEMS, respectively (Ge et al., 2014; Li et al., 2015).
Monovalent selective IEMS can be used to produce energy from reverse electrodialysis (Güler et al., 2014), concentration of brine by reverse osmosis using electrodialysis (Xu et al., 2018), and the removal of nitrate ions and arsenic from groundwater . others.
Pervious Concrete and Mortar
Pervious Concrete Components
The amount of cement is dependent on the water content and aggregate's quantity and sizes. Coarse aggregate is another major component of computing. 2007) and Yang and Jiang (2003) found that the type, as well as its grading and size of coarse aggregate, influence the character of PC. Sometimes a fine aggregate is used in PC to improve its mechanical capabilities, however, the permeability will normally decrease (Mehta & . Monteiro, 2006; Neville, 2011; Ollivier, 2012).
They reported that the compressive strength of PC was significantly improved by the addition of fine aggregate and the maintenance of adequate water permeability. In order for the cement hydration to fully develop, sufficient water must be added. Conversely, an excessive amount of water will clog the pores and remain at the base of the concrete.
Temporarily, excessive amount of water will cause lower strength and higher porosity, thus increasing the distance between particles. Furthermore, they confirmed that maximizing the strength without compromising the permeability properties of the computer is through an accurate amount of water.
Different Studies Employing Pervious Concrete in Water Purification Pervious concrete is a form of concrete that allows wastewater to move through
The effect of several parameters on the mechanical characteristics and capacity of the activator to absorb heavy metal ions was investigated. These factors included the RM content, the molar ratio of sodium hydroxide to silicate (Na2O/SiO2), and the alkali concentration of the activator. Both the Na2O/SiO2 mole ratio and the alkali content of the activator had a significant influence on the strength of the RM-GBFS-based PC geopolymer, but had a negligible effect on the adsorption of heavy metal ions.
In addition, when the proportion of RM increased, the strength of the RM-GBFS-based geopolymer PC decreased, but the adsorption of heavy metal ions improved dramatically. The nitrogen and phosphorus reduction ratios were investigated using PC and the results were presented in terms of filtration and adsorption effects. FA/B, 0.04% NS/B and 1.71 M NH, which resulted in a maximum possible compressive strength of 22.2 MPa after a seven-day curing period at ambient temperature (25.5°C) and the optimum flow of pasta at 110 percent.
There is a negative correlation between the water purification and the water permeability of the pervious concrete. Considering the water purification, water permeability and strength qualities of PC, the optimum BPA was 30% and the optimum P/A was 0.25.
It is found that, with the bulk porosity of aggregate (BPA) increasing, the adsorption to Pb2+. Yehia and Emam (2017) conducted a comprehensive laboratory study on the effects of adding zeolite as pozzolan in various levels of substitution for Portland cement (0-40%). Regarding the control mix comparison, zeolite admixed concrete has an improved compressive strength of 10 % cement replacement level in 7-, 28- and 56-day hydration age.
The efficiency of zeolite as cement replacement for up to 20% was reported by Chen et al. Results showed that at a fixed water-cement ratio, up to 10% zeolite addition did not significantly affect the 7- and 28-day age strength, but marginally enhanced the 70-day age strength. strength, but slightly increased the 70-day strength. On the other hand, Eskandari et al. 2015) used only 5, 8, and 10 weight percent zeolite replacement in the Portland composite as well as standard cylindrical samples.
The values for concrete with up to 20% natural zeolite can still be considered acceptable in the mixed binder. A summary of the zeolite cement substitution studies revealed that the small decrease in initial strength due to the zeolite mixture can be explained by the following theories: (1) the chemical reaction of cement is usually slower than the hydration reaction, which is generally faster is; (2) the replacement of cement with zeolite has actually reduced the amount of cement which clearly contributes to its initial strength; and (3) although zeolite is ground to a higher fineness than cement, its chemical reaction is still not sufficient to compensate for the lower strength development caused by the reduction in cement content.
In addition to these, various zeolite applications were also presented to highlight the study of zeolite significantly, before finally introducing this study's zeolite application, which is an ion exchange material. Previous studies on zeolite applications were highlighted so that the study can present the different ways of using zeolites in different applications such as adsorbent, ion exchangers, catalysts and separators to focus on the specific application investigated in this study, which is ion exchange. All these preliminary discussions lifted from various literatures highlight the important point of the synthesis process, which is the preparation of the synthesis mixture including all its parameters, because any variation that may occur from these parameters changes the final output, which is zeolite A.
On the other hand, the various studies using electrodialysis in desalination are included here to refer to the literature done before this study so that we can see the current studies under electrodialysis, a membrane technology, which can have a significant impact on the novelty of this research. Studies demonstrating voltage and cell pairs were studied to parallel them with the need of the current study to explore their comparison and optimization. As for the literature on cementitious materials included, the study integrated different binder ratios in which zeolite was included for the study to develop a zeolite membrane with cement mortar structure that will be used as a membrane.
These studies considered many different cement additives, both natural and artificial, as reinforcements of the concrete material. Studies on many important IEM developments were also included to evaluate various industrial applications using IEM so that the author could reinforce the core of his study.