Antimicrobial Activity of Some Sudanese Medicinal Plants Against its Pollutant Isolated Bacteria.

<b>Background and Objective:</b> Medicinal plants have been known to cure many diseases due to the presence of active bio constituents, the goal of this study to detect and evaluate the effectiveness of antimicrobial activity of some Sudanese medicinal plants. <b>Materials and Methods:</b> Methanolic extracts of the following types of local medicinal plants <i>Artemisia herba-alba</i>,<i> Cyperus rotundus</i>,<i> Cymbopogon schoenanthus </i>sb<i> </i>sp.<i> Proximus</i>,<i> Trigonella foenum-graecum</i>,<i> Nigella sativa</i>,<i> Hyphaene thebaica</i>,<i> Nauclea latifolia</i> and <i>Ziziphus spina-christi</i> were tested against eight types of bacteria that were isolated from the same plants as their pollutants. Cup-plate method was used and then the inhibition zone of each plant was measured and compared with the inhibitory zone of some antibiotics used for the same isolates. <b>Results:</b> Methanol extracts of some plant species showed antibacterial activity against most of the studied bacterial species. <i>Cymbopogon schoenanthus </i>ssp.<i> Proximus </i>showed antibacterial activity against most isolated bacterial species in comparison with commercial antibiotics used. <b>Conclusion:</b> According to the findings of this research, severalmedicinal plants have efficacy and effect on certain types of bacteria and are superior or comparable to certain types of antibiotics. When compared to the other medicinal plants used in this study<i>, Cymbopogon schoenanthus </i>sbsp. <i>proximus </i>has the highest activity on most types of Gram-positive and Gram-negative bacteria, as well as the superiority of some antibiotics.

Microbial Sensing and Removal of Heavy Metals: Bioelectrochemical Detection and Removal of Chromium(VI) and Cadmium(II).

The presence of inorganic pollutants such as Cadmium(II) and Chromium(VI) could destroy our environment and ecosystem. To overcome this problem, much attention was directed to microbial technology, whereas some microorganisms could resist the toxic effects and decrease pollutants concentration while the microbial viability is sustained. Therefore, we built up a complementary strategy to study the biofilm formation of isolated strains under the stress of heavy metals. As target resistive organisms, Rhizobium-MAP7 and Rhodotorula ALT72 were identified. However, Pontoea agglumerans strains were exploited as the susceptible organism to the heavy metal exposure. Among the methods of sensing and analysis, bioelectrochemical measurements showed the most effective tools to study the susceptibility and resistivity to the heavy metals. The tested Rhizobium strain showed higher ability of removal of heavy metals and more resistive to metals ions since its cell viability was not strongly inhibited by the toxic metal ions over various concentrations. On the other hand, electrochemically active biofilm exhibited higher bioelectrochemical signals in presence of heavy metals ions. So by using the two strains, especially Rhizobium-MAP7, the detection and removal of heavy metals Cr(VI) and Cd(II) is highly supported and recommended.

Removing Pb2+ with a pectin-rich fiber from sisal waste.

A pectin-rich dietary fiber from sisal waste (P-SF), containing 11.8% pectin, was produced by a sequential enzymatic-ultrasonic process. P-SF was effective in adsorbing Pb2+ from aqueous solution with a maximum adsorption amount of 184 mg g-1. Adsorption isotherms were fitted well by the Langmuir equation, and the adsorption kinetics could be described by a pseudo-second-order model. X-ray photoelectron spectroscopy and energy dispersive spectroscopy suggested that Pb2+ was adsorbed by P-SF via ion exchange, complexation and mineral precipitation. Dietary supplementation with 10% (w/w) P-SF in basal feed led to a significant decrease in Pb2+ in the brain, liver and kidney. P-SF has greater in vivo efficacy of Pb2+ removal as compared to commercial soybean dietary fiber. The reduction of brain Pb2+ level by P-SF was as effective as by a Pb2+ excretion drug. These findings suggested that P-SF has a great potential to be used as a dietary supplement to cope with Pb2+ poisoning.

Harnessing Peptides against lead pollution and poisoning: Achievements and prospects.

Among the broad applicability of peptides in numerous aspects of life and technologies, their interactions with lead (Pb), one of the most harmful substances to the environment and health, are constantly explored. So far, peptides were developed for environmental remediation of Pb-contaminations by various strategies such as hydrogelation and surface display. They were also designed for Pb detection and sensing by electrochemical and fluorescent methods and for modeling natural proteins that involve in mechanisms by which Pb is toxic. This review aims at summarizing selected examples of these applications, manifesting the enormous potential of peptides in the combat against Pb pollution. Nevertheless, the absence of new medicinal treatments against Pb poisoning that are based on peptides is noticeable. An overview of previous achievements utilizing Pb-peptide interactions towards various goals is presented and can be therefore leveraged to construct a useful toolbox for the design of smart peptides as next-generation therapeutics against Pb.

Dynamic performance of a fungal biofilter packed with perlite for the abatement of hexane polluted gas streams using SIFT-MS and packing characterization with advanced X-ray spectroscopy.

The use of Fusarium solani fungi in an expanded perlite packed biofilter was investigated for the treatment of a hexane polluted waste gas stream using selected ion flow tube mass spectrometry (SIFT-MS). The latter analytical technique proved to be of utmost importance to evaluate the performance of the biofilter at high time resolution (seconds) under various transient conditions, analogous to industrial situations. The biofilter was operational for 277 days with inlet loads varying between 1 and 14 g m-3 h-1 and applying an empty bed residence time of 116 s. The results showed a positive behaviour of the biofilter against different types of disruptions such as: (i) changes in the relative humidity of the inlet gas, (ii) stopping the carbon supply for 1, 5 and 10 days, (iii) varying the inlet hexane concentration (step increases and intermittent pulses) and (iv) limiting the availability of nutrients. X-ray imaging (both conventional 2D µCT and X-ray fluorescence, XRF) was applied for the first time on biofilter media in order to get insight in the internal structure of expanded perlite and to visualise the biomass growth. The latter in combination with online porosity measurements using SIFT-MS provides fundamental information regarding the biofiltration process.

Low-cost field production of biochars and their properties.

Biochar has been intensively investigated for carbon sequestration, soil fertility enhancement, and immobilization of heavy metals and organic pollutants. Large-scale use of biochar in agricultural production and environmental remediation, however, has been constrained by its high cost. Here, we demonstrated the production of low-cost biochar ($20/ton) in the field from Robinia pseudoacacia biowaste via a combined aerobic and oxygen-limited carbonization process and a fire-water-coupled method. It involved aerobic combustion at the outer side of biomass, oxygen-limited pyrolysis in the inner core of biomass, and the termination of the carbonization by water spray. The properties of biochar thus produced were greatly affected by exposure time (the gap between a burning char fell to the ground and being extinguished by water spray). Biochar formed by zero exposure time showed a larger specific surface area (155.77 m2/g), a higher carbon content (67.45%), a lower ash content (15.38%), and a higher content of carboxyl and phenolic-hydroxyl groups (1.74 and 0.86 mol/kg, respectively) than biochars formed with longer exposure times (5-30 min). Fourier-transform infrared spectroscopic (FTIR) spectra indicated that oxygen-containing functional groups of biochar played a role in Cd and oxytetracycline sorption though a quantitative relationship could not be established as the relative contribution of carbon and ash moieties of biochar to the sorption was unknown. Outcomes from this research provide an option for inexpensive production of biochar to support its use as a soil amendment in developing countries.

Green Analysis: High Throughput Analysis of Emerging Pollutants in Plant Sap by Freeze-Thaw-Centrifugal Membrane Filtration Sample Preparation-HPLC-MS/MS Analysis.

Emerging and fugitive contaminants (EFCs) released to our biosphere have caused a legacy and continuing threat to human and ecological health, contaminating air, water, and soil. Polluted media are closely linked to food security through plants, especially agricultural crops. However, measuring EFCs in plant tissues remains difficult, and high-throughput screening is a greater challenge. A novel rapid freeze-thaw/centrifugation extraction followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis was developed for high-throughput quantification of 11 EFCs with diverse chemical properties, including estriol, codeine, oxazepam, 2,4-dinitrotoluene, 1,3,5-trinitroperhydro-1,3,5-triazine, bisphenol A, triclosan, caffeine, carbamazepine, lincomycin, and DEET, in three representative crops, corn, tomato, and wheat. The internal aqueous solution, i.e., sap, is liberated via a freeze/thaw cycle, and separated from macromolecules utilizing molecular weight cutoff membrane centrifugal filtration. Detection limits ranged from 0.01 µg L-1 to 2.0 µg L-1. Recoveries of spiked analytes in three species ranged from 83.7% to 109%. Developed methods can rapidly screen EFCs in agriculture crops and can assess pollutant distribution at contaminated sites and gain insight on EFCs transport in plants to assess transmembrane migration in vascular organisms. The findings contribute significantly to environmental research, food security, and human health, as it assesses the first step of potential entry into the food chain, that being transmembrane migration and plant uptake, the primary barrier between polluted waters or soils and our food.

Insight into the mechanisms for hexavalent chromium reduction and sulfisoxazole degradation catalyzed by graphitic carbon nitride: The Yin and Yang in the photo-assisted processes.

As robust polymeric catalysts, graphitic carbon nitride (g-C3N4) has been known to have great application potential in environmental remediation. However, the mechanisms in the photo-assisted catalytic processes during the reduction or oxidation of pollutants are still difficult to discern and therefore not well studied. In this work, visible-assisted catalytic reduction of hexavalent chromium (Cr(VI)) or oxidation of sulfisoxazole (SIZ) by g-C3N4 with the addition of formic acid (FA) or potassium peroxydisulfate (PS) were systematically investigated. Effects of operation parameters such as g-C3N4 dosage, FA concentration, Cr(VI) concentration, solution pH, PS concentration were studied. The results showed g-C3N4 can be effective and robust catalyst for both the reduction (Yin) and oxidation (Yang) reactions in the environmental remediation. Mechanisms were studied by using electron spin resonance (ESR) spectroscopy. The results revealed the CO 2- is the predominant radical for Cr(VI) reduction in the g-C3N4/FA/Vis system and the SO4- and OH are all the main radicals for the oxidation of SIZ in the g-C3N4/PS/Vis system. The photo-generated carriers by g-C3N4, act as radical initiator, were responsible for the production of the reactive radical species in aqueous solution. This work not only shed a new light on the application of semiconductor polymers for the removal of micropollutants and also will expand the applicability of the polymeric photocatalysts for environmental remediation.

Production, characterization and biotechnological potential of lipopeptide biosurfactants from a novel marine Bacillus stratosphericus strain FLU5.

This work aimed at studying the potential of a new hydrocarbonoclastic marine bacterium, Bacillus stratosphericus FLU5, to produce an efficient surface-active agent BS-FLU5. Biosurfactant production was examined on different carbon sources; using the surface tension measurement and the oil displacement test. Strain FLU5 showed its capacity to produce biosurfactants from all tested substrates, in particular the residual frying oil, which is a cheap renewable carbon source alternative, thus minimizing the high cost of producing those surfactants. MALDI-TOF MS/MS analysis confirmed the presence of lipopeptides, which are identified as members of surfactin and pumilacidin series. The critical micelle concentration (CMC) of the purified lipopeptides produced by strain FLU5 was 50 mg/l. At this concentration, the surface tension of the water was reduced from 72 to 28 mN/m. Furthermore, the crude lipopeptides showed an interesting stability against a broad range of pH, temperature and salinity. In addition, the application of BS-FLU5 in oil recovery from hydrocarbons-contaminated soil (used motor oil) showed that it was more effective on the hydrocarbon-remobilization than some tested synthetic surfactants. Interestingly, the biosurfactant BS-FLU5 showed a negligible cytotoxic effect against the mammalian cells HEK293. These results highlight the applicability of the lipopeptides BS-FLU5 in different fields, especially in environmental remediation processes.

TriPleX™ waveguide-based fluorescence biosensor for multichannel environmental contaminants detection.

In order to realize the multi-analyte assays for environmental contaminants, an optical biosensor utilizing laser-induced fluorescence-based detection via the binding of biomolecules to the surface of an integrated TriPleX™ waveguide chip on a glass substrate (fused silica, FS) is described. As far as we know, this is the first demonstration of using the TriPleX™ technology to fabricate the waveguide chip on a FS substrate. The sensor consists of 32 individually addressable sensor patches, which were formed on the chip surface by exploiting 3 Y-junction splitters, creating four equal rows of eight evanescently excited windows in parallel. The basic low-loss SiO2/Si3N4 TriPleX™ waveguide configuration in combination with on-chip spotsize convertors allows for both high fiber-to-chip coupling efficiency and enables at the same time individually optimized high chip surface intensity and low patch-to-patch deviation. Moreover, the complementary metal-oxide-semiconductor compatible fabrication of waveguide chip allows for its mass production at low cost. By taking MC-LR, 2,4-D, atrazine and BPA as the model analytes, the as-proposed waveguide based biosensor was proven sensitive with the detection limits of 0.22 µg/L for MC-LR, 1.18 µg/L for 2, 4-D, 0.2 µg/L for atrazine and 0.06 µg/L for BPA. Recoveries of the biosensor towards simultaneous detection of MC-LR, 2, 4-D, atrazine and BPA in spiked real water samples varied from 84% to 120%, indicating the satisfactory accuracy of the established technology.

Preparation of activated petroleum coke for removal of naphthenic acids model compounds: Box-Behnken design optimization of KOH activation process.

This study employed Box-Behnken design and response surface methodology to optimize activation parameters for the production of activated petroleum coke (APC) adsorbent from petroleum coke (PC) to achieve highest adsorption capacity for three model naphthenic acids. Activated petroleum coke (APC) adsorbent with a BET surface area of 1726 m2/g and total pore volume of 0.85 cc/g was produced at the optimum activation conditions (KOH/coke mass ratio) of 3.0, activation temperature 790 °C, and activation time 3.47 h). Effects of the activation parameters on the adsorption pefromances (adsortion capaciy and kinetics) were investigated. With the APC obtained at the optimum activation condition, the maximum adsorption capacity of 451, 362, and 320 (mg/g) was achieved for 2-naphthoic acid, diphenylacetic acid and cyclohexanepentanoic acid (CP), respectively. Although, generally APC adsorbents with a higher specific surface area and pore volume provide better adsorption capacity, the textural properties (surface areas and pore volume) are not the only parameters determining the APC adsorbents' adsorption capacity. Other parameters such as surface functionalities play effective roles on the adsorption capacity of the produced APC adsorbents for NAs. The KOH activation process, in particular the acid washing step, distinctly reduced the sulfur and metals contents in the raw PC, decreasing the leaching potential of metals from APC adsorbents during adsorption.

Reduction of heavy metal (Pb2+) biosorption in zebrafish model using alginic acid purified from Ecklonia cava and two of its synthetic derivatives.

Heavy metal contamination has become a major problem that causes severe environmental and health issues due to their biosorption, bioaccumulation, and toxicity. This study was designed to evaluate heavy metal chelating abilities of alginic acid (AA) extracted from the brown seaweed Ecklonia cava and two of its derivatives prepared by the partial oxidation of the 2° OH groups (OAA) and partial carboxylation of the monomeric units (CAA) upon reducing the heavy metal biosorption in zebrafish (Danio rerio) modal. Metal ions were quantified using ICP-OES and biopolymers were characterized by FTIR and XRD analysis. All investigated biopolymers indicated potential ability for chelating Pb2+, Cu2+, Cd2+, As3+, and Ag+. The sorption capacities were in the order of CAA>OAA>AA. All biopolymers indicated a comparatively higher chelation towards Pb2+. AA, OAA, and CAA could effectively reduce Pb2+ induced toxicity and Pb2+ stress-induced ROS production in zebrafish embryos. Besides, they could reduce the biosorption of Pb2+ in adult zebrafish which could lead to bioaccumulation. Since alginic acid purified from E. cava and its derivatives could be utilized as seaweed derived biopolymers to purify heavy metals contaminated water and as a dietary supplement to reduce heavy metal biosorption in organisms.

Analysis of Recent Patenting Activities in the Field of Bioremediation of Petroleum Hydrocarbon Pollutants Present in the Environment.

BACKGROUND: In today's world one of the major environmental problems is the contamination of aquatic or terrestrial ecosystem due to spillage of hydrocarbon compounds produced due to various activities related to the petrochemical industry. In recent years, bioremediation has emerged as a promising technology for the restoration of these contaminated sites in an ecofriendly way. OBJECTIVE: The aim of present review literature is the compilation of patent documents on bioremediation of petroleum hydrocarbon pollutants to know technological advancements in this field. METHODS: This analysis was based on various criteria i.e. patenting trend over time, country-wise and assignee-wise comparisons and types of technology used in various patents. Some publicly available patent databases were used to retrieve the patent information from the year 2000 to 2016. RESULTS: Patent applications were retrieved and it was observed that different types of technological approaches were used in developing the patents. United States accounted for maximum patent publications, followed by China, Korea, Japan, Russia, Great Britain, Mexico, India and Canada in developing bioremediation technologies. US based organization DU PONT is the leading group as patent assignee followed by Biosaint Co. Ltd in Korea. CONCLUSION: Patenting activity in the field of bioremediation of petroleum hydrocarbon was not much commendable in the early 20th century. However, an increased trend was observed in the past few years. Further contribution in this aspect would help in stabilizing various global environmental as well as economic issues.

Adsorption behavior of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin on pristine and doped black phosphorene: A DFT study.

Polychlorinated dibenzo-p-dioxins (PCDDs) are highly toxic to humans. The search for novel and effective methods and materials for detecting or removing these gas pollutants is becoming more important and urgent. With its high specific surface area, abundance, and variety of potential applications, phosphorene has attracted much research interest. In this study, density functional theory was used to study the interactions between a doped phosphorene sheet and a tetrachlorodibenzo-p-dioxin (TCDD) molecule. The initial configurations of the TCDD and metallic (Ca or Ti) or nonmetallic (S and Se) dopants were investigated during the TCDD-phosphorene interaction study. Adsorption energy, isosurface of electron density difference, and density of states analysis were utilized to explore the interactions between TCDD and phosphorene. The results indicated that Ca dopant effectively improved the interaction between TCDD and phosphorene. Se dopant reduced the interaction between TCDD and phosphorene. Combining interactions between TCDD and the pristine, Ca-doped, and Se-doped phosphorenes, phosphorene could be a promising candidate for TCDD sensing and removal.

Degradation of anthropogenic pollutant and organic dyes by biosynthesized silver nano-catalyst from Cicer arietinum leaves.

The work represents the potent catalytic activity of silver nanoparticles synthesized from Cicer arietinum (chickpea) leaf extract (CAL-AgNPs). Here, silver nano-catalysts were used against the anthropogenic pollutants mainly involving nitro-amines and azo dyes. These pollutants are extremely harmful to our environment and causes severe health issues. The CAL-AgNPs have the potential to degrade harmful toxins and their by-products, thereby decreasing the pollutants from the environment. The green synthesis of nano-catalyst includes a simple, cost effective and eco-friendly method using the leaf extract from the plant. A systematic study was conducted, including synthesis, optimization and characterization of the silver particles. The AgNPs were further assessed through DLS and TEM for size and morphological evaluation. The obtained particles have shown spherical morphology with the size range of 88.8nm. Further, FTIR were performed for compositional and functional group analysis of the particles. The antibacterial efficiency was also evaluated against E. coli and P. aeruginosa. For their catalytic evaluation, CAL-AgNPs were assessed for 4-nitrophenol, methylene blue and congo red. The results obtained through catalytic evaluation suggested that the CAL-AgNPs could be helpful to surmount the environmental pollution in a very effective manner.

Novel Palm Fatty Acid Functionalized Magnetite Nanoparticles for Magnetic Solid-Phase Extraction of Trace Polycyclic Aromatic Hydrocarbons from Environmental Samples.

A novel adsorbent, palm fatty acid coated magnetic Fe3O4 nanoparticles (MNP-FA) was successfully synthesized with immobilization of the palm fatty acid onto the surface of MNPs. The successful synthesis of MNP-FA was further confirmed by X-Ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Energy dispersive X-Ray spectroscopy (EDX) analyses and water contact angle (WCA) measurement. This newly synthesized MNP-FA was applied as magnetic solid phase extraction (MSPE) adsorbent for the enrichment of polycyclic aromatic hydrocarbons (PAHs), namely fluoranthene (FLT), pyrene (Pyr), chrysene (Cry) and benzo(a)pyrene (BaP) from environmental samples prior to High Performance Liquid Chromatography- Diode Array Detector (HPLC-DAD) analysis. The MSPE method was optimized by several parameters such as amount of sorbent, desorption solvent, volume of desorption solvent, extraction time, desorption time, pH and sample volume. Under the optimized conditions, MSPE method provided a low detection limit (LOD) for FLT, Pyr, Cry and BaP in the range of 0.01-0.05 ng mL-1. The PAHs recoveries of the spiked leachate samples ranged from 98.5% to 113.8% with the RSDs (n = 5) ranging from 3.5% to 12.2%, while for the spiked sludge samples, the recoveries ranged from 81.1% to 119.3% with the RSDs (n = 5) ranging from 3.1% to 13.6%. The recyclability study revealed that MNP-FA has excellent reusability up to five times. Chromatrographic analysis demonstrated the suitability of MNP-FA as MSPE adsorbent for the efficient extraction of PAHs from environmental samples.

Anticancer, antibacterial and pollutant degradation potential of silver nanoparticles from Hyphaene thebaica.

We present here the biosynthesis of AgNps from the aqueous extract of H. thebaica fruit, and monitored through UV-Vis spectrophotometer. The functional group were characterized through ATR-FTIR spectroscopy, the particle size, morphologies and elemental composition of the nanoparticles were investigated by using TEM, FESEM and EDS respectively. The anti-proliferation activity of the synthesized AgNps was carried out using MTT assay on human prostate (PC3), breast (MCF7) and liver (HepG2) cancer cell lines. The anti-proliferation assay showed that the AgNps were able to inhibit the proliferation of the cancer cell lines in a dose depending manner. The effect was found more pronounced on prostate (IC50 2.6 mg/mL) followed by breast (IC50 4.8 mg/mL) and then liver cancer cell lines (IC50 6.8 mg/mL). The prepared AgNps were found to inhibit 99% growth of both E. coli and S. aureus after 24 h of incubation. The nanoparticles were used for the degradation of 4-nitrophenol (4-NP) and Congo red dyes (CR), which efficiently degrade CR, but make complex formation with 4-NP. Therefore, the AgNps synthesized from the aqueous fruit extract of H. thebaica have potential application in pharmacology and waste water treatment.

Permeable bio-reactive barriers to address petroleum hydrocarbon contamination at subantarctic Macquarie Island.

A reliance on diesel generated power and a history of imperfect fuel management have created a legacy of petroleum hydrocarbon contamination at subantarctic Macquarie Island. Increasing environmental awareness and advances in contaminant characterisation and remediation technology have fostered an impetus to reduce the environmental risk associated with legacy sites. A funnel and gate permeable bio-reactive barrier (PRB) was installed in 2014 to address the migration of Special Antarctic Blend diesel from a spill that occurred in 2002, as well as older spills and residual contaminants in the soil at the Main Power House. The PRB gate comprised of granular activated carbon and natural clinoptilolite zeolite. Petroleum hydrocarbons migrating in the soil water were successfully captured on the reactive materials, with concentrations at the outflow of the barrier recorded as being below reporting limits. The nutrient and iron concentrations delivered to the barrier demonstrated high temporal variability with significant iron precipitation observed across the bed. The surface of the granular activated carbon was largely free from cell attachment while natural zeolite demonstrated patchy biofilm formation after 15 months following PRB installation. This study illustrates the importance of informed material selection at field scale to ensure that adsorption and biodegradation processes are utilised to manage the environmental risk associated with petroleum hydrocarbon spills. This study reports the first installation of a permeable bio-reactive barrier in the subantarctic.

Microalgal Cultivation in Secondary Effluent: Recent Developments and Future Work.

Eutrophication of water catchments and the greenhouse effect are major challenges in developing the global economy in the near future. Secondary effluents, containing high amounts of nitrogen and phosphorus, need further treatment before being discharged into receiving water bodies. At the same time, new environmentally friendly energy sources need to be developed. Integrating microalgal cultivation for the production of biodiesel feedstock with the treatment of secondary effluent is one way of addressing both issues. This article provides a comprehensive review of the latest progress in microalgal cultivation in secondary effluent to remove pollutants and accumulate lipids. Researchers have discovered that microalgae remove nitrogen and phosphorus effectively from secondary effluent, accumulating biomass and lipids in the process. Immobilization of appropriate microalgae, and establishing a consortium of microalgae and/or bacteria, were both found to be feasible ways to enhance pollutant removal and lipid production. Demonstrations of pilot-scale microalgal cultures in secondary effluent have also taken place. However there is still much work to be done in improving pollutants removal, biomass production, and lipid accumulation in secondary effluent. This includes screening microalgae, constructing the consortium, making use of flue gas and nitrogen, developing technologies related to microalgal harvesting, and using lipid-extracted algal residues (LEA).

Removal of nitrate and phosphate using chitosan/Al2O3/Fe3O4 composite nanofibrous adsorbent: Comparison with chitosan/Al2O3/Fe3O4 beads.

In the present study the chitosan/Al2O3/Fe3O4 composite nanofibrous adsorbent was prepared by electrospinning process and its application for the removal of nitrate and phosphate were compared with chitosan/Al2O3/Fe3O4 composite bead adsorbent. The influence of Al2O3/Fe3O4 composite content, pH, contact time, nitrate and phosphate initial concentrations and temperature on the nitrate and phosphate sorption using synthesized bead and nanofibrous adsorbents was investigated in a single system. The reusability of chitosan/Al2O3/Fe3O4 composite beads and nanofibers after five sorption-desorption cycles were carried out. The Box-Behnken design was used to investigate the interaction effects of adsorbent dosage, nitrate and phosphate initial concentrations on the nitrate and phosphate removal efficiency. The pseudo-second-order kinetic model and known Freundlich and Langmuir isotherm models were used to describe the kinetic and equilibrium data of nitrate and phosphate sorption using chitosan/Al2O3/Fe3O4 composite beads and nanofibers. The influence of other anions including chloride, fluoride and sulphate on the sorption efficiency of nitrate and phosphate was examined. The obtained results revealed the higher potential of chitosan/Al2O3/Fe3O4 composite nanofibers for nitrate and phosphate compared with chitosan/Al2O3/Fe3O4 composite beads.