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The invasion of foodborne pathogens remains a serious problem for researchers and regulators in the food industry. The introduction of a new type of potent antibacterial agent is of great importance for controlling bacteria and fungi. This study aimed to investigate a novel antimicrobial agent, such as iron oxide nanoparticles (IONPs), which are biosynthesized by a simple, fast, eco-friendly, and efficient method using Penicillium roqueforti MK805460.1. The obtained iron oxide nanoparticles were covered by SiO2 layer using stober method. The biosynthesized nanoparticles were characterized by UV-Vis spectroscopy, energy dispersive X-ray (EDX), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Antibacterial activity of the nanoparticles with different concentrations of 50, 100, 150, and 200 μg/ml was examined against Gram-positive bacteria (Staphylococcus aureus ATCC 25923 and bacillus subtilis ATCC 6633) and Gram-negative bacteria (Salmonella typhimurium ATCC 14028 and Escherichia coli ATCC 8739) by agar well diffusion and kinetic bacterial growth methods. While, the antifungal activity of nanoparticles was tested against Aspergillus niger, Aspergillus fumigatus, and Aspergillus flavus using the dry weight mycelial method. According to UV-Vis spectroscopic study, the wavelength band observed in the region 204–266 nm, indicating the formation of iron oxide nanoparticles. In addition, spheres of 5–16 nm-sized iron oxide nanoparticles were confirmed via TEM. Also, the results showed that the modified silica nanoparticles had more significant antimicrobial activity than the iron oxide nanoparticles.

The X-ray repair cross-complementing 1 (XRCC1) enzyme plays an important role in the DNA repair pathway. XRCC1 polymorphism increased the risk of human oral squamous cell carcinoma. Loading of thymoquinone on gold nanoparticles as a drug carrier, had revealed a superior anti-cancer effect as a chemotherapeutic agent in DMBA-induced OSCC. This study aimed to evaluate the expression of DNA repair enzyme X-ray repair cross-complementing 1 (XRCC1) following treatment of induced oral cancer in hamster buccal pouch with thymoquinone (TQ) only and loaded on gold nanoparticles (AuNps). Sixty male Syrian golden hamsters were divided into 4 groups: Group A: (negative control). The left pouches of the rest of animals were painted with the carcinogen DMBA (3times / week/ 12 weeks), then: Group B: (positive control), Group C: painted and injected intraperitoneally (i.p) with TQ only (3 times/week for 6 and 12 weeks). Group D: painted with TQ loaded on AuNps (3 times/week for 6 and 12 weeks). After euthanization, all pouches were surgically excised, fixed and processed for H&E and XRCC1 immunohistochemical stains. Groups B, C1, C2, and D1 showed well-differentiated squamous cell carcinoma with low intensity of immune staining. Groups D2 showed remarkable regression of tumors both clinically and histologically with high intensity of IHC staining. Loading of TQ at low concentration (0.001 mg/kg) on AuNps /12 weeks was a promising chemotherapeutic combination, through enhancing XRCC1 expression to regress the carcinogenesis process. This effect could be due to the anti-oxidant, free-radicle scavenging effect and enhancing apoptosis by TQ.

Different types of DNA damages occur during the induced oral carcinogenesis, which can be eliminated through several DNA repair pathways. XRCC1 and ERCC1 are the main repair enzymes involved in repair of oral squamous cell carcinoma. A combination of thymoquinone with gold nanoparticles as a novel chemotherapeutic modality is the aim of the present work against chemically induced SCC in the classic model of HBP/DMBA carcinogenesis. One hundred male Syrian golden hamsters were divided into: Group A: Ten animals (negative control), group B: Ten animals (positive control) painted with DMBA only 3times / week/ 12weeks. The rest of animals were painted with DMBA (3times / week/ 12weeks) then painted and injected intraperitoneal with TQ only, 0.01mg/kg TQ-GNps, 0.001mg/kg TQ-GNps or GNps only for 6- and 12- weeks, intervals. By end of the experiment, both pouches from all groups were surgically excised, fresh samples from each pouch were processed for RT-PCR technique. The rest of the pouches were fixed and processed for H&E evaluation. Loading of thymoquinone on gold nanoparticles was promising chemotherapeutic combination, through regression of well-differentiated SCC (positive control) to dysplasia and enhanced expression of the studied DNA repair enzymes compared to either thymoquinone or gold nanoparticles groups.

Scenedesmus species, immobilized on alginate gel, was found effective in removing nitrate, atrazine, magnesium, phosphorus, zinc, oxadiazon, and triallate from groundwater in a continuous flow reactor. The laboratory-scale experiments with synthetic groundwater, made of 8.8 mg/L NO3 -N and 90 µg/L atrazine, were performed at a hydraulic retention time of 7 days and the temperatures of 20 and 35°C. The highest uptake of nitrate and atrazine was observed at 20°C (97% and 70%, respectively). When tested in actual groundwater, 92% of nitrate, 100% of magnesium, 99.9% of phosphorus, and 92% of zinc were successfully removed at the end of 29 days' treatment operations. The algal beads removed 100% of oxadiazon and triallate in the first 10 days, but some of the herbicides diffused back into the solution toward the end of the treatment process. PRACTITIONER POINTS: Immobilized algae-alginate beads can remove nitrate, atrazine, oxadiazon, and triallate from groundwater in continuous flow reactor. The uptake rate of nitrate and atrazine is higher in room temperature (20°C). Same algae beads could be reused for herbicide uptake for the average of 10 days. The immobilized system is a natural sustainable alternative that can be used in groundwater pump and treat.

Aluminum chloride (AlCl3) is commonly used in daily life; meanwhile, it is the potential etiology of various neurodegenerative as well as hepatorenal diseases. Therefore, the present study was carried out to investigate the correlation between AlCl3-induced biochemical alterations and the toxicity induced in various organs such as the brain, liver, and kidney. Male mice received AlCl3 in an oral dose of 50 mg kg−1 in addition to (50 mg) in drinking water for 2 weeks. Two weeks post-AlCl3 intoxication, the brain, liver, and kidney biochemical indices were assessed via molecular and western blot analysis. The results are as follows: AlCl3 intoxication induced a significant elevation in serum malondialdehyde in addition to a significant reduction in serum glutathione (GSH) and superoxide dismutase (SOD) levels. Brain β-secretase (tubulin-binding protein) and tau proteins which are responsible for the synthesis of β-amyloid protein that may interfere with neuronal communication in Alzheimer’s disease (AD) were also upregulated; regarding hepatic function, AlCl3 elevated serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Moreover, it upregulated hepatic mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) protein expressions as well as renal kidney-inducible molecule-1 (KIM-1) which indicated the deleterious effect of AlCl3 on these organs. These results were confirmed by histopathological investigations. So, we hypothesize that acute AlCl3 administration is responsible for oxidative cell damage that interferes with brain function inducing β-amyloid accumulation, Alzheimer’s disease, and neurodegenerative damage as well as hepatorenal injuries.

This study evaluated the effect of the addition of green iron microparticles (Fe-MPs) as a three-dimensional electrode on efficiency of the electrochemical oxidation process. Polyphenols present in green tea extract act as a reducing and capping agent during green synthesis of the Fe-MPs. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis indicates that the average size of particles is 100 µm, with about ~47 wt % of Fe in oxide form. The addition of Fe-MPs as a third electrode in the conventional electro-oxidation (EO) process converts it into a three-dimensional (3D) catalytic EO process to enhance the decolorization efficiency. Green synthesized Fe-MPs function as several microelectrodes in the process. Adsorption study indicated that only 12% of decolorization is due to adsorption on the Fe-MPs surface. Moreover, improvement in generation of hydroxyl radicals was validated by applying dimethyl sulfoxide as scavenger, and it was observed that generation of hydroxyl radicals decreased with the addition of DMSO. Results showed that decolorization efficiency increased in the 3D EO process with Fe-MPs by about 24% compared to the conventional 2D process without the Fe-MPs dosing, and initial pH as well as the Fe-MPs dose has a significant effect on decolorization efficiency during the 3D process. It is observed that reaction works better at highly acidic pH (2-4), and decolorization efficiency improved with higher doses of Fe-MPs.

A laboratory-scale bio-trickling filter (BTF) was initialized to evaluate the removal of formaldehyde biologically. However, generating formaldehyde gas in the lab is one of the grand challenges hindering research efforts. Formaldehyde was introduced into the gaseous phase by aerating the required air flowrate through a diluted formaldehyde solution mixed with methanol as a stabilizer by a bubbler. However, achieving stable gaseous influent concentrations of formaldehyde was challenging since it polymerizes while volatilizing. Resulting in paraformaldehyde. The resulting white powder clogged the pipes and generated uneven gaseous concentrations. To solve this problem, sodium hydroxide (NaOH) was added with a phosphate buffer to the aqueous formaldehyde solution to maintain the pH between 7.00-7.20. Additionally, the aqueous solution needed to be heated at 60℃ to eliminate the polymerization. The exhausted formaldehyde by volatilization was replaced by a continuous supply of aqueous diluted formaldehyde solution to keep the volume and mass of the aqueous solution and formaldehyde constant, respectively. Stable gaseous concentration was achieved for extended periods of time and verified by Fourier transform infrared (FTIR) spectroscopy.

Acute liver failure (ALF) is a clinical condition with an unclear history of pathophysiology, Punica granatum L peel and Pistacia atlantica leaves are differentiated by the presence of a wide range of flavonoids and phenolic as antioxidant compounds. The purpose of this study was to investigate the hepatoprotective effects of Punica granatum L. peel and Pistacia atlantica leaves either in their normal and/or in their nano forms against thioacetamide induced acute liver failure in a rodent model. Male Wistar rats (n=60) were divided into six equal groups, the first group employed as a control; The second group administered a dose of 350 mg /Kg/ b.w of thioacetamide (TAA)-ip, from the third to the sixth group received TAA + [2mls / 100 g b.w/d] of aqueous extracts of Punica granatum L and Pistacia atlantica either in their normal and/or Nano forms consecutively for (14 days) .In the TAA challenged group, there was a substantial increase in liver enzymes, lipid profiles, LPO ( p= 0.05), and NO, as well as a substantial drop in GSH and SOD, which was followed by an increase in inflammatory cytokine (IL6, TNF-, and AFP), as well as a considerable increase in HSP70 level and DNA degradation. However, ip nano treatment of both extracts resulted in considerable and subsequent improvement of most of the compromised indicators. In conclusion: The current findings demonstrated the great performance of both plant nano extracts, as well as their hepatoprotective effects and possible therapeutic usefulness in the treatment of TAA-induced acute liver failure in experimental animals.

The water-soluble acidic polysaccharide from Thalassodendron ciliatum (Forss.) den Hartog was successfully extracted, fractionated and purified. The phytochemical profile of the two water-soluble fractions (F1 and F2), were detected using different analytic techniques. GC-MS analysis revealed the presence of 22 saccharide. Acidic polysaccharide, galacturonic and glucuronic acid were the most abundant. Moreover, paper chromatography and electrophoresis also performed as a preliminary chemical characterization of the polymer. The hepatoprotective activity of the fractions against thioacetamide (TAA) induced liver failure; antioxidant potential and preliminary immunomodulatory activity were assigned in-vivo. The results revealed a potent competence to improve the liver function profile (ALT, AST, total bilirubin, total glyceride, etc.) and a remarkable improvement in liver architecture in comparison to the challenged intoxicated groups. Moreover, they showed high anti-oxidative properties and a promising immunomodulatory influence via Il6. These findings provide new insight into the possible role of polysaccharide purified two fractions in the treatment of acute liver injury.

This study carried out at a private farm in Elmhamid village ,Arment district , Luxor governorate, Egypt in 2016/2017 and 2017/2018 growing seasons for determine the effect of plant densities , different nitrogen sources and doses on the safflower cv. Giza (carthamus tinctorius) morphological and physiological characteristics. The experimental design was split-split plot set up with three replicates in both studied seasons was followed. The main plots were devoted to three plant densities viz, 35, 47 and 70 thousand plants/fad., and sub-plots were allotted to the three forms of nitrogen, i.e. ammonium sulphate, ammonium nitrate and urea, while the four nitrogen fertilizer levels were randomely arranged in the sub-sub-plots. The highest plant density of 70000 plants fad.-1 recorded the highest values of plant height and LAI at the growth stages i.e 65, 86 and 107 days from sowing in both seasons, while, the lowest plant density of 35000 plants/fad.-1 recorded highest values of number of green leaves plants/fad.-1 , number of branches plants-1, dry weight plants-1(gm) and leaf area plants-1in the three growth stages in both growing seasons. The nitrogenous fertilizer forms had a significant effects on plant height at 107 days in the two growing seasons, But the other studied traits not show any significant response by the studied treatments under the two growing season at any growth stages . The highest values were recorded by using urea as the best form of nitrogen fertilizer under this experiment conditions. The nitrogenous fertilizer levels had a significant effects on all studied traits at the different growth stages and the two growing seasons indicated the important of nitrogen fertilization on safflower under site of experiment. Conclusively, from these results it could be concluded that to increase the number of branches’ / plant and leaf area index should be apply 60kg/fed level of nitrogen with low plant density.

The industrial wastewater discharge is a major contributor to environmental degradation in Pakistan. To make conditions more deplorable, discharges from various industries such as paint, electroplating, battery, etc., are rich in heavy metals concentrations. The effluents from industries are generally used for irrigation or are directly discharged into waterways, ultimately leading to the deterioration of the local ecology and becoming part of the food chain through uptake by vegetation. Various studies are being conducted to figure out the most efficient nature-based solutions. One such technique is to develop constructed wetlands. These are engineered systems employing indigenous wetland plants to remove various pollutants from wastewater. In this study, a sub-surface horizontal flow constructed wetland (SSHW) was used to remove heavy metals lead (Pb), cadmium (Cd), and zinc (Zn). The heavy metal aqueous solution was prepared in the laboratory with a concentration of 30 mg/l for each metal. The removal efficiency was calculated for different detention times from day 1 to day 7. Zn showed maximum removal efficiency of 76.56% on day 6, while lead and cadmium showed maximum removal efficiency of 72.6% and 69.67%, respectively, on day 7. The metal’s mobility in a plant, translocation factor, and accumulation coefficient was calculated. The results indicated that Typha angustifolia serves as a bio-indicator for all three metals, and most of the accumulation of metals occurred in the plant's root zone. The results indicated that this technology gives good removal of heavy metals and has a scope for its efficiency. Since it has low operational and maintenance costs, it is comparatively a step toward a green economy.

Mixing the Scenedesmus species with nanoclay and immobilizing in sodium alginate was evaluated as a sustainable treatment method for removing nitrate, atrazine, and metals from groundwater. Gel beads containing the hybrid mixture removed 100% of 10 mg/L N nitrate and 98% of 100 µg/L atrazine from synthetic groundwater in three days. The optimal amount of nanoclay was found to be 0.30 mg per bead. The experimental data fit well into a Freundlich adsorption isotherm and followed pseudo first-order kinetics. When tested in actual groundwater, 91% of nitrate and 100% of Cr, Se, and V were eliminated in three days without need for any nutrients or carbon source. Immobilizing algal beads embedded with nanoclay is a natural, low-cost alternative for groundwater treatment. The gel beads can be reused for at least two cycles without a compromise in performance. They are water-insoluble, easy to harvest, and offer high removal efficiency.

Detoxification is one of the main vital tasks performed by the liver. The purpose of this study was to investigate whether mustard in its normal or nanoparticles could confer a protective/therapeutic effect against TAA-induced acute liver failure in experimental animal models. Mustard ethanolic extract was analyzed by HPLC/MS. To induce liver failure, male rats were injected with 350 mg/kg bw TAA IP, then treated orally with a dose of 100 mg/kg for 15 d of mustard extract and its nanoform before and following induction. The levels of serum liver functions, total cholesterol (TCHo), total glyceride (TG), total bilirubin (TBIL), hepatic malonaldhyde (MDA) and nitric oxide (NO),glutathione (GSH), sodium oxide dismutase (SOD), as well as tumor necrosis factor (TNF-&alpha, ) and interleukin 6 (IL-6), were estimated. DNA genotoxicity and hepatic pathology, and immunohistologic (IHC) changes were assayed. The antioxidant content of Phenolic acids, flavonoids in mustard ethanolic extract substantially decreased the levels of ALT, AST, ALP and rehabilitated the histopathological alterations. In addition, nanoforms of mustard ethanol extract have notably increased the levels of GSH, SOD and significantly reduced the levels of MDA. The expression levels of TNF-&alpha, and IL-6 in serum and tissue were markedly downregulated. DNA genotoxicity was significantly reversed. Mustard introduced a protective and medicinal effect against TAA in both its forms.

The treatment efficiency of Chlorella sorokiniana and Scenedesmus species, immobilized in sodium alginate, was evaluated for removing nitrate from groundwater. The experiments were performed initially in batch mode and the best-performing conditions were replicated in sequencing batch reactor mode. S. sp. showed a higher nitrate uptake in short term than C. sorokiniana. Immobilized S. sp. and C. sorokiniana cells showed 90% nitrate removal in 9 and 12 days, respectively. The optimal ratio of algal beads/water was found to be 12.5% (v:v). Comparatively, suspended S. sp. cells were able to remove only up to 35% of nitrate in 8 days. Alginate immobilized S. sp. beads were capable of uptaking nitrate for 100 consecutive days in sequencing batch reactor mode. When tested in actual groundwater, 90% of nitrate was eliminated in 2 days without need for any additional carbon source. Immobilized algal beads can be a low-cost alternative technique to remove nitrate from groundwater as they are water-insoluble, non-toxic, easy to harvest, and offer high removal efficiency.

Phormidium keutzingianum performed biodesalination of brackish water (10 g/L). The electrical conductivity (EC) was measured to evaluate the salt concentration over 80 days of cyanobacterial inoculation. Anion concentrations were measured using ion chromatography to estimate salt removal. EC-based measurements showed ∼8–10% removal efficiency in the first 20 days. However, the removal efficiency based on chloride ion concentration showed ∼40% removal in the same time frame. The pH increase was observed with growth of algal biomass. The increasing pH proposes the formation of hydroxyl and carbonate ions. Sulfuric acid was added at day 110 to neutralize them. At pH 4, the EC reduced significantly to about ∼37% confirming the chloride removal. EC should not be used to measure salt reduction as it is an obscure parameter, and therefore, EC is not the best choice to measure salinity removal using algae. Some recently published studies used only EC to estimate biodesalination, and it is anticipated that salt removal is misrepresented in those studies.

Wastewater with 0.2, 0.4, 0.8, 1.0 mg/L free chlorine was biologically treated using co-immobilized microalgae/bacteria. In contrast, non-pretreated wastewater was treated with beads (control) and blank beads (blank) under the same operating condition. Results showed that NaClO pretreatment removed 8–33% total nitrogen (TN), 31–45% true color and 0.7–2.5 log CFU/mL aerobic-bacteria. At the end of treatment, maximum algal biomass (2,027 dry weight mg/L) was achieved with 0.2 mg/L free chlorine. Bacterial growth in wastewater was decreased by NaClO pretreatment before reaching 7.2–7.7 log CFU/mL on the fifth day. Beads with microorganisms (control) removed 15% more chemical-oxygen-demand (COD), 16% more TN, and 13% more total phosphate (PO43−) than blank. Pretreatment with 0.2 mg/L free chlorine increased TN removal from 75% to 80% while pollutants removal was substantially decreased with 0.4–1.0 mg/L free chlorine. Considering algal biomass growth and pollutants removal, 0.2 mg/L free chlorine pretreatment was recommended for microalgae/bacteria co-immobilized system.

Microalgae immobilization was widely studied to address the challenge of algal cells harvesting, however, its stability and efficiency in treating real food industrial wastewater has not been well studied. In this study, microalgae were co-immobilized with sludge bacteria in alginate beads for treatment of real meat processing wastewater and an annular photobioreactor was designed to facilitate efficient light transmission at high beads-to-wastewater ratios. Results showed that increasing alginate mixture from 1.25% to 2.00% (w/v) extended beads stability in real wastewater from three to seven days. When beads were suspended in wastewater the overshading effect at beads-to-wastewater ratio of 20% (v/v) was significant and average algal growth (0.17 mg/bead) was lower than 2% (0.46 mg/bead) and 5% (0.36 mg/bead). Nevertheless, the ratio of 20% (v/v) was preferred as the higher beads count may compensate the disadvantage, however, the light transmission efficiency needed to be improved. The effect of environmental temperature indicated that at 37 °C beads started rupturing after three-days treatment due to the excessive growth of immobilized microorganisms. In comparison with suspended photobioreactor, in improved annular photobioreactor algal growth increased from 1412.6 to 3191.0 mg/L and removal of chemical oxygen demand (COD) and total nitrogen (TN) were improved from 78.5 to 82.9% and from 68.5 to 84.4% respectively with 89.4% total phosphate (PO43−) being removed. By the end of treatment, 135.9 mg/L TN and 99.2 mg/L total PO43− were removed and it was speculated that most of nitrogen and phosphorus were removed by algal assimilation rather than the physical adsorption of alginate gel. Findings of this study provided directions for the application of immobilized microalgae in the real world.

Algae is an appropriate natural resource to augment the optimal use of undesired ions in water and wastewater. Increasing algal cells, the consumption of particular ions, including chloride, nitrate, phosphate, and ammonium, provides a suitable way to optimize water treatment processes. Different algal species have the capability to survive in extreme salinities by developing resistance against osmotic pressure in saline water. The current study reviews the effect of salinity on algal biomass production, algal growth rate, chlorides, nitrates, phosphates, chemical oxygen demand (COD), total nitrogen, total phosphorus, and ammonium ions. Mainly algae cultivated in freshwater, synthetic brackish water, seawater, and hypersaline water, were studied for this review. Various ion uptake mechanisms used by the algal cell are summarized, focusing on biosorption and bioaccumulation processes. Critical parameters such as light intensity, pH, and temperature variations significantly influence ion and nutrients uptake efficiencies. Analysis performed on collected data indicated that halophytic algae could survive in high salinities at elevated growth rates compared to freshwater. The halotolerant algal species showed an inclining trend of chloride ion removal with an elimination capacity of 7.5 g.m−3.h−1. Moreover, the nitrate uptake rate in halophytic algae is 10-folds higher to phosphate, regardless of salinity level. It could be concluded that microalgae will be beneficial for ion and nutrient uptake processes in treating high saline water.

Using alcohol-based disinfectants is an effective method for preventing the spread of COVID-19. However, non-traditional manufacturers of alcohol-based disinfectants, such as ethanol plants, need to undergo additional treatment to curb their impurities to limits set by the Food and Drug Association (FDA) to produce alcohol-based disinfectants. To transform them to disinfectant-grade alcohol, 17 process streams in a dry-mill ethanol plant were analyzed to determine the quality parameters for acetaldehyde, acetal, propanol, methanol, and water, including chemical oxygen demand, total suspended solids, and nutrients. Results suggest that the process stream generated by the distillation column requires further treatment because the acetaldehyde and acetal concentrations are significantly higher than the impurity limit set by the FDA. The addition of a second distillation column could be a potential method for addressing impurities and it will have minimal influence on hazardous air pollutant generation and water use., Graphical abstract Image 1

Natural organic matter (NOM) affects the stability and transport of nanoparticles (NPs) in natural waters by modifying their physiochemical properties. Source location, and seasonal variations, influence their molecular, physical and electrical charge properties. To understand the variations of NOM on the mobilization of NPs, large volumes of water were collected from the Ohio River (OR) over winter and summer seasons and dissolved NOMs were concentrated. The chemical and structural differences of these NOMs were compared with the Suwannee River humic acid (SRHA) SRHA using 1H and 13C nuclear magnetic resonance spectroscopy, and Fourier transforms infrared (FTIR) spectroscopy. Thermal analysis and FTIR confirmed that differences in composition, structure, and functional groups are a result of SRHA fractionation compared to whole molecule OR-NOM. The influence of OR-NOMs on the surface charge of CeO2 NPs and the effects on the transport and retention in a three-phase (deposition-rinse-re-entrainment) sand-packed columns were investigated at CeO2 NPs initial concertation of 10ppm, pH6.8, increasing ionic strength (3, 5, and 10mM), retention time of 1min, and increasing NOM concentration (1, 5, and 10ppm). The summer OR-NOM showed higher stabilization and mobilization effect on the CeO2 than the winter NOM; while their effect was very different form the SRHA. The stabilization of NPs is attributed to both electrostatic and steric effects. The differences in the chemical structure of the complex and heterogeneous NOMs showed disparate reactivity and direct impact on CeO2-NPs stability. Using SRHA to study the effect of NOM for drinking water related assessment does not sufficiently represent the natural conditions of the environment.

Despite decades of research, metallic corrosion remains a long-standing challenge in many engineering applications. Specifically, designing a material that can resist corrosion both in abiotic as well as biotic environments remains elusive. Here a lightweight sulfur-selenium (S-Se) alloy is designed with high stiffness and ductility that can serve as an excellent corrosion-resistant coating with protection efficiency of ≈99.9% for steel in a wide range of diverse environments. S-Se coated mild steel shows a corrosion rate that is 6-7 orders of magnitude lower than bare metal in abiotic (simulated seawater and sodium sulfate solution) and biotic (sulfate-reducing bacterial medium) environments. The coating is strongly adhesive, mechanically robust, and demonstrates excellent damage/deformation recovery properties, which provide the added advantage of significantly reducing the probability of a defect being generated and sustained in the coating, thus improving its longevity. The high corrosion resistance of the alloy is attributed in diverse environments to its semicrystalline, nonporous, antimicrobial, and viscoelastic nature with superior mechanical performance, enabling it to successfully block a variety of diffusing species.

The biofiltration of n-hexane is studied to optimize determinants factors of hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs) were employed; two of which were supplied with nutrients buffered at a neutral pH, while another two at an acidic pH of 4 to induce and enhance fungal growth. The loading rate of n-hexane was kept constant in all TBABs at 13 g/m3/h. At each pH levels studied, the biomass of the TBABs was pre-acclimated using different ratios of n-hexane and methanol. The fungal biomass responsible for the degradation of n-hexane was then examined and quantified. Dichloran Rose Bengal Chloramphenicol agar was used for fungi quantification, and optical microscopy for classification. Effluent biomass was validated by measuring volatile suspended solids. Fungal counts resulting from n-hexane biodegradation were related to nitrate and carbon consumption. It was found that n-hexane elimination capacity closely followed biomass growth, and reached a steady-state at an optimum biomass density of roughly 3000 cfu/ml. Major shifts in fungal species were observed in all TBABs. Dominant fungal species grew slowly to become the most numerous, and were found to provide maximum elimination capacity, although TBABs pre-acclimated to higher methanol concentrations took less time to reach this steady-state. It was concluded, therefore, that steady and monitored growth of TBAB biomass is an essential factor in maximizing fungi’s ability to metabolize VOCs and that a new ecological biofiltration model may be the most effective at VOC purification. Keywords

Metal-organic frameworks (MOFs) are the coordination polymers of particular interest for targeted drug delivery in a controlled manner. MOFs have several interesting properties in terms of high porosity, large surface area, biodegradable and biocompatible nature for efficient encapsulation of active molecules. We have addressed here the challenge to load the active molecules of benzimidazole group during the synthesis of Cu-MOF. This one-pot approach is advantageous over existing approaches that require multistep post-functionalization for encapsulation of drug-molecules. The prepared MOFs are characterized using FT-IR, UV-Vis spectroscopy, XRD, and SEM analysis. The Cu-MOF are found incipient stable for delivery of active molecules along with high encapsulation efficiency (∼96%).

Over the past few decades, enormous development has been reported in nanosensor technology mainly because of our ever-increasing understanding of nanoscale phenomenon and growth of innovative nanofabrication techniques. Among the different nanomaterials, carbon-based nanomaterials (such as buckminsterfullerene, nanodiamonds, carbon nanotubes/nanofibers, carbon nanodots, graphene) have gained considerable research interest owing to their novel chemical and physical properties. Many of the extraordinary properties of carbon nanomaterials make them ideal transducers in the fabrication of nanosensors for environmental monitoring, healthcare, food safety control, and so forth for the detection of different analytes, e.g., heavy metal ions, food additives, gas molecules, antibodies, and toxic pesticides. This chapter discusses the application of carbon nanomaterials in the development of nanosensors for different analytes. In particular, we describe the significant potential of carbon nanomaterials as highly sensitive platforms and also articulate the research challenges and perspectives confronting this emerging field.

In this study, the feasibility of using carbonaceous nanomaterials was explored for adsorptive removal of methylene blue (MB) and methyl orange (MO) dyes from contaminated water under dark conditions. The morphology and crystalline nature of synthesized carbonaceous nanomaterials (e.g., multi-walled carbon nanotubes [MWCNTs], activated carbon [AC], and their nanocomposite) were characterized by different microscopic and spectroscopic techniques. Furthermore, adsorption experiments were carried out by controlling several key parameters including solution pH, adsorbent dosage, dye concentration, contact time, and temperature. First, the adsorptive behavior of MWCNTs was explained with the aid of adsorption isotherms and kinetics. Thereafter, the adsorptive performance of MWCNTs was compared with those of AC and MWCNTs/AC, and the maximum adsorption capacity (mg/g) of MB/MO was in the order of MWCNTs/AC nanocomposite (232.5/196.1) > MWCNTs (185.1/106.3) > AC (161.3/78.7). The improved adsorption performance (e.g., in terms of adsorption capacity and partition coefficient) of the MWCNTs/AC nanocomposite could be attributed to the presence of more active sites on its surface. Furthermore, their reusable efficiency was in the order of MWCNTs/AC nanocomposite (90.2%), MWCNTs (81%), and AC (67%) after the first step of recovery. The performance of these adsorbents was also evaluated for real field samples. In comparison to MWCNTs and AC, the MWCNTs/AC sorbents offered excellent performance in both single and binary systems, i.e., ~99.8% and 98.7% average removal of MB and MO, respectively.

At ethanol plants, the control of acetaldehyde emissions is accomplished by scrubbers and regenerative thermal oxidizers. However, their operation imposes substantial operating costs. Alternatively, two biotrickling filters were operated in parallel under acetaldehyde loadings ranging from 4 to 136 g m−3 hr−1. One filter was operated at room temperature while the other one was heated to 60 °C, to mimic hot drier emissions. The unheated filter maintained 100% removal efficiency up to 45.28 g m−3 hr−1 loading rate at 30-s empty bed residence time. Highest elimination capacity recorded was 112 g m−3 hr−1 at 83.2% removal efficiency. The heated filter achieved removal efficiency larger than 60% at influent concentrations of 200 ppmv and lower, however, removal was significantly lower at 400 and 600 ppmv influent concentrations. Performance was improved by reseeding with cooking compost resulting in increased thermophilic bacterial population. Main byproduct formed was acetic acid with traces of formic acid. Mathematical modelling was used to successfully describe acetaldehyde concentration profiles.

The excessive discharge of phosphate in water bodies is one of the primary factors causing eutrophication. Therefore, its removal is of significant research interest. The present study deals with the development and performance of highly effective phosphate-adsorbent. Here, we have synthesized MIL-100(Fe) metal-organic frameworks as a facile strategy to effectively remove phosphate from eutropic water samples. The adsorbent was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and wavelength dispersive X-ray fluorescence (WDXRF). The phosphate adsorption performance of MIL-100(Fe) was evaluated with the help of different batch experiments relating to the effect of adsorbent/adsorbate concentrations and the solution pH. The MOF offered a maximum adsorption capacity of 93.6 mg g−1 for phosphate from aqueous solutions with Langmuir isotherm model (R2 = 0.99). MIL-100(Fe) offered an absolute phosphate adsorption performance with a partition co-efficient of 15.98 mg g−1 µM−1 at pH 4 and room temperature conditions. Final experiments with real water samples were also performed to examine the effectiveness of MIL-100(Fe) for phosphate adsorption even in the presence of other ions. These findings support the potential utility of MIL-100(Fe) as nanoadsorbent in phosphate removal for water management.

Copper oxide (CuO) nanomaterials (NMs) of different size and morphology were synthesized by Chemical precipitation, Microwave irradiation and Hydrothermal method and characterized by TEM, BET, FTIR, XRD and EDX analysis. As synthesized CuO NMs were utilized for elimination of harmful dyes viz. Direct Red 81 (DR-81) and Coomassie Brilliant blue R-250 (BBR-250) and pathogenic bacteria (Staphylococcus aureus). Owing to their morphology, smaller size and relatively high surface area (40.320 m2 g−1), CuO NMs prepared by chemical precipitation method were observed to show better adsorption capacity for both the dyes (68.70 (DR-81) and 73.04 (BBR-250) mg g−1). The influence of different experimental conditions was studied by the methodical assessments of various parameters such as pH, adsorbent dose, concentration and contact time. Moreover, different adsorption isotherms and pseudo-second order kinetic model were applied to understand the adsorption mechanism. Langmuir model was found to be best fit thus confirming the monolayer adsorption process. To ensure the practical utility of CuO NMs for organic waste removal, the adsorption studies were performed in the presence of different inorganic ions and real water samples. In addition, recovery of the dye and NMs were also carried out effectively by simple method, thus avoiding the secondary pollution. CuO NMs were observed to exhibit significant antibacterial activity against the human pathogenic bacteria. These studies demonstrated that synthesized CuO NMs showed good adsorption efficiency for the removal of harmful dyes and antimicrobial activity against the pathogenic bacteria, which vary as a function of size and surface area.

Use of biotrickling filter (BTF) for gas phase treatment of volatile trihalomethanes (THMs) stripped from water treatment plants could be an attractive treatment option. The aim of this study is to use laboratory-scale anaerobic BTF to treat gaseous chloroform (recalcitrant to biological transformation) as a model THM and compare results with aerobic BTF. Additional investigations were conducted to determine the microbial diversity present within the BTFs. Chloroform is a hydrophobic volatile THM known to be difficult to biodegrade. To improve the degradation process, ethanol was used as a cometabolite at a different ratio to chloroform. The experimental plan was designed to operate one BTF under anaerobic condition and the other one under aerobic acidic condition. Higher elimination capacity (EC) of 0.23 ± 0.01 g/[m(3)·h] was observed with a removal efficiency of 80.9% ± 4% for the aerobic BTF operating at pH 4 for the concentration ratio of 1:40 chloroform to ethanol. For similar ratio, the anaerobic BTF supported lower removal efficiency of 59% ± 10% with corresponding lower EC of 0.16 ± 0.01 g/[m(3)·h]. Carbon recovery acquired for anaerobic and aerobic BTFs was 59% and 63%, respectively. The loading rate for chloroform on both BTFs was 0.27 g/[m(3)·h] (per m(3) of filter bed volume). Variations of the microbial community were attributed to degradation of chloroform in each BTF. Azospira oryzae and Azospira restrica were the dominant bacteria and potential candidates for chloroform degradation for the anaerobic BTF, whereas Fusarium sp. and Fusarium solani were the dominant fungi and potential candidates for chloroform degradation in the aerobic BTF.

The objective of this research was to evaluate the biodegradation of chloroform by using biotrickling filter (BTF) and determining the dominant bacteria responsible for the degradation. The research was conducted in three phases under anaerobic condition, namely, in the presence of co-metabolite (Phase I), in the presence of co-metabolite and surfactant (Phase II) and in the presence of surfactant but no co-metabolite (Phase III). The results showed that the presence of ethanol as a co-metabolite provided 49% removal efficiency. The equivalent elimination capacity (EC) was 0.13 g/(m3.hr). The addition of Tomadol 25 - 7 as a surfactant in the nutrient solution increased the removal efficiency of chloroform to 64% with corresponding EC of 0.17 g/(m3.hr). This research also investigated the overall microbial ecology of the BTF utilizing culture-independent gene sequencing alignment of the 16S rRNA allowing identification of isolated species. Taxonomical composition revealed the abundance of deltaproteobacteria and deltaproteobacteria with species level of 97%. A. oryzae (formally dechlorosoma suillum), A. restrica and Geobacter spp. together with other similar groups were the most valuable bacteria for the degradation of chloroform.

This study focuses on the interaction of ceria nanoparticles (CeO2-NPs) with Pseudomonas fluorescens and Mycobacterium smegmatis biofilms. Confocal laser microscopy and transmission electron microscopy determined the distribution of NPs in the complex structures of biofilm at molecular levels. Visual data showed that most of the adsorption takes place on the bacterial cell walls and spores. The interaction of nanoparticles (NPs) with biofilms reached equilibrium after the initial high adsorption rate regardless of biofilm heterogeneity and different nanoparticle concentrations in the bulk liquid. Physical processes may dominate this sorption phenomenon. Pseudo first order sorption kinetics was used to estimate adsorption and desorption rate of CeO2-NPs onto biofilms. When biofilms got exposed to CeO2-NPs, a self-protecting mechanism was observed. Cells moved away from the bulk solution in the biofilm matrix, and portions of biofilm outer layer were detached, hence releasing some CeO2-NPs back to the bulk phase.

This study focuses on evaluating the degradation of n-hexane/methanol mixture in trickle-bed-air-biofilters (TBABs). Two different concentration ratios of methanol:n-hexane were evaluated (3:1) for TBAB “A” and (5:1) for TBAB “B”. Both TBABs were run and fed with nutrients buffered at pH 4 for encouraging the growth of fungi. The TBABs were loaded with pelletized diatomaceous earth support media and were run at an empty bed residence time of 120 s. n-Hexane loading rates (LRs) ranged from 0.9 to 13.2 g/m 3 h for both TBABs. The corresponding methanol LRs varied from 2.3 to 37.7 g/m 3 h and from 4.6 to 64.5 g/m 3 h for TBABs “A” and “B”, respectively. Experimental results have shown that the degradation of n-hexane in presence of methanol is enhanced for n-hexane LRs less than 10.6 g/m 3 h as compared to previous study for sole-fed n-hexane, but for n-hexane LRs of 13.2 g/m 3 h, the performance of TBABs in eliminating n-hexane depended on the methanol to n-hexane ratios. The impact was less severe for TBAB “A” (RE 85%) as compared to TBAB “B” (RE 72%). This is attributed to the high LRs of methanol in TBAB “B”. n-Hexane performance stability was another advantage attained.

Step-by-step tensile tests were applied to flat-braided carbon-fiber-reinforced polymers with and without added dispersions of carbon nanofibers (CNFs) and with and without sample sides cut off to study their mechanical properties and destructive mechanisms by means of in situ observation and stress–strain measurements. An ex situ nondestructive evaluation technique, using a high-temperature superconductor superconducting quantum interference device gradiometer, was also applied to the samples to study their electrical properties; the relationships between the mechanical and electrical properties by visualizing current maps in the samples during ac current injection was also studied. Clear differences were observed in the mechanical and electrical properties and the destructive mechanisms between the samples with and without CNFs and with and without cut off sides. These differences were mainly attributed to the addition of CNFs, which enhanced the mechanical and electrical connections between the carbon fiber bundles.

Controlled titanium dioxide (TiO2) thin films were deposited on stainless steel surfaces using the flame-aerosol synthetic technique, which is a one-step coating process that does not require further calcination. Solid state characterization of the coatings was conducted by different techniques, including X-ray diffraction (XRD) spectrum, scanning electron microscope, and atomic force microscope. The coated thin films were used in a gas phase photoreactor for the partial oxidation of hydrocarbons to alcohols and ketones as an alternative production method for the highly sought oxygenates. For this purpose, the oxidation reaction of cyclohexane to form cyclohexanol and cyclohexanone was chosen as a model reaction. The effects of the film thickness, anatase-to-rutile ratio, and particle morphology on the reactivity of the catalyst were studied. Experimental results revealed that there is an optimal film thickness (between 400 and 700 nm) for the photooxidation process that gave a maximum rate of rea...

This study investigated the removal of recalcitrant compounds in the presence of a hydrophilic compound. n-Hexane is used as a model compound to represent hydrophobic compounds. Methanol has been introduced in mixture with n-hexane in order to increase the bioavailability of n-hexane in trickle-bed-air-biofilters (TBABs). The mixing ratios investigated were: 70% methanol:30% n-hexane, and 80% methanol:20% n-hexane by volume. n-Hexane loading rates (LRs) ranged from 0.9 to 13.2 g m −3 h −1 . Methanol LRs varied from 4.6 to 64.5 g m −3 h −1 and from 2.3 to 45.2 g m −3 h −1 depending upon the mixing ratio used. Biofilter performance, effect of mixing ratios of methanol to n-hexane, removal profile along biofilter depth, COD/nitrogen consumption and CO 2 production were studied under continuous loading operation conditions. Results have shown that the degradation of n-hexane is significantly enhanced by the presence of methanol for n-hexane LRs less than 13.2 g m −3 h −1 . For n-hexane LR greater than 13.2 g m −3 h −1 , even though methanol had impacted n-hexane biodegradation, its removal efficiency was higher than our previous study for biodegradation of n-hexane alone, in presence of surfactant, or in presence of benzene. On the other hand, the degradation of methanol was not impacted by the presence of n-hexane.

Processing, mechanical properties, and ablation behavior of SiC fiber/carbon matrix composites for a thermal protection system material of a re-entry vehicle were examined. Orthogonal 3-D woven fabrics ( V f = 0.21, 0.21 and 0.02 for x , y , z directions) made of SiC fibers (Tyranno ZMI) were applied for reinforcement with a carbon matrix formed by polymer impregnation and pyrolysis (PIP) and/or chemical vapor infiltration (CVI). This SiC/CVI-C composite has high ultimate tensile strength of 415 MPa at 25 °C. Air plasma exposure in a plasma wind tunnel revealed no surface recession. The mass loss rate decreased over time. The SiC/C composites exhibit excellent oxidation resistance in high enthalpy plasma air for short durations.

Trickle-bed air biofilters (TBABs) are suitable for treatment of hydrophilic volatile organic compounds, but they pose a challenge for hydrophobic compounds. Three laboratory-scale TBABs were used for the treatment of an airstream contaminated with different ratios of n-hexane and benzene mixtures. The ratios studied were 1:1, 2:1, and 1:3 n-hexane:benzene by volume. Each TBAB was operated at a pH of 4 and a temperature of 20 degrees C. The use of acidic-buffered nutrient solution was targeted for changing the microorganism consortium to fungi as the main biodegradation element. The experimental plan was designed to investigate the long-term performance of the TBABs with an emphasis on different mixture loading rates, removal efficiency with TBAB depth, volatile suspended solids, and carbon mass balance closure. n-Hexane loading rate was kept constant in the TBABs for comparison reasons and ranged from 4 to 22 g/(m3 x hr). Corresponding benzene loadings ranged from 4 to 43 g/(m3 x hr). Generally, benzene behavior in the TBAB was superior to that of n-hexane because of its higher solubility. n-Hexane showed improved performance in the 2:1 mixing ratio as compared with the other two ratios.

Selective photocatalytic oxidation of 1-phenyl ethanol to acetophenone using titanium dioxide (TiO2) raw and doped with Fe or V, prepared by flame aerosol deposition method, was investigated. The effects of metal doping on crystal phase and morphology of the synthesized nanostructured TiO2were analyzed using XRD, TEM, Raman spectroscopy, and BET nitrogen adsorbed surface area measurement. The increase in the concentration of V and Fe reduced the crystalline structure and the anatase-to-rutile ratios of the synthesized TiO2. Synthesized TiO2became fine amorphous powder as the Fe and V concentrations were increased to 3 and 5%, respectively. Doping V and Fe to TiO2synthesized by the flame aerosol increased photocatalytic activity by 6 folds and 2.5 folds, respectively, compared to that of pure TiO2. It was found that an optimal doping concentration for Fe and V were 0.5% and 3%, respectively. The type and concentration of the metal dopants and the method used to add the dopant to the TiO2are critical parameters for enhancing the activity of the resulting photocatalyst. The effects of solvents on the photocatalytic reaction were also investigated by using both water and acetonitrile as the reaction medium.

Trickle Bed Air Biofilters (TBABs) are considered to be economical and environmental-friendly for treatment of Volatile Organic Compounds (VOCs). Hydrophilic VOCs are easily degradable while hydrophobic ones pose a great challenge for adequate treatment due to the transfer of the VOC to the liquid phase. In this study the utilization of acidic pH is proposed for the treatment of benzene vapors. The acidic pH would encourage the growth of fungi as the main consortium. A TBAB operated at pH 4 was used for the treatment of an air stream contaminated with benzene under different loading rates ranging from 37 to 76.8 g/(m(3)h). The purpose of introducing fungi was to compare the performance with traditional TBAB operating under neutral pH in order to assess the biodegradation of benzene in mixtures with other compounds favoring acidic conditions. The experimental plan was designed to assess long-term performance with emphasis based on different benzene loading rates, removal efficiency with TBAB depth, and carbon mass balance closure. At benzene loading rate of 64 g/(m(3)h), the removal efficiency was 90%. At the maximum loading rate of 77 g/(m(3)h), the removal efficiency was 75% marking the maximum elimination capacity for the TBAB at 58.8 g/(m(3)h). Operating at acidic pH successfully supported the degradation of benzene in TBAB. It is worthwhile to note that benzene appears in mixtures with n-hexane and toluene, which are reported to be better degraded under such conditions.

Trickle Bed Air Biofilter (TBAB) could be an attractive treatment option for removal of hydrophobic Volatile Organic Compounds (VOCs) from air streams. In this study, three independent parallel laboratory-scale TBABs were run simultaneously to degrade n-hexane, a hydrophobic VOC known to be difficult to degrade. The loading rate of n-hexane varied from 13.4 and 47.7 g/(m3 h) (1.14–4.04 kg COD/(m3 day)). The experimental plan was designed to operate one TBAB at pH 7, another at pH 7 utilizing surfactant for enhancing the solubility of n-hexane, and finally a third one operating at pH 4 to promote fungi growth. Elimination capacities up to 38.7 g/(m3 h) (3.28 kg COD/(m3 day)) were observed with a removal efficiency of 90% for the TBAB operating at pH 4. The operating conditions for the TBABs include 120 s of Empty Bed Residence Time (EBRT), 1.4 L/min air flow rate and fixed temperature of 20 °C. Biomass control within the TBAB was investigated through two strategies, namely, stagnation (off flow for 2 days/week) and flow switching.

BACKGROUND: Degrading hydrophobic volatile organic compounds in biofilters is very challenging. Previous research in our laboratories examined the degradation of hydrophobic contaminants by several methods including changing the empty bed resident time, utilization of surfactants and change of the microorganism consortium. As n-hexane is considered relatively soluble in benzene and alongside benzene is more soluble in water, it was anticipated that a mixture of both volatile organic compounds fed to a trickle bed air biofilters (TBABs) would lead to an improved performance of n-hexane degradation. RESULTS: The ratio of benzene:n-hexane studied was 2: 1 byvolume, corresponding to a concentration ratio of 3: 1, respectively. The TBAB was operated at pH 4 to provide favorable conditions for fungi growth. The effects of changing loading rates ranging from 20 to 80 g m -3 h -1 on the biofilter performance, acclimation period, and removal profile along biofilter depth, nitrogen consumption and CO 2 production were studied under continuous loading operation conditions and compared to previous data of TBABs degrading single feed of benzene and n-hexane separately. CONCLUSIONS: Results have shown that the degradation of n-hexane is significantly impacted by the presence of benzene; however, the degradation of benzene was not impacted to the same extent as n-hexane.

While hydrophilic compounds are degraded easily in Trickling bed air biofilters (TBABs), hydrophobic compounds are retarded until biological cultures produce a sufficient RNA or enzyme/protein to utilize this compound. Hydrophobic compounds are not readily bio-available which makes them reluctant to biodegradation as mass transfer between the gas and liquid phases is a rate limiting step. To enhance the destruction of hydrophobic compounds in TBABs, the utilization of surfactant was introduced to increase the solubility which helps overcoming the rate limiting step. The surfactant was used as well to limit the growth of excess biomass ensuring smooth flow through the biofilter bed and preventing short circuits. Two different non-ionic non-toxic surfactants were used in this study: Triton X-100 and Tomadol® 25-7. Two lab-scale controlled TBABs were operated for investigating the performance difference for n-Hexane as an example of hydrophobic volatile organic compound (VOC) with and without the addition of surfactant. Operating conditions in both TBABs were as follows: nutrient feed rate (2L/day), air flowrate (1.4L/min), bed depth (60cm), empty bed retention time (120s), bed material (diatomaceous earth pellets) and room-temperature. The inlet concentration was changed from 50 to 100ppmv. Acclimation period, removal profile along biofilter depth, nitrogen consumption, and CO2 production were compared under continuous loading operation condition. The optimum concentration of surfactant in the nutrient feed was determined by a batch experiment. The effect of different surfactant concentrations on VOC water solubility with time was studied by considering different VOC concentration sets within the TBAB loading rate range.

The objective of this study was to investigate the effect of chloride ions (Cl−) on Cu2+ adsorption to carbon nanotubes (CNT). The isotherms showed a significant decrease in adsorption capacity on F-400, pristine, and acid-functionalized CNT in the presence of Cl−, but had little effect on alcohol-functionalized CNT. Several inductively coupled plasma (ICP) analyses measured the impurities concentration of (1) aqueous-phase isotherm solute, (2) as-received, and (3) acid-washed CNT solutions. Chemical-equilibrium-modeling software MINEQL+ calculations were applied to compare ICP results to complexes formation. The model suggested that some solid-phase residual-catalytic metals, such as Cr2+, after released in water from as-received CNT, formed aqueous-phase complexes and were readsorbed. The 18-metal ICP results were more than two orders of magnitude lower ( 5.1, when less Cu2+ ions are present in solution. scanning electron microscopy–energy dispersive X-ray spectroscopy analysis showed impurities on as-received F-400 and positively charged surface at pH 5.1 (pHpzc 7.1) explaining possible electrostatic attraction of Cl− ions, blocking adsorptive sites, reducing its adsorptive capacity for Cu2+.

On propose dans ce travail un nouveau systeme pour le traitement biologique in situ du pentachlorophenol dans l'eau souterraine. Celui-ci s'appuie sur le concept de l'immobilisation du sol, dont on a deja montre l'efficacite lorsqu'il est applique au genie des bioreacteurs. Dans cet article, on utilise du sol immobilise pour mettre au point un systeme de bioreacteur pour une biodegradation in situ (dans le puits) du pentachlorophenol (PCP). Le procede a ete realise a 9°C, une temperature typique de l'eau souterraine. L'efficacite volumetrique de degradation du PCP de ce nouveau systeme est tres elevee - jusqu'a 400 mg/(L.h). On a etudie l'effet de certains parametres physicochimiques (temperature, concentration de substrat) sur la cinetique de biodegradation. Les resultats obtenus montrent que l'application de l'immobilisation du sol a la biodegradation in situ de l'eau souterraine contaminee au PCP est tres prometteuse.

The need for aeration of microcosms during mineralization of 14C-labeled compounds in high oxygen demand environments was assessed using active compost-soil mixtures as the model system. Rapid mineralization of 14C-hexadecane occurred in continuously aerated microcosms while no mineralization occurred in unaerated microcosms. Daily flushing with air also yielded no mineralization. Mineralization of 14C-glucose was much less dependent on aeration. The alkaline solution volume and number of CO2 traps required for continuous aeration were calculated and tested experimentally.

A mixture of endo- and exoxylanases were used to produce a hemicellulose hydrolysate containing 29.6 g L −1 of xylose equivalents based on reducing sugars analysis. Propionibacterium acidipropionici was grown in a 2-l batch reactor in mineral salts medium containing 60% (v/v) hemicellulose hydrolysate, 5 g l −1 proteose peptone, and 2.5 g l −1 yeast extract. Propionic acid production was growth associated. The maximum specific growth rate and maximum specific propionic acid production rate were 0.1 and 0.23 g g −1 h −1 , respectively. Growth and acid production were inhibited at propionic acid concentrations greater than 2 g l −1 . The final concentration of propionic acid attained was 18 g l −1 . This study demonstrates the feasibility of propionic acid production by P. acidipropionici on an enzymatically hydrolyzed, hemicellulosic fraction of steam-exploded Populus tremuloides .