Utilization of aquatic biomass as biosorbent for sustainable production of high surface area, nano- microporous, for removing two dyes from wastewater.

The majority of environmental researchers are becoming increasingly concerned with the manufacture of inexpensive adsorbents for the detoxification of industrial effluents. To address one of the significant and well-known pollution issues with certain drains that act as hotspots and contribute to coastal pollution in Alexandria, this study aims to develop an economical, ecologically friendly sorbent. This study assessed the efficacy of a biomass-coated magnetic composite and a magnetic active adsorbent for the removal of two dyes from an industrially contaminated sewer using a wetland plant (Phragmites australis). Using magnetic biosorbent, the biosorption of Xylenol orange and Congo red ions from polluted drain discharge in Abu Qir Bay was evaluated in the current study. Using scanning electron microscopy imaging and Fourier transform infra-red analysis; the surface function and morphology of the nano-biosorbent were examined. At room temperature, the effects of initial dye concentration, pH, contact time, and nano-biosorbent concentration have all been investigated. The greatest percentages that nano-biosorbent can remove from Congo red and Xylenol orange are 97% and 47%, respectively. The removal of the initial Congo red concentration varied from 42 to 97%, while the removal of the initial Xylenol orange concentration varied from 30 to 47%. The adsorption capacity was shown to be strongly pH-dependent; capacity dose as pH value increased, with pH 10 being the ideal pH for Congo red and pH 6 being the ideal pH value for Xylenol orange. The adsorption capacity for Congo red varied between 0.96 and 3.36 and the adsorption capacity for Xylenol orange varied between 0.18 and 17.58. The removal capacity decreased from 3.36 to 0.96 mg/g when the biosorbent dosage was increased from 0.05 to 0.5 g/L for Congo red, in case of Xylenol orange, the removal capacity increased from 0.18 to 17.58 mg/g when the biosorbent dosage was increased from 0.05 to 0.5 g/L. The removal capacity of Congo red increases quickly with time and varied from 1.66 to 1.88 of contact time; while the removal capacity of Xylenol orange varied between 3.08 and 4.62 of contact time. For the dyes under study, kinetics and adsorption equilibrium were examined. Within 180 min, the equilibrium was attained because to the quick adsorption process. For Congo red and Xylenol orange, the highest adsorption capacities were 3.36 and 17.58 mg g-1, respectively. The equilibrium data were assessed using a number of isotherm models, including Langmuir, Freundlich, BET, and Tempkin, while the kinetic data were examined using a variety of kinetic models, including pseudo-first- and pseudo-second-order equations. The pseudo-second-order equation provides the greatest accuracy for the kinetic data and Langmuir model is the closest fit for the equilibrium data.

Bioaccumulation and biomagnifications of toxic metals in tissues of loggerhead turtles (Caretta caretta) from the Mediterranean Sea coast, Egypt.

Heavy metal concentrations in the different tissues of marine turtles are presented; the most frequently monitored elements are mercury, cadmium, and lead. Concentrations of Hg, Cd, Pb, and As in different organs and tissues (liver, kidney, muscle tissue, fat tissue, and blood) of loggerhead turtle Caretta caretta from the southeastern Mediterranean Sea were determined using Atomic Absorption Spectrophotometer, Shimadzu and mercury vapor unite (MVu 1A) for Hg measurements. The highest levels of cadmium and arsenic were found in the kidney (Cd: 61.17 µg g-1; As: 0.051 µg g-1 dry weight). For lead, the highest level was found in muscle tissue (35.80 µg g-1). Mercury tended to be higher in the liver than in other tissues and organs (0.253 µg g-1 dry weight) which showed a higher accumulation of this element. Fat tissue generally displays the lowest trace element burdens. The concentrations of As remained low in all the considered tissues, possibly the result of low trophic levels in sea turtles. In contrast, the diet of loggerhead turtles would result in significant exposure to Pb. This is the first study into metal accumulation in the tissues of a loggerhead turtle from the Egyptian Mediterranean coastline.

Levobupivacaine versus Levobupivacaine Plus Dexmedetomidine in Transversus Abdominis Plane Block in Patients Undergoing Abdominal Aortic Surgery.

Background: Severe postoperative pain is a major dilemma for patients undergoing abdominal aortic surgery. Transversus abdominis plane (TAP) block has been described a successful pain management technique after major abdominal surgery. Dexmedetomidine was proved to enhance the analgesic action of local anesthetics. Aim: This study was aimed to assess the impact of adding dexmedetomidine to levobupivacaine during TAP block in patients undergoing abdominal aortic operations. Patients and Methods: We included 114 patients in this prospective trial, and they were enrolled into two groups; the L group received levobupivacaine only, and the LD group received levobupivacaine plus dexmedetomidine. The block was performed before anesthetic induction. Postoperative pain score was our main outcome. Statistical Analysis: The collected data were tabulated and analyzed through the SPSS software program IBM's Statistical Package for the Social Sciences (SPSS) statistics for Windows (version 25, 2017) (IBM Corporation, Armonk, NY, USA). The categorical data were expressed as numbers and percentages and then compared using the Chi-square test. The continuous data were expressed as mean and standard deviation if normally distributed, or median and range if abnormally distributed. The former data were compared through the one-way ANOVA, while the latter were compared through the Kruskal-Wallis test. Any P < 0.05 was considered statistically significant. Results: Group LD showed significantly earlier sensory blocks compared to the other group. Postoperative pain scores were comparable between the two groups for the initial 4 h following the surgery. Adjuvant dexmedetomidine was associated with better pain scores for the subsequent 12 h compared to Group L. The duration till the first analgesic request showed a significant increase in the LD group (13.3 vs. 11.09 h in Group L). In addition, the same group showed a significant decline in their opioid consumption after the operation (48.95 µg vs. 72.63 µg in the other group). Postoperative nausea and vomiting were significantly increased in Group L. Conclusion: Adjuvant dexmedetomidine has a significant beneficial impact on postoperative analgesic profile. Its use as an adjuvant to peripheral and neuraxial nerve blocks should be recommended in pain management practice.

Lactic Acid-Based Natural Deep Eutectic Solvents to Extract Bioactives from Marine By-Products.

Natural deep eutectic solvents (NaDES) were used to extract bioactive compounds from marine by-products: codfish bones, mussel meat, and tuna vitreous humor. NaDES were prepared using natural compounds, including lactic acid (Lac), fructose (Fru), and urea (Ur), and were characterized to define their physicochemical properties, including the viscosity, density, surface tension, and refractive index. FTIR and NMR analysis confirmed the presence of intermolecular hydrogen bonding in NaDES. The extracts obtained using these NaDES were characterized to define their composition. Results demonstrated that the extract's composition differed highly, depending not only on the DES used, but also on the structure and composition of the raw material. Proteins and lipids were mainly present in extracts obtained from mussels, while ash content was highest in the extracts obtained from codfish bones. The biocompatibility of NaDES and the soluble fractions (SF) of the raw materials in NaDES was evaluated, and it was possible to conclude that the soluble ingredients obtained from the raw materials improved the biocompatibility of NaDES.

Potential Ophthalmological Application of Extracts Obtained from Tuna Vitreous Humor Using Lactic Acid-Based Deep Eutectic Systems.

A green technique was developed to extract hyaluronic acid (HA) from tuna vitreous humor (TVH) for its potential application in managing dry eye disease. Deep eutectic solvents (DES) were used to extract HA and were synthesized using natural compounds (lactic acid, fructose, and urea). The DES, the soluble fraction of TVH in DES (SF), and the precipitated extracts (PE) were evaluated for their potential use in dry eye disease treatment. In vitro experiments on human corneal epithelial cell lines and the effect on dry eye-associated microorganisms were performed. The influence of the samples on the HCE viability, their intracellular reactive oxygen species (ROS) scavenging capacity, inflammatory response, and antimicrobial properties were studied. According to the results, all samples displayed an antioxidant effect, which was significantly higher for PE in comparison to SF. Most of the tested samples did not induce an inflammatory response in cells, which confirmed the safety in ophthalmic formulations. In addition, the DES and SF proved to be efficient against the studied bacterial strains, while PE did not show an antimicrobial effect. Hence, both DES and SF at defined concentrations could be used as potential compounds in dry eye disease management.

Cytotoxicity and Cellular Death Modality of Surface-Decorated Gold Nanorods against a Panel of Breast Cancer Cell Lines.

Herein, the antiproliferative effect of surface-decorated gold nanorods (GNRs) was investigated against three different breast cancer cell lines. The results indicate that the cell lines exhibited different biological responses and death modalities toward the treatment. The cell lines exhibited similar cellular uptake of the nanoparticles; however, MDA-MB-231 demonstrated the highest cytotoxicity compared to other cell lines upon treatment with GNRs. The expression of the CDH1 gene, which is involved in cell adhesion and metastasis, was dramatically increased in treated MDA-MB-231 cells compared to other cell lines. Early apoptosis and late apoptosis are the dominant cellular death modalities of MDA-MB-231 cells upon treatment with GNRs.

Physicochemical Characterization and Simulation of the Solid-Liquid Equilibrium Phase Diagram of Terpene-Based Eutectic Solvent Systems.

The characterization of terpene-based eutectic solvent systems is performed to describe their solid-liquid phase transitions. Physical properties are measured experimentally and compared to computed correlations for deep eutectic solvents (DES) and the percentage relative error er for the density, surface tension, and refractive index is obtained. The thermodynamic parameters, including the degradation, glass transition and crystallization temperatures, are measured using DSC and TGA. Based on these data, the solid-liquid equilibrium phase diagrams are calculated for the ideal case and predictions are made using the semi-predictive UNIFAC and the predictive COSMO RS models, the latter with two different parametrization levels. For each system, the ideal, experimental, and predicted eutectic points are obtained. The deviation from ideality is observed experimentally and using the thermodynamic models for Thymol:Borneol and Thymol:Camphor. In contrast, a negative deviation is observed only experimentally for Menthol:Borneol and Menthol:Camphor. Moreover, the chemical interactions are analyzed using FTIR and 1H-NMR to study the intermolecular hydrogen bonding in the systems.

Efficacy of Dexmedetomidine versus Propofol in Patients Undergoing Endoscopic Transnasal Transsphenoidal Pituitary Tumor Resection.

Background: Dexmedetomidine is associated with good perioperative hemodynamics together with decreased opioid requirements. Furthermore, propofol has been used to achieve hypotensive anesthesia as a part of total intravenous anesthesia. Aims: This study was performed to compare dexmedetomidine and propofol on the adequacy of hypotensive anesthesia during transsphenoidal resection of pituitary tumors. Patients and Methods: A total of 110 cases were included in this prospective randomized study. They were randomized into two equal groups; Group D commenced on Dexmedetomidine, and Group P, which received propofol. Comparing intraoperative hemodynamic parameters and the Boezaart Bleeding Scale was our primary outcome. The secondary outcomes included isoflurane and propranolol consumption, recovery, postoperative analgesic profile. Statistical Analysis: IBM's SPSS Statistics (Statistical Package for the Social Sciences) for Windows (version 25, 2017) was used for the statistical analysis of the collected data. Shapiro-Wilk test was used to check the normality of the data distribution. The quantitative variables were expressed as mean and standard deviation, whereas the categorical variables were expressed as frequency and percentage. Independent sample t and Mann - Whitney tests were used for the comparison of parametric and nonparametric continuous data, respectively. For pair-wise comparison of data (within-subjects), the follow-up values were compared to their corresponding basal value using the paired samples t-test or Wilcoxon matched-pairs signed-ranks test. Fisher exact and Chi-square tests were used for inter-group comparison of nominal data using the crosstabs function. Results: Age, gender, body mass index, and systemic comorbidities did not significantly differ between the two groups. Furthermore, heart rate and blood pressure were comparable at baseline, during operation, and after extubation. Boezaart score, blood loss, isoflurane, and propranolol consumption were also comparable between the two groups. Group D expressed significantly longer emergence and extubation times than Group P. Nevertheless, cases in the same group expressed lower Visual Analog Scale values and postoperative analgesic requirements. Conclusion: Although Dexmedetomidine and propofol are associated with comparable intraoperative hemodynamic changes, the former drug appears to be superior regarding pain control, postoperative analgesic requirement.

Hyaluronic acid and Chondroitin sulfate from marine and terrestrial sources: Extraction and purification methods.

Hyaluronic acid (HA) and chondroitin sulfate (CS) are valuable bioactive polysaccharides that have been highly used in biomedical and pharmaceutical applications. Extensive research was done to ensure their efficient extraction from marine and terrestrial by-products at a high yield and purity, using specific techniques to isolate and purify them. In general, the cartilage is the most common source for CS, while the vitreous humor is main used source of HA. The developed methods were based in general on tissue hydrolysis, removal of proteins and purification of the target biopolymers. They differ in the extraction conditions, enzymes and/or solvents used and the purification technique. This leads to specific purity, molecular weight and sulfation pattern of the isolated HA and CS. This review focuses on the analysis and comparison of different extraction and purification methods developed to isolate these valuable biopolymers from marine and terrestrial animal by-products.

Growth, Yield and Biochemical Impact of Anti-transpirants on Sunflower Plant Grown under Water Deficit.

BACKGROUND AND OBJECTIVE: Climate change affecting on weather in many different ways especially drought and temperature rise. This will drastically down plant production, if not start looking for another source to increase water productivity to cope up with water stress conditions. In this study efforts were conducted to interpret the use of anti-transpirants to conserving irrigation water, aiding plant survival under dry conditions and protecting plant against drought stress. MATERIALS AND METHODS: Two field experiments were carried out during 2017 and 2018 successive growing summer seasons at the experimental farm of National Research Centre, Nubaria, El-Beheira Governorate, Egypt. Anti-transparent ,i.e., chitosan (100 and 150 mg L-1), calcium carbonate (5 and 10 g L-1), salicylic acid (200 and 300 mg L-1) were foliar sprayed on sunflower plants grown under two water levels (normal 100% and deficit 50%). RESULTS: The results showed that water stress decreased growth criteria, photosynthetic pigments, osmoprotectants, yield components, oil and carbohydrate (%) as compared to 100% of irrigation requirements. Meanwhile, water deficit induced significant increases in (proline). Foliar treatments of sunflower plant with chitosan, calcium carbonate, salicylic acid increased growth criteria, yield components, photosynthetic pigments, total soluble sugars, proline and free amino acid as compared to control plant. Data also illustrated that, all used treatment improved seed yield, oil and carbohydrate% of sunflower plants. CONCLUSION: Generally, it could be concluded that 10 g L-1 CaCO3 and 300 mg L-1 SA at 50% level of water irrigation could be recommended for sunflower plant grown under similar field conditions in order to get optimum yield and to save irrigation water.

Nano-Zinc Oxide and Arbuscular mycorrhiza Effects on Physiological and Biochemical Aspects of Wheat Cultivars under Saline Conditions.

BACKGROUND AND OBJECTIVE: Saline soils are restrictive factors to agriculture in arid and semi-arid regions, plant growth and productivity. Thus, it was important to consider how, nano-zinc oxide or bulk zinc oxide alleviates the oxidative salt stress in the presence of Arbuscular mycorrhiza (AM) fungi by two wheat cultivars (Sids 13 and Sakha 94). MATERIALS AND METHODS: A field experiment was carried out during two winter successive seasons to study the beneficial role of nano-zinc oxide or bulk zinc oxide with different concentrations (5 and 10 mg L-1) in enhancing growth, some biochemical and physiological of two wheat cultivars under saline soil. RESULTS: Soaking both wheat cultivars with nano-zinc oxide or bulk zinc oxide in the presence of AM improved growth parameters. All treatments increased significantly photosynthetic pigments, IAA, phenols contents, organic antioxidant enzyme activities and significant decrease in lipid peroxidation. some changes are observed in protein patterns, so several proteins were disappear, but others were selectively improved and synthesis of the new groups of protein was formed, some of these responses were observed through the effect of nano-zinc oxide or bulk zinc oxide and AM. CONCLUSION: Nano-ZnO (10 mg L-1) in the presence of AM was the most effective treatments on both cultivars. Results showed superiority of Sakha 94 cultivar in most growth parameters and biochemical aspects than Sids 13 cultivar.

Fluconazole conjugated-gold nanorods as an antifungal nanomedicine with low cytotoxicity against human dermal fibroblasts.

Herein, a nanotechnology-based approach was adopted to develop a facile and effective nanoplatform for the treatment of superficial fungal infections. Gold nanorods (GNR) functionalized with thiolated poly ethylene glycol (PEG-SH) or thiolated PEGylated cholesterol (Chol-PEG-SH) moieties were conjugated with Fluconazole and loaded into poloxamer 407 hydrogel. The obtained nanocomplexes; PEG-Fluc-GNR and Chol-Fluc-GNR were characterized by optical spectroscopy, hydrodynamic size and effective surface charge. The anti-fungal activity of the nanocomplexes was investigated by estimating the minimum inhibitory concentration (MIC) and the percentage reduction of fungal viable count against Candida (C.) albicans. PEG-Fluc-GNR and Chol-Fluc-GNR resulted in 5-fold and 14-fold reduction in MIC of GNR, and in 9-fold and 12-fold reduction in MIC of Fluconazole, respectively. The average log-reduction of the viable fungal cells upon treatment with the nanocomplexes was 5 log cycles, and it ranged from 1.3-3.7 log cycles when loaded into poloxamer 407 hydrogel. Transmission electron microscope imaging of the treated C. albicans revealed an enhanced uptake of the nanoparticles into the fungus's cell wall within the first 120 min of exposure. The nanocomplexes demonstrated low cytotoxicity towards human dermal fibroblasts which represent the human skin dermal cells. Conjugating Fluconazole with GNR is a promising approach for the effective treatment of superficial fungal infections.

Cholesterol-coated gold nanorods as an efficient nano-carrier for chemotherapeutic delivery and potential treatment of breast cancer: in vitro studies using the MCF-7 cell line.

Gold nanorods (GNRs) have a recognized role in treatment of cancers as efficient nanocarriers for chemotherapeutic drug delivery. In this study, GNRs modified with cholesterol-PEG were employed as a nanocarrier for a hydrophobic compound having a promising phosphatidylinositol 3-kinase (PI3Kα) inhibitory activity. The acquired nanocomplex was characterized by optical and infra-red (IR) absorption spectroscopies, in addition to hydrodynamic size and zeta potential. Glide docking and superposing of docked poses of the hydrophobic ligand and cholesterol moiety demonstrated that hydrophobic interactions drive the conjugation and attachment of the ligand to the cholesterol moiety of the nanocarrier. In vitro release study under a cellular environment indicates that the presence of cells has enhanced the release and the cellular uptake of the conjugated ligand. Furthermore, the anti-proliferative assay of the nanocomplex revealed potent cytotoxicity over a low concentration range of the nanocomplex against MCF-7 breast cancer cells compared to the free compound or the nanocarrier alone. Analysis of cellular death modality by flow cytometry showed that the nanocomplex has a rapid effect on cell death, as cells went toward the late apoptotic/necrotic stage rapidly and proportionally to the increase of the nanocomplex concentration. The overall results propose that cholesterol-decorated GNRs could be considered as a promising nanocarrier for hydrophobic drugs to achieve efficient delivery and potential therapy against breast cancer cells.

Public perception of female paramedics at King Abdulaziz Medical City, Saudi Arabia.

BACKGROUND: Although emergency medical service (EMS) providers recognize that both male and female paramedics are necessary, Saudi EMSs are currently fully staffed by men. Cultural bias against care provision by male paramedics to female victims in the absence of male guardians underscores the need for female paramedics. Consequently, we explored public perception of female paramedics at King Abdulaziz Medical City (KAMC), Riyadh. METHOD: This observational, cross-sectional study used convenience sampling to assess the perceptions of patients, visitors, and employees at the emergency rooms in KAMC and King Abdullah Specialized Children's Hospital via self-administered English- and Arabic-language questionnaires. Questionnaire reliability and validity were assessed in a pilot study. RESULTS: Three hundred twelve respondents completed the survey (67.30% men). The sample included 43.27% medical (40% paramedics, 22% physicians, 12% nurses, and 23% other) and 56.73% nonmedical participants, of whom 53% and 63%, respectively, strongly agreed regarding the importance of female paramedics. Moreover, in the male participant group, 6% of medical and 8% of nonmedical participants strongly disagreed with treatment of their female relatives by male paramedics, and 20% of medical and 30% of nonmedical participants declined medical help because female paramedics were unavailable. CONCLUSIONS: Respondents rated the importance of trained female paramedics in the EMS system. Most strongly agreed that female and male paramedics had equal patient-management capabilities and skills.

Mechanistic studies of antiproliferative effects of Salvia triloba and Salvia dominica (Lamiaceae) on breast cancer cell lines (MCF7 and T47D).

Ethanol extracts obtained from two Salvia species, S. triloba and S. dominica, collected from the flora of Jordan, were evaluated for their antiproliferative activity against MCF7 and T47D breast cancer cell lines by the sulforhodamine B assay. The ethanol extracts were biologically active with IC50 values of (29.89 ±0.92) and (38.91 ±2.44) µg/mL for S. triloba against MCF7 and T47D cells, respectively, and (5.83 ±0.51) and (12.83 ±0.64) µg/mL for S. dominica against MCF7 and T47D cells, respectively. Flow cytometry analysis and the annexinV-propidium iodide (PI) assay revealed apoptosismediated, and to a lesser extent necrosis-induced, cell death by the S. triloba and S. dominica ethanolic extracts in T47D cells. The mechanism of apoptosis was further investigated by determining the levels of p53, p21/WAF1, FasL (Fas ligand), and sFas (Fas/APO-1). The extract from S. triloba induced a more pronounced enrichment in cytoplasmic mono- and oligonucleosomes than that from S. dominica (p < 0:05) in T47D cells. In response to the extract from S. dominica, but not from S. triloba, the proapoptotic efficacy was specifically regulated by p21. Extracts from both Salvia spp. did not enhance p53 levels, and apoptosis induced by them was not caspase-8- or sFas/FasL-dependent. Thus, our findings indicate that S. triloba and S. dominica ethanolic extracts may be useful in breast cancer management/treatment via proapoptotic cytotoxic mechanisms.

Persistent organochlorine pollutants and metals residues in sediment and freshwater fish species cultured in a shallow lagoon, Egypt.

Six freshwater fish species cultured in Lake Edku fish farm, one of the northern Nile Delta lakes in Egypt that receives input from numerous anthropogenic activities in addition to agriculture wastes through several huge drains, were collected for the detection and evaluation of residues of the persistent organochlorine (OC) pollutants polychlorinated biphenyls (PCBs), 1,1,1 -trichloro-2,2-di(4-chlorophenyl)ethane (DDT), total cyclodienes (TC), hexachlorocyclohexanes (HCHs) and heavy metals (Cu, Cd and Pb) in their edible parts. In all fish and sediment samples, PCBs were found in higher concentrations than pesticides; the edible parts of Mugil capito, Tilapia galilaeus, Tilapia zilli and Clarias lazera had the highest PCBs (3.49, 0.83, 1.06 and 4.29 ng/g wet weight respectively), PCB 28 being most prevalent in Mugilcapito and Clarias lazera with ratios 86 and 62%, respectively, of the total PCBs. PCB 180 was most prevalent in Tilapia zilli (about 56% of the total PCBs). In these four fish species OCs were found in the order: PCBs > DDTs > HCHs > TC. The other two species (Tilapia nilotica and Tilapia aureus) had the highest concentrations of pesticides (7.58 and 1.13 ng/g wet weight, respectively) with HCHs being most prevalent (96% and 74% of the total pesticides, respectively). OCs were found in the order: HCHs >> PCBs > DDTs > TC in the edible Tilapia nilotica, and in the order: PCBs > HCHs > DDTs > TC in the other species. The mean concentrations of PCBs and pesticides in sediments are 539.66 +/- 48.8 and 259.17 +/- 81.2 ng/g dry weight, respectively. Among the studied metals in the edible parts of the fish samples, about 67% of the samples contained marginally higher Pb content in the edible parts, above the European Community's legal limit. About 50% of the samples contained marginally higher Cd content (N.D to 0.88 microg/g) above the permissible level of Cd in fish edible parts; the Cu content ranged from 0.37-2.36 microg/g, with a marginally higher content in the fish but below the maximum permissible limits. As for the concentration of the studied metals in sediments of Edku lagoon, results showed that copper had the highest concentration (2.2 +/- 0.37 microg/g) in the lake sediment.

Bioaccumulation of heavy metals in mollusca species and assessment of potential risks to human health.

Along the Alexandria coast of the Egyptian Mediterranean Sea, five edible species of bivalve molluscs and one gastropoda species (Mactra coralline, Ruditapes decussates, Paphia undulate, Venerupis rhomboids, Crista pectinata and Coralliophila meyendorffi) were analyzed for content of metals (Cadmium, Chromium, Lead, Cobalt and Nickel) in the muscle and in the sediments where they live. The potential health risks of metals to humans via consumption of seafood were assessed by estimated daily intake and target hazard quotient. Significant positive correlations (p < 0.05) were obtained between tissue concentrations for all pairs of metals, with the exception of Cadmium. Significant positive correlations were also obtained for the concentrations of Cd and Ni in tissues of all studied species relative to their concentrations in surface sediments. However, correlations between tissue and sediment concentrations for Chromium, Lead and Cobalt were negative. Ruditapes decussates and C. meyendorffi had the highest values for the summed target hazard quotient and may pose a potential risk to local inhabitants through their consumption in the diet. The potential risk would arise from exposure to high tissue concentrations of Cd and Pb, which exceeded published guidelines for safety of seafood products in some cases. Chromium contributed a considerable fraction of the total target hazard quotient for all metals combined, but did not exceed the published guidelines. Cobalt and Ni did not contribute greatly overall to the target hazard quotient, except in the case of Ni in V. rhomboids.

The potential of different bio adsorbents for removing phenol from its aqueous solution.

The use of natural resources for the removal of phenol and phenolic compounds is being looked upon by researchers in preference to other prevailing methods. In the present study, different biosorbents, brown algae (Padina pavonia), fresh water macrophyta (Ceratophyllum demersum), and black tea residue, were tested as adsorbent for the removal of phenol from aqueous solutions. The optimum conditions for maximum adsorption in terms of concentration of the adsorbate and pH were identified. The results show that the initial concentration increases as the removal of phenol increases in C. demersum; in the case of the other two adsorbents, the initial concentration increases as the removal of phenol decreases, especially for an initial concentration lower than 100 and 1,000 µg/L for P. pavonia and black tea residue, respectively. Maximum percentage removal of phenol by each adsorbent is 77, 50.8, and 29 % for C. demersum, P. pavonia, and black tea residue, respectively. Also, the biosorption capacity was strongly influenced by the pH of the aqueous solution with an observed maximum phenol removal at pH of around 6-10. The first biosorbent (black tea residue) displays the maximum adsorption capacity at a pH of 10 with a percentage sorption capacity of 84 %; P. pavonia revealed a greater adsorption percentage at pH 10, reaching 30 %, while for C. demersum, the removal of phenol increases with the increase in initial pH up to 6.0 and decreases drastically with further increase in initial pH. The Freundlich, Langmuir, and Brauner-Emmet-Teller adsorption models were applied to describe the equilibrium isotherms. The results reveal that the equilibrium data for all phenol adsorbents fitted the Freundlich model which seemed to be the best-fitting model for the experimental results with similar values of coefficient of determination.

Phytoremediation of heavy metals from aqueous solutions by two aquatic macrophytes, Ceratophyllum demersum and Lemna gibba L.

Wetland plants are being used successfully for the phytoremediation of trace elements in natural and constructed wetlands. Under the present investigation, two aquatic macrophytes, Ceratophyllum demersum and Lemna gibba, were tested for their effectiveness at removing two toxic metals (Pb and Cr). These plants were grown at four different concentrations in single-metal solutions of the two metals and were separately harvested after 2, 4, 6, 9 and 12 days in a laboratory experiment. These plants performed extremely well at removing the chromium and lead from their solutions and were capable of removing up to 95% of lead and 84% of chromium during the 12-day incubation period. The removal continued through the 12 days and up to the highest value on the 12th day of the experiment. The results revealed that, of the two species, L. gibba was the most efficient for the removal of selected heavy metals. The plants accumulated heavy metals without the production of any toxicity or reduction in growth.