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Rice husk is considered as a waste in the rice industry but is proficient in manufacturing different materials, such as zeolites, which is produced in large quantities all over the world, for example in Brazil. Zeolite is an adsorbent support material, which can be synthesized from rice husk ash (RHA) with external sources of aluminium (ESA). The scientific community has been conducting several measures to minimize the environmental impacts caused by greenhouse gases. Several mitigation processes are presently investigated, which includes carbon dioxide injections into adsorbent materials (e.g. zeolites). The efficiency of this technology involves a zeolitic material with high crystallinity and high concentrations of SiO 2 and Al 2 O 3 (aluminosilicates). In the present work, zeolites have been synthesized from rice husk ash (SiO 2 source) and external aluminium sources (Al 2 O 3 -alumina, gibbsite and metakaolin) to fulfill that purpose. With the aid of XRF, XRD, SEM/ EDS and FTIR techniques, the zeolitic material was characterized in two distinct crystalline phases: Mordenite and ZSM-5. The synthesis was carried out by the ideal addition of ESA (2.5 g) to RHA. According to the literature, the zeolitic materials formed by the mixture of Mordenite and ZSM-5 can be availed for gas separation and greenhouse gas storage.

Application of efficient technologies is imperative to minimize the impact of textile effluents on the environment. A solution to this problem is the application of molecular sieves such as zeolites. The sodalite zeolite has structural characteristics that allow its application as an adsorbent of heavy metals and chromophoric groups, responsible for coloring the clothing fabric. The objective of this work was to synthesize and evaluate the application of sodalite zeolite with four Si/Al ratios (1.0, 1.5, 2.0 and 2.5), using organic template. X-ray diffraction exhibits the crystalline phases of sodalite zeolite, marking the presence of minerals like kaolinite, mullite and quartz. Cation-exchange-capacity is 37% more in case of 2.5-SOD zeolite, compared to that of 1.0-SOD in the zeolitization process. The dye adsorption process was efficient at low concentrations (5, 10 and 25 mg/L) of the textile dye than higher concentrations (50, 75 and 100 mg/L) of the dye and hence, determining the concentration of the dye was of fundamental importance for efficiency regarding color removal. Therefore, it can be concluded that the synthesized sodalite zeolites (with low concentrations) in our study have substantial success potential in the effective removal of dyes from the textile industry.

Several probes have been conducted by the scientific community to reduce emissions of greenhouse gases such as carbon dioxide (CO 2 ). A zeolitic material is capable of CO 2 adsorption with the aid of such technologies. Our present work is to efficiently synthesize zeolite Y with four Si/Al ratios (2.0, 2.5, 3.0, and 3.5) from green materials such as rice husk ash (source of Si) and metakaolin (source of Al). The method for preparing zeolite Y involves hydrothermal synthesis in a hydrodynamic reactor at 120 C temperature, for a reaction time of 24 hours. These synthetic zeolites represent high values for surface area as well as pore volume in micropore range and are compatible with the size of CO 2 molecules. The zeolite Y (with Si/Al ratio 3.5) has an absorption capacity of 3.35 mmol CO 2 /g at (900 kPa) pressure, thereby

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Violet crystal and malachite green are dyes used in the textile industry. These organic compounds are toxic agents capable of polluting water resources as well as destroying the existing biota in this location. The decolorization of textile effluents has always been a global problem, but it has accentuated over time with increasing scale operation and changes in the origin of the dyes used. Decolorization of wastewater achieved by physically removing the dye from the water or by destroying its chromophore group. Adsorption is referred to as one of the most efficient and feasible methods for discoloring an effluent. Molecular sieves (zeolites) showed to be an efficient alternative in the discoloration of textile effluents when compared to other processes in the industry. Sodalite is a zeolite that has the ability to adsorb the azo functional groups related to color. The focus of this work is to use sodalite in the process of discoloration of a synthetic solution of crystal violet and malachite green. The experiments performed by varying the contact times between the zeolitic material and the synthetic solutions of the dyes. The results revealed that both dyes had a decolorization process. According to analyzes, greater times of contact (12, 24, 48, and 72 hours) with sodalite is more efficient in the removal color. A decisive factor in this process is the higher Si/Al ratio (2.5) of sodalite that potentiates the process and efficiency of the experiments.