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To investigate the adsorption performance of different substrates for ammonia nitrogen in wastewater, adsorption experiments are conducted on four substrates, namely, zeolite, quartz sand, volcanic rock, and biological ceramsite, and the experimental data are analyzed using adsorption isotherms and three kinetic models. The results show that with the increasing dosage of the substrates, the adsorption capacity gradually decreases, and the removal rate gradually increases. The removal rates all show a rapid increase in the early stage (the first 14 h) and gradually reach a stable state in the later stage (after more than 48 h). The higher the concentration of ammonia nitrogen in the NH4Cl solution, the greater the unit adsorption capacity of ammonia nitrogen by the substrate, the longer the adsorption time required to reach adsorption equilibrium, the lower the total removal rate of ammonia nitrogen, and the longer it takes for the concentration of ammonia nitrogen in the substrate and solution to reach equilibrium. The adsorption capacity of zeolite to ammonia nitrogen is much higher than that of quartz sand, biological ceramsite, and volcanic rock, so zeolite is suitable as the wetland substrate. The adsorption of ammonia nitrogen by the four substrates is principally multi-molecular layer adsorption, and the adsorption phase is heterogeneous. [ABSTRACT FROM AUTHOR]

Abstract Microbial flora plays an important role in microorganism-enhanced technology. The pollutant degradation ability and viable counts of these agents are crucial to guarantee their practical application. In this study, an efficient pollutant-degrading microbial flora was screened, its medium components and culture conditions were optimized, and its effect was verified in zeolite trickling filter towers. After a 24 h culture under the optimal conditions, the viable count reached 4.76 × 109 cfu/mL, with the degradation rates of ammonia nitrogen (NH4 +-N), nitrate nitrogen (NO3 −-N), total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) increased to 93.5%, 100%, 68.3%, 32.6%, and 85%, respectively. After optimizing the feeding strategy, the concentration of viable bacteria reached 5.80 × 109 cfu/mL. In the application effect verification experiment, the degradation rates of NH4 +-N, TN, TP, and COD in the experimental group reached 96.69%, 75.18%, 73.82%, and 90.83%, respectively, showing a significant improvement compared to the results of the control group. The main components in the control group were Dokdonella, Brevundimonas, Alishewanella, Rhodobacter, Pseudoxanthomonas, and Thauera, whereas those in the experimental group were Dokdonella, Proteocatella, Rhodobacter, Dechlomonas, and Nitrospira. Proteocatella, Dechlomonas, and Nitrosra, which were unique to the experimental group, are common bacteria used for nitrogen and phosphorus removal. This explains the difference in the sewage treatment capacity between the two groups. This study provides an alternative sewage treatment microbial flora with a reasonable production cost and high degradation efficiency for NH4 +-N, TN, TP, and COD.

Introduction Pomegranate has many secondary metabolites such as tannins and phenolic compounds, which have various properties such as antimicrobial, antioxidant, anti-inflammatory, and immune system stimulating effects. The amount of tannin in pomegranate skin has been reported up to 20.6%. The limiting effects of tannins can be related to reducing the use of nutrients, especially protein, reducing growth and performance, reducing palatability and feed consumption, and reducing the activity of digestive enzymes. In addition to the anti-nutritional effects in high concentration, the positive impact of dense tannins in optimal concentration includes improving live weight gain, preventing flatulence, increasing milk production, reducing intestinal nematodes, and reducing the production of NH3-N and methane in the rumen. Therefore, the present experiment was carried out to improve the nutritional value of pomegranate peel as a tannin-containing edible material by treating it with some tannase-producing bacteria for ruminants.Materials and methods Pomegranate peel was treated with tannin-degrading bacteria including Klebsiella pneumoniae and Acinetobacter (isolated from deer rumen), Lactobacillus fermentum (isolated from Najdi goat rumen), and commercial Lactobacillus fermentum, and its nutritional value including chemical composition, digestibility, and fermentation ability alone (first experiment) or as a combination in a standard fattening lamb diet (second experiment), with two-stage digestion method and gas production test were studied. In the first experiment, five experimental treatments included 1- Pomegranate peel without treatment (control treatment), treatment 2 to 5- Pomegranate peel treated with each of the four tannin-degrading bacteria. The five treatments of the second experiment included 1- Diets containing pomegranate peel without treatment (control treatment), 2-5- Diets containing pomegranate peel treated with each of the four tannin-degrading bacteria.Results and discussion Applying tannin-degrading bacteria reduced the tannin in pomegranate peel (P

Nitrogen fertilizer supports agricultural intensification, but its manufacturing results in substantial contaminated sites. Ammonia nitrogen is the main specific pollutant in retired nitrogen fertilizer sites with potential human health and odor risks. However, few studies focus on ammonia nitrogen risk assessment at contaminated sites, particularly considering its solid-liquid partitioning process (Kd) and ammonium/ammonia equilibrium process (R) in the soil. This study took a closed nitrogen fertilizer factory site as an example and innovatively introduced Kd and R to scientifically assess the human health and odor risk of ammonia nitrogen. The risk control values (RCVs) of ammonia nitrogen based on human health and odor risk were also derived. The maximum concentration of ammonia nitrogen was 3380 mg/kg in the unsaturated soil, which was acceptable for human health because the health RCVs were 5589 ∼ 137,471 mg/kg in various scenarios. However, odor risk was unacceptable for RCVs were 296 ∼ 1111 mg/kg under excavation scenarios and 1118 ∼ 35,979 mg/kg under non-excavation scenarios. Of particular concern, introducing Kd and R in calculation increased the human health and odor RCVs by up to 27.92 times. Despite the advancements in ammonia risk assessment due to the introduction of Kd and R, odor risk during excavation remains a vital issue. These findings inform a more scientific assessment of soil ammonia risk at contaminated sites and provide valuable insights for the management and redevelopment of abandoned nitrogen fertilizer plant sites.

Polyacrylic acid/sodium alginate-based titanium dioxide (PAA/SA@TiO2) composite hydrogel has the good nitrogen removal properties in the nitrogen-containing wastewaters. Under the optimal adsorption conditions, which include pH 7, temperature 35°C, adsorbent dosage 6 g/L, adsorption equilibrium time 70 min, the adsorption efficiency is 85.56%, 79.46%, and 67.63% when the initial ammonia nitrogen concentrations of 100, 200, and 300 mg/L, respectively, indicating that the hydrogel has good adsorption performance for ammonia nitrogen. The adsorption process conforms to the monolayer adsorption of the Langmuir model, and the adsorption kinetic process belongs to the pseudo-second-order kinetic model of chemical adsorption. The structure of PAA/SA@TiO2 composite hydrogel is stable. The thermogravimetric analysis revealed that its main chain of the composite hydrogel began to break and degrade only at 446°C with thermally decomposed hydroxyl and carboxyl groups. At 800°C, the thermal loss rate was 48%. After 5 cycles of adsorption regeneration, the adsorption efficiency only drops by about 10%. The research results showed that PAA/ SA@TiO2 composite hydrogel had great application prospects in the field of nitrogen-containing wastewater treatment, which provided the theoretical basis and operating parameters for the hydrogel applying in the nitrogen-containing wastewaters treatment. [ABSTRACT FROM AUTHOR]

The water quality of Nanliujiang River basin, which is an important river entering the sea in the south of Guangxi, has a very important impact on the ecological environment around the surrounding areas of rivers and even the entire Beibu Gulf. Based on measured data, this study analyzed the pollution characteristics that affect the spatio-temporal distribution of the main water quality indicators( i. e., ammonia nitrogen and total phosphorus) in the Nanliujiang River basin. Statistical analysis shows that the total phosphorus is the limiting indicator leading to unqualified water quality, and the primary pollution source is the pollution of livestock and poultry breeding. Meanwhile, the pollution load of pollutants from livestock and poultry breeding sources in Bobai County was much higher than that in other administrative regions. The results of correlation analysis between livestock and poultry production and tributary water quality show that the livestock and poultry activities in Bobai County directly affect the concentration of ammonia nitrogen and total phosphorus in the tributaries of the Nanliujiang River basin. And in addition, the impact of free-range farming activities was greater than that of large-scale farming activities. After the prevention and control of livestock breeding pollution has been promoted, the water quality of Nanliujiang River basin has obviously improved. At the same time, the key areas that need to be focused on and strenghthened in the future are in Bobai County which is a key breeding area in Nanliujiang River basin, with the key tributaries including Xiaobai River, Wudou River, Shuiming River, Yashan River, Zhoucun River, Heshui River, Chunshi River, Dongping River, etc. [ABSTRACT FROM AUTHOR]

The excessive nitrogen in aquaculture easily causes the deterioration of water quality and threatens the growth and reproduction of aquatic animals, thus a safe and efficient nitrogen removal method is urgently needed. An ammonia‑degrading bacterium was selected from the sludge at the bottom of an aquaculture pond in Fujian province. After the strain identification, the adaptive domestication was carried out. The effects of different conditions on the growth of the strain and its ammonia‑nitrogen degradation were studied. Subsequently, nitrite was used as the only nitrogen source to detect the aerobic denitrification characteristics of the strains. The strain was identified as Bacillus aryabhattai by 16S rRNA and named as JN01. After acclimation, the growth of the strain and removal rate of ammonia nitrogen increased at varied degrees, and the removal rate of nitrogen was up to 87.29% with the initial NH4 + ‑N concentration was 200 mg/L. The results of single factor experiment showed that the degradation rate of ammonia nitrogen of the strain reached 92.78% when NH4 + ‑N concentration was 200 mg/L, sodium succinate as carbon source, carbon to nitrogen ratio was 15∶1, pH 7.5 and culture temperature was 30℃ . Under the condition that nitrite nitrogen was the only nitrogen source, strain JN01 also performed aerobic denitrification, and the degradation rate of NO2 - ‑N was 82.30%. In conclusion, B. aryabhattai JN01 has promising heterotrophic nitrification and aerobic denitrification characteristics, and has the potential to concurrently solve the excessive ammonia nitrogen and nitrite in aquaculture wastewater [ABSTRACT FROM AUTHOR]

This review describes the mechanism of adsorbent materials for the removal of ammonia nitrogin from wastewater; analyzes the current research status of different adsorbent materials for the adsorption of ammonia nitrogen: single form adsorbent materials such as zeolite, activated carbon, fly ash, bentonite still have problems such as low removal rate when treating ammonia nitrogen wastewater, and the adsorption capacity of ammonia nitrogen can be improved by different modification methods; introduces the adsorption effect of composite and other new adsorbent materials for ammonia nitrogen. Prospects for the application of adsorbent materials for treating ammonia nitrogen in wastewater. [ABSTRACT FROM AUTHOR]

Ammonia nitrogen contamination in groundwater along the Yangtze River in Anhui Province has become increasingly serious. However, the cause of the excessive ammonia nitrogen is not clear, especially the scan data concerning its source. Taking the QY10A monitoring well as an example, the source of ammonia nitrogen was studied using pollutant tracing, water quality detection, leaching tests, and nitrogen isotope analysis. No sources of high concentrations of ammonia nitrogen were identified in the study area. There was no evidence of a close hydraulic relationship between groundwater with high ammonia nitrogen and surface water. Silty clay and the lower gray-black silty clay were the main locations of ammonia nitrogen. Nitrate 8"N and 8"O of groundwater with high ammonia nitrogen originated from NH, in the soil. The findings indicate that the excessive ammonia nitrogen in the QY10A monitoring well was caused by the high content of the primary geological environment. [ABSTRACT FROM AUTHOR]

This study aimed to investigate pollutant concentration and nitrogen interception characteristics of a forward osmosis (FO) process for concentrating black odorous water. The membrane cell was operated in active layer facing feed solution (AL-FS) mode with aquaporin (AQP) as the membrane material and NaCl solution as the draw solution (DS). The organic pollutants (COD), TP, NH+4–N, NO−3–N, TN, Fe and Mn in black odorous water were concentrated non-intermittently for 24 h, and their interception characteristics were investigated. The results showed that the average interception rates of COD, TP, NO- 3-N, TN, Fe and Mn were 97.2%, 98.0%, 58.7%, 54.3%, 61.8% and 60.0%, respectively, while the average interception rate of NH+4–N was only 1.27%–3.47%. To explore the characteristics of nitrogen interception, a comparison was conducted between AQP membrane and thin film composite (TFC) membrane. Because the surface electronegativity of AQP membrane was stronger than that of TFC, the effect of cation exchange on ammonia nitrogen interception was more serious with AQP membrane. With NaCl solution as DS, the reverse osmosis flux of Na+ was (0.53 ± 0.02 mol·m−2·h−1), which was significantly higher than that of Cl− (0.29 ± 0.03 mol·m−2·h−1) (P < 0.05). The interception effect of AQP membrane on TN was related to the proportion of NH+4–N in TN. The pretreatment of black odorous water by aeration could transform part of NH+4–N into NO−3-N, and reduce the negative effect of cation exchange effect on nitrogen interception. The TN interception rate increased from 54.3% to 66.1%. [ABSTRACT FROM AUTHOR]

Potato starch wastewater, a byproduct of potato processing, is an escalating environmental concern due to its high concentrations of COD (chemical oxygen demand), ammonia nitrogen, and total phosphorus (TP). Addressing this challenge, this research introduced a novel method combining chitosan-modified biochar film (CBC) adsorption with subsequent ultrafiltration. SEM (scanning electron microscope), FTIR (Fourier transform infrared spectral), XRD (X-ray diffractometer), and BET (specific surface area) analyses validated CBC's enhanced surface characteristics, confirming successful chitosan (CS) film impregnation. CBC exhibited superior adsorption capacities, especially 40%wt-CBC, optimizing COD removal at 79.8%, ammonia nitrogen at 93.3%, and TP at 91.2%. Kinetic studies associated the adsorption process with a pseudo-second-order model, highlighting chemical adsorption. Additionally, the Langmuir isotherm model suggested monolayer adsorption with no inter-adsorbate interactions. The treated effluent, post adsorption, was directed through an ultrafiltration membrane, ensuring water quality suitable for reuse. This integrative treatment not only offers an effective solution for potato starch wastewater management but also underscores the potential for sustainable water resource recovery in the food processing sector. [ABSTRACT FROM AUTHOR]

Reducing the environmental problems caused by nitrogen loss and nitrogen pollution is of great significance. The addition of biochar to soil is a new method for increasing nitrogen interception due to the special structural and physicochemical properties of biochar. The optimal modified biochar was screened out after acid–base modification and batch adsorption test in this paper. And then the effects of different soil and biochar mixing methods on soil physicochemical properties and nitrogen adsorption and retention were explored through soil column leaching test. The results showed that the biochar with a pyrolysis temperature of 700 °C had the best adsorption effect on nitrogen after being modified by 0.1 mol/L HCI, and the adsorption capacity of nitrate nitrogen reached 121.46 mg/g. The adsorption process of ammonia nitrogen and nitrate nitrogen conformed to the Langmuir model and was mainly homogeneous monolayer. After mixing the selected modified biochar with black soil, the pH increased by 4.77%, the content of ammonia nitrogen increased by 4.89%, and the nitrate content increased by 16.62%. In this study, the adsorption effect of biochar on nitrogen in black soil was discussed, so as to explore the optimal use of biochar in soil, which provided some reference basis for the relevant research. [ABSTRACT FROM AUTHOR]

Standalone and combined leachate treatment mechanisms suffer from low treatment efficiencies due to leachate's complex, toxic, and recalcitrant nature. Bioelectrochemical system (BES) was used for the first time to investigate the treatment of leachate mixed wastewater (WW) (i.e., diluted leachate, DL) (DL ≈ L:WW = 1:4) to minimize these complexities. A natural clay (palygorskite) was used as adsorbent material for further treatment on the BES effluent (EBES) while using two different masses and sizes (i.e., 3 g and 6 g of raw crushed clay (RCC) and 75 μ of sieved clay (75 μSC)). According to bioelectrochemical performance, BES, when operated with low external resistance (Rext = 1 Ω) (BES 1), showed a high removal of COD and NH3-N with 28% and 36%, respectively. On the other hand, a high Rext (100 Ω, BES 100) resulted in low removal of NH3-N with 10% but revealed high COD removal by 78.26%. Moreover, the 6 g doses of 75 μSC and RCC showed the maximum COD removals of 62% and 38% and showed the maximum removal of NH3-N with an average range of 40% for both sizes. After efficient desorption, both clay sizes resulted in regeneration performance which was observed with high COD (75%) and NH3-N (34%) on EBES. Therefore, when BES and clay adsorption technique sequentially treated and achieved with combined removal of ~ 98% for COD and ~ 80% of NH3-N, it demonstrated an efficient treatment method for DL treatment. [ABSTRACT FROM AUTHOR]

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Introduction: Rumen fermentation manipulation aims to maximize the feed efficiency and increase the usefulness of rearing ruminants; in simpler words, the goal of rumen manipulation is to increase processes in rumen fermentation that are beneficial for the host animal and to reduce, change, or eliminate inefficient or harmful processes in rumen fermentation. In this regard, trying to use natural products such as medicinal plants has been widely accepted. The desire and demand of consumers to use healthy meat and livestock products has increased the research to search for natural compounds and additives of plant origin that are beneficial for animal health. The positive effects of medicinal plants on the process of microbial fermentation and reduction of greenhouse gases through their active compounds (such as anthole in fennel or thymoquinone in black seed) have been shown. The present study was designed in two experiments to evaluate the effect of different levels of Foeniculum vulgare and Nigella sativa powder on rumen fermentation parameters and protozoa population of Sanjabi sheep by in vitro and in vivo methods. Materials and methods: The present study was designed and carried out in two experiments, in vitro and in vivo. In the first experiment (in vitro), 18 Sanjabi lambs (four to six months of age) with an average weight of 30.8 ± 6.7 kg were randomly divided into three groups with six replicates. Treatments included: control (basal diet without additives), fennel (basal diet plus 20 grams of fennel per kilogram of concentrate), and black seed group (basal diet plus 20 grams of black seed per kilogram of concentrate). In the second experiment (invitro), 0, 5, 25, and 50 mg of fennel and black seed powder were added to the rumen liquor collected from six Sanjabi lambs (the control group of the first experiment). In both experiments, rumen liquor was taken through the esophageal tube. Gas production, pH, ammonia nitrogen concentration, total volatile fatty acids, in vitro digestibility of organic matter, and protozoa count were measured. In the in vivo experiment, the amount of excrement of sheep was measured by installing nets under the boxes of the animals. Data analysis was done using SAS statistical software. The normality of the counting data (population of protozoa) was first checked by a non-parametric KolomogorovSmirnov test and then analysis was done. The experimental design used in this research was completely randomized and for the first experiment, it was repeated measurements in time. Duncan's multiple range test was used to compare the mean of the treatments. Results and discussion: The results of the in vivo experiment showed that the use of fennel and black seed increased the amount of digested organic matter in the rumen significantly compared to the control (P<0.05). In the in vivo experiment, all studied protozoa populations decreased in all treatments (P<0.05). In the in vitroexperiment, the addition of fennel caused a significant decrease in gas production (P˂0.0001), organic matter digestibility, and microbial mass at the levels of 25 and 50 mg compared to the control (P<0.05). Ammonia nitrogen concentration at all levels of black seed and the level of 50 mg of fennel had a significant decrease compared to the control (P<0.05). Total protozoa population and Entodinium spp. subfamily was affected by both fennel and black seed treatments in vitro and showed a significant decrease (P˂0.0001). The results of this study showed that black seed and fennel have anti-protozoa properties and can reduce different protozoa populations both in vitro and in vivo. Also, low levels of fennel can improve the fermentation efficiency by increasing the degraded organic matter and reducing gas production. In addition, the results obtained from this research showed that fennel and black seed medicinal plants had the potential to manipulate and change the process of rumen fermentation, and their anti-protozoal effects were evident and significant in both experiments. However, the effects of these plants on the fermentation process in vitro and in vivo did not follow the same process in most of the fermentation parameters, and in vitro results cannot be fully and reliably generalized to the conditions inside the rumen of live sheep. Conclusions: The levels of fennel and black seed used in this study can reduce different protozoa populations and improve the process of rumen fermentation, although more researches are needed with different levels of these herbs to get more results. [ABSTRACT FROM AUTHOR]

Atmospheric pressure gas–liquid discharge plasma has garnered considerable attention for its efficacy in wastewater contaminant removal. This study utilized atmospheric oxygen gas–liquid discharge plasma for the treatment of ammonia nitrogen wastewater. The effect of applied voltage on the treatment of ammonia nitrogen wastewater by gas–liquid discharge plasma was discussed, and the potential reaction mechanism was elucidated. As the applied voltage increased from 9 kV to 17 kV, the ammonia nitrogen removal efficiency rose from 49.45% to 99.04%, with an N2 selectivity of 87.72%. The mechanism of ammonia nitrogen degradation by gas–liquid discharge plasma under different applied voltages was deduced through electrical characteristic analysis, emission spectrum diagnosis, and further measurement of the concentration of active species in the gas–liquid two-phase system. The degradation of ammonia nitrogen by gas–liquid discharge plasma primarily relies on the generation of active species in the liquid phase after plasma–gas interactions, rather than direct plasma effects. Increasing the applied voltage leads to changes in discharge morphology, higher energy input, elevated electron excitation temperatures, enhanced collisions, a decrease in plasma electron density, and an increase in rotational temperatures. The change in the plasma state enhances the gas–liquid transfer process and increases the concentration of H2O2, O3, and, ⋅ O H in the liquid phase. Ultimately, the efficient removal of ammonia nitrogen from wastewater is achieved. [ABSTRACT FROM AUTHOR]

Microbial flora plays an important role in microorganism-enhanced technology. The pollutant degradation ability and viable counts of these agents are crucial to guarantee their practical application. In this study, an efficient pollutant-degrading microbial flora was screened, its medium components and culture conditions were optimized, and its effect was verified in zeolite trickling filter towers. After a 24 h culture under the optimal conditions, the viable count reached 4.76 × 109 cfu/mL, with the degradation rates of ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) increased to 93.5%, 100%, 68.3%, 32.6%, and 85%, respectively. After optimizing the feeding strategy, the concentration of viable bacteria reached 5.80 × 109 cfu/mL. In the application effect verification experiment, the degradation rates of NH4+-N, TN, TP, and COD in the experimental group reached 96.69%, 75.18%, 73.82%, and 90.83%, respectively, showing a significant improvement compared to the results of the control group. The main components in the control group were Dokdonella, Brevundimonas, Alishewanella, Rhodobacter, Pseudoxanthomonas, and Thauera, whereas those in the experimental group were Dokdonella, Proteocatella, Rhodobacter, Dechlomonas, and Nitrospira. Proteocatella, Dechlomonas, and Nitrosra, which were unique to the experimental group, are common bacteria used for nitrogen and phosphorus removal. This explains the difference in the sewage treatment capacity between the two groups. This study provides an alternative sewage treatment microbial flora with a reasonable production cost and high degradation efficiency for NH4+-N, TN, TP, and COD. Keypoints: A mixed-bacteria group with a high degradation rate of NH4+-N, TN, TP, and COD was screened. The viable cell concentration and pollutant degradation efficiency of the screened microbial flora was increased significantly by optimizing its cultivation conditions. Increased pollutant degradation efficiency was verified in a zeolite trickling filter tower and explained by the microbial composition of the screened microbial flora. [ABSTRACT FROM AUTHOR]

In order to reduce the agglomeration of tourmaline, silane coupling agent (3‐aminopropyl)‐triethoxysilane (KH‐550) was used to modify tourmaline. Then the modified tourmaline particles were added to the polyvinylidene fluoride (PVDF) casting solution by blending, and a series of PVDF/TMKH‐550 composite membranes were prepared by Nonsolvent Induce Phase Separation (NIPS). The results showed that the agglomeration of tourmaline could be reduced by modification. With the increase of TMKH‐550 nanoparticles content, the removal efficiency of ammonia nitrogen wastewater increased gradually. For PVDF/TMKH‐550 composite membranes, the results showed that the addition of TMKH‐550 nanoparticles improved the hydrophilicity, porosity, and pore size of the membrane, and increased the permeation flux. The removal efficiency of the composite membrane on ammonia nitrogen solutions could reach 75.40%, The pH and conductivity of deionized water after membrane filtration were tested. At 0.2 MPa, it was found that both pH and conductivity increased. The above results showed that tourmaline can not only activate water bodies but also remove pollutants in water. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the performance of modified wood ceramics in removing ammonia nitrogen from water. The modified wood ceramic is a carb on-carbon composite material, which is made of pine wood as raw material, montmorillonite and magnesium chloride as modifiers, and calcined under nitrogen protection. The orthogonal experiment design was used to analyze the influence of various experimental parameters on the ammonia nitrogen adsorption capacity of the modified wood ceramics, and the significant factors affecting the ammonia nitrogen adsorption capacity were determined. The structure and properties of the modified wood ceramics were characterized by scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and specific surface area. The results showed that the filling weight, the mass ratio of phenolic resin to anhydrous ethanol, the mass ratio of montmorillonite to anhydrous ethanol, the heating rate, the carbonization temperature, and the carbonization time had a significant effect on the ammonia nitrogen removal of the sample. The adsorption of ammonia nitrogen on the modified wood ceramics conforms to the quasi second order kinetic model. Freundlich isotherm can better fit the adsorption behavior of the modified wood ceramics. The open porosity of the prepared modified wood ceramics is 77.4%, the pore size distribution is mainly mesoporous, and the specific surface area is 12. 56 m²/g. The experiment shows that the modified wood ceramics can effectively remove ammonia nitrogen from water. [ABSTRACT FROM AUTHOR]

Introduction: Pomegranate has many secondary metabolites such as tannins and phenolic compounds, which have various properties such as antimicrobial, antioxidant, anti-inflammatory, and immune system stimulating effects. The amount of tannin in pomegranate skin has been reported up to 20.6%. The limiting effects of tannins can be related to reducing the use of nutrients, especially protein, reducing growth and performance, reducing palatability and feed consumption, and reducing the activity of digestive enzymes. In addition to the anti-nutritional effects in high concentration, the positive impact of dense tannins in optimal concentration includes improving live weight gain, preventing flatulence, increasing milk production, reducing intestinal nematodes, and reducing the production of NH3-N and methane in the rumen. Therefore, the present experiment was carried out to improve the nutritional value of pomegranate peel as a tannin-containing edible material by treating it with some tannase-producing bacteria for ruminants. Materials and Methods: Pomegranate peel was treated with tannin-degrading bacteria including Klebsiella pneumoniae and Acinetobacter (isolated from deer rumen), Lactobacillus fermentum (isolated from Najdi goat rumen), and commercial Lactobacillus fermentum, and its nutritional value including chemical composition, digestibility, and fermentation ability alone (first experiment) or as a combination in a standard fattening lamb diet (second experiment), with two-stage digestion method and gas production test were studied. In the first experiment, five experimental treatments included 1-Pomegranate peel without treatment (control treatment), treatment 2 to 5- Pomegranate peel treated with each of the four tannin-degrading bacteria. The five treatments of the second experiment included 1- Diets containing pomegranate peel without treatment (control treatment), 2-5- Diets containing pomegranate peel treated with each of the four tannin-degrading bacteria. Results and Discussion: Applying tannin-degrading bacteria reduced the tannin in pomegranate peel (P<0.05), which is caused by the tannin-degrading bacteria. In an experiment of ensiling and adding polyethylene glycol and urea to pistachio hull for tannin removal, total tannin decreased. The concentration of total tannin with the potential and rate of gas production, truly decomposed organic matter, microbial biomass production, and microbial biomass production efficiency improved in pomegranate peel treated with tannindegrading bacteria compared to the control (P<0.05). Perhaps the reason for the decrease in gas production potential in the control treatments compared to the treatments treated with bacteria is their higher amount of tannins, because tannins and phenolic substances by forming bonds and complexes with nutrients such as carbohydrates, proteins, reduce the availability of microorganisms. Ruminants to them and as a result reduce their decomposition. Similar to the results of the present experiment, other studies have also shown the positive effect of tannin removal on the improvement of gas production parameters. NH3 concentration and population of protozoa of pomegranate peel treated alone and in the diet increased compared to the control (P<0.05). The reason for the increase in NH3 concentration and protozoa population after degrading the tannins with bacteria can be the presence of tannins and polyphenolic compounds in this edible material. By binding to protein and reducing the rate of protein decomposition, tannins reduce the concentration of NH3, on the other hand, these structures lead to the rupture of the protozoa cell membrane, the inactivation of enzymes, and the reduction of the substrate needed for cell metabolism. The percentage of digestibility of dry matter, NDF, and ADF of pomegranate peel processed alone and in the diet with tannin-degrading bacteria increased compared to the control (P<0.05). Due to the reduction of the tannin level by the isolates, the activity of proteolytic enzymes has probably increased, and releasing nutrients from the binding of tannin, has improved the digestibility of the materials. An increase in cell wall digestibility has been reported as a result of treatment with tannin-degrading bacteria in laboratory conditions. Gas production potential and rate, separation coefficient, microbial viable mass production, and microbial viable mass production efficiency were improved in diets containing processed pomegranate peel compared to the control (P<0.05). Conclusion: The use of tannin-degrading bacteria in the processing of pomegranate peel by reducing the tannins concentration led to an increase in the digestion and fermentation potential of pomegranate peel and diets containing pomegranate peel processed with tannins-degrading bacteria compared to the control. Therefore, considering the positive effects of processing pomegranate peel with tannins-degrading bacteria, it can be said that processing it by reducing tannins is a suitable solution to improve its nutritional value. [ABSTRACT FROM AUTHOR]

Nitrogen from ammonia is one of the most common pollutants toxics to aquatic species in aquatic environment. The intestinal mucosa is one of the key mucosal defenses of aquatic species, and the accumulation of ammonia nitrogen in water environment will cause irreversible damage to intestinal function. In this study, histology, immunohistochemistry, ultrastructural pathology, enzyme activity analysis and qRT-PCR were performed to reveal the toxic effect of ammonia nitrogen stress on the intestine of Pelteobagrus fulvidraco. According to histological findings, ammonia nitrogen stress caused structural damage to the intestine and reduced the number of mucous cells. Enzyme activity analysis revealed that the activity of bactericidal substances (Lysozyme, alkaline phosphatase, and ACP) had decreased. The ultrastructure revealed sparse and shortened microvilli as well as badly degraded tight junctions. Immunohistochemistry for ZO-1 demonstrated an impaired intestinal mucosal barrier. Furthermore, qRT-PCR revealed that tight junction related genes (ZO-1, Occludin, Claudin-1) were downregulated, while the pore-forming protein Claudin-2 was upregulated. Furthermore, as ammonia nitrogen concentration grew, so did the positive signal of Zap-70 (T/NK cell) and the expression of inflammation-related genes (TNF, IL-1β, IL-8, IL-10). In light of the above findings, we conclude that ammonia nitrogen stress damages intestinal mucosal barrier of Pelteobagrus fulvidraco and induces intestinal inflammation. [ABSTRACT FROM AUTHOR]

Introduction: Considering that soybean is mainly used in human nutrition and its meal is mostly used in poultry feed, and also due to the high price of soybean meal and its impact on the cost of each kilogram of feed, using of other protein sources such as camellia meal in the diet of fattening lambs can reduce the need of soybean meal for ruminant animals. Previous studies have shown that camelina meal with a suitable percentage of omega-3, crude protein, crude fat and poly unsaturated fatty acids (alpha-linolenic acid) makes it a suitable feedstuff for livestock, poultry and fish. However, due to the presence of anti-nutritional compounds such as trypsin inhibitor and glucosinolate, the limitations of camellia meal should be taken into consideration when used in the diet of animals. In many experiments, it has been determined that camelina is a plant resistant to harsh weather conditions compared to other oil plants, has a high yield potential, and it has been reported that it is possible to plant it in crop rotation with cereals. In this study, the possibility of using camelina meal (CM) instead of soybean meal (SBM) in the diet of fattening lambs was investigated. Material and Methods: Twenty-four male lambs aged four to six months with an average weight of 34.21±2.18 kg in a completely randomized design with four treatments and six replications were used. Animals were placed in the individual cages. Treatments included: 1) control (basal diet containing SBM), 2) basal diet with 33% replacement of SBM with CM, 3) basal diet with 67% replacement of SBM with CM, and 4) basal diet with 100% replacement of SBM with CM. Ruminal fluid was taken by esophageal tube and blood samples were taken from the jugular vein on days 0, 45 and the end of the experiment. Results and Discussion: The final weight and daily weight gain were not affected by the replacement of oil meals, but it caused a decrease in dry matter intake (P˂0.05). Ruminal ammonia nitrogen concentration increased in a way that was significant in 33 and 67% replacement (P<0.05). Volatile fatty acids concentration and pH were not affected by treatments. The total population of protozoa and genus Entodinium decreased with the increase in replacement percentage, and according to the interaction effect of time and treatment, the population increased with the increase in the duration of the experiment (P<0.05). The concentration of blood urea increased with the replacement of meals (P<0.05), although this process was influenced by the interaction of treatment and time. With the complete replacement of meals, the concentrations of blood cholesterol and triglycerides increased (P<0.05). Malondialdehyde in the blood of lambs was not affected by replacing SBM with CM. Conclusion: According to the results, camelina meal can be used instead of soybean meal at a maximum level of 67% in diet of fattening lambs. [ABSTRACT FROM AUTHOR]

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Pt/RuO 2 /g-C 3 N 4 photocatalyst was prepared for simultaneous removal of NH 4 +-N and bacteria in saline waters. • Pt and RuO 2 facilitate the production of active chlorine without causing chlorine loss in saline waters. • The Pt/RuO 2 /g-C 3 N 4 photocatalyst is effective in natural sunlight on actual water. The removal of ammonia nitrogen (NH 4 +-N) and bacteria from aquaculture wastewater holds paramount ecological and production significance. In this study, Pt/RuO 2 /g-C 3 N 4 photocatalysts were prepared by depositing Pt and RuO 2 particles onto g-C 3 N 4. The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis diffuse reflectance spectrometer (UV–vis DRS). The photocatalysts were then applied to the removal of both NH4+-N and bacteria from simulated mariculture wastewater. The results clarified that the removals of both NH 4 +-N and bacteria were in the sequence of g-C 3 N 4 < RuO 2 /g-C 3 N 4 < Pt/g-C 3 N 4 < Pt/RuO 2 /g-C 3 N 4. This magnificent photocatalytic ability of Pt/RuO 2 /g-C 3 N 4 can be interpreted by the transfer of holes from g-C 3 N 4 to RuO 2 to facilitate the in situ generation of HClO from Cl− in wastewater, while Pt extracts photogenerated electrons for H 2 formation to enhance the reaction. The removal of NH 4 +-N and disinfection effect were more pronounced in simulated seawater than in pure water. The removal efficiency of NH 4 +-N increases with an increase in pH of wastewater, while the bactericidal effect was more significant under a lower pH in a pH range of 6–9. In actual seawater aquaculture wastewater, Pt/RuO 2 /g-C 3 N 4 still exhibits effective removal efficiency of NH 4 +-N and bactericidal performance under sunlight. This study provides an alternative avenue for removement of NH 4 +-N and bacteria from saline waters under sunlight. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the removal of ammonia nitrogen (NH4-N) on activated carbon prepared from waste tyres was conducted in batch studies as a function of adsorbent dosage, pH, temperature, contact time and initial concentration. The pore structure of activated carbon was characterized by N2 adsorption. The optimal conditions for the efficient adsorption of ammonia nitrogen onto waste tyre-activated carbon were found to be an adsorbent dosage of 0.4 g/L, pH 9.0, temperature of 20 °C, contact time of 90 min and initial ammonium nitrogen concentration of 50 mg/L. The kinetics studies showed that the pseudo-second-order model offered the best connection of the adsorption data. The Langmuir model was found to provide the best fit for the experimental data. The thermodynamic results showed that the adsorption of ammonia onto waste tyre-activated carbon was exothermic, random and spontaneous in nature. HIGHLIGHTS Ammonia nitrogen was removed from wastewater using activated carbon prepared from waste tyres.; Pore structure of activated carbon was characterized by N2 adsorption.; Optimal conditions for efficient adsorption were found as follows: an adsorbent dosage of 0.4 g/L, pH 9.0, temperature of 20 °C, contact time of 90 min and initial concentration of 50 mg/L.; The adsorption process, isotherms, kinetic and thermodynamic parameters were evaluated.;

The biological treatment of wastewater with high concentrations of ammonia nitrogen has become a hot research issue, but there are limited reports on the mechanism of ammonia nitrogen utilization by microorganisms. In this paper, a transcriptomic approach was used to investigate the differences in gene expression at 500.0 mg/L (Amo 500) and 100.0 mg/L (Amo 100) ammonium concentrations to reveal the mechanism of ammonia nitrogen removal from water by Pseudomonas stutzeri F2. The transcriptome data showed 1015 (459 up-regulated and 556 down-regulated) differentially expressed genes with functional gene annotation related to nitrogen source metabolism, glycolysis, tricarboxylic acid cycle, extracellular polysaccharide synthesis, energy conversion and transmembrane transport, revealing the metabolic process of ammonium nitrogen conversion to biological nitrogen in P. stutzeri F2 through assimilation. To verify the effect of ammonium transporter protein (AmtB) of cell membrane on assimilation, a P. stutzeri F2-ΔamtB mutant strain was obtained by constructing a knockout plasmid (pK18mobsacB-ΔamtB), and it was found that the growth characteristics and ammonium removal rate of the mutant strain were significantly reduced at high ammonium concentration. The carbon source components and dissolved oxygen conditions were optimized after analyzing the transcriptome data, and the ammonium removal rate was increased from 41.23% to 94.92% with 500.0 mg/L ammonium concentration. The study of P. stutzeri F2 transcript level reveals the mechanism of ammonia nitrogen influence on microbial assimilation process and improvement strategy, which provides a new strategy for the treatment of ammonia nitrogen wastewater.

Ozone advanced oxidation has been widely used in water treatment, but little research has been reported on the application of ozone to difficult-to-degrade mineral wastewater. In this paper, the effect of ozonation application in the treatment of copper mineral processing wastewater, which is difficult to be effectively treated by traditional processes due to its complex composition, was investigated. The effects of ozonation time, ozone concentration, temperature and pH on the degradation of organic compounds in the wastewater by ozonation were researched. It was found that the chemical oxygen demand (COD) of the wastewater could be reduced by 83.02% by ozonation under optimal treatment conditions. In addition, the mechanism of ozone degradation of the difficult-to-degrade wastewater was studied, and the reasons for the fluctuating variations of COD and ammonia nitrogen during ozonation treatment were explained. HIGHLIGHTS The mechanism of chemical oxygen demand (COD) and NH3-N removal in actual copper mineral processing wastewater (CMPW) treated by ozone was analyzed.; The effect of ozone-treating CMPW did not necessarily get better with the increase in temperature.; Ozonation showed a better treatment effect on CMPW under alkaline conditions.; COD concentration fell with ozonation time, then rose and finally fell.; NH3-N concentration rose and fell twice with ozonation time.;

In this article, COD, volatile phenol and ammonia nitrogen concentrations of the wastewater from semicarbon are reported as 38,000; 6,400 and 5,700 mg/L, respectively. According to the field test, when the pH of the wastewater is 9, the field test temperature is 20 °C, the adsorption time is 30 min and the optimal dosing ratio of nitrogen-doped gasification slag (HX-NGS) to the wastewater is 1:4, HX-NGS has the best removal effect on COD, volatile phenol and ammonia nitrogen in the wastewater from the semicarbon. The removal rates of COD, volatile phenol and ammonia nitrogen are 94, 91 and 85%, respectively, and the concentrations of the remaining COD, volatile phenol and ammonia nitrogen are 2,280, 576 and 855 mg/L, respectively, after regeneration, the material HX-NGS has a good effect on the treatment of the wastewater from the semicarbon. The reuse rate of the adsorption material is at least eight times. The adsorption effect of the material HX-NGS conforms to the mechanism law of dynamics and thermodynamics. HIGHLIGHTS Physical extraction is adopted without adding chemical agents, which will not lead to secondary pollution of water in the treatment link with no increase in solid and liquid wastes.; Moreover, the extraction materials can be recycled for use, with a strong adsorption capacities for oil and phenol.; The first adsorption can handle about 80% of polyphenol, SS, etc.;

The purpose of this experiment was to evaluate the effects of different levels of BSF on rumen in vitro fermentation gas production, methane (CH4) production, ammonia nitrogen (NH3-N), and volatile fatty acids (VFAs). The experiment comprised four treatments, each with five replicates. The control group contained no BSF (BSF0), and the treatment groups contained 5% (BSF5), 10% (BSF10), and 15% (BSF15) BSF, respectively. Results showed that at 3 h, 9 h, and 24 h, gas production in BSF5 and BSF10 was significantly higher than in BSF0 and BSF15 (p < 0.05). Gas production in BSF5 and BSF10 was higher than in BSF0, while gas production in BSF15 was lower than in BSF0. At 6 h and 12 h, CH4 emission in BSF15 was significantly lower than in the other three groups (p < 0.05). There were no differences in the pH of in vitro fermentation after BSF addition (p > 0.05). At 3 h, NH3-N levels in BSF10 and BSF15 were significantly higher than in BSF0 and BSF5 (p < 0.05). At 6 h, NH3-N levels in BSF5 and BSF10 were significantly higher than in BSF0 and BSF15 (p < 0.05). Acetic acid, propionic acid, butyric acid, and total VFAs in BSF0, BSF5, and BSF10 were significantly higher than in BSF15 (p < 0.05). In conclusion, gas production, CH4 emission, NH3-N, acetic acid, propionic acid, butyric acid, and VFAs were highest in BSF5 and BSF10 and lowest in BSF15.

A low-cost functionalization method was used to treat diatomite, and an efficient adsorbent for ammonia nitrogen was prepared by optimizing the functionalization conditions. The functionalized diatomite (DTCA-Na) was characterized by SEM, EDS, BET, XRD, FT-IR, and TG. The results demonstrate that DTCA-Na has excellent adsorption performance after being modified with H2SO4 (60.00 wt.%), NaCl (5.00 wt.%), and calcination at 400 °C for 2 h. While studying the effect of adsorption factors on the removal of ammonia nitrogen, the kinetic and thermodynamic behaviors in the adsorption process were discussed. The removal efficiency of the simulated wastewater with the initial ammonia nitrogen concentration of 10.00 mg L−1 by the DTCA-Na was more than 80% when the contact time was 60 min, pH was 6–10, the dosage of adsorbent was 1.00 g, and the temperature was 25 °C. The adsorption process of ammonia nitrogen was conformed to the pseudo-first-order and Langmuir isothermal model. The removal efficiency of ammonia nitrogen was still above 80% after 5 times adsorption–desorption experiments. The DTCA-Na has a brighter prospect of application in the field of ammonia nitrogen wastewater treatment due to its excellent adsorption performance and low-cost advantage. [ABSTRACT FROM AUTHOR]

Natural kaolin (NK) is not used as a material for removal of ammonia nitrogen in wastewater because of its low ammonia adsorption capacity. In this study, sodium-modified kaolin adsorbent (NaCK) with high ammonia nitrogen adsorption capacity was prepared by NaOH modification of calcined NK, which was developed to address this problem. The adsorption properties were evaluated by batch static adsorption test. The results showed that when the initial concentration of ammonia nitrogen was 10 mg/L, pH = 8, and dosage of adsorbent was 1 g/L, the adsorption capacity of NaCK-600 for ammonia nitrogen was the best, reaching 6.23 mg/g, which was 34.6 times higher than that of NK (0.18 mg/g). Batch static adsorption test combined with adsorption kinetics, adsorption isothermal, and characteristic data showed that NaCK prepared at different temperatures had different adsorption mechanisms. Batch static adsorption test data of NaCK-600 was in good agreement with the pseudo-second-order model and Langmuir model, and the main mechanism of its adsorption of ammonia nitrogen was the ion exchange of NH4+ and Na+ in NaCK. After the third cycle, the removal rate of NaCK-600 was still up to 76.44%, which indicates that NaCK-600 has considerable potential for removal of ammonia nitrogen in wastewater and provides a new way for the application of kaolin in removal of ammonia nitrogen. [ABSTRACT FROM AUTHOR]

This paper mainly studies the mechanism and efficiency of ammonia-nitrogen removal from circulating sewage in closed fish tank system. According to some factors affecting the removal efficiency (ultrasonic power, ultrasonic time and water oxygen concentration). Simulated circulating sewage mixed with oxygen through a venturi tube and then entered a closed experiment box for ultrasonic experiments. Finally, the removal efficiency was determined by Knott's reagent photometry. In the experiment, the PH value of the simulated sewage was 7.5, the indoor water temperature was 20 °C, and the free ammonia was selected as 0.02 mg/L (total ammonia-nitrogen was 1.6 mg/L) according to the standard. The experiment found that when the ultrasonic power is 400 W, the action time is 2 h, and the oxygen concentration of water is 23.8 mg/L, the efficiency of removing ammonia-nitrogen in water is about 65 %. When applied on fishing vessels, increasing the power can increase the removal efficiency. [ABSTRACT FROM AUTHOR]

This paper reviews the effects of salinity on activated sludge biological treatment systems, including the effects on sludge properties such as settling performance and sludge activity, and system treatment effects such as degradation efficiency of organic matter and ammonia nitrogen, and further elaborates the mechanisms. The development direction of this research field is prospected to provide a reference for future efficient and stable operation of activated sludge treatment systems. [ABSTRACT FROM AUTHOR]

From the perspective of resource recovery, this paper summarized the physical and chemical method ( evaporation method, the remove method, adsorption, membrane separation, magnesium ammonium phosphate precipitation) and recycling organic waste anaerobic biological method and other methods in the fermented liquid ammonia nitrogen form and its mechanism, analyses the anaerobic fermentation liquor pH, temperature, gas liquid ratio and suspended solids and organic matter, high concentration of ammonia nitrogen on the effects of the ammonia nitrogen recycling in view of the existing in the running cost is high, the adsorption capacity is small, membrane fouling and concentration ability is limited and difficult problems such as separation, puts forward the delve into a stable and efficient, low cost, convenient operation, nitrogen recovery technology and combination of the process and optimize the process conditions of research direction, in order to organic waste anaerobic fermentation contained ammonia nitrogen utilization to provide the reference. [ABSTRACT FROM AUTHOR]

Acid-modified red mud supported by peanut shells (MRP) catalysts were prepared for the catalytic wet persulfate oxidation (CWPO) process of dyes wastewater (containing methyl orange (MO), NH3-N, and Cr6+) in batch and continuous fixed bed reactors. Importantly, the influence of NH3-N and Cr6+ on the catalytic performance of the MRP catalyst was primarily studied. In the CWPO process, the reactors had a remarkable degradation efficiency (72–97%) of MO in the dyes wastewater. In the batch reactor, with the increase of NH3-N concentration (5–20 mg L−1), the degradation efficiency of MO was maintained at 93%. When NH3-N, Cr6+, and MO coexist, the degradation of MO had slight inhibition with 87.24%, which indicated that MO concentration was still controlled by MRP under the coexistence system, and the order of the removal effect of MRP on the three pollutants in the reactors was as follows: MO > NH3-N > Cr6+. Furthermore, in the fixed reactor, with the increasing of NH3-N or Cr6+ concentration, the MO degradation removal decreased to about 84%. The results showed that the degradation effect of MO in a fixed bed is still considerable. Then, the SEM and FTIR results indicated that SO4·−, ·OH, and O2−· generated in the CWPO process and Fe2+ and oxygen-containing functional groups on MRP played a major role on the degradation of pollutants. This study showed that this novel MRP is a promising catalyst with promising applications in composite dyes wastewater. [ABSTRACT FROM AUTHOR]

Differences between specific anions and cations have a greater contribution to the physiological performance of animals than their individual effect. The difference between cations and anions in milliequivalents of the diet is referred to as the cation-anion difference or the anion-cation balance (Razzaghi 2009). DCAD manipulation by altering blood buffering capacity, improves milk production in dairy cow (Sanchez 2003). Feeding diets with low DCAD during the Prepartum period is a practical nutritional strategy to increase blood calcium and produce more milk Postpartum. Diets containing low DCAD increased the concentration of hydrogen ions in the blood, resulting in mild acidosis and increased calcium absorption (Moore et al 2000). Decreasing DCAD by feeding anionic salts lowers blood pH and increases the binding of parathyroid hormone to the parathyroid hormone receptor on bone, intestinal, and kidney cells (Goff 2004). However, feeding anionic salts reduces prenatal feed intake due to its bitterness; but it improves postpartum calcium metabolism (Golfert et al 2010). One way to activate postpartum calcium homeostasis is to use DCAD-negative diets in the Prepartum period. Nutrition High-anion diets, commonly known as "anion-salt diets," have been used to prevent milk fever for the past 40 years. One possible reason is that dietary metabolic acidosis increases the tissue response to parathyroid hormone. Therefore, the aim of this experiment was to investigate the effect of anion source type and anion and cation balance on rumen fermentation parameters in dry cows in vitro. Material and methods: This study was done at the Research Farm and laboratories of the Department of Animal Sciences, Faculty of Agriculture, in University of Birjand, using the ruminal fluid of two dry Holstein cows with ruminal fistula. In order to investigate the effect of source and dietary anion-cation difference (DCAD) of dry cow's diet on gas production parameters, ammonia nitrogen concentration(NNH3), rumen pH and dry matter digestibility in in vitro condition. Basal diet was prepared based on the requirements of dry cows. In the next step, concentrations of calcium, sodium, potassium, magnesium, chlorine, phosphorus and sulfur in the basal diet were determined by atomic absorption spectroscopy and the DCAD of the basal diet was calculated. After this, the anionic salts of calcium sulfate hemihydrates, sulfuric acid, phosphoric acid and monobasic ammonium phosphate were added as a percentage of the diet in solution form to the base diet with a sampler to reach the desired anion-cation balance. The factorial experiment conducted in a completely randomized design with 12 treatments and 15 replications. Anionic salts of calcium sulfate hemihydrates, sulfuric acid, phosphoric acid, ammonium phosphate monobasic and different DCAD levels (-56.6, -11.33 and -17.0 meq/100gDM) were used. Each treatment was including a DCAD level and a sulfur and phosphorus source that balanced according to each element ratio in table of requirements. In the next step, the gas from fermentation was measured based on the modified method of Bloomel et al. (1997). The produced gas pressure was recorded at times of 2, 4, 6, 8, 12, 24, 36, 48, 72, 96 and 120 hours from the beginning of incubation. The data were plotted against time and analyzed using the exponential Schofield model (P = v (1-exp (-k (t)))) in the NLIN procedure of SAS software. At times of 12, 24, 48 and 72 hours after incubation, three vials of each replicate were removed from incubator and after recording gas production, immediately after opening the cap, the pH of each vial was measured Using a digital pH meter (Metrohm 727 pH lab). In order to determine the concentration of ammonia nitrogen after centrifugation of the contents of each vial, 5 ml of clear supernatant was removed from it and combined with 333 μl of 3 N hydrochloric acid and then stored at -20 ° C. Phenol and hypochlorite reagents were used to measure ammonia nitrogen and the adsorption was read by ELISA at 650 nm (Broderick and Kang, 1980). In order to determine the rumen digestibility of the dry matter, the residues obtained from each vial were oven dried in 60 ° C for 48 hours. Results and discussion: The results showed that the effects of experimental treatments on gas production parameters, rumen pH and ammonia nitrogen concentration were significantly different at different incubation times (p <0.05). The highest gas production potential per fermentable substrate is related to Treatment containing DCAD level of -5.66, which is supplied from two sources of phosphoric acid and sulfuric acid. As expected, the total gas production at 120 hours of incubation and also gas production at t0.5 is related to this treatment. The fermentation rate and time to reach half of the gas production potential in this treatment is average. Therefore, it can be concluded that this treatment has been able to provide suitable ruminal buffering conditions for microorganisms due to good results in DM digestibility too. The highest area below the pH curve of ruminal fluid was related to treatment with DCAD of -5.66, which was obtained from ammonium phosphate and sulfuric acid sources. The lowest level below the pH curve of ruminal fluid is related to the treatment containing DCAD -11.33, which is provided from sources of phosphoric acid and sulfuric acid. The highest ammonia nitrogen production is related to the treatment containing the anion-cation balance of 170 with two sources of sulfuric acid and phosphoric acid. Ammonia nitrogen is strongly influenced by the breakdown of crude dietary protein by microorganisms and the breakdown of the microbial population due to nitrogen recycling under adverse conditions (Ebrahimi Khoramabadi et al 2015). On the other hand, because the dry matter digestibility has increased at this time and in this treatment, this increase is probably related to the breakdown of feed crude protein due to improve fermentation conditions (Eugène et al 2004). Conclusion: In general, the use of phosphoric acid and sulfuric acid sources with the anion-cation balance of -5.66 MEq/100gDM improved the gas production parameters, the rumen pH curve under area, and the ammonia nitrogen concentration. However, in terms of the effect of anion and cation balance and anion sources, the reduction of DCAD more than -5.66 MEq/100gDM has no practical justification in terms of economic and palatability. [ABSTRACT FROM AUTHOR]

In recent years, the discharge of major pollutants in China's wastewater has been decreasing but remains at a high level. Controlling the discharge of pollutants in sewage is of great importance for protecting water quality and maintaining ecological balance. Based on data collected from 31 provinces in China from 2011 to 2020 (except 2018), this study analyzes the spatiotemporal variation emissions of the wastewater pollutants: chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen (TN), and total phosphorus (TP). The entropy method was used to evaluate the effectiveness of water pollution control in different provinces. Our results revealed that the total emission per gross domestic product (GDP) for COD, NH3-N, TN and TP in China decreased by 50.7%, 81.9%, 65.4% and 70.8%, respectively. In terms of regional annual emission differences, the Northwest region was the lowest compared with other regions, accounting for 4.87%-6.59% of the national pollutant emissions, and the Central China region was the highest, accounting for 22.4%-26.05% of the national pollutant emissions. The average value of pollutant emissions per unit of GDP decreased year-to-year overall, but Guangxi and Tibet showed a trend of first decreasing and then increasing. The correlation results indicated a significant correlation (0.977) between TN and TP emissions in wastewater in China during 2011–2020. Through clustering and Multidimensional Scaling model (MDS) analysis, Beijing and Shanghai have been performing well in controlling water pollution discharge, while the provinces of Tibet and Guangxi must still increase their efforts in water pollution control. Furthermore, these results demonstrate the experience and achievements of the Chinese government in the treatment of wastewater pollution and provide a useful reference for treatment of wastewater pollution in the world. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heavy metals (HMs) and ammonia nitrogen (AN) leaching from electrolytic manganese residue (EMR) result in the contamination of agricultural soils and water bodies. Batch and column leaching tests were conducted to simulate the release of HMs and AN in EMR during precipitation, as well as their migration and transformation in agricultural soils. The results show that Mn, AN, Cd, Ni, and Zn present in the EMR had high acid soluble fraction (un-fixed AN) content, and the leachability of Mn and AN was significantly higher than that of other hazardous elements. The cumulative release of hazardous elements in the EMR stockpile was well-fitted (R2 > 0.95) by the HILL model. Significant HMs and AN accumulated in the agricultural soils after contamination from the EMR leachate. The pollution degree of HMs in agricultural soils was ranked as Mn > Ni > Pb ≈ Zn ≈ Cr > Cd. The acid soluble fraction (un-fixed AN) content of Mn, Ni, Zn, and AN in agricultural soils increased significantly. The risk assessment code shows that the risk level of Mn in agricultural soils changed from medium to high; Ni and Zn in surface soils changed from low to medium. These results indicated that the leaching from EMR would significantly increase the ecological risk of HMs in surrounding agricultural soils, and the large release of AN would pose a great threat to aquatic systems if not properly addressed. [ABSTRACT FROM AUTHOR]

Ammonia nitrogen is an unavoidable factor in aquaculture, and it may have a severe effect on clam breeding. To explore the toxic effect of ammonia nitrogen on the clam Cyclina sinensis, the clam was exposed to ammonia nitrogen (8.07 mg/L) for 768 h (32 days) and then challenged with Vibrio parahaemolyticus. During the exposure, the hydrolases (acid phosphatase, ACP; alkaline phosphatase, AKP; lysozyme, LZM) and the interleukin 17–3 (IL-17–3) gene were assessed. The result showed that during ammonia nitrogen exposure, the activity of ACP in the hepatopancreas showed an overall upward trend, and the activity of AKP and LZM showed a trend of increasing first and then decreasing. Following infection with V. parahaemolyticus, all the hydrolases activities fluctuated in 144 h. The full-length IL17-3 cDNA is 1027 bp in length and contains a 144-bp 5′-untranslated region (UTR), a 284-bp 3′-UTR with a poly (A) sequence, and an open reading frame (ORF) of 603 bp encoding an IL17-3 protein of 200 amino acids with a deduced molecular weight of 21,986.7 Da and a theoretical isoelectric point of 6.57. The expression of IL-17–3 m RNA was detected in all selected tissues of the clam. At the onset of ammonia nitrogen stress, the expression of IL-17–3 was significantly upregulated in the hepatopancreas of C. sinensis, and reached the maximum value at 6 h. Following infection with V. parahaemolyticus, the expression of IL-17–3 in the hepatopancreas was also significantly upregulated, and reached the maximum value at 48 h. Our study may provide the first evidence of the role of the main hydrolases and IL-17–3 in clam responding to ammonia nitrogen stress. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Chinese Society of Rare Earths is the property of Editorial Department of Journal of the Chinese Society of Rare Earths and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Excessive ammonium and phosphate in aquatic settings may produce major eutrophication. Adsorbents can be used to reduce the eutrophication of natural water bodies. In this study, a sustainable and efficient ceramic adsorbent (sludge/biomass ash ceramsite [SBC]) was prepared by using sludge and biomass ash with a weight ratio of 1:1; the sintering parameters were 1070°C for 15 min. The NH4+‐N and P adsorption capabilities were improved by utilizing 1 mol L−1 NaOH and 1.6 mol L−1 La(NO3)3·6H2O for modification. When the pH and duration were 7 and 1440 min, respectively, the maximum bending capacity of ammonia nitrogen and phosphorus was 3.2 and 2.1 mg g−1 at 308 K. The pseudo‐second‐order kinetic model better describes the adsorption dynamics of NH4+‐N and P, whereas the Langmuir model better describes the adsorption isotherm models of NH4+‐N and P. The adsorption mechanism of SBC‐NaOH on NH4+‐N is ion exchange between Na+ and NH4+, whereas the adsorption mechanism of SBC‐La on phosphorus is ion exchange and La3+ adsorption. SBC combines efficient wastewater purification with the reuse of solid waste. The findings gave rise to the possibility of recycling ceramics as a plant fertilizer with a delayed release in the future. Practitioner Points: New ceramsite was made from sludge and biomass ash.NH4+‐N (3.2 mg g−1) and P (2.1 mg g−1) were effectively adsorbed by ceramsite.The mechanism of NH4+‐N and P adsorption by ceramsite was studied.Absorbed ceramsite can be used as slow‐release fertilizer in plant cultivation. [ABSTRACT FROM AUTHOR]

In order to explore the high-value utilization of agricultural and forestry waste, six common types of agricultural and forestry waste, including corn stalks, rice straw, soybean stalks, pine branches, bamboo branches, and biogas residue, were used as raw materials to prepare biochar by limiting oxygen and temperature controlling carbonization in vacuum tube furnace. The physicochemical properties and structural characteristics of biochar were analyzed by surface area analyzer, scanning electron microscope and Fourier transform infrared spectroscopy, and the adsorption capacity of biomass carbon on ammonia nitrogen and total phosphorus in swine wastewater was investigated. The results showed that six kinds of biomass carbons were alkaline, and the alkalinity of biogas residue biochar was stronger than that of plant biochar. The yield order of six kinds of biochar was as following: biogas residue biochar(64.83%) > soybean stalk biochar(57.22%) > rice straw biochar(48.80%) > corn stalk biochar(46.87%) > bamboo biochar(41.42%) > pine branch biochar(40.01%). Among them, the soybean stalk biochar had a larger specific surface area(5.84 m²/g) and developed pores. All six kinds of biochar contained abundant oxygen-containing functional groups on their surfaces, and both chemically stable C--H and benzene rings had strong stability. The six kinds of biochar had certain adsorption effects on ammonia nitrogen and total phosphorus in aquaculture wastewater, with corresponding adsorption capacities ranging from 20.00 to 31.00 mg/g and 4.00 to 6.69 mg/g, respectively. Soybean stalk biochar had the best adsorption effect on ammonia nitrogen and total phosphorus, with a saturated adsorption capacity of 31.00 mg/g and 6.69 mg/g, respectively. [ABSTRACT FROM AUTHOR]

The fermentation characteristics and microbial counts of Megathyrsus maximus ensiled at varying inclusions of Moringa oleifera seeds at different ensiling periods were investigated. Factorial experiment consisting of 3 varying proportions of grass and seeds (100:0, 75:25, and 50:50) and 4 ensiling duration (30, 60, 90, and 120 days) was carried out. The pH was significantly highest (p < 0.05) with the highest inclusion of seeds while pH decreased with increased ensiling duration. Colour and odour changed as the level of seed inclusion increased in the silage while the moisture content (9.10) was significantly higher (p < 0.05) at 30 days of ensiling. Ammonia nitrogen was highest at the highest level of seed inclusion while lactic acid was highest at 60 days of ensiling. Crude protein and tannin contents of the silage increased (p < 0.05) following the increased seed inclusion while there was a reduction as the ensiling duration increased. The total anaerobic bacteria count, total lactobacilli count, and total yeast count of the silage decreased following the increased inclusion of seeds in the silage. As the ensiling duration increased, a reduction in all the silage microbial counts was observed. Inclusion of 25 % of the seeds to 75 % of the grass for silage with ensiling up to 120 days supported improved fermentation characteristics, microbial and crude protein contents as well as a reduction in tannin content which implies that there will not be a detrimental effect on animals that feed on the silage.

Introduction: Energy and protein sources are of prime importance for ruminants as they stimulate microorganisms in the rumen and enhance the productive functions of the animals. Many species of rumen microorganisms can use ammonia as a nitrogen source for their growth and formation of microbial biomass that is key to meet the amino acid needs of the host animal. Because low-quality forages (<7% CP) are often limiting in protein, a positive relationship exists between ruminally degradable protein (RDP) supplementation and forage utilization (Koster et al., 1996). In contrast, it has been shown that forage intake did not affect mature ewes fed low-quality grass hay in response to increasing levels of supplemental RUP (Swanson et al., 2000). Similarly, Salisbury et al. (2004) reported no difference in roughage intake in wethers consuming low-quality hay supplemented with high or low RUP. However, those researchers suggested that RDP from forage could have been adequate to support ruminal fermentation. Urea is the main NPN source used in ruminants diets. However, there are still concerns regarding its use due to the rapid release of ammonia (NH3–N), which can be faster than its use by microorganisms for protein synthesis. The efficiency of protein synthesis from urea depends, among other factors, on energy availability in the rumen (Russell et al., 1992). Despite evidence of positive effects of RUP supplementation of fiber digestion, little information has been published observing the influence of slow-release urea (SRU) supplementation on the nutrient digestibility and DMI of ewe’s fed by low-quality forage. Also, feed sorting behavior that could be related to fiber digestibility in the rumen, has not been investigated in ruminant animals fed by increasing levels of slow-release coated urea. Therefore, the objective of this study was to determine how urea supplementation affects feed intake, nutrient digestibility, ruminal NH3–N, blood urea nitrogen concentration and feed sorting behavior in ewes. Material and methods: A total of 28 Arabian ewes (40±2 kg live weight) were used in a completely randomized design with four treatments for 60 days. Experimental diets included 1- control (no urea), 2-1.2% conventional urea, 3- mixture of conventional and coated urea (Optigen®) (50:50 mixture; 0.6% and 0.675% ration DM respectively), and 4- coated urea (1.35% ration DM). Ewes were housed individually in pens (1.3 m×1.5 m) in an open shed building and were allowed ad libitum access to feed and water throughout the trial. All diets contained 60% forage (wheat straw) and 40% concentrate (60 : 40; forage : concentrate). The ingredients and chemical composition of the rations fed to ewes are shown in Table 1. The ewes were fed the total mixed rations ad libitum twice daily at 0800 h and 1700 h and had free access to fresh water at all times. Feed offered and refusal of each lamb were recorded daily. Digestibility was measured by the total collection of feces during a 5-d period. Samples of ruminal fluid were collected from each ewe 0 (before morning feeding), 3, 6 and 9 h post-feeding using a stomach tube attached to an Erlenmeyer flask and vacuum pump. The first 50 ml of collected rumen fluid was discarded to avoid saliva contamination. The remaining was filtered through four layers of cheesecloth. Rumen fluid pH was measured using a portable pH meter. Blood samples were taken from each lamb at the same time as ruminal fluid sampling by venipuncture of the jugular vein in 10-mL tubes treated with sodium heparin. Samples were centrifuged in a refrigerated centrifuge at 850 × g for 30 min within 30 min of sampling, and the plasma was frozen at −20 °C until used. The sorting index was calculated as the ratio of actual intake to the expected intake of particles retained on each sieve of the PSPS (Leonardi and Armentano 2003). The predicted intake of an individual fraction was calculated as the product of the DMI of the total diet multiplied by the DM percentage of that fraction in the fed TMR. A sorting index of 100, >100 and <100 indicated no sorting, sorting for, and sorting against respectively. Data were analyzed using a GLM procedure of SAS 9.2 (SAS Institute, Inc., Cary, NC). Comparisons between treatments were completed with Tukey’s test. Treatment effects were declared significant at P≤0.05. Results and discussion: The results showed that the experimental treatments had no significant effect on intake of dry matter, organic matter, neutral detergent fiber and acid detergent fiber. Crude protein intake was lower in the control treatment relative to the other treatments (P <0.05). This finding was expected urea-containing diets designed to have higher CP content. Apparent digestibility of dry matter, crude protein, neutral detergent fiber and acid detergent fiber was not affected by the treatments. Apparent digestibility of organic matter increased in animals who received coated urea relative to the control treatment (P < 0.05). The ruminal pH of ewes was not affected by dietary treatments before morning feeding and 9 hours post-feeding. An increase in rumen pH was observed in coated urea treatment relative to the control group, 3 and 6 hours post-feeding (P < 0.05). Animals fed coated urea also had higher rumen pH compared to those fed common urea and a mixture of coated urea and common urea (P < 0.05). Rumen ammonia nitrogen concentrations were higher in all urea-containing treatments compared to the control treatment, 3 hours post-feeding (P = 0.002). At 9 hours post feeding, coated urea treatment had higher ammonia nitrogen concentration than common urea and mixture of coated urea and common urea treatments and lowest concentration observed in the control treatment (P = 0.009). Blood urea nitrogen was also higher in 3 and 6 hours post feeding in all urea-containing treatments than the control treatment (P <0.05). Ewes fed a mixture of conventional and coated urea sorted in favor of medium particles relative to other treatments (P = 0.03). Regardless of treatments ewes sorted against the longest ration particles (>19 mm) and sorted for fine particles (<4 mm) dietary particles. Conclusion: Results of this study showed that increasing levels of coated urea in diets containing low-quality forage have the potential to keep higher rumen ammonia nitrogen concentration for a longer period but this increase didn’t have a positive effect on nutrients digestibility compared to conventional urea. [ABSTRACT FROM AUTHOR]

With the rapid development of tourism and agriculture in the alluvial fan and lacustrine sedimentary plain on the western side of Erhai Lake in Dali, Yunnan Province, large amounts of NH4 +-N, NO3 --N, and NO2 --N pollutants have been generated by agricultural cultivation at the margins of the alluvial fan and by human activities within the alluvial fan. The infiltration of the 18 streams in the Cangshan Mountains drives the nitrogen-contaminated groundwater to continuously discharge into Erhai Lake, which further increases the risk of eutrophication of the water bodies of the alpine lake. The hyporheic zone has a purifying effect on the infiltrated surface water. To investigate the migration and removal patterns of nitrogen in the hyporheic zone in the alluvial fan, a simulated infiltration system of the hyporheic zone was designed, including three hydrological processes affecting the migration of the aforementioned nitrogen pollutants, namely, the infiltration of urban domestic sewage in the alluvial fan, the vertical infiltration of fertilizer applied at the margins of the alluvial fan, and the alternate recharge of the hyporheic zone by surface water and groundwater at the apex of the alluvial fan. The experimental results revealed that the hyporheic zone has good NH4 +-N and NO3 --N removal efficiencies. Their removal in the alluvial fan mainly relies on denitrification during their vertical infiltration, which generally involves two processes with opposite effects: (1) a positive-effect process involving the alternate adsorption of anions and cations in the hyporheic zone, accompa nied by nitrification and denitrification, where denitrification is the primary nitrogen removal step and nitrification plays a supplementary role, leading to pollutant concentration reduction and water purification, and (2) a negative-effect process involving nitrification and anion/cation adsorption followed by the release of Ca2+ and Mg2+ into the aqueous phase, leading to increased total hardness of the water. During the alternate recharge of the hyporheic zone by surface water and groundwater at the apex of the alluvial fan, NO3 --N removal and water purification are mainly achieved through denitrification and partial ly through dissimilatory nitrate reduction to ammonium. [ABSTRACT FROM AUTHOR]

Algal cell proliferation has posed significant problems for traditional water treatment facilities; these problems are attributed to surface hydrophilicity and electrostatic repulsion. Biological aerated filters (BAFs) have been extensively used in wastewater treatment to remove pollutants such as algal cells by utilizing the adsorption and separation capabilities of the filter media. In this study, a BAF was supplemented with biological filter medium (Marchantia polymorpha) to assess its effectiveness of pretreating aquaculture wastewater. In terms of process performance, steady and consistent treatment was achieved by the BAF with M. polymorpha (BAF2) under an algal cell density as high as 1.65 × 108 cell/L, with average removal rates for NH4+-N and algae cells of 74.4% and 81.9%, respectively. The photosynthetic activity parameters (rETRmax, α, Fv/Fm, and Ik) of the influent and effluent were quantitatively assessed, and M. polymorpha was found to remove algae by disrupting the photosynthetic system of the algal cells. Furthermore, the addition of the M. polymorpha filter medium enhanced the community structure of the functional microbes in the BAF system. The highest microbial community richness and diversity were observed in the BAF2. Meanwhile, M. polymorpha promoted an increase in the abundance of denitrifying bacteria, including Bdellovibrio and Pseudomonas. Overall, this work offers a unique perspective on the aquaculture wastewater pretreatment process and BAF design. [ABSTRACT FROM AUTHOR]

The adsorption of soil can reduce the leaching of NH4+-N from the external environment into groundwater. The adsorption of NH4+-N is affected by many factors. It is critical to use statistical model to quantitatively describe the effects of interaction between two or more factors on the system response. In this study, HJ–Biplot was used to analyze the correlation characteristics of soil water, salt, and nitrogen, and the response surface methodology and artificial neural network were used to statistically visualize the interaction between factors, including concentration, total dissolved solids (TDS), temperature, and pH. The results showed that the study soil was a typical saline soil, with maximum soil NH4+-N content of 85.45 mg/kg. For the adsorption experiments of NH4+-N on saline soils, the effects of factors on the adsorption capacity were assessed using the RSM model. The RSM model was coupled with an ANN to predict the adsorption of NH4+-N by saline soils. The NH4+-N concentration and water pH were both significant at a linear level (p < 0.0001). The interaction between NH4+-N concentration and pH was also more significant (p < 0.01). Under optimal conditions (concentration: 800 mg/L; temperature: 24 °C; TDS: 637 mg/L; pH: 7.83), the NH4+-N adsorption capacity was 1650.2 ug/g, which was in general agreement with the calculated values from the Box–Behnken and RSM model. In addition, a statistical error criterion for the model showed that the RSM–ANN model had greater predictive ability than RSM model. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)