NH3-N Concentration Research Articles

Effects of Saccharomyces cerevisiae and Bacillus subtilis on in vitro fermentation in the rumen of Hu sheep.

The demand for animal products is increasing in developing countries due to population growth. However, livestock production contributes significantly to global warming, accounting for 25%. Probiotics can help improve livestock efficiency by enhancing gut microbes and fat metabolism. They can modify rumen populations, enhance fermentation, reduce methane emissions and improve feed digestion. In this study, the goal was to determine the most effective method of reducing methane emissions in the rumen of sheep in vitro by adding different concentrations of Saccharomyces cerevisiae and Bacillus subtilis. Adding 8 × 106 CFU g-1 S. cerevisiae during fermentation reduced pH levels after 48 h. This also increased the concentrations of NH3-N, microbial protein and total gas production. At the same time, it decreased methane emissions. Furthermore, adding 20 × 106 CFU g-1 B. subtilis to the mixture increased total gas production (TGP) and methane production, with the highest production observed after 48 h. However, it did not affect pH levels after 48 h. It can be concluded that S. cerevisiae had significantly increased microbial protein and NH3-N concentrations after fermentation without altering pH. Additionally, the addition of S. cerevisiae enhanced TGP and reduced methane emissions. It is worth noting that TGP increased because B. subtilis was added at a concentration of 20 × 106 CFU g-1, with no significant differences between concentrations. Therefore, we recommend adding S. cerevisiae and B. subtilis to the diet at doses of 8 and 20 × 106 CFU g-1, as it resulted in higher TGP and reduced methane emissions. © 2024 Society of Chemical Industry.

Effect of Ensiling Density on Fermentation Characteristics and Aerobic Stability of Pennisetum giganteum Silages

The current work aimed to evaluate the effect of ensiling density on the fermentation quality and aerobic stability of Pennisetum giganteum silages. The silage was ensiled in laboratory silos (1 L), and three treatments were designed according to different ensiling densities: (1) low density (LD, 750 kg/m3); (2) medium density (MD, 900 kg/m3); and (3) high density (HD, 1050 kg/m3). During ensiling, the silage was sampled for a fermentation quality analysis. All silages were well preserved, as indicated by the high lactic acid (LA) content and low pH (<4.2). The MD treatment had the highest acetic acid content (24.9 g/kg dry matter) and the HD treatment had the lowest ammonia nitrogen (NH3-N) content (68.2 g/kg total nitrogen, TN) among all silages after 45 days of ensiling. The aerobic stability of HD, MD, and LD persisted for 51 h, 54 h, and 48 h, respectively. The NH3-N contents of HD and MD were below 80 g/kg TN during aerobic exposure. These results show that the increase in ensiling density improved the fermentation quality and aerobic stability of Pennisetum giganteum silages.

Use Of Ginger (Zingiber Officinale Roscoe) In The Diet Of Confined Sheep

The objective of this study was to evaluate the inclusion of ginger (0.0%, 0.2%, 0.4% and 0.6%) in the diet of sheep as a natural additive on the intake and digestibility of nutrients, in addition to ruminal parameters. Four mixed breed sheep with an initial body weight of 25 kg were used, distributed in a Latin square experimental design (4x4). The diets were balanced with 12.0% crude protein (isoprotein) and 69.5% total digestible nutrients (isoenergetic). The studied variables were subjected to analysis of variance and the observed differences were determined by regression analysis considering 5% significance. The mean values obtained for the intake values expressed in kg animal-1 day-1 for DM; OM; CP; EE, NDF; ADF; TCH and CNF were 0.64; 0.60; 0.058; 0.011; 0.29; 0.19; 0.51; and 0.22, respectively. The mean values of the nutrient digestibility coefficients were 51.59; 64.92; 55.97; 76.86; 39.73; 30.68; 52.54; and 69.50%, respectively, for DM, OM, CP, EE, NDF, ADF, TCH, and NFC. No interaction effect was observed for the pH of the ruminal fluid; however, the pH value differed in relation to time. The concentration of N-NH3 in the ruminal fluid differed. The inclusion of up to 0.6% ginger in the diet of confined sheep does not alter the values of intake and nutrient digestibility coefficient; however, the inclusion of 0.4% ginger allows a higher concentration of N-NH3 in the ruminal fluid in the time interval of 2h12min after feeding, requiring the inclusion of rapidly fermented carbohydrates in the diet

Effects of Storage Time and Temperature on the Fermentation Characteristics of Rumen Fluid from a High-Forage Diet

The objective of this experiment was to investigate the effects of storage temperature and preservation time on the fermentation characteristics of rumen fluid collected from six Hu sheep fed a high-forage diet. The storage temperatures were set at −80 °C and −20 °C, and the preservation times were labelled as follows: 0 d (fresh rumen fluid, D0), 7 d (D7), 14 d (D14), 30 d (D30), 60 d (D60), 120 d (D120), and 240 d (D240). A repeated-measures design was applied to analyze the fermentation characteristics of rumen fluid across each preservation time point and storage temperature. The results showed that storage temperature had no significant effects on pH value, ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acid (VFA) concentration and proportion (p > 0.05). Specifically, the pH value increased on D7, D14, and D60 (p < 0.05), while the MCP concentration decreased on D7, D14, D30, D120, and D240 but increased on D60 (p < 0.05), and the concentration of NH3-N decreased on D14 (p < 0.05). The acetate concentration increased on D30, while the concentrations of propionate, butyrate, valerate, and total VFA increased on D60 (p < 0.05). The concentration of isovalerate decreased on D60, and isobutyrate and branched-chain VFA concentrations decreased on D120 (p < 0.05). The proportion of acetate increased on D30, while the butyrate and valerate proportions increased on D60, and the proportions of isovalerate, isobutyrate, and branched-chain VFA decreased on D60 (p < 0.05). For rumen fluid from a high-forage diet, the storage temperature (−80 °C and −20 °C) did not affect its fermentation characteristics, suggesting that rumen fluid could be preserved at −80 °C or −20 °C without altering its fermentation characteristics. The fermentation parameters of rumen fluid changed significantly after 7 days of preservation; hence, it is recommended to finish determining the fermentation parameters of rumen fluid within 7 days of collection. The concentrations and proportions of most VFA changed after 30 days of preservation; therefore, it is recommended that VFA determination should be completed within 30 days of rumen fluid collection.

Hydrochemical processes and inorganic nitrogen sources of shallow groundwater in the Sanjiang Plain, northeast China.

This study investigates the chemical characteristics, formation, and sources of inorganic nitrogen (IN) of shallow groundwater across the Sanjiang Plain, aiming to enhance drinking water safety management and pollution control. A total of 167 groundwater and 27 surface water samples were collected for constituents and isotopes (H2 and O18). The hydrogeochemical characteristics showed that the major type is HCO3- Ca·Mg, with low total dissolved solids and a neutral to weak alkaline nature. Rock weathering processes govern the hydrochemical composition of groundwater. Hydrogen and oxygen stable isotopes analyses revealed that precipitation serves as the main water source. In alluvial areas, oxidative conditions lead to the enrichment of NO3-N concentrations, with sewage, manure, and fertilizers being the primary IN sources. In lacustrine areas, intensive rice cultivation results in reductive conditions and strong denitrification processes, causing the loss of NO3-N and leaving NH4-N as the dominant IN form. Organic matter mineralization is likely a more significant contributor to NH4-N concentrations than ammonium fertilizers. These findings provide valuable information for further research on natural sources and groundwater pollution in areas with similar hydrogeological conditions. PRACTITIONER POINTS: Rock weathering processes govern the hydrochemical composition of groundwater, and precipitation serves as the main water source. In alluvial areas, oxidative conditions lead to the enrichment of NO3-N. In lacustrine areas, intensive rice cultivation results in reductive conditions and strong denitrification processes. Organic matter mineralization is likely a more significant contributor to NH4-N concentrations than ammonium fertilizers. These findings provide references for water management and information for further research on natural sources and groundwater pollution in areas with similar hydrogeological conditions.

Study of an electrochemical system with dual cathodes for the treatment of mariculture wastewater

The salinity properties of mariculture wastewater make it a suitable candidate for electrochemical treatment. In this study, an electro-Fenton synergistic electrocatalytic system was developed using a mixed metal oxide anode, often called Dimensionally Stable Anodes (DSA), and dual cathodes, an iron-carrying activated carbon sheet as the first cathode and a stainless-steel plate as the second cathode, to treat mariculture wastewater. The reaction conditions of the system were investigated and optimized. The chemical oxygen demand (COD) removal rate reached 100 % after 80 min under the optimal conditions: an applied voltage of 3.39 V, a plate spacing of 1.07 cm, and an aeration rate of 34.84 L·h−1. The system effectively removed COD and nitrogen from mariculture wastewater. Analyses using GC–MS, UV–visible spectroscopy, and Fourier-transform infrared spectroscopy showed that the system could degrade macromolecular organic pollutants in the wastewater. Mechanistic studies revealed that active chlorine and hydroxyl radicals play crucial roles in pollutant removal. The dynamic operation study indicated that the optimal operating conditions included a vertical water flow direction through the electrodes, and a flow rate of 10 mL·min−1. The oxidant reuse experiment determined a reflux ratio of 1:1 and a reaction time of 60 min, achieving effluent COD and NH3-N concentrations that met the primary discharge standards. The study on residual chlorine removal showed that the input amount of sodium thiosulfate was 0.36 kg, with a treatment cost of 0.32 yuan per ton of water, and the treated effluent met the discharge standards. These results provide a reference for the industrial application of electrochemical methods in treating mariculture wastewater.

Feeding almond hulls to light lambs: Effects on growth performance, digestive utilization and blood metabolites

The effects of including almond hulls (AH) in the concentrate fed to light lambs on animal performance, diet utilization, and blood metabolites. Three isonitrogenous and isoenergetic concentrates were formulated with either 0 (control), 6 (AH6) or 12 (AH12) g of AH per 100 g (fresh matter basis). Thirty Manchega breed lambs (15 males and 15 females; 12.3 ± 0.18 kg body weight (BW)) were distributed into six homogeneous groups according to BW (3 groups of each sex), which were randomly assigned within sex to each experimental concentrate. Lambs were fed concentrate and barley straw ad libitum until reaching about 23.0 kg BW. There were no differences (P ≥ 0.182) between groups in final BW, intake of concentrate and straw, and feed conversion rate. Average daily gain and digestibility of dry matter and crude protein tended (P < 0.10) to decrease by the AH inclusion in the concentrate. Lambs fed AH12 showed greater (P < 0.05) urinary losses than those fed the control concentrate (15.4 and 11.5 g per 100 g of N intake, respectively), despite the similar N intake in all groups. Feeding AH did not affect (P ≥ 0.213) blood concentrations of albumin, globulins, urea, creatinine, glucose, total bilirubin and cholesterol or blood activities of hepatic enzymes. The post-mortem analysis revealed no differences among groups in pH and total volatile fatty acids (VFA) concentrations in the rumen of lambs, but NH3-N concentrations were lower (P < 0.05) in the lambs fed the concentrates with AH. In addition, lambs fed AH12 diet had lower (P < 0.05) molar proportions of propionate and greater (P < 0.05) proportions of butyrate compared with lambs fed control and AH6 concentrate. In general, no concentrate x sex interactions were observed, and sex had no effect on the measured parameters except for some differences in ruminal VFA profile. In conclusion, AH can be included at in light lambs’ concentrate up to 12 g per 100 g of concentrate without impairing animal growth.

Seasonal and interannual variations of nutrients in the Subei Shoal and their implication for the world's largest green tide

The world's largest “green tide” (Ulva prolifera) has occurred every year since 2007 in the Yellow Sea. The Subei Shoal area is thought to be the origin of the green tide. Based on field data from 2016 to 2023, seasonal and interannual variations of dissolved nutrients and their ecological effects in the Subei Shoal were analyzed. Spatial distribution of dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) and dissolved silicate (DSi) showed clear terrestrial sources, while ammonia (NH4-N) and dissolved organic nitrogen (DON) were not solely controlled by terrestrial sources. The seasonal variations of NH4-N, DIN, DON, DIP and DSi concentrations were significant, and the interannual variations of DIN, DON, DIP and DSi concentrations showed general decreasing trends from 2016 to 2023. The key factors affecting the seasonal and interannual variations of DIN and DIP concentrations were terrestrial input, aquaculture wastewater discharge, atmospheric deposition, submarine groundwater discharge and macroalgae absorption, while the dominant factor determining the variations of DSi concentrations was terrestrial input. NH4-N and DON concentrations were mainly influenced by aquaculture wastewater discharge and the absorption and release of macroalgae. The high nutrient concentrations in the Subei Shoal throughout the year provided sufficient material basis for the growth of Ulva prolifera in the source area of green tide outbreak.

Effects of sanitary conditions with lipopolysaccharide injection and dietary valine supplementation on growth performance, immune response, bacterial profile, and microbial metabolites in weaned pigs

ABSTRACT This study investigated the effects of dietary L-valine (Val) supplementation and sanitary conditions with lipopolysaccharide injection on growth performance, immune response, and intestinal bacterial profiles and metabolites in weaned pigs. Thirty-two weaned pigs (6.98 ± 0.47 kg) were randomly assigned to treatments in a 2 × 2 factorial arrangement based on dietary Val levels and sanitary conditions (low or high). The pigs were fed either a basal diet containing the standard levels of Val suggested by (NRC), (2012) or a basal diet supplemented with 0.1% L-Val. A room designated as a high sanitary room was washed weekly, whereas the designated low sanitary room was not washed throughout the experiment and 5 kg of manure from the nursery pig barn was spread on the pen floors on day 1. All data were analysed using a mixed procedure of SAS, with the individual pen as the experimental unit. The pigs raised in low sanitary conditions exhibited a lower (p < 0.05) average daily gain, average daily feed intake, and gain-to-feed ratio and a higher (p < 0.05) incidence of diarrhoea than those raised in high sanitary conditions during the 14-d experimental period. The pigs in the low sanitary group also had a lower (p < 0.05) concentration of butyrate in the jejunum and a higher (p < 0.05) concentration of NH3-N in the colon than those in the high sanitary group. Dietary Val supplementation was reduced (p < 0.05) plasma interleukin (IL)-1β and IL-1 receptor antagonist concentrations as well as isovalerate and NH3-N concentrations in the colon, regardless of sanitary conditions. Interactions between dietary Val supplementation and sanitary conditions were observed in the abundances of mRNA-encoding β-defensins 113, 125 and 129 (p < 0.05). In conclusion, dietary Val supplementation beneficially modulates inflammatory responses and microbial metabolites regardless of sanitary conditions while transcriptional levels of β-defensins are regulated by dietary Val supplementation in a manner dependent on housing hygiene conditions.

The Anti-Methanogenic Activity of Lovastatin in Batch Cultures Using Rumen Inoculum from Sheep, Goats, and Cows

Enteric methanogenesis in ruminants is identified as one of the primary anthropogenic sources of total atmospheric methane. Recent evidence suggests that rumen methanogenesis is significantly suppressed by lovastatin. Nevertheless, it has not been reported whether the methane reduction by lovastatin depends on ruminant livestock type, nor has fiber degradability been examined. The current research aimed to analyze the in vitro effect of lovastatin on the major fermentation end-products, gas production (GP) kinetics, and fiber degradation of a forage-based diet using rumen inoculum from sheep, goats, and cows. The experiment was conducted as a 3 × 3 factorial arrangement of treatments (dose of lovastatin: 0, 80, and 160 mg/L and three inoculum sources) in a completely randomized design. The results suggested that lovastatin did not affect the GP kinetics parameters. The anti-methanogenic properties of lovastatin were variable depending on dose and inoculum source. Lovastatin demonstrated a superior methane-lowering effect in sheep rumen inoculum compared with goat and cow inocula. The total volatile fatty acid (VFA) production was unaffected by lovastatin, but changes in acetate and valerate proportions were registered. Remarkably, lovastatin decreased the NH3-N concentration with goat and sheep inocula and the in vitro neutral fiber detergent (NDF) degradation for all inoculum sources.

Effect of Replacing Alfalfa Hay with Common Vetch Hay in Sheep Diets on Growth Performance, Rumen Fermentation and Rumen Microbiota.

The aim of this study was to determine whether the inclusion of 40% of common vetch (CV) hay as a feed ingredient in place of alfalfa hay (AH) would improve performance and ruminal fermentation and microbiota in fattening lambs. Twenty lambs were equally divided into two groups: control group (fed 40% AH with 20% rice straw) and CV group (fed 40% CV hay with 20% rice straw). Concerning hay quality, CV hay had greater in vitro digestibility of dry matter and neutral detergent fiber (p < 0.05) than AH. Lambs fed the CV diet had a higher average daily gain (ADG) and efficiency of feed and economy than lambs fed the control group. The NH3-N content and estimated methane produced per unit of ADG of the CV diet group were significantly lower (p < 0.05) than control group. Multiple differential microbial genera were identified, with Prevotella being the most dominant genus and a tendency towards higher (p = 0.095) in lambs offered CV diet. The higher Ruminococcus abundance (p < 0.05) was found in animals of the CV group compared to the control group. In summary, CV can be incorporated into lamb diets as a low-cost forage alternative to AH to improve feed efficiency and animal performance and to reduce methane produced per unit of ADG.

The effects of acute ammonia stress on liver antioxidant, immune and metabolic responses of juvenile yellowfin tuna (Thunnus albacares)

The impact of acute ammonia nitrogen (NH3−N) stress on the antioxidant, immune, and metabolic capabilities of the liver in juvenile yellowfin tuna (Thunnus albacares) is not yet fully understood. This study set NH3-N concentrations at 0 (natural seawater, control group), 5, and 10 mg/L, and sampled the liver at 6, 24, and 36 h for analysis. As time progresses, NH3-N exposure leads to an increase in malondialdehyde (MDA) concentrations. The activity of superoxide dismutase (SOD) and the relative expression levels of related genes, as well as the activity of immune enzymes and ATPase, decrease. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and interleukin-10 (IL-10) exhibit different fluctuation patterns. Low concentrations of NH3-N increase the activity of catalase (CAT) and glutathione peroxidase (GHS-PX) and the relative expression levels of the Na+K+-ATPase gene. The relative expression levels of the interleukin-6 receptor (IL-6r) gene show a decreasing trend. High concentrations of NH3-N decrease the activity of CAT, GSH-PX, and the relative expression levels of related genes. When the NH3-N concentration is below 5 mg/L, the stress duration should not exceed 36 h. When the NH3-N concentration is between 5 and 10 mg/L, the stress duration should not exceed 24 h, otherwise, it will have a negative impact on the liver of the juvenile yellowfin tuna. This study provides scientific data for the artificial breeding and recirculating aquaculture of juvenile yellowfin tuna.

The Effect of Covering Corn Silage with Tomato or Apple Pomace on Fermentation Parameters and Feed Quality

The current study assessed the effects of covering corn silage with tomato or apple pomace on fermentability and feed quality. The in vitro gas production test was performed using graded 100 mL syringes. Incubation times were 3, 6, 12, 24, 48, 72, and 96 h. In vitro gas generation characteristics were significantly altered by TP (tomato pomace) and AP (apple pomace), both alone and in conjunction with PE (polyethylene) films, regardless of their presence. As a result of the effects found on NH3-N concentration, aerobic stability, and yeast activity, TP and AP have the potential to become an eco-friendly alternative to PE films. The gas production from the immediately soluble fraction (a) of corn silage was only affected when the corn silage was covered with a combination of AP and PE compared to the CPE group (p &lt; 0.001). The largest cluster includes correlations of the DOM-TDDM (r = 0.90), DOM-AA (r = 0.88), and Ash-TDDM (r = 0.86) correlations. The most substantial negative correlations were identified between DM-CO2 (r = −82), DM-Yeast (r = −0.79), and CF-DOM (r = −0.79). Nonetheless, the use of pomace as a silage cover presents an inexpensive alternative to plastic films for silage that does not have the environmental problems associated with persistent micro- and nanoplastics.

Effect of high oxalic acid intake on growth performance and digestion, blood parameters, rumen fermentation and microbial community in sheep

Oxalic acid, a crucial secondary metabolite prevalent in most plants, often constitutes an unavoidable component of the diet for grazing animals, particularly in saline-alkaline grasslands. This research focused on examining the effects of elevated oxalic acid consumption on various aspects of sheep health and metabolism, including growth performance, nutrient digestibility, blood biochemical indices, rumen fermentation, and microbial populations. Employing a single-factor experimental model, 24 six-month-old German Merino sheep (with an average body weight of 32.08 ± 3.43 kg) were systematically segregated into three distinct groups. Each group contained eight replicates, with each replicate comprising a single sheep. The diet of the experimental groups was enhanced with oxalic acid concentrations of 1 % (T1) and 2 % (T2), whereas the control group received no oxalic acid addition. Under ad libitum feeding, the duration of the experimental phase spanned a total of 60 days. Outcomes demonstrated that a 2 % oxalic acid augmentation notably diminished the sheep's daily weight gain (ADG) (P<0.05), elevated the feed conversion ratio (FCR) (P<0.05), and reduced the ruminal pH levels (P<0.05), compared to both control group and 1 % oxalic acid group. This pH reduction markedly curtailed the synthesis of essential ruminal constituents such as acetic acid, propionic acid, and butyric acid (P<0.05). Furthermore, there was a notable decline in serum alkaline phosphatase (ALP) levels, alongside rises in both blood urea nitrogen (BUN) and serum creatinine (CREA)(P<0.05), coupled with a significant reduction in serum calcium concentrations (P<0.05) in 2 % oxalic acid group, compared to both control group and 1 % oxalic acid group. Moreover, the 2 % oxalic acid addition adversely impacted the digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF), as well as the concentration of NH3-N in the rumen fluid (P<0.05), compared to both control group and 1 % oxalic acid group. Pertaining to rumen microorganisms, there was a significant escalation in the relative abundance of Proteobacteria at the phylum level, contrasted by a substantial reduction in the presence of Fibrobacteres (P<0.05). At the genus level, an increased concentration of oxalic acid in the diet correlated with a pronounced decline in the relative abundance of Prevotella_1, and a substantial decrease was observed in the relative abundance of Ruminococcaceae_UCG-014 (P<0.05). In summary, while sheep can acclimate to an inclusion of 1 % oxalic acid in their diet, an augmentation of 2 % oxalic acid appears detrimental, impinging upon growth performance, fiber and crude protein (CP) digestibility, blood calcium levels, rumen pH, volatile acid content, and the microbial ecosystem within the sheep’s rumen.

Effects of Replacing Soybean Meal with Cottonseed Meal, Peanut Meal, Rapeseed Meal, or Distillers' Dried Grains with Solubles on the Growth Performance, Nutrient Digestibility, Serum Parameters, and Rumen Fermentation in Growing Lambs.

Considering the frequently large price fluctuations for soybean meal, an alternative is the increased use of locally produced high-protein ingredients. The objective of this study was to evaluate the effects of the total replacement of soybean meal with different sources of protein on the growth performance, nutrient digestibility, serum parameters, rumen fermentation parameters, and bacterial communities in growing lambs. Sixty sheep with similar body weights (38.46 ± 0.71 kg) were distributed to one of five treatments: soybean meal (SBM); cottonseed meal (COM); peanut meal (PEM); rapeseed meal (RAM); and distillers' dried grains with solubles (DDGS). The experiment lasted 62 days with a 10-day adaptation period and a 52-day growing period. The results indicated that the body weight and average daily gain were not affected by different protein sources (p > 0.05), but the dry matter intake of the SBM group was lower than that of the other groups (p < 0.05); otherwise, the feed efficiency was higher (p < 0.05). The digestion of dry matter was higher in the SBM, COM, and RAM groups than in the DDGS and PEM groups (p < 0.05). Meanwhile, compared to the other groups, the SBM group had the highest digestion of gross energy and crude protein (p < 0.05). In addition, the concentration of glutathione peroxidase was highest in the SBM group (p < 0.05). Regarding the rumen fermentation, the SBM group had the highest concentration of NH3-N (p < 0.05). The rumen bacterial community was not affected by treatments (p > 0.05). In conclusion, the total replacement of soybean meal with cottonseed, peanut, rapeseed, or DDGS reduced digestibility but did not impact the body weight or average daily gain of growing lambs and had no effect on the immune function and rumen bacterial community; thus, they can be used to substitute the soybean meal.

Application of municipal solid waste (MSW) char during rotary drum co-composting (RDC) of vegetable waste and its characterization.

Composting, a sustainable method for handling biodegradable waste constituting nearly 50% of municipal solid waste (MSW), can be enhanced by incorporating char produced from MSW pyrolysis. This study investigates the impact of MSW char (0% char-Control, 2.5% char-Trial 1, 5% char-Trial 2) on the physicochemical properties of vegetable waste compost. A thermophilic temperature range of 53.8°C was detected in Trial 2, 50.8°C in Trial 1, and 46.8°C in Control. The pH of the mixes increased at day 20 to 7.5, 7.87, and 8.2 in Control, Trial 1, and Trial 2, respectively. The highest drop of total organic carbon (TOC) and volatile solids in Trial 2 is about 21.18% and 21.02%, respectively. Total Kjeldahl nitrogen (TKN) increased, particularly in Trial 2 (2.35%), while NH4-N concentrations decreased, and phosphorus levels rose notably to 23.48mg/kg, with 2.49mg/kg available phosphorus in Trial 2. The C/N was reduced to 10 in Trial 2. Total potassium increase was highest for Trial 1 (6.9g/kg). Trial 2 had the highest overall macronutrient concentration and correspondingly showed the greatest decrease in volatile solids. Furthermore, Trial 1 demonstrated a reduction in heavy metal concentration in comparison to Control and Trial 2. Consequently, the utilization of MSW char during rotary drum composting enhances the process of composting and significantly improves compost quality, making it a sustainable waste management solution.

Feeding milk thistle (Silybum mariamum) seed powder to fattening lambs: Effects on growth performance, digestibility and rumen metabolism

This experiment was conducted to evaluate the effect of milk thistle (Silybum marianum) seed powder supplementation in the diet on weight gain, feed conversion efficiency, and physiological parameters in fattening lambs. In this experiment, thirty crossbred Shawl × Romanov male lambs were divided into three groups based on a completely randomized design. The experimental treatments included a control group receiving a diet without milk thistle seed powder (MSP), a group receiving a diet containing 1 % MSP, and a group receiving a diet containing 2 % MSP. Animals fed the diet containing 2 % MSP exhibited higher nutrient intake, average daily gain, and final body weight compared to the other treatment groups (P < 0.05). Lambs receiving the 2 % MSP diet had the most favorable feed conversion ratio (P < 0.05). The apparent digestibility of dry matter, organic matter, and crude protein was highest in lambs fed the diet containing MSP compared to the control group (P < 0.05). Ruminal NH3-N concentration and populations of total protozoa and Entodinium genus were lowest in lambs fed the MSP-containing diets (P < 0.05). The molar concentrations of acetate and valerate in the rumen fluid of lambs receiving the diet containing 2 % MSP were lower compared to the control group, while propionate concentration was higher (P < 0.05). Feeding the diet containing 2 % MSP reduced serum cholesterol, triglycerides, LDL, and liver enzyme activities compared to the control group (P < 0.05). Based on these results, supplementing lamb diets with 2 % MSP increased growth performance measures, nutrient digestibility coefficients, and reduced blood cholesterol and LDL concentrations.

Fast hydrothermal co-liquefaction of high-ash sludge and Chlorella for biocrude production

Fast hydrothermal liquefaction (HTL) shows great potential for producing biocrude. This research examined the influences of mixing ratios of sludge and Chlorella during both isothermal (300 °C, 1800 s) and fast (500 °C, 20 s) co-HTL. Adding Chlorella could efficiently retard repolymerization reaction and increase the biocrude production. The highest co-liquefaction effect was achieved from a sludge to Chlorella ratio of 2:6 by fast HTL, producing a biocrude yield of 29.65 wt%, closely approaching the calculated yield of 29.39 wt% and demonstrating an additive effect. However, for the high ash content of sludge, all isothermal and other fast HTL conditions presented an antagonistic effect on biocrude production. Meanwhile, co-liquefaction also exhibited a slight antagonistic effect on the heating value and energy recovery of biocrude, with experimental values reaching 32.73 MJ·kg−1 and 52.74 %, respectively. FT-IR and maturity analyses indicated that compared to isothermal co-HTL, fast co-HTL biocrude was more favorable for the conversion into gasoline/diesel due to its lower paleo-temperature. GC–MS analysis identified amides (isothermal co-HTL) and nitrogen heterocycles (fast co-HTL) as the dominant components, suggesting that the holding time significantly influenced the competition of Maillard and amidation reactions. Besides biocrude, the major composition of aqueous phase products (APs) was also nitrogen heterocycles. Notably, fast co-HTL induced a substantial decrease in COD, NH3-N, and TN contents of APs, reducing the discharge challenge of the by-products.

Performance and microbial community in a constructed rapid infiltration system with hydrochar and coke as filler for advanced treatment of N, N-dimethylformamide

In this study, the treatment of wastewater with N, N-dimethylformamide (DMF) was carried out by a constructed rapid infiltration system (CRIS). The decontamination efficiency of the system with different fillers was investigated and the microbial communities and metabolic pathway were also analyzed. It was indicated that the removal of COD and DMF in the hydrochar-coke group (RA) and coke group (RB) were 58.91–59.93 % and 71.89–51.46 %, respectively. Compared with the influent, the average NH3-N concentration in the effluent increased by 77.04 % and 55.09 %, and the average removal rate of NO3--N by the two group was 72.95 % and 62.04 %, respectively. The abundance of DMF-degrading Paracoccus (5.10 %, 21.01 %) in the hydrochar and coke layers in RA was higher than the coke layer of RB (0.44 %), indicating that hydrochar promoted the growth and propagation of DMF-degrading bacteria. Hydrochar promoted the expression of gene PFK (0.2113 %), GADPH (0.3038 %), IDH (0.1832 %) and MDH (0.1758 %). In nitrogen metabolism, the relative abundance of glutamine synthetase was the highest. This research provided a theoretical foundation and technical support for the treatment DMF wastewater by CRIS.

Scalable development of photocatalysis-mediated aquatic habitat restoration devices based on TiO2/graphene/BiVO4 and the application in black-odorous river treatment

A novel concept of photocatalysis-mediated aquatic habitat restoration materials (PMAHRM) has been introduced in this study. The primary objective of development lies in enhancing the aquatic habitat, indirectly fostering favorable living conditions for aquatic organisms and fostering their growth. TiO2/Graphene/BiVO4 (TGB), serving as a PMAHRM, was constructed through a hydrothermal process. The absorption wavelength extends to 504 nm. Furthermore, a PMAHRM device with a dual-function area structure based on TGB and in-situ microorganisms immobilized separately has been designed. Both sections were seamlessly integrated through the use of conductive fibers. The device demonstrates a RhB removal rate of 85.70 % under visible light. During the nearly six-month field trial for the restoration of a black-odorous river, the scalable developed TGB devices, in conjunction with Myriophyllum verticillatum, were employed to achieve comprehensive restoration outcomes. The results showed significant decreases in NH3-N, TP, and COD concentrations by 85.96 %, 77.78 % and 73.53 %. The transparent index rising 3.3 times. TN, TP, and OM concentrations of sediment decreased by 10.64 %, 9.60 % and 34.08 % respectively. The enhancement of habitat quality led to various positive biological responses. The Shannon-Wiener biodiversity index increased for plankton and zoobenthos. Furthermore, the density of Cyanophyta decreased by 57.33 %, and the emergence of a substantial population of Chlorophyta and Bacillariophyta contributed to a balance algal facies. Additionally, the average density of zooplankton increased fivefold, while the density of zoobenthos decreased slightly. PMAHRM devices, utilizing newly developed TGB materials, played a pivotal role in aquatic habitat restoration, thereby fostering the sustainable development of aquatic ecosystems.