Noxious Gas Research Articles

Adsorbents for Noxious Gas Sequestration: State of the Art

Adsorbents such as metal-organic frameworks (MOFs), polymers, activated carbon (AC), and membranes are becoming prominent for CO2, SO2, H2S and NH3 capture and in some cases, storage. Using the standard adsorbent properties (SAPs) such as adsorption capacity, selectivity, permeability/permeance, regenerability and reusability, ease of functionability and tunability, thermal and chemical stability, suitable candidates for noxious gas sequestration can be determined. To foster the development and selection of a more efficient adsorbent, proper documentation of adsorbent performance in terms of SAPs is crucial. In this study, a critical review of metal-organic framework (MOF), polymer, activated carbon (AC) and membrane adsorbents was performed. Using the SAPs, an up to date comparative analysis was done to select the best performing adsorbents. The results of the comparative analysis were then used to categorize the adsorbents' suitability for pre-combustion and post-combustion applications. A perspective of future study on adsorbents for noxious gas sequestration was also presented.

Effects of multi-enzyme on production performance, egg quality, nutrient digestibility, and excreta noxious gas emission of early phase Hy-line brown hens

The purpose of this study was to investigate the effects of dietary supplementation of non-starch polysaccharide multi-enzyme (NME) in early laying phase of hens on production performance, egg quality, nutrient digestibility, and excreta noxious gas emission. In total, 432 Hy-line brown laying hens at 18 wk of age were used in a 10-wk feeding trail. Hens were randomly assigned to 1 of 3 treatments with 24 replication and 6 hens per replication (1 hen per cage). Dietary treatments were corn-soybean meal-DDGS-based diets supplemented with 0 (based diet, CON), 0.05% (NME1), and 0.1% (NME2) of NME. No significant (P > 0.05) response to increasing NME supplementation was observed for damaged egg rate shown throughout the experiment. Significant (P < 0.05) linear increase was observed for egg production at week 4, 6, and 8; moreover, egg production at week 8 also showed quadratic (P = 0.0344) increase. No significant effects were found on yolk color, eggshell strength, and eggshell thickness during the experiment (P > 0.05) with the increase in NME supplemental levels. Albumin height, haugh unit, and egg color values were linearly (P < 0.05) increased at week 2 and 6 following the increasing NME supplementation, respectively. Additionally, quadratic (P = 0.0013) effect was observed on egg weight at week 6 with the increasing level of NME. Moreover, apparent total tract digestibility of nitrogen and excreta ammonia emission was linearly (P < 0.05) affected increasing NME supplementation. In summary, inclusion of NME containing xylanase, β-glucanase, galactosidase, and galactomannanase activities in corn-soybean meal-DDGS-based diets increased nitrogen digestibility, decreased excreta ammonia emission, and had no negative effects on production performance and egg quality parameters.

Inclusion of fish waste silage in broiler diets affects gut microflora, cecal short-chain fatty acids, digestive enzyme activity, nutrient digestibility, and excreta gas emission

A study was conducted to determine the impacts of dietary inclusion of fish waste silage (FWS) substituting soybean meal (SBM) on the performance, gut microflora, cecal short-chain fatty acid, apparent ileal digestibility (AID), digestive enzyme activity, and excreta noxious gas emission in broiler chickens. A total of 720-day-old male broilers (Cobb 500) were randomly allocated to 3 dietary treatments with 12 replicates each accommodating 20 birds for 42 d. Birds received diets as follows: a corn-SBM-based diet (CON) and 2 diets that replaced SBM with FWS at 60g/kg (FWS60) and 120g/kg (FWS120). During the entire period, replacing SBM with FWS60 and FWS120 increased body weight gain and decreased feed conversion ratio (P < 0.05). The lowest pH values in the crop, proventriculus, duodenum, ileum, and ceca were observed in birds fed diets containing FWS60 and FWS120 (P < 0.05). Likewise, birds fed FWS60 and FWS120 had lower numbers of coliform and E. coli and higher Bifidobacterium and Lactobacillus count in the ceca than those fed CON (P < 0.05). Feeding FWS60 and FWS120 diets increased cecal butyrate and lactic acid contents (P < 0.05). Birds fed FWS120 diets had greater intestinal amylase and protease activity than birds fed CON (P < 0.05); however, no significant differences were recorded between the treatment groups for digestive enzymes activity in the pancreas. The use of both levels of FWS in broiler diet increased AID of crude protein and ether extract (P < 0.05). The lowest excreta ammonia concentration was recorded in birds fed FWS120 diet (P < 0.05). In conclusion, the inclusion of FWS in broiler diets could improve the performance by enhancing gut function, derived from the improved digestive enzyme activity and nutrient digestibility, as well as by elevating the population of beneficial bacteria and short-chain fatty acid contents. Therefore, the biological silage can be considered as a promising option for recycling and recovery of fish wastes and effectively be used in broiler diets.

Effect of protease derived from Pseudoalteromonas arctica supplementation on growth performance, nutrient digestibility, meat quality, noxious gas emission and blood profiles in finishing pigs.

This study was conducted to evaluate the effects of dietary supplementation of protease derived from Pseudoalteromonas arctica (PPA) in finishing pigs. A total of 160 pigs were used in this 10-week trial. Dietary treatment groups were as follows: CON (basal diet); TRT1 (basal diet+0.1% PPA); TRT2 (basal diet+0.2% PPA); and TRT3 (basal diet+0.3% PPA). During weeks 1-5, pigs fed with different levels of PPA-supplemented diet showed linear increase (p<.05) in the apparent total tract digestibility (ATTD) of nitrogen (N) and linear decrease (p<.05) in the concentrations of serum total protein. During weeks 6-10, pigs fed with different levels of PPA-supplemented diet showed a linear decrease in feed conversion ratio (p<.05). During the overall period, there was a linear decrease in feed conversion ratio (p<.05) associated with the inclusion of PPA. Pigs fed diets with 0.2% PPA supplementation had lower (p<.05) feed conversion ratio than those fed CON diet during weeks 6-10 and the overall period, and had higher (p<.05) ATTD of N than those fed CON diet during weeks 1-5. Pigs fed diets with PPA supplementation had lower (p<.05) concentrations of serum total protein than those fed CON diet on week 5. In conclusion, dietary supplementation with PPA diet has beneficial effects on growth performance, nutrient digestibility, backfat thickness and the concentrations of serum total protein.

A new high-voltage H2S single noxious gas reliability test for power modules

The impact of H2S on the corrosion of Cu electrodes under applied bias is investigated for a test structure that simulates the conditions in a power module. Growth of Cu sulphide dendrites is identified as the predominant aging mechanism, and the influence of the main impact parameters such as humidity, concentration and voltage is modelled. The concept of reactivity monitoring of Cu coupons is applied to a proposed test condition, and the acceleration compared to a standardized operational condition is explained.

Evaluation of Weissella Cibaria JW15 Probiotic Derived from Fermented Korean Vegetable Product Supplementation in Diet on Performance Characteristics in Adult Beagle Dog.

Simple SummaryDogs are the most popular companion animals worldwide, and their popularity is still increasing. Maintaining health and seeking optimal nutritional feed for dogs is an important component of responsible pet ownership. Probiotics have been widely used in animals; however, little research exists on some probiotic species which have been reported to have good probiotic properties. The present study investigated the effects of Weissella cibaria JW 15 isolated from the traditional Korean fermented vegetable product (kimchi) as a probiotic feed additive on the nutrition and health characteristics in the adult Beagle dogs. The results of this study indicated that Weissella cibaria probiotics have beneficial effects in dogs, which provide evidence and insight for the application of probiotics in dogs.This study was conducted to evaluate the effects of dietary supplementation of Weissella cibaria JW15 (WJW15) isolated from traditional Korean fermented vegetable product (kimchi) as a probiotic feed additive on nutrient digestibility, blood profiles, feces noxious gas emission, and feces Escherichia coli and Lactobacillus counts in adult Beagle dogs. In total, 15 Beagle dogs with an average initial body weight of 10.20 ± 0.38 kg were randomly assigned into three dietary treatments in a 14-day feeding trial. Dietary treatments consisted of basal diet (CON); MJW = CON + 50 g of WJW15 (3.0 × 108 cfu/g); and BJW = CON + 50 g WJW15 (3.0 × 109 cfu/g). At the end of the experiment, the serum concentration of triglycerides and feces ammonia emissions were decreased (P < 0.05) with the increasing level of WJW15 supplementation. High-density lipoprotein cholesterol in serum and feces lactic acid bacteria count was improved (P < 0.05) with increasing levels of WJW15. In conclusion, WJW15 isolated from kimchi supplementation in adult Beagle dog diet may have beneficial effects as a probiotic feed additive.

Boron-doped graphene coated Au@SnO2 for high-performance triethylamine gas detection

Confronted with challenges in obtaining lower power consumption and higher gas response for triethylamine (TEA) gas detection, it becomes very important to rational induce heterointerface to enhance gas-sensing properties. In this work, we demonstrate that the boron-doped reduced graphene oxide (B-RGO) coated Au@SnO2 heterostructure is using as the sensor material for TEA gas detection with a response of 69.1% for 1 ppm of TEA gas at low working temperature (100 °C). With the wrapping of B-RGO, the response value of the Au@SnO2-based sensor for TEA detection is boosted by 5.6 times and a detection limit of ppb (parts per billion) level is achieved. The sensors are selectively sensitive to TEA gas, which is about 10 times higher than the response to the other four gases. The outstanding sensing performance is mainly attributed to the synergistic effect of the B-RGO/SnO2 and Au/SnO2 heterostructure. The present work shows that heterostructure engineering together with boron-doped graphene has excellent potential for promoting highly selective and low concentration noxious gas sensing detection.

A comparative evaluation of fermented and unfermented soybean and guar meal on growth performance, nutrient retention, caecal microflora, and excreta gas emission of broiler chickens

Abstract This experiment was conducted to evaluate the possibility of a 10% replacement of soy bean meal (SBM) with guar meal (GM) in broiler diets and the effects of fermentation of SBM and GM with Bacillus subtilis. A total of 384 Ross 308 (1-d old) broilers were selected for 4 treatments, with 6 replications, and 16 broilers per replication for 35 d. Experimental treatments consisted of a 2 × 2 factorial design with the following factors: i) two protein sources (SBM or GM), and ii) 10% of the SBM resp. GM fermented with B. subtilis. The results showed that broilers fed SBM or fermented diets showed improved body weight gain and feed conversion ratio compared to those fed GM ( P<Â 0.05). The nutrient retention of dry matter, nitrogen, and energy of broilers fed SBM or fermented diets were higher than those fed GM ( P<Â 0.05). The caecal microflora counts were improved (increased Lactobacillus and decreased coliforms) with the addition of fermented diets ( P<Â 0.05). Ammonia gas emission in the fermented treatments was lower than that in the unfermented treatments ( P<Â 0.05). Together, these findings suggest that adding SBM and GM fermented with Bacillus subtilis in the diet can improve growth performance and nutrient retention and decrease excreta noxious gas emission. Finally, GM fermented with Bacillus subtilis could replace SBM by 10% with no adverse effect on broiler performance.

An excellent heterojunction nanocomposite solar-energy material for photocatalytic transformation of hydrogen sulfide pollutant to hydrogen fuel and elemental sulfur: A mechanistic insight

Hydrogen sulfide (H2S) is a noxious gas for living organisms and devastating/corrosive agent for metallic structures, which is generated in large scale through natural [geothermal/bacterial] activities or industrial processes, particularly by petroleum and gas industries. Photocatalytic elimination of this plentiful-perilous pollutant and its transformation into hydrogen green fuel and elemental sulfur is a novel/sustainable strategy, which is intriguing from energy and environmental science as well as technological viewpoints. To this end, the design and synthesis of low-price, environmentally friendly, effective photocatalyst/solar-energy materials are highly in demand. Herein, through a facile hydrothermal route, a set of new pn junction xBi2S3·yMnS nanocomposite photocatalysts were synthesized and employed in an alkaline H2S medium (pH = 11) to generate hydrogen fuel and elemental sulfur under atmospheric pressure at room temperature conditions. The maximum conversion yield was attained at the molar ratio xy=2, where the photocatalyst exhibited the lowest charge recombination, strong photon absorption, and the greatest surface area among the synthesized nanocomposite materials. Furthermore, it was witnessed that disulfide (S22-) was the only oxidation product in the reaction medium, which could be effortlessly precipitated as elemental sulfur by acidification of the medium and lowering the pH to about 5.

Axial-Swept Influence on Inner Flow Performance of HP Steam Turbine Based on CFD

Swept blade technology was used to redesign the supercritical steam turbine sets that could improve the inner-efficiency of turbine sets and decrease the consumption of coal the noxious gas such as NOx. The eighth high-pressure stages, including static and rotor cascades, were selected as tested prototypes that were blew in the low-velocity wind tunnel. We used the five-hole ball head needle to measure the aerodynamic parameters distribution along the width and span direction of the high-pressure stage cascades. With the inkblot display technology, the limit flow spectrums were displaced in the blade surface and the endwalls. These tested data could be used to check the simulation results of CFD software. To improve the efficiency of the steam turbine high-pressure (HP) stage, we selected the supercritical steam turbine HP stage cascade blade as the prototype to research into its inner flow performance of the axial-swept blade by the CFD software. Two different redesigned blades, with ±20°, swept angle, and 30% swept height, named axial fore-swept and axial aft-swept, were built up. The stage passages flow field of the prototype blade, and the two redesigned swept blades were simulated using CFD software with stage interface planes between the stages. The CFD simulation results indicated that the leading edge of swept blades influenced the inlet flow field; the pressure in aft-swept blade stage in both endwalls was higher than in the middle and was beneficial to improve the passage flow properties of HP stage. But for the fore-swept HP stage, its pressure distribution was lower in both endwalls than in the middle and not beneficial to passage flow.

Continuous photocatalytic mitigation of indoor noxious gases over a Z-scheme g-C3N4/V2O5 monolithic structure

A Z-scheme g-C3N4/V2O5 heterostructure was freshly applied to the removal of indoor noxious gases. In addition, to continuously remove noxious organic gases with minimal photocatalyst loss in a steady-flow chamber, the Z-scheme g-C3N4/V2O5 photocatalytic system having a three-dimensional monolithic structure was realized by immobilizing the photocatalytic nanocomposite powder into a melamine sponge. The g-C3N4/V2O5 monolith (CN/VOM) exhibited the best photocatalytic capability, followed in order by the g-C3N4 and V2O5 ones; specifically, the nonanaldehyde removal efficiency over the CN/VOM photocatalyst was as high as 97% under certain experimental conditions. The removal efficiency patterns of these three photocatalytic systems were consistent with their photoelectrochemical properties. In addition, a reusability test revealed prominent photocatalytic stability of the CN/VOM system, which was supported by X-ray diffraction analysis of used and unused samples. The good capability and stability of the CN/VOM were ascribable to its elevated charge-separation ability given by the Z-scheme charge transmission process at the interfaces between g-C3N4 and V2O5. The effects of the V2O5 content and the pollutant feed concentration on the CN/VOM photocatalytic performance were also investigated; a Z-scheme process was defined in the removal of gas pollutants over these CN/VOM systems. This study demonstrates that improved photocatalytic performance of designed materials in the removal of model pollutants can expedite the development of upcoming photocatalytic systems for the continuous removal of noxious organic gas gases without significant photocatalyst losses.

Effects of partial and total substitution of dietary spray-dried porcine plasma (SDPP) with spray-dried krill hydrolysate (SDKH) on growth performance, nutrient digestibility, and noxious gas emission in weaning piglets

The aim of this study was to evaluate the effects of partial replacement of spray-dried porcine protein (SDPP) with spray-dried krill hydrolysate (SDKH) on growth performance, nutrient digestibility, noxious gas emission, fecal score, blood profile of post-weaning piglets during the first 2 weeks, and the subsequent impact of these criteria on weaned piglets. A total of 200 crossbred piglets [(Duroc × Yorkshire) × Landrace] weaned at day 21with an initial BW of 6.85 ± 1.00 kg was allocated into 1 of the following 5 dietary treatments: 1) CON, Phase 1(Basal diet without plasma protein); TRT1, Phase 1 (4% Plasma protein); 3) TRT2, Phase 1 (3% Plasma protein + 1% SDKH); 4) TRT3, Phase 1 (2% Plasma protein + 2% SDKH); 4) TRT4 (4% SDKH) in this 6-week feeding trial. During phase 2, all the piglets were fed the same diets. (Phase 1: 0–2nd week; Phase 2: 3rd-6th week). For each treatment, 8 replication pens consisting of five pigs (3 barrows and 2 gilts) per pen were used in a randomized complete block design. In phase 1, the weaned piglets fed the diets containing 4% SPDD had greater BW than the ones fed other treatment diets (P < 0.05), and the weaned piglets fed the diets formulated with 1, 2 or 4% SDKH showed bigger BW than that fed CON diet (P < 0.05). In phase 1 and the end of this trial, the highest ADG was found in Trt 1 and the lowest ADG was detected in CON treatment (P < 0.05). There was no significant difference in ADG in piglets fed other diets (P > 0.05). Similarly, in phase 1, the piglets fed the 4% SDPP showed a better nitrogen digestibility compared to the ones fed other dietary treatments (P < 0.05). Trt.2 and Trt.3 revealed a greater nitrogen digestibility than Trt.4 and CON (P < 0.05). The Blood Urea Nitrogen (BUN) concentration decreased with increasing SDPP inclusion level (P < 0.05). SDKH treatment showed a lower BUN concentration than CON (P < 0.05). No significant difference was observed in fecal score, intestinal E. coli and Lactobacilli and noxious gas emission throughout the trial (P > 0.05). In conclusion, dietary SDPP could not be partially or totally replaced by SDKH because of the negative effect on growth performance and nutrient digestibility in weaning pig.

Reversible and irreversible magnetocaloric effect: The cases of rare-earth intermetallics YbPt2Sn and Ce0.5La0.5B6

Abstract Magnetocaloric effect (MCE) has drawn much attention because its magnetic cooling property enables refrigeration without producing noxious gas or using rapidly depleting resources. However, applications for everyday life are yet distant. In addition, we need to understand more about the practical aspect of the MCE. Here, we introduce a phenomenological model to explain the quasi-adiabatic MCE. Correction factors to the equilibrium thermodynamic feature implied by the entropy landscape are devised in analytic forms. To demonstrate the validity of the model, the MCE from two different materials is investigated. The recently discovered metallic paramagnet, YbPt 2 Sn, shows a linear and reversible MCE which is typical of a paramagnetic system and suitable for cryogenics without 3He. On the other hand, a complex-phase material, Ce 0.5 La 0.5 B 6 , exhibits a pronounced irreversible MCE especially across a magnetic phase boundary. A term that describes the field induced heating near a phase transition turns out to be essential in resolving the irreversible, non-equilibrium MCE.

Drywall Waste Blocks: A Novel Masonry Material Utilizing Recycled Construction &amp; Demolition Waste

This paper describes patent-pending mixtures and methods for producing masonry blocks using gypsum drywall waste and preliminary investigation of Drywall Waste Block (DWB) engineering properties. Recycling waste from building construction and demolition (C&amp;D) provides many environmental and economic benefits. However, challenges remain for recycling certain low-value C&amp;D materials, such as gypsum drywall waste, and there are few uses for drywall waste from demolition, which constitutes the majority of the drywall waste stream. Recycling drywall waste is desirable as this waste produces noxious hydrogen sulphide gas in landfill conditions, resulting in bans on landfilled drywall waste in some localities. Investigation of compressive strength, water absorption, and thermal performance of DWB specimens is described, and results are compared to specifications for concrete masonry units (CMU), and other comparable masonry blocks. Technical gaps for DWB to be recognized as a CMU alternative are also discussed.

Tailoring fibre lengths to fabricate a highly permeable SiC fibre porous medium for more efficient combustion

Traditional ceramic foam and metal fibre media combustion were usually restricted owing to their intrinsic brittleness and easy corrosion, respectively. In order to obtain higher gas permeability, longer durability, and less noxious gas emissions for gas flame combustion, a novel SiC fibre porous medium (FPM) is investigated in this study. SiC fibre mat were firstly produced from chopped SiC fibres using solution dispersion and vacuum filtration, then a boron nitride interphase for antioxidation and subsequent SiC coating for rigidity were deposited by chemical vapor infiltration, resulted in the formation of self-supporting SiC FPM. Findings demonstrate that the microstructure, gas permeability, thermal physical and combustion properties of SiC FPM can be improved by tailoring fibre length. As the fibre length was 4.5 mm, the density of SiC FPM was 0.113 g/cm3, and it exhibited excellent properties in permeability and utilization of fuel gas, pollutant emissions and combustion temperature accompanied by slight reduction in thermal conductivity. Such ultra-light SiC FPM could respond fast during the heating process and help gas mixture burn off.

Premises of Sustainable Development Concept Occurence

Abstract It has long been considered that the environment can withstand all the pressure exerted by human activities on it: extensive agriculture, pesticide use, strong industrialization, noxious gas emissions into the atmosphere, toxic product discharge into lakes, rivers, seas and oceans, massive deforestation to obtain new areas for housing or agriculture. The result was environmental and soil degradation, increased water and/or air pollution, climate change, biodiversity loss, the disappearance of plant and/or animal species, the depletion of some natural resources. These environmental changes have begun to be studied by specialists in the field, who have raised a flag to irreversible environmental changes. The concept of “sustainable development” arose at a time when environmental issues were at the heart of political debate: sustainable development is seen as a complex and difficult issue to solve because there is a diversity of interests of different states. International agreements and cooperation from the point of view of globalization and economic harmonization have also had as their object the issues of sustainable development, by launching the attempt to reconcile the economy with the environment.

Effects of multi-enzyme supplementation in a corn and soybean meal-based diet on growth performance, apparent digestibility, blood characteristics, fecal microbes and noxious gas emission in growing pigs

Effects of multi-enzyme supplementation in a corn and soybean meal-based diet on growth performance, apparent digestibility, blood characteristics, fecal microbes and noxious gas emission in growing pigs

Iron Carbide@Carbon Nanocomposites: A Tool Box of Functional Materials.

Iron carbide (Fe3C) is a ceramic magnetic material with high potential for applications in different fields, including catalysis, medicine imaging, coatings, and sensors. Despite its interesting properties, it is still somehow largely unexplored, probably due to challenging synthetic conditions. In this contribution, we present a sol-gel-based method that allows preparing different Fe3C@C nanocomposites with tailored properties for specific applications, in particular, we have focused on and discussed potential uses for adsorption of noxious gas and waste removal. Nanocomposites were prepared using readily available and “green” sources, such as urea, simple and complex sugars, and chitosan. The nanocomposite prepared from chitosan was found to be more efficient for CO2 uptake, while the sample synthetized from cellulose had optimal capability for dye absorption and waste oil removal from water.

Effects of Salicornia herbacea on Growth Performance, Meat Quality, Excreta Microbial Populations, and Noxious Gas Emissions in Broiler Chicks.

The current study was conducted to evaluate the effects of adding Salicornia herbacea extracts to the drinking water on the growth performance, meat quality, excreta microbial population, and noxious gas emission in broiler chicks. A total of 544 one-day-old broiler chicks (Ross 308) were used in a 35-d experiment. Broiler chicks were allocated to four treatments with eight replicates, based on a completely randomized design. Diet was the same for all treatments, but a liquid phytogenic supplementation using different quantities of S. herbacea was provided in the drinking water as follows: control (CON), with no S. herbacea; 1 cc/L S. herbacea (SAL1); 5 cc/L S. herbacea(SAL2); and 10 cc/L S. herbacea (SAL3). During d 22–35, and d 1–35, broilers supplemented with S. herbacea extracts had a higher body weight gain (BWG) compared with the broilers in the CON group (P<0.05), but broilers supplemented with S. herbacea extracts had a lower feed conversion ratio (FCR) when compared with broilers in the CON group (P<0.05). Supplementation with S. herbacea extracts had linear effects on the abdominal fat and the redness (a*) of meat (P<0.05). There were no significant differences between excreta microbial populations and excreta noxious gas emissions in broilers in the CON group, or broilers supplemented with S. herbacea extracts. In conclusion, the results of this study demonstrate that S. herbacea supplementation positively affected the growth performance and meat quality in broilers, indicating that S. herbacea can be safely used to replace antibiotic as a growth promoter, thereby reducing the risk of antibiotic resistance issues.

Evaluation of effect of probiotics mixture supplementation on growth performance, nutrient digestibility, faecal bacterial enumeration, and noxious gas emission in weaning pigs

A total of 180 twenty-eight-day-old weaning pigs [Duroc × (Yorkshire × Landrace)] with an average body weight of 7.62 ± 1.25 kg were used in a 42-day trial to evaluate the effect of probiotics mixture supplementation on weaning pigs. Pigs were randomly allotted to one of four dietary treatments: (1) CON, basal diet, (2) T1, CON + 0.1% probiotics mixture, (3) T2, CON + 0.2% probiotics mixture, and (4) T4, CON + 0.3% probiotics mixture. Increasing dietary inclusion of probiotics mixture levels linearly increased average daily gain (ADG) and average daily feed intake (ADFI) during day 0–7 as well as ADG and gain to feed ratio (G:F) during day 8–21 (p < .05). There was a quadratic effect in improving ADFI during day 0–7, day 22–42, and ADG during day 8–21 (p < .05). In addition, increasing inclusion of probiotics mixture levels in the diets linearly increased (p < .05) dry matter (DM), nitrogen (N), energy digestibility, and faecal Lactobacillus counts and decreased Escherichia coli counts and ammonia (NH3) emission. However, no significant differences were observed in ADG, ADFI, G:F during day 22–42, and day 0–42 except for a quadratic increase of ADFI for day 22-42 (p < .05). Feeding the pigs with the diets containing different probiotics mixture levels did not affect the faecal hydrogen sulfide emission (p>.05). In conclusion, increasing inclusion of probiotics mixture up to 0.3% linearly improved growth performance during day 0–7 and day 8–21. Pigs fed the diets with probiotics mixture suplementation improved the nutrient digestibility, faecal bacterial enumeration, and decreased NH3 emission.HighlightsProbiotics mixture supplementation increased growth performance and nutrient digestibility in weaning pigs.Increased fecal Lactobacillus and reduced E. coli counts.Reduced fecal ammonia emission that can contribute in reducing environmental pollution.