Ammonia Treatment Research Articles

Impact of ammonia treatment and platinum group or nickel metal decoration on the activated carbon storage of carbon dioxide and methane

Greenhouse gases, chiefly carbon dioxide (CO2) and methane (CH4), emission is responsible for the global warming and heat waves which strike the world causing floods and droughts everywhere with more CO2 attributions. The adsorption and desorption capacities of CO2 and CH4 at room temperature and up to 5.0 and 100 bar, respectively, were investigated for the untreated and ammonia-treated activated carbons (ACs), metal-anchored (metal: Ru, Rh, Pd, Ir or Ni) samples. We merged ammonia treatment and metal decoration to discover their influences on the CO2 and CH4 storage capability of ACs and the potential use of such modified ACs for capturing greenhouse gases and purifying natural gas from CO2. The CO2 storage capacities ranged between 25.2 and 27.7 wt% at 5.0 bar with complete regeneration upon desorption, while the uptakes for CH4 were in the range of 9.6 − 12.6 wt% at 35 bar with hysteresis behavior of the adsorbed gas. The highest adsorption capacities were achieved for the pristine samples, showing that metal decoration reduced slightly the adsorption. Ammonia-treated samples showed minor enhancing effect on the CH4 adsorption in comparison to the CO2 adsorption. The higher adsorption capacities of CO2 than those of CH4 could be employed for upgrading the natural gas, while the 9.6 wt% (2.2 mmol g−1) CO2 storage capacity would allow for its removal from the flue gases at ambient temperature and pressure. The higher adsorption capacity and preferentiality of CO2 over CH4 could be attributed mainly to its higher quadrupole moment and its higher clustering above the AC surfaces, while a minor effect, if any, would be attributed to the modifications of the ACs, implying that physisorption mechanism acted significantly in the adsorption process in comparison to chemisorption mechanism at the studied conditions.

Application of proteomics and metabolomics to assess ammonia stress response and tolerance mechanisms of juvenile ornate rock lobster Panulirus ornatus.

Ammonia is a common pollutant in the aquatic ecosystem and closed aquaculture systems. It may pose a threat to the lobster growth, reproduction and survival. However, there is lack of research of the mechanisms on the toxic effects ammonia at molecular levels. In this work, proteomics and metabolomics were integrated to analyze the proteome and metabolome responses in the ornate spiny lobster Panulirus ornatus treated with ammonia (20 mg L-1) for 48 h. A total of 199 proteins and 176 metabolites were significantly altered in P. ornatus following ammonia treatment. The responsive proteins and metabolites were predominantly involved in immune response, phase I and phase II biotransformation, carbohydrate metabolism, amino acid metabolism, and lipid metabolism. Furthermore, an increase in urea levels was observed, and amino acid metabolism was induced, indicating that the urea cycle was utilized to biotransform ammonia so as to reduce endogenous ammonia content. Ammonia exposure also affected the antioxidant system and induced cellular apoptosis. Overall, our results provide comprehensive insights into the molecular mechanisms underlying the response of P. ornatus to ammonia stress. We believe that the data reported herein should contribute to the development of novel, efficient methods for P. ornatus aquaculture.

Mitochondrial Changes in Rat Brain Endothelial Cells Associated with Hepatic Encephalopathy: Relation to the Blood–Brain Barrier Dysfunction

The mechanisms underlying cerebral vascular dysfunction and edema during hepatic encephalopathy (HE) are unclear. Blood–brain barrier (BBB) impairment, resulting from increased vascular permeability, has been reported in acute and chronic HE. Mitochondrial dysfunction is a well-documented result of HE mainly affecting astrocytes, but much less so in the BBB-forming endothelial cells. Here we review literature reports and own experimental data obtained in HE models emphasizing alterations in mitochondrial dynamics and function as a possible contributor to the status of brain endothelial cell mitochondria in HE. Own studies on the expression of the mitochondrial fusion-fission controlling genes rendered HE animal model-dependent effects: increase of mitochondrial fusion controlling genes opa1, mfn1 in cerebral vessels in ammonium acetate-induced hyperammonemia, but a decrease of the two former genes and increase of fis1 in vessels in thioacetamide-induced HE. In endothelial cell line (RBE4) after 24 h ammonia and/or TNFα treatment, conditions mimicking crucial aspects of HE in vivo, we observed altered expression of mitochondrial fission/fusion genes: a decrease of opa1, mfn1, and, increase of the fission related fis1 gene. The effect in vitro was paralleled by the generation of reactive oxygen species, decreased total antioxidant capacity, decreased mitochondrial membrane potential, as well as increased permeability of RBE4 cell monolayer to fluorescein isothiocyanate dextran. Electron microscopy documented enlarged mitochondria in the brain endothelial cells of rats in both in vivo models. Collectively, the here observed alterations of cerebral endothelial mitochondria are indicative of their fission, and decreased potential of endothelial mitochondria are likely to contribute to BBB dysfunction in HE.

The synergetic effect of Bacillus species and Yucca shidigera extract on water quality, histopathology, antioxidant, and innate immunity in response to acute ammonia exposure in Nile tilapia

Acute ammonia toxicity suppresses the immune function and enhances the inflammatory pathways in Nile tilapia. The aim of this study was to compare the effect of Bacillus strains probiotic mixture (BS) or Yucca shidigera liquid extract (YSE) alone or their combination in water treatment and in reliving toxicity of an acute ammonia exposure in Nile tilapia through the assessment of fish immune response, inflammatory pathway, oxidative stress response with respect to the histopathological changes, gene expression, enzymes levels and phagocytosis. Five groups were used; the 1st and 2nd groups fed the basal diet; the 3rd group fed basal diet with BS in water, 4th group fed basal diet and supplemented with YSE in water and 5th group received a combination of BS and YSE. After two weeks of treatments, the 2nd, 3rd, 4th, and the 5th groups were exposed to acute ammonia challenge for 72 h. Fish exposed to ammonia displayed significant decreases in RBCs, Hb, PCV, WBCs, phagocytic activity (PA) and index (PI), lysozyme activities and serum antioxidant enzymes (glutathione peroxidase (GPX) and catalase (CAT)). Also, a significant increase in Malondialdehyde (MDA), degenerative changes in the gills, hepatopancrease and spleen associated with an elevated un-ionized ammonia level. A significant restoration of the hematological parameters was observed with the use of BS, YSE or their combination. Additionally, they improved the innate immunity, antioxidant responses, and histopathological changes. At transcriptomic level, ammonia toxicity significantly lowered the mRNA transcription levels of Nuclear erythroid 2-related factor 2 (Nrf2), quinone oxidoreductase 1 (NQO-1), Heme oxygenase 1 (HO-1) and Heat shock proteins (HSP70). While nuclear factor kappa β (NFкβ), Tumor necrosis factor α (TNF-α), Interleukin 1β (IL-1β), and Interleukin 8 (IL8), transcription levels were increased. Interestingly, BS and YSE and their combination significantly increased the expression of these genes with the highest levels reported with BS and YSE combination. We observed that, the most pronounced restoration of some important inflammatory and immune related genes close to the control level was observed when BS-YSE mix was used. Furthermore, a restored water pH, and a maintained ammonia level to the control level were observed in this group. Otherwise, equal effects for the three treatments were observed on the assessed parameters. We recommend the used of BS-YSE mix for water ammonia treatment and relieving ammonia toxicity in fish.

Removal of lignin and silica from rice straw for enhanced accessibility of holocellulose for the production of high-value chemicals

The intricate nature and rigidity of rice straw, particularly the presence of lignin and silica, hinders the catalytic valorization, consequently decreasing the yield of target products. This study reports the concurrent removal of lignin and silica from rice straw to obtain enriched holocellulose, then transforming it to furfural (FUR) and levulinic acid (LA). Interestingly, rice straw in the form of powder displays an improved removal of lignin (51.0%) and silica (92.0%) during ammonia treatment. Encouragingly, adding organic solvents, such as THF, to the aqueous system during the pretreatment of rice straw improves the lignin removal to 60.0%. Upon improving lignin removal to 60%, the obtained holocellulose enriched solid residue yields 71.0% FUR along with 52.0% LA, which is 8 and 4-fold higher than what is obtained with parent rice straw, signifying the importance and the prerequisite of lignin and silica removal from rice straw.

(Digital Presentation) Electrocatalytic Ammonia Oxidation Coupled with Hydrogen Production - Moving Towards a Carbon Neutral Water Treatment Cycle

Ammonia is a common pollutant, present in municipal wastewater streams. With the continuous shift of people moving to cities and the growing world’s population, the overall wastewater amount is rising. Current ammonia treatment processes in wastewater treatment plants include biological nitrification. Here the ammonia is converted to nitrate or nitrogen. Unfortunately, the capital and operational expenditure costs of such processing are high and the ammonia is converted to products that have no value.Ammonia is a carbon-free energy carrier. Recently, technological solutions have been introduced to strip ammonia from wastewater [1]. The recovered ammonia can be electrochemically oxidised to benign nitrogen in an electrolyser, which can offer a cost-efficient technology to couple wastewater remediation at an anode with the production of a valuable by-product at the cathode, hydrogen. Currently, the commercialisation of the ammonia electrolyser technology is hindered by slow reactions at the anode and the cathode as well as the deactivation or degradation of the catalysts over time [2,3]. Consequently, the development of inexpensive, efficient anode material is imperative to reduce costs associated with ammonia destruction and electrochemical hydrogen production.This study focuses on a non-noble metal NiCu catalyst as a durable anode for alkaline ammonia electrolysis. We report that nickel-copper catalysts can oxidise ammonia to nitrogen at room temperature, see figure below. During electrolysis experiments, gas chromatography of the off-gases confirmed that both, nitrogen at the anode and hydrogen at the cathode, are generated with high faradaic efficiencies. Anode morphology and structure before and after electrolysis was investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray Photoelectron Spectroscopy (XPS), and scanning electron microscopy (SEM). To monitor possible intermediates produced by electrolysis, the electrolyte was analysed for NOx regularly by cuvette test and the electrode off-gasses were continuously monitored by GC-TCD. Overall, the electrode showed stability after continuous electrolysis in ammonia for over 30 hours. Further results will be presented at the conference.

(Digital Presentation) High-Temperature Ammonia Treatment for Carbon Felt Electrodes in All-Vanadium Redox Flow Batteries

Ammonia gas treatments of varying temperature were performed on carbon felt electrodes in this study. Their physical and electrochemical properties were investigated.Carbon felt electrodes are often used in vanadium redox flow batteries (VRFBs). Without processing, carbon felt has poor wettability which frustrates electrochemical activity. This material must be modified to improve performance, which has been historically accomplished with thermal treatments ostensibly to promote oxygen functional groups, although this has been the subject of debate as morphological impacts have also been observed. [1-3] Many attempts have been made to improve performance of carbon felt in VRFBs, but some of the more successful modifications have resulted in an increase in the specific surface area. [4-6] Previous research at the University of Tennessee Knoxville suggests edge sites play a role in improving performance. Preliminary experiments on carbon felt performed by this lab with ammonia at high temperatures have shown promising results. Additional experiments were performed at 900°C by varying length of treatment time, finding four hours to be optimal. [3] New experiments have been done to investigate the kinetic effects of temperature.For these experiments, commercially available carbon felts (SIGRACELL® GFD3 by SGL Carbon, Meitingen, Germany) were modified by exposure to flowing ammonia gas through a furnace at (500°C, 700°C, 900°C, and 1100°C) varying temperatures for four hours. The samples were tested in a single-cell flow battery using cyclic voltammetry (CV), polarization curves, and electrochemical impedance spectroscopy (EIS). This treatment results in a significant increase in electrochemical surface area and performance.The physical properties were characterized using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and Raman spectroscopy. This was done to study the mechanism and kinetic effects of ammonia on the carbon felt material as temperature increases during the treatment itself. Samples treated at the highest temperatures exhibited a notable loss of mass, which is observed in the SEM images in Figure 1. This resulted in a significant increase in edge sites and active surface area, along with a substantial increase in cell performance, which was achieved with the ammonia-modified carbon felts described in this work, with over three times the current density at 80% voltage efficiency compared to untreated felt. Sun, B. and M. Skyllas-Kazacos, Modification of graphite electrode materials for vanadium redox flow battery application—I. Thermal treatment.Electrochimica Acta, 1992. 37(7): p. 1253-1260.Pezeshki, A.M., "Impedance-Resolved Performance and Durability in Redox Flow Batteries. " PhD diss., University of Tennessee, 2016.Gass, K., High Performance Vanadium Redox Flow Battery Electrodes. [manuscript under submission], 2021.Lu, W., et al., High-performance porous uncharged membranes for vanadium flow battery applications created by tuning cohesive and swelling forces.Energy & Environmental Science, 2016. 9(7): p. 2319-2325.Zhou, X.L., et al., A high-performance dual-scale porous electrode for vanadium redox flow batteries.Journal of Power Sources, 2016. 325: p. 329-336.Wei, L., et al., Highly catalytic hollow Ti3C2Tx MXene spheres decorated graphite felt electrode for vanadium redox flow batteries.Energy Storage Materials, 2020. 25: p. 885-892. Figure 1. SEM images at 30,000X magnification of carbon felt electrodes: a) untreated, b) 4 hours NH3 treated at 500°C, c) 4 hours NH3 treated at 700°C, d) 4 hours NH3 treated at 1100°C. Scale was identical for all micrographs Figure 1

Cattail leaf-derived nitrogen-doped carbons via hydrothermal ammonia treatment for electrocatalytic oxygen reduction in an alkaline electrolyte

Cattail leaf-derived nitrogen-doped carbons (CL-NCs) were prepared by hydrothermal treatment in ammonia solution and subsequent pyrolysis for application as catalysts for the oxygen reduction reaction (ORR). The ammonia concentration was varied at 1.0, 1.5, and 2.0 M to alter the nitrogen doping content. The characterization results revealed that CL-NCs exhibited an amorphous structure, while the density of structural defects increased as the ammonia concentration increased. The CL-NC prepared without hydrothermal ammonia treatment had a nonporous structure with a low specific surface area (5 m2 g−1). With hydrothermal ammonia treatment, CL-NCs exhibited a micro–mesoporous structure with a higher surface area (113–496 m2 g−1); however, the surface area was significantly diminished at higher ammonia concentrations due to the deterioration of the pore structure. The nitrogen-doping content in CL-NCs varied from 0.65 to 1.55 atom% with the predominant ratios of pyridinic-N and graphitic-N. For electrochemical evaluation in an alkaline electrolyte (0.1 M KOH), CL-NC prepared at an ammonia concentration of 1.0 M showed the highest ORR activity among all samples, as indicated by the most positive onset potential (−0.05 V vs. Ag/AgCl) and half-wave potential (−0.22 V vs. Ag/AgCl) as well as the highest diffusion-limiting current density with a more favorable reduction via a direct four-electron pathway (n = 3.23–3.52). The ORR activity of CL-NCs had a similar trend to their specific surface area rather than nitrogen doping content, indicating the important role of surface area and porosity in enhancing the ORR activity. Moreover, it possessed excellent stability under long-term operation and exposure to methanol. The results obtained in this work could be helpful information for the further development and utilization of biomass-derived NCs for ORR catalysts.

Vacuum-enhanced anaerobic fermentation: Achieving process intensification, thickening and improved hydrolysis and VFA yields in a single treatment step

This study assessed the feasibility of a novel vacuum-enhanced anaerobic digestion technology, referred to as IntensiCarbTM (IC), under mild vacuum pressure (110 mbar), compared to a control (conventional fermenter), and evaluated the impact of the vacuum on the activities of various microbial groups. Both fermenters (test and control) were operated with mixed (50% v/v) municipal sludge at solids concentrations of 2–2.5%, pH of 7.8–8.1, 40–45 °C, a theoretical solids retention time (SRT) of 3 days with different hydraulic retention times (HRT). The intensification factor (IF) of the IC, defined as SRT/HRT, was controlled at 1.3 and 2.0. Simultaneous thickening and fermentation intensification were achieved. Compared with the control, the IC, despite the shorter HRTs, achieved 29.5 to 90.2% increase in the VFA yield (79 to 116 mg ΔVFA/ g VSS vs 61 mg ΔVFA/ g VSS), and 16.2% to 56.4% increase (280 to 377 mg ΔsCOD/ g VSS vs 241 mg ΔsCOD/ g VSS), in the hydrolysis yield. Fermentate from the IC exhibited comparable specific denitrification rates to acetate. Further, the solids-free condensate contained low nutrient concentrations, and thus was far superior to a typical centrates from dewatering as a carbon source. No adverse effects of vacuum on the activity of fermentative bacteria and methanogens were observed. This study demonstrated that the IC can be deployed as an intensification technology for both fermentation and anaerobic digestion of biosolids with the additional significant advantage, i.e. elimination of sidestream ammonia treatment requirements.

Effects of ammonia-treated maize on growth performance of beef cattle

High-moisture cereal grains are often treated with ammonia to prevent spoilage and for perceived animal performance advantages, but there are few reports on the effects of ammonia treatment of cereal on cattle performance. This study was carried out on 101 Charolais cattle to quantify the effects of feeding ammonia-treated maize on the performance of intensively fattened beef cattle. Animals were assigned to 16 pens in two sheds and all animals in each pen were fed on the same diet for 176 d. The cereal in the diets was either ammonia-treated maize (ATM) or untreated maize diet (UTM), formulated to be approximately isoenergetic and isonitrogenous. Cattle fed ATM had a lower feed conversion ratio (FCR) (6.14 ± 0.39 vs 6.49 ± 0.41 kg DM/kg BW; p = 0.011) and tended to have a higher average daily liveweight gain (ADG) (1.60 ± 0.10 vs 1.54 ± 0.10 kg/d; p = 0.060). The pH of the ruminal fluid at slaughter was higher (p < 0.001) in animals that were fed the ATM diet (6.35 ± 0.69) compared to those fed the UTM diet (5.46 ± 0.33). No differences were found in the concentrations of NH3 or total VFA in ruminal fluid between the two groups. The molar proportion of butyric acid from all VFAs was lower in animals fed ATM than UTM (14.69 ± 3.55% and 18.04 ± 2.97% respectively; p = 0.012), and the molar proportion of propionic acid was higher in the ATM than the UTM groups (22.14 ± 1.54% and 19.54 ± 1.72% respectively; p < 0.001). The ratio of acetic acid to propionic acid was significantly lower in animals fed ATM compared to those fed UTM (ATM vs UTM: 2.64 ± 0.26 vs 2.97 ± 0.29; p = 0.0038). Faecal starch was lower in cattle fed ATM than untreated maize (UTM) (14.73 ± 5.65 vs 18.14 ± 4.27% DM; p < 0.001). The pH of faeces in the ATM group was higher than that in the UTM group (4.75 ± 0.19 vs 4.55 ± 0.19; p < 0.001). In conclusion, ammonia treatment of maize resulted in increased ADG and decreased FCR, with reduced faecal starch concentration, suggesting possible gains in efficiency of starch utilisation.

Characterization of Isolated Aerobic Denitrifying Bacteria and Their Potential Use in the Treatment of Nitrogen-Polluted Aquaculture Water

Ammonia and nitrite treatments are the critical steps that must be done to ensure the healthy growth of aquatic animals. The nitrification process is often used for nitrogen removal purposes due to its efficiency and environmentally friendly properties. However, the varied growth rate between ammonia and nitrite-oxidizing bacteria can cause nitrite accumulation, leading to the massive mortality of aquatic animals at high concentrations. Therefore, this study aimed to integrate the fast-growing heterotrophic nitrite-reducing bacteria with nitrifying bacteria to achieve a quicker nitrite removal activity. The two denitrifying Bacillussp. ST20 andBacillussp. ST26 were screened from shrimp ponds in Bac Lieu province, Vietnam. Obtained results showed that under anoxic conditions, the nitrite removal efficiency of these two strains reached 68.5-82% at nitrite initial concentration of 20mgN-NO2/L after 72h. Higher efficiency of over 95% was gained under oxic conditions. Hence, it enabled the use of denitrifying and nitrifying bacteria-co-immobilized carriers for ammonia oxidation and nitrite reduction simultaneously in a single-aerated bioreactor. A total of over 96% nitrogen content was removed during the bioreactor operation, despite the increase of inputting nitrogen concentration from 40 to 200mgN/L. Moreover, the suitable conditions for bacterial growth and nitrite conversion activity of the ST20 and ST26 were detected as 15‰ salinity and 35°C. The isolates also utilized various C-sources for growth, hence widening their applicability. The present study suggested that the isolated aerobic denitrifying bacteria are potentially used for the complete removal of nitrogen compounds from aquaculture wastewater.

Evaluation of Growth Performance, Nitrogen Balance and Blood Metabolites of Mutton Sheep Fed an Ammonia-Treated Aflatoxin B1-Contaminated Diet.

Experiments were conducted to evaluate the effects of an aflatoxin B1 (AFB1)-contaminated diet treated with ammonia on the diet detoxification and growth performance, nutrient digestibility, nitrogen utilization, and blood metabolites in sheep. Twenty-four female mutton sheep with an initial body weight of 50 ± 2.5 kg were randomly assigned to one of three groups: (1) control diet (C); (2) aflatoxin diet (T; control diet supplemented with 75 μg of AFB1/kg of dry matter); and (3) ammoniated diet (AT; ammoniated aflatoxin diet). The results showed decreases (p < 0.05) in average daily feed intake, nutrient digestibility of dry matter, crude protein and ether extract, and retained nitrogen, and an increase (p < 0.05) in urine nitrogen excretion in sheep fed diet T compared with those fed the other diets. In comparison to C and AT, feeding T decreased (p < 0.05) the concentrations of total protein, immunoglobulin A, immunoglobulin G, immunoglobulin M, superoxide dismutase, and total antioxidants and increased (p < 0.05) the concentrations of alanine amino transferase, malondialdehyde, and interleukin-6. In summary, ammonia treatment has the potential to decrease the concentration of AFB1 and alleviate the adverse effects of AFB1.

An overview of the biological ammonia treatment, model prediction and control strategies in water and wastewater treatment plant

Water disruption has always been a major issue in Malaysia. The reason for the frequent water disruption is due to the shutdown of water treatment plant (WTP) for unable to process contaminated raw water from the river. In wastewater treatment plant (WWTP), main source of ammonia is from the breakdown of proteins and amino acids in organic waste. Typically, ammonia is not fully removed from the WWTP and most of the ammonia is being discharged together with the plant effluent into the river streams. High levels of ammonia in the water exerts an oxygen demand which causes oxygen depletion. Hence, affecting the aquatic ecosystem and creates a toxic environment for the aquatic life. Biological treatment is known to be the most cost saving method as it only constructs of simple components, chemical free treatment and producing no harm by-products which later cause cost increment for additional treatment. Furthermore, biological treatment is capable in producing high quality treated drinking water that meets the standard water guidelines and regulations. In this paper, the aim is to conduct an overview on the application of biological treatment as an alternative treatment method of ammonia removal in water and wastewater treatment plant. This overview presents the cohesive approach of biological treatment in water and wastewater treatment plant, source of ammonia pollution, standard implies on ammonia concentration to control potential hazards, reported cases and recent pollution status of ammonia globally. In addition, the use of an artificial intelligence for model prediction and control strategies for water treatment have been included in this overview.

Injected Anhydrous Ammonia Is More Effective Than Broadcast Urea as a Source of Nitrogen for Drill Seeded Rice

Anhydrous ammonia is a cheaper source of nitrogen (N) fertiliser than granular urea for rice production, but it is not widely used in developing countries. It can only be applied pre-crop with any in-crop applications being applied in the form of urea. This 2-year study conducted in the Nile delta region of Egypt compared pre-crop anhydrous ammonia injected to a depth of 20 cm with broadcast urea as N sources for rice, along with 4 combinations of pre-crop ammonia and in-crop urea. Each treatment supplied a total of 165 kg N/ha. The rice crop was direct seeded rather than transplanted. The highest yields were achieved in the full anhydrous ammonia treatment, which yielded 53% more grain than the nil-N control, while the full urea treatment yielded 22% more than the control; most combination treatments were intermediate. The higher grain yield of the anhydrous ammonia treatment was through a higher panicle density per unit area and more filled grains per panicle. An economic analysis found that the anhydrous ammonia treatment had a net return 70–94% higher than supplying the same quantity of N as urea. Counts of bacteria, fungi and actinomycetes showed a decline by day 2 after injection of anhydrous ammonia, followed by an increase to numbers similar to or above pre-injection levels by day 5. The findings indicated that pre-crop anhydrous ammonia in rice is both economically promising and not deleterious to soil microbes.

Water quality assessment and pollution threat to safe water supply for three river basins in Malaysia

Pollution in raw water poses increasing threats to safe water supply in many developing countries. Therefore, a comprehensive water quality assessment is essential to provide various stakeholders the information to deal with this problem. This study applies chemometrics to interpret a recent 10-year water quality data from three major river basins (Selangor River basin, Langat River basin, and Klang River basin) frequented by water supply disruptions in Selangor, Malaysia. We present the application of selected chemometrics approaches, namely agglomerative hierarchical cluster analysis, principal component analysis, factor analysis and Man-Kendall trend analysis. The results showed three spatial groups of monitoring stations with similar land use practices and pollution characteristics. Besides spatial differences, periodic variations were observed when similar pollutants exhibited different pollution loads during rainy and dry periods. We found that nitrogen species, total suspended solids, and dissolved solids represented the major pollution loads in the studied basins. The results further confirmed a significant increasing trend in ammonia pollution. Our study demonstrates how ammonia pollutant is likely to pose a threat to water supply and highlights the vulnerability of Selangor's water resource system to water pollution. The results of this study could facilitate decision making towards more holistic strategies, specifically, incorporating ammonia treatment facilities into the conventional water treatment plant will help achieve smooth water supply operations.

Effects of water activity, ammonia and Corynebacterium urealyticum on the survival of Salmonella Typhimurium in sterile poultry litter.

This study examined the effects of water activity (aw ), ammonia and Corynebacterium urealyticum on the survival of Salmonella Typhimurium in sterile poultry litter. Sterile poultry litter inoculated with S. Typhimurium was adjusted to pH 9.0, various aw levels (0.84, 0.92 and 0.96), and total ammonia nitrogen levels were increased either by the addition of ammonium sulphate or C. urealyticum inoculation with 1% urea added. All litter treatments were incubated at 30°C and sampled daily for five days. Similar results were observed at each aw level in both experiments. At 0.84 and 0.92 aw , S. Typhimurium populations in litter fell below 1logCFUg-1 within 5days, with no significant differences between the controls and increased ammonia treatments. At 0.96 aw , Salmonella populations treated with increased ammonia levels were significantly lower than control treatments on days 1-5. This study showed that C. urealyticum can produce ammonia in litter at higher aw levels with sufficient available urea and that the antimicrobial efficacy of ammonia is dependent on high aw (~0.96) in litter. These results provide insights into the production of ammonia in litter, its antimicrobial efficacy in litter and the importance of aw in this interaction.

Comparison of lipid metabolism between broodstock and hybrid offspring in the hepatopancreas of juvenile shrimp (Macrobrachium nipponense): Response to chronic ammonia stress.

Ammonia nitrogen is a major pollutant that causes great physiological harm to crustaceans in culture. In this study, we conducted a 28 day chronic ammonia nitrogen stress experiment with broodstock populations (Dianshan, DS) and hybrid offspring populations (DS ♀ × CD (Changjiang ♂ × Dongting ♀), SCD) exposed to 0, 1 and 10mg/L of ammonia concentrations. A 28 day feeding trial and chronic ammonia nitrogen stress were used to investigate the effects on the growth performance, histological structure and lipid metabolism of juvenile shrimp, Macrobrachium nipponense. Our results indicated that survival rates in the SCD groups were significantly higher than those in the DS groups, whereas weight and length gain rates were not significantly different between the groups (p > 0.05). Histological structure results showed that the number of vacuoles in the DS group was significantly higher than that in the SCD group and hepatopancreas cell structures were disrupted in the ammonia treatment groups. The results of oil red staining showed that the number of lipid droplets increased significantly with the increase in ammonia concentration. As the ammonia concentration increased, fatty acid contents, lipid enzyme activities and lipid metabolism-related gene expression all tended to rise. In conclusion, ammonia nitrogen exposure caused damage to the hepatopancreas structure of juvenile shrimp and disturbed the lipid metabolism of the hepatopancreas. In addition, the SCD population had stronger stress resistance than the DS population when subjected to the same concentration of ammonia nitrogen stress.

Facile fabrication of natural superhydrophobic eleostearic acid-SiO2@cotton fabric for efficient separation of oil/water mixtures and emulsions

Oily wastewater generated by industrial production and marine oil spill accidents has caused great damage to the environment and human health. The development of superhydrophobic materials prepared from natural resources for oil/water separation is of great significance. In this work, a bio-based modified fabric for oil/water separation was prepared by coating SiO2 and eleostearic acid (EA) on cotton fabric. Due to the rough surface provided by SiO2 and the low-surface-energy EA, the eleostearic acid-SiO2@cotton fabric (EA-SiO2@CF) displayed durable superhydrophobicity even under various harsh environments. The acid-stable SiO2 particles and EA molecules endowed the modified cotton fabric with resistance to high concentrations of strong acid. EA-SiO2@CF also showed pH-responsive behavior, converting between superhydrophobic and superhydrophilic states by ammonia treatment and immersion in EA solution. The superhydrophobic EA-SiO2@CF was used to separate various immiscible oil/water mixtures and surfactant-stabilized (oil-in-water and water-in-oil) emulsions with high separation efficiencies of about 99.5%. This work provides an easy strategy to prepare an environmentally friendly superhydrophobic material which can be applied to the treatment of oily wastewater, anti-corrosion protection, and intelligent response.

Influence of Sequential Liquid Ammonia and Caustic Mercerization Pre-Treatment on Dyeing Performance of Knit Cotton Fabric.

A two-stage sequential pretreatment including caustic mercerization (CM) and liquid ammonia (LA) treatment was applied to investigate the influence on dyeing performance and handle of knit cotton fabric, and the relationship between dye size and dyeing properties. Various techniques were applied to characterize all the treated fabrics. X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) analyses of the treated fabrics confirmed that both sequential treatments decreased the crystallinity of cotton fabric more than only the CM or LA treatment. The pattern of cellulose I was transferred to a mixed configuration of cellulose II and cellulose III after the CM/LA or LA/CM treatment. Thermal performances measured by thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) techniques showed that the thermal stability of the treated cotton only marginally decreased. The wicking height increased after the sequential CM/LA treatment, indicating that the hydrophilicity of the fabric increased. The dye absorption and color uniformity were better for the reactive dye with a smaller molecular weight (Reactive Red 2) compared with the one with a larger molecular weight (Reactive Red 195). The total dye fixation efficiency (T%) increased to 72.93% and 73.24% for Reactive Red 2 dyeings of CM/LA- and LA/CM-cotton fabric from 46.75% of the untreated fabric, respectively; the T% increased to 65.33% and 72.27% for Reactive Red 195 dyeings of CM/LA- and LA/CM-cotton fabric from 35.17% of the untreated fabric, respectively. The colorfastness and dye exhaustion and fixation percentages of the samples were enhanced after the treatments. Furthermore, compared to the single CM or LA treatment, the softness handle properties were further improved after the fabrics were sequentially treated by CM/LA. The developed pre-treatment of CM/LA can be used in the textile industry to promote the dyeability, handle, and mechanical properties of knit cotton fabrics.

Zirconia prepared from UIO-66 as a support of Ru catalyst for ammonia synthesis

The development of effective Ru catalyst for ammonia synthesis is of important practical value and scientific significance because of the wide application of ammonia as a fertilizer and its promising applications in the renewable energy. Generally, ZrO2 was regarded as an inferior support for Ru catalyst used in ammonia synthesis. Here we prepare ZrO2 with monoclinic phase and carbon species from ZrCl4 following the preparation route of UiO-66 as well as ammonia treatment. Owing to the presence of a larger amount of hydrogen adsorption as well as the easier desorption of hydrogen species, the ill effect of hydrogen species on the nitrogen adsorption-desorption and ammonia synthesis can be effectively alleviated. The resulting ZrO2-supported Ru catalyst showed 4 times higher ammonia synthesis activity than the conventional Ru/ZrO2 obtained from zirconium nitrate.