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The main concern in fish transportation is minimizing stress during transportation. In this study, the effect of zeolite and clove essence in terms of transportation on survival and stress rainbow trout was investigated. 4 treatments (each treatment included 3 replicate) including control treatment, clove essence (25 mg/l), zeolite (14g/l) and clove essence (25mg/l) + (14g/l) were considered. 156 fish (with average weight 80 ± 4.4 g) were randomly distributed with a 130 kg/m3 density. At time zero, 6, 12 and 18 hours after starting transportation, survival rates, cortisol and glucose levels (as indicators of stress) were measured and analyzed. In the end, results showed a significant difference in the survival rates that control treatment had the lowest survival rates (P

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In a randomly and factorially designed experiment, the interaction effects of dietary zeolite (0 and 2%) and three salinity levels (80, 130 and 180 ppt) on growth, survival, reproductive performance and total longevity of A. franciscana were determined (6 treatments in total). The experiment was carried in two stages: nauplius to maturity and maturity to death of all females. The results indicated that the total body length of Artemia fed with zeolite were not significantly different among treatments in the third week of rearing (P>0.05), except for nauplii fed zeolite in salinity 180 ppt. However, Artemia fed with zeolite in 80 ppt had a higher body length and furcal length compared with other treatments. Nauplii in all treatments reached sexual maturity within 17-23 days (P>0.05). Survival rate was far higher in groups fed with zeolite compared to unfed groups; the highest values were recorded in group fed with zeolite at the salinity 130 ppt (P<0.05). The reproductive period and total longevity of females decreased with increasing salinity, but this trend was not affected by diet type. Average offspring production in the groups fed with zeolite was in the range of 861-1160 offspring compared to unfed groups (604-741 offspring) (P<0.05). The encysted embryos percentage was different in the range of 20-35%. According to the results, the inclusion of 2% zeolite in salinity within 80-130 ppt were better for growth of the Artemia to maturity. Also, it is recommended to add zeolite in the Artemia diet with the increasing trend in salinity from 80 to 180 ppt for improving broodstock reproductive performance.

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Research subject: Hydrodesulfurization is one of the effective methods to remove sulfur compounds from oil fractions and improve fuel quality. One of the major challenges in this process is to find the proper catalyst support that performs best. In the meantime, modified supports with zeolite have allocated a lot of attention due to their strong acidic sites, specific surface area and high hydrothermal and chemical stability; But the acidity and volume of zeolite mesopores need to be corrected.
Research approach: In this study, first, hierarchical Y zeolite was prepared using post-synthesis (Dealumination) and using ammonium form of zeolite and NH₄F solution (0.75 M) at 90˚C for 3h under reflux conditions. Physicochemical properties of zeolite were investigated by BET, FESEM, FTIR, AAS and XRD analyzes. Modified zeolites were used in the support synthesis of the HDS process catalyst. The sulfidation and performance evaluation of the prepared catalysts were carried out in the fixed-bed microreactor were performed with diesel cutting feed from the Isomax unit of the target refinery.
Main results: The results show that the volume of mesopores, specific surface area and SiO₂/Al₂O₃ ratio in hierarchical zeolites has increased 0.073 cm³ g^-1, 783.36 m² g^-1 and 5.2, respectively (initial values are 0.032 cm³ g^-1, 567.18 m² g^-1 and 4.5). The results of zeolite analysis show the preservation of the structure and crystallinity during the zeolite modification process. The effect of zeolite modification, especially the Si/Al ratio variations, mesopores and specific surface area, was investigated on the activity of NiMo/Zeolite+Al₂O₃ catalysts. Increasing the acidity and improving the physicochemical properties of the modified zeolites has increased the catalyst performance in the process of diesel hydrodesulfurization (Conversion= 90%). Improving the activity of catalysts can be attributed to the positive effect of zeolites on the dispersion of the metallic site, surface area, acidity, optimal size of pores and volume of catalyst mesopores.

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Research Subject: In recent years, industrial-scale production of propylene based on oxidative dehydrogenation of propane has been of particular importance due to the lack of thermodynamic limitations. In this regard, the use of natural zeolites with high abundance and low price has placed a special position. In this research, perlite natural zeolites were treated with ionic liquid solution and acid, then supported vanadium catalysis were synthesized. Performance of catalysis were investigated in oxidative dehydrogenation of propane to propylene process with a mixed feed of propane and air in a fixed bed quartz reactor under condition of atmospheric pressure and temperature of 500˚C with a flow rate of 40000 h^-1 (GHSV).
Research Approach: In this study, natural perlite support as a source of aluminum oxide (Al₂O₃) and silica (SiO₂) was ion exchanged by one molar solution of ammonium nitrate (NH₄NO₃ 1 M). Continuously, to investigate the effect of delamination, different acid molar concentrations of nitric acid (HNO₃) equal to 0.75, 1.5, and 2.25 were used and then compared with the just modified ion exchange sample without acid leaching (V/PERLIT-I). Dry vanadium impregnation, as an active metal, was carried out to synthesize 8% wt. catalysts. X-ray diffraction analyzes (XRD), scanning electron microscopy (FE-SEM), and ammonia Temperature-programmed desorption program (NH₃-TPD) were used to characterization and evaluate the properties of the catalyst.
Main Result: The results showed that the concentration of acid used affects the conversion and selectivity of the catalysis. In comparison, a significant difference was observed between the performance of V/PERLIT-I sample compared to V/PERLIT-IA samples. The maximum selectivity value for V/PERLIT-IA(2.25) was 74%. According to the results, the treated perlite support with suitable selectivity can be considered in the studies of use as an industrial support.

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The effects of natural zeolite as a bed medium in increasing lettuce and red tilapia growth as well as improvement of water quality parameters in an aquaponic system were investigated. An experiment with a completely randomized design was run with two treatments in triplicates, 1) an aquaponic system without use of zeolite as a control group and 2) use of a small cotton bag, containing 10 g zeolite as a bed medium for planting a lettuce seedling. In each experimental unit, 42 seedlings of lettuce were introduced. The individual weight of fish and lettuce yield in treatment 2 was significantly higher (P< 0.05) than treatment 1 at the end of experiment. The initial mean individual weight of red tila-pia juveniles was 6.23 ± 0.06 g and increased to 32.50 ± 2.00 and 37.50 ± 2.20 in treat-ments 1 and 2, respectively by the end of experiment. The yield of lettuce was higher in treatment 2 (1507 ± 445.00 g/unit) compared to the control (275 ± 83 g/unit). The concen-tration of total ammonia-N in the water was significantly lower (P< 0.05) in treatment 2 compared to treatment 1 at the end of experiment. The concentration of phosphorous and potassium in the fish rearing tanks was significantly lower (P< 0.05) in treatment 2. These results indicated that the use of zeolite, as a bed medium to plant lettuce seedlings in a re-circulating aquaponic system could increase the growth of lettuce seedlings as well as im-proving water quality parameters.

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 Biofloc technology is considered as a culture system for fish production reduced environmental impacts. In the present study investigated the impact of zeolite nanoparticle on water quality, growth performance, digestive enzymes and immune response of common carp (Cyprinus carpio) reared under biofloc conditions. Fish fingerlings (initial weight of 7.99 ± 0.36 g) were divided into four treatments and fed four levels of zeolite nanoparticles in the following 0 (control), 50, 100 and 200  mg kg⁻¹ diet in biofloc system (NZ1, NZ2 and NZ3) for 60 days. Carbon to nitrogen ratio (15:1) was provided using sucrose. Water quality parameters such as nitrogen compounds were measured during the test period. At the end of the experiment, the highest growth indices and the lowest feed conversion ratio were obtained in 50 mg kg⁻¹ diet (NZ1). Intestinal protease activities in NZ1 and NZ2 treatments were significantly higher than in the other treatments, and the highest lipase and amylase activity was related to the NZ1 treatment. The 50 and 100 Zeolite diets in biofloc conditions significantly enhanced fish immune system activity. The present study suggests that dietary supplementation with 50 and 100 mg Zeolite nanoparticles in biofloc system significantly increases growth performance, digestive enzyme, and immunological response in common carp in fish culture tanks.

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The indirect application of silver nanoparticles (AgNPs) in controlling the common fungal infection during the incubation period of Persian sturgeon -saprolegniasis - was investigated in this research. Filters containing 0.2%, 0.5% and 1% of AgNPs in two states without agent and with aminopropyltriethoxysilane (APTES) coupling agent along with the control treatment (without filter) were the treatments investigated in the present study. The results showed that in the first 48 hours of incubation, which corresponds to embryonic growth before the start of neurulation, despite the start of contaminating the water in the incubators with Saprolegnia fungus, fungal infection was not seen in any of the investigated treatments. The results of measuring the amount of silver released from the studied filters at the end of the first 12 hours of incubation showed that the amounts of silver released in the water in the treatments of 1% AgNP filters without APTES and with APTES were significantly higher than other filters containing AgNPs. This trend was repeated at the next sampling rounds (48 and 96 hours) with the difference that the release rate was significantly higher only in the 1% AgNP-APTES filter treatment. In the treatment of AgNP-APTES filters, the percentage of hatching showed a significant increase compared to the control filter treatment.

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The lack of accessibility of high quality materials and the increased costs associated with the use of these materials will finally demand engineers to use local soils. In such cases, ground improvement performed reasonably in many conditions. Ground improvement can be defined as the procedure of increasing shear strength parameters and decreasing the permeability and compressibility of the soil. Different methods can be used to improve the geotechnical properties of the problematic soils such as loose sand that one of them is using additives. The stabilization of soils with cement is an attractive technique due to economic and environmental issues and avoiding the use of borrow materials from elsewhere. Cementation of sand results in increased brittle behavior as peak compression strength increases. The compressive strength of artificially cemented soils has been studied in the past by several investigators.A number of studies have also reported on the influence fiber, glass, fly ash, silica fume and nono particle on the mechanical behavior of cemented sands .However, to the author’s knowledge, there has been a little effort devoted to the research on the use of pozzolans such as natural zeolite as an addictive material to the cemented sands. Natural zeolite, an extender, has been investigated for use as cement and concrete improver by some researchers.
It is widely known and well emphasized that the cemented sand is one of economic and environmental topics in soil stabilization. In some instances, a blend of sand, cement and other materials such as fiber, glass, nano particle and zeolite can commercially available and effectively used in soil stabilization in road construction. In this investigation, zeolite and its effect on unconfined compression studied as one of addictive material to cement. Therefore, cilinopiolite kind of zeolite, Neka cement type II and Babolsar sand are used. A total number of 144 unconfined compression tests were carried out on 24 combination type of cement and zeolite include different cement percentages 2, 4, 6 and 8 percent of total dry weight of samples and replacement percent’s of 0, 10, 30, 50, 70 and 90 zeolite with cement based on 50,70 and 85% relative densities in7 and 28 days curing times. Results show that in 28 day curing time, by replacement percentage of 30 zeolite material by cement, the unconfined strength increased 20 to80% in comparison with cemented samples by increasing shear strain. For higher cement content and less compacted blends, these improvement rates are more. At the end, a power function fits presented to relate unconfined compressive strength (UCS) and zeolite-cement-soil parameters (porosity (n) and voids/ polynomial model of cement and zeolite voids).It is widely known and well emphasized that the cemented sand is one of economic and environmental topics in soil stabilization. In some instances, a blend of sand, cement and other materials such as fiber, glass, nano particle and zeolite can commercially available and effectively used in soil stabilization in road construction. In this investigation, zeolite and its effect on unconfined compression studied as one of addictive material to cement. Therefore, cilinopiolite kind of zeolite, Neka cement type II and Babolsar sand are used. A total number of 144 unconfined compression tests were carried out on 24 combination type of cement and zeolite include different cement percentages 2, 4, 6 and 8 percent of total dry weight of samples and replacement percent’s of 0, 10, 30, 50, 70 and 90 zeolite with cement based on 50,70 and 85% relative densities in7 and 28 days curing times. Results show that in 28 day curing time, by replacement percentage of 30 zeolite material by cement, the unconfined strength increased 20 to80% in comparison with cemented samples by increasing shear strain. For higher cement content and less compacted blends, these improvement rates are more. At the end, a power function fits presented to relate unconfined compressive strength (UCS) and zeolite-cement-soil parameters (porosity (n) and voids/ polynomial model of cement and zeolite voids).

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Water shortage and wastewater discharge into environment have led to significant research in the field of environmental engineering for developing high efficient, fast, and cheap wastewater treatment. In recent years, advanced oxidation processes (AOP) have been subjected to significant attention for wastewater treatment due to feasibility of the process in mild reaction conditions, requiring low cost equipment, and short time of the process. Electro-Fenton process addresses the potential drawbacks of Fenton reaction including transportation of H₂O₂ and regeneration of ferrous ions which act as catalyst. In the present study, ZSM-5 catalyst was synthesized by hydrothermal technique and promoter was introduced through wet impregnation method. Ir-ZSM-5 catalyst w::as char::acterized by XRD, FE-SEM, BET, FT-IR and NH₃-TPD techniques. The XRD patterns revealed the high crystallinity for the both parent and Ir impregnated ZSM-5 catalysts. FE-SEM images showed micro-spherical morphology. N₂-adsorption-desorption confirmed mesoporous structure for the synthesized catalyst including 321.1 and 327.3 m²/g specific surface area for the parent and Ir-ZSM-5 catalysts, respectively. FT-IR spectrum confirmed formation of ZSM-5 zeolite and also revealed presence of surface hydroxyl groups. NH₃-TPD revealed that acidity of the impregnated ZSM-5 catalyst was increased due to interaction of Ir with zeolite structure. Acidimetric-alkalimetric titration determined pH_PZC for the parent and Ir-ZSM-5 catalysts equal to 3.6 and 3.9, respectively. Catalytic performance of Ir-ZSM-5 catalyst for removal of methylene blue (MB) from wastewater in heterogeneous electro-Fenton like reaction was evaluated. Different operation conditions were tested including concentration of catalyst, pH of wastewater solution and applied current between graphite electrodes. The results showed that Ir-ZSM-5 catalyst had acceptable performance in near neutral pH level due to the improved adsorption of MB molecules on Ir-ZSM-5 structure. The stable catalytic activity resulted from formation of no sludge related to active phase. Detected OH groups at the surface of the catalyst attained positive charge at pHpzc and negative charge at pH>pH_pzc which influenced the adsorption capacity of the catalyst at different pH levels through electrostatic adsorption of ionized MB molecules on the catalyst. Blank test using no amount of Ir-ZSM-5 catalyst led to only 77% MB removal which was attributed to anodic oxidation on the surface of the graphite electrodes. Increasing applied current led to the improved MB removal owing to the faster degradation of the sacrificial graphite anode. The optimum operational conditions for the proposed system were pH=3, 0.2 gL^-1 of Ir-ZSM-5 catalyst and 100 mA applied current which resulted in the highest MB removal (100%). The reusability test of the catalyst was carried out by 3 consecutive runs at the optimum conditions. After each run, the used catalyst was regenerated at 550 °C to remove the adsorbed organic molecules due to adsorption of either MB or its oxidation intermediates. The regenerated catalyst showd the high catalytic performance with insignificant change of the removal efficiency as result of the high crystallinity and specific surface area of the synthesized catalyst. A pseudo first order kinetic was proposed for the reaction of removal which fitted the experimental data with the high correlation factor. The results confirmed the high potential of the heterogeneous electro fenton-like process for wastewater treatment.

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Increasing builders waste of autoclaved aerated concrete (AAC) require new concepts for future recovery processes. There are two main aspects, underlining this basic necessity for developing AAC recycling models. Environment protection ranks first because of the risk of groundwater pollution by compounds leached out from AAC waste during its deposition. The second aspect is raw materials preserving because of the high content of the valuable potential recyclable calcium- silicate-hydrate phase 11 Å tobermorite (5CaO 6SiO2 5H2O) besides pure quartz and minor aluminate. In general the main constituents of AAC amount around 40–50 wt-% for tobermorite and approx. 30–40 wt-% for quartz. The tobermorite phase is causing the AAC strength and forms hydrothermally at 180–200 °C and 10–12 bar pressure during autoclaving from the raw materials lime, quartz, and water. Minor parts of aluminum powder for pore-forming and small amounts of cement and anhydrite for better handling of the AAC-green bodies are the further additives of the AAC raw materials mixture. The high silicate content, as well as the valuable calcium parts, display AAC waste as an interesting raw material for zeolite formation as known from the treatment of fly ashes and slags. According to their outstanding properties zeolites are used in sorption techniques, catalysis, molecular sieving, and ion exchange processes, and in previous studies, we already could show zeolite hydro sodalite formation beside hydrogarnet and other valuable calcium- and sodium aluminosilicates applying NaAlO2 as an aluminum source in the reaction mixture. Those previous syntheses were performed in water and under low alkaline (1 m NaOH) and low acid (1 m citric acid) conditions. This mild reaction milieu was found to be responsible for relatively low AAC conversion rates and the formation of multiphase products. In reference, the aluminum source NaAlO2 was added to the AAC always before the leaching reactions were performed. In contrast, the presented study investigates leaching of pure AAC in stronger alkaline media of 4–8 m NaOH and the combination with acid treatment, before the aluminate is added for the final crystallization process. This procedure is expected to be much more effective to synthesize uniform zeolite products at 100% AAC conversion rates, as shown in the following experimental study. Autoclaved Aerated Concrete (AAC) used in low-rise buildings and infilled frames as a structural member. One of the weaknesses of AAC is low mechanical strength. In addition, AAC blocks absorb water of mortar which can lead to executive problems. In this paper, the effect of silica fume, zeolite and granulated blast furnace slag (7%, 14% and 21% by weight of cement) was investigated on improving mechanical properties and water absorption of AAC. The compressive and tensile strength tests and water absorption test was conducted on 10 x 20 cm cylindrical and 10 x 10 x10 cm cubical specimens. The results showed that pozzolanic materials can improve mechanical properties and water absorption of AAC. The compressive strength for AAC mixes containing silica fume, zeolite, and granulated blast furnace slag, increased up to 184%, 200%, and 172% compared with AAC control mix. In addition, the use of pozzolanic materials with the ratio of 21% by weight of cement improved tensile strength of AAC up to 25%. Generally, silica fume, zeolite and granulated blast furnace slag in different replacement levels decreased water absorption up to 50%, 45%, and 35%, respectively.

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Although cement stabilization is used extensively to modify the soft clays, it may show limited success in some applications. Hence, this paper presents a multiscale investigation on the viability of employing zeolite and fiber to enhance the durability of cement treated soil against the freezing-thawing (F-T) cycles. In so doing, a wide range (0 to 30%) of additives including sole cement and cement-zeolite mixture (CZ) with different cement replacement were separately added to a soft soil sample and then mixed with the optimal fiber content of 0.75% (by weight), which was determined by the indirect tensile strength test. A set of experiments at various curing days (up to 90 days) were performed to study the mechanical and microstructural changes of the stabilized soils. The results indicated that while a low level of cement can modify the geo-mechanical parameters of soil sample, the compressive strength of cemented soil could decay up to 60% when the specimens exposure to the successive F-T cycles. Such changes may be ascribe to the F-T-induced particles rearrangement and degradation of the cementation structure-bonding, forming many new voids and cracks subsequently decreasing the interlocking of matrix. As a result, to get the strength guidelines threshold and make the composite water proofing a high dosage of sole cement and a long time of curing (at least 28-day) are needed, which may be uneconomical and lade to the brittle behavior. Adding zeolite (≤ 25% proportion) to supplant part of cement could effectively enhance the engineering properties of cement-mixed soil, due to an increase in the cementitious products [e.g. Calcium-aluminate-hydrate (CAH) and Calcium-silicate-hydrate (CSH)] induced by the pozzolanic activity, subsequent reduction of the inter pore-spaces and eventually a more compacted microstructure, as confirmed by the X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images. It should be emphasized that the zeolite/cement ratio is a very influential factor on the behavior of cement-zeolite mixture. Therefore, the cemented soil mixes with Z_opt showed a further (up to 1.3 folds) resistance relative to the mere cemented soil as well as a greater tensile strength; however, the binary system was still vulnerable under the F-T action. In this case, the insertion of fiber could significantly enhance the soil durability (decrease the degree of damage by an average value of 50%), which was more evident at the small binder dosage and early stage of curing time. Incorporating fiber into the system also led to a higher tensile strength (nearly 1.5 times) than those deduced from the stabilization alone. Moreover, this strategy was effective to overcome the brittle nature of stabilized mixes, resulting an increase the post-strength up to 270%. These observations can be justified by the extended cementing gels formation and the enhanced interlocking of matrix through the CZ-fiber application. Overall, the combination of CZ blend and fiber can be considered as an effective technique for the soft soil modification with the fact that triggered a prominent reduction (~ 30%) in the needed amount of cement an time of curing (up to 3 folds) for the successful treatment against the F-T cycles.

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One of the main objectives of infrastructure managers is the timely and rapid operation of airports and freeways. A goal that is challenging when utilizing concrete pavements, due to their different behavior during the initial stages of implementation. This research aims to improve the mechanical characteristics of concrete pavements and increase their durability against the combined effects of the freeze-thaw cycle and surface desalination, especially during early ages. This paper examines the use of cementitious material in combination with hydrated lime, metakaolin, and zeolite to remove the hurdles to the early operability of concrete pavements. To this end, micro-structural studies have been performed using XRD and SEM analysis and comparisons in two states of water processing and exposure to freeze-thaw cycle. During which replacing cement with zeolite and metakaolin in calcareous concrete resulted in reduced porosity and homogeneous density with the formation of CSH in the concrete structure. 
Accordingly, improvements in the mechanical properties and durability of concrete pavements against the combined effects of freeze-thaw cycle and surface desalination were studied and analyzed in four mixtures of Control Concrete (CC), 15% lime (CL), 15% lime, and 15% Metakaolin (CLM) and 15% lime and 15% Zeolite (CLZ). It was noted that at age of 7 days the CLM, CL, and CLZ samples showed an increase of 20%, 32%, and 48% respectively compared to the CC sample. This increase continued throughout the study. During the freeze-thaw test and after 55 cycles the CLM and CLZ samples always exhibited lower degradation and showed a weight loss of 48.7% and 75.2% less than the CC sample. In addition, as per the results of the capillary absorption test the CLM and CLZ mixtures had at lower ages had less permeability than the CC mixture and this behavior continued with better performance at older ages.
 
 Also, the results of flexural strength indicate the positive effect of additives in all samples over time, and at 28 days, the CL, CLM, and CLZ samples increased flexural strength by 39%, 42%, and 57% respectively in comparison to the CC sample. The positive effect of hydrated lime due to its high paste property in increasing the flexural strength of mixtures containing metakaolin and zeolite is quite evident and has increased the mechanical properties at all ages of the samples, but has weakened the durability performance compared to the control sample. This issue has been addressed in composite mixtures containing lime with metakaolin or zeolite, and the results of durability tests indicate a significant improvement in both pozzolans, especially in the zeolite. It can therefore be concluded that with improving mechanical characteristics and durability of CLM and CLZ mixtures, utilizing metakaolin and zeolite in concrete containing hydrated lime is a suitable solution to eliminate the challenges of early usage in concrete pavements.

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Today, the use of self-healing concretes has attracted the attention of various researchers. In this paper, the effect of Bacillus subtilis bacteria with different concentrations were used for evaluation on concrete containing zeolite.The mentioned bacteria were produced in the laboratory and added to the concrete mixing plan. In order to evaluate the effect of Bacillus subtilis bacteria on specimen with zeolite, resistance and durability tests including compressive strength, ultrasonic, water penetration test and water absorption tests were performed on the specimen at different ages. Also, using scanning electron microscope (SEM) and optical microscope, the self-healing of concrete was evaluated. The results of the compressive strength test showed that the specimen containing zeolite with a concentration of 2.8×10⁸ cells/ml increased the compressive strength by 16.76% and the specimen without zeolite increased the compressive strength by 13.51%. Also, the presence of Bacillus subtilis bacteria in the mixing design led to a 15% decrease in water absorption of specimens without zeolite and 30% of specimens with zeolite. Based on the results of the experiments, the most suitable concentration, for the simultaneous improvement of the resistance parameters and durability among the different concentrations of Bacillus subtilis bacteria, is suggested to be 2.8 x 10⁸.