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Simple Summary: In pig farming, maintaining an optimal temperature for nursing piglets is critical for their health and growth. Traditional localized heating methods, such as heating lamps, often lack precise temperature control, leading to energy waste and suboptimal conditions for piglets as they grow. This study developed a Programmable Logic Controller-based intelligent thermal insulation box that uses a strip heater to automatically adjust its temperature based on the piglets' age and environmental conditions. We tested the system's effectiveness by comparing it to traditional heating in terms of temperature stability, energy consumption, and piglet growth. The new system significantly improved the temperature stability, reduced energy consumption by over 50%, and enhanced piglet growth. This intelligent thermal insulation box could provide an effective, energy-saving solution for improving piglet welfare and farming efficiency. Local heating of the activity area for nursing piglets is crucial for piglet health and the energy efficiency of barn climate control. Traditional heating methods using lamps or covers lack precise control, result in significant energy waste, and cannot be dynamically adjusted according to piglet age or changing environmental temperatures. To address these issues, this study designed a Programmable Logic Controller (PLC)-based thermal insulation box for nursing piglets, utilizing a strip heater instead of the conventional round heating lamp. The design incorporates a movable thermal insulation box that dynamically adjusts the heater's power based on the real-time monitoring of environmental temperatures and target temperatures specific to piglet age. First, in a controlled laboratory environment, the study tested and compared the spatial temperature uniformity, temporal stability, and power consumption of the new thermal insulation box versus traditional heating methods. Subsequently, animal trials were conducted in a farrowing barn using eight sows with similar farrowing dates as test subjects. The new thermal insulation box was installed in one group, and the traditional heating lamp in the control group. During the trial, ambient temperature, insulation area temperature, piglet behavior, growth performance, and power consumption were recorded. The results showed that compared to the control group, the new system reduced average temperature fluctuations in the insulation area by 31.6% and spatial temperature variation by 78.3%. During animal trials, the average temperatures directly under the heater for the new system versus the control in the insulation area were 39.7 ± 0.2 °C and 30.2 ± 1.4 °C in the first week, 40.9 ± 0.5 °C and 31.6 ± 0.7 °C in the second week, and 32.3 ± 1.5 °C and 28.6 ± 1.7 °C in the third week—significantly (p < 0.05) higher in the test group. The new system also reduced total energy consumption by 58.3%. The usage rate of the thermal insulation area by piglets in the test and control groups was 47.5 ± 5.3% and 42.1 ± 6.6%. The daily weight gain of piglets in the test group was 9.8% higher than that of the control group, also significantly (p < 0.05) higher. This intelligent thermal insulation box enables precise and dynamic temperature control, reducing heating energy consumption and supporting improved piglet health and welfare. [ABSTRACT FROM AUTHOR]

C. vulgaris has a positive effect on the removal of nutrients from pig farm biogas slurry. However, swine wastewater often contains heavy metal ions, such as Cu (II), which may have impacts on the nutrient removal performance of C. vulgaris. Additionally, the heavy metal ions in wastewater can be adsorbed by microalgae. In this study, the stress effect of Cu (II) on the growth of Chlorella vulgaris, the Cu (II) removal by microalgae, and the effect of different concentrations of Cu (II) on the nutrient removal efficiency of C. vulgaris in biogas slurries were explored. The results showed that the microalgae biomass of microalgae on the sixth day of the experiment was the highest in the treatment with a Cu (II) concentration of 0.5 mg/L, which was 30.1% higher than that of the 2.5 mg/L group. C. vulgaris had higher removal efficiencies of Cu (II) at a Cu (II) concentration of 0.1~1.5 mg/L. The–OH, C=O, –COOH, and C–O groups on the surface of the algal cells play a significant role in the removal of Cu (II). The removal rates of COD, NH3–N, TN, and TP by C. vulgaris at a Cu (II) concentration of 0.5 mg/L were the highest, which were 89.0%, 53.7%, 69.6%, and 47.3%, respectively. [ABSTRACT FROM AUTHOR]

Excretion and lying are key behavioral factors that cause pen fouling, thereby affecting pig welfare, pathogen fecal–oral transmission, and air quality in pig housing. This study investigated the effect of space allowance and toy provision on the spatiotemporal distribution of pigs' excreting and lying behavior, as well as the score of floor cleanliness in finishing pig pens. A total of 144 Landrace × Yorkshire × Duroc hybrid fattening pigs were randomly assigned to 12 part-slatted pens at stocking densities of 0.75, 1.05, and 1.35 m2/pig with 12 pigs per pen, and 2 pens at each density level were provided with hanging chains and rubber stars as toys. The results showed that for the average daily gain (ADG) of the pigs, the main effect of space allowance was significant (p < 0.05). The ADG at the stocking density level of 1.35 m2/pig was significantly higher than 0.75 and 1.05 m2/pig (p < 0.05). The ADG of the pigs at a density of 0.75 m2/pig in the toys group was significantly higher than the no toys group (p < 0.05). When occupied space was limited, the provision of toys was beneficial to the growth performance of the pigs. Space allowance and toy provision did not affect the time-varying regularity of the pigs but had a certain impact on the areas where the two behaviors occurred. At a density of 1.35 m2/pig, the excreting rate in the corner areas of the slatted floor and the lying rate in the middle area of the solid floor were significantly higher than at a density of 0.75 and 1.05 m2/pig (p < 0.05). Under the conditions of this study, when the stocking density was 1.35 m2/pig and toys were provided, the average daily gain of the pigs was the highest, and the pigs excreted more in the defined excretion area, lay more in the lying area, and the cleanliness of the lying area was also higher. In the case of space constraints, the provision of toys can offset some of the adverse effects of space constraints on pig growth and pen cleanliness. [ABSTRACT FROM AUTHOR]

The purpose of this paper is centred on the kinetics of removal of main pollutants in wastewater and to compared different hydraulic loading conditions of the constructed rapid infiltration system (CRI system) in terms of removal efficiencies, effluent concentrations, mass removal rate (MRR), and the first-order removal rate coefficient (k) of COD, TOC, NH4+-N, TN, and TP. The results showed that the higher the hydraulic loading, the higher the effluent concentration. The results that synthesized hydraulic loading, effluent concentrations, removal efficiencies, and other conditions showed that the best hydraulic loading was 40 cm/d. When the hydraulic load was 40 cm/d, the effluent average concentrations of COD, TOC, NH4+-N, TN, TP, Cu2+ and the removal efficiencies were 27.31 ± 16.40 mg/L, 86.11%, 10.55 ± 5.25 mg/L, 84.64%, 0.59 ± 0.87 mg/L, 99.60%, 143.31 ± 14.77 mg/L, 7.04%, 5.64 ± 1.38 mg/L, 79.20%, and 0.13 ± 0.47 mg/L, 97.51%, respectively. According to a kinetic study of the primary pollutants, the MRR increased with an increase in the hydraulic loading, except for ammonia nitrogen. CRI-3, CRI-4 were high significant correlated with ammonia nitrogen (with R2 = 93.65% and R2 = 95.03%, respectively), while CRI-2, CRI-3, and CRI-4 were high significant correlated with total nitrogen (with R2 = 94.56%, R2 = 96.70% and R2 = 96.56% respectively). [ABSTRACT FROM AUTHOR]

In this study, an (A-R)TiO2 catalyst (ART) was prepared via the sol–gel method, and g-C3N4 (CN) was used as an amendment to prepare the g-C3N4/(A-R)TiO2 composite catalyst (ARTCN). X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, N2 adsorption–desorption curves (BET), UV–Vis diffuse absorption spectroscopy (UV–Vis DRS), and fluorescence spectroscopy (PL) were used to evaluate the structure, morphology, specific surface area, optical properties, and photocarrier separation ability of the catalysts. The results showed that when the modifier CN content was 0.5 g, the dispersion of the ARTCN composite catalyst was better, with stronger light absorption performance, and the forbidden band width was smaller. Moreover, the photogenerated electrons in the conduction band of ART transferred to the valence band of CN and combined with the holes in the valence band of CN, forming Z-type heterostructures that significantly improved the efficiency of the photogenerated electron-hole migration and separation, thus increasing the reaction rate. Gaseous and liquid ammonia were used as the target pollutants to investigate the activity of the prepared catalysts, and the results showed that the air wetness and initial concentration of ammonia had a great influence on the degradation of gaseous ammonia. When the initial concentration of ammonia was 50 mg/m3 and the flow rate of the moist air was 0.9 mL/min, the degradation rate of gaseous ammonia by ARTCN-0.5 reached 88.86%, and it had good repeatability. When the catalytic dose was 50 mg and the initial concentration of NH4+ was 100 mg/L, the degradation rate of liquid ammonia by ARTCN-0.5 was 71.60% after 3 h of reaction, and small amounts of NO3− and NO2− were generated. The superoxide anion radical (·O2−) and hydroxyl radical (·OH) were the main active components in the photocatalytic reaction process. [ABSTRACT FROM AUTHOR]

{001}TiO2/TiOF2 photocatalytic composites with a high activity {001} crystal plane were prepared by one-step hydrothermal methods using butyl titanate as a titanium source and hydrofluoric acid as a fluorine source. X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), raman spectroscopy, N2 adsorption-desorption curve (BET), UV-Vis diffuse absorption spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS), and fluorescence spectroscopy (PL) were used to evaluate the structure, morphology, specific surface area, optical properties, and photocarrier separation ability of {001}TiO2/TiOF2. Ammonia nitrogen was taken as the target pollutant, and the degradation performance of the catalyst was investigated. The results show that hydrofluoric acid improves the content of {001} crystal plane of TiO2 with high activity; it also improves the specific surface area and dispersion of the composite material and adjusts the ratio of {001}TiO2 to TiOF2 in the composite material to enhance the absorption capacity of the composite material and reduce the band gap width of the composite material. The degradation rate of ammonia nitrogen by 100 mg F15 is 93.19% when the initial concentration of ammonia nitrogen is 100 mg/L and pH is 10. Throughout the reaction process, the {001}TiO2/TiOF2 composite produces superoxide anion radical (·O2−) and hydroxyl radical (·OH) to oxidize NH3·H2O and generate N2 accompanied by a small amount of NO3− and NO2−. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM), including PM2.5 in pig houses, has received increasing attention due to the potential health risks associated with PM. At present, most studies have analyzed PM2.5 in Chinese pig houses utilizing natural ventilation. These results, however, are strongly affected by the internal structure and regional environment, thus limiting their applicability to non-mechanically ventilated pig houses. This experiment was carried out in an environmentally controlled pig house. The animal feeding operation and manure management in the house were typical for Southwest China. To reduce the influence of various environmental factors on PM2.5, the temperature and humidity in the house were maintained in a relatively stable state by using an environmental control system. The concentration of PM2.5 in the pig house was monitored, while the biological contents and chemical composition of PM2.5 were analyzed, and feed, manure, and dust particles were scanned using an electron microscope. Moreover, bacterial and fungal contents and some water-soluble ions in PM2.5 were identified. The results showed that the concentration of PM2.5 in the pig house was strongly affected by pig activity, and a phenomenon of forming secondary particles in the pig house was found, although the transformation intensity was low. The concentration of PM2.5 had negative correlations of 0.27 and 0.18 with ammonia and hydrogen sulfide, respectively. Interestingly, a stronger correlation was observed between ammonia and hydrogen sulfide and ammonia and carbon dioxide concentrations (the concentration of ammonia had stronger positive correlations with hydrogen sulfide and carbon dioxide concentrations at +0.44 and +0.59, respectively). The main potential sources of PM2.5 production were feed and manure. We speculate that manure could contribute to the broken, rough, and angular particles that formed the pig house PM2.5 that easily adhered to other components. [ABSTRACT FROM AUTHOR]

To improve the removal efficiency on hydrogen sulfide (H2S), a biofilter was developed and was made of polyvinyl chloride (PVC) pipes. The effects of three different packings (i.e., packing A, packing B, and packing C), containing different proportions of activated carbon, sawdust, wormcast, perlite, and pig manure compost, based on different biofilter parameters on H2S removal efficiency, were investigated. With the extension of running time, the H2S removal rate of packing A reached up to 90.12%, that of packing B reached a peak at 92.96%, and that of packing C was highest at 87.21%. The contribution rate of each packing at the bottom of the device was significantly greater (p < 0.01) than that of other parts, and those of the top of the devices were all greater than those of the middle of the devices. The H2S removal rate increased with greater filler layer height. The removal rate of group B increased first with humidity, and then declined, with the optimal humidity level for the removal of H2S 50-65% in this study. With the prolongation of the run, the pH of packing A was reduced from 7.1 to 5.91, while the pH of packing B and C remained within the range of 6.53-7.10. An increase was found in the number of bacteria and fungi over time. The count of bacteria in packing B and C and following a decreasing order was bottom > middle > top, whereas that for fungi was the opposite. In conclusion, it is thought that packing B (comprising wormcast + sawdust + activated carbon) is more efficient in the removal of H2S than the other packings and may thus be utilized in biofilters. These results hope to provide useful information for future related research on the removal efficiency of H2S using packings. Implications: Wormcasts use as biological filter packing to remove H2S is limited and needs yet to be explored. A comparative study on the removal efficiency of H2S using three packings showed the packings that included wormcast were more efficient than others, and showed the combined features of physical absorption and biological removal with long sustainability and good efficiency, although these were largely influenced by environmental factors and nutrient content for the microorganisms. In summary, wormcast could be utilized in biological filters in the future in related research beacuse of its good efficiency and low cost. [ABSTRACT FROM AUTHOR]