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The concentrations, potential sources, and compositional profile of PBDEs in the surface water and sediment of Nahoon Estuary, East London, South Africa, were investigated with solid-phase extraction and ultra-sonication, respectively, followed by gas-chromatography-electron capture detection. The seasonal range of the contaminants’ concentrations in water and sediment samples in spring season were ƩPBDE 329 ± 48.3 ng/L (25.32–785 ng/L) and ƩPBDE 4.19 ± 0.35 ng/g dw (1.91–6.57 ng/g), but ƩPBDE 62.1 ± 1.50 ng/L (30.1–110 ng/L) and ƩPBDE 65.4 ± 15.9 ng/g dw (1.98–235 ng/g) in summer, respectively. NH1 (first sampling point) was the most contaminated site with PBDE in the Estuary. The potential source of pollution is attributed to the stormwater runoff from a creek emptying directly into the Estuary. This study's dominant PBDE congener is BDE- 17, ranging from below detection limit to 247 ng/L and 0.14–32.1 ng/g in water and sediment samples, respectively. Most commonly detected at all the sites were BDE- 17, 47, 66, and 100. Most BDE- 153 and 183 are found in sediment in agreement with the fact that higher brominated congeners of PBDE adsorb to solid materials. There was no correlation between the congeners and organic carbon and organic matter. However, the human health risk assessment conducted revealed that the PBDE concentration detected in the estuary pose low eco-toxicological risk. Nevertheless, constant monitoring should be ensured to see that the river remains safe for all the users, as it serves as a form of recreation to the public and a catchment to some neighbourhoods around the river.

Listeria monocytogenes (L. monocytogenes) is the etiologic agent of listeriosis which significantly affects immunocompromised individuals. The potential risk of infection attributed to L. monocytogenes in irrigation water and agricultural soil, which are key transmission pathways of microbial hazards to the human population, was evaluated using the quantitative microbial risk assessment modelling. A Monte Carlo simulation with 10,000 iterations was used to characterize the risks. High counts of L. monocytogenes in irrigation water (mean: 11.96 × 102 CFU/100 mL; range: 0.00 to 56.67 × 102 CFU/100 mL) and agricultural soil samples (mean: 19.64 × 102 CFU/g; range: 1.33 × 102 to 62.33 × 102 CFU/g) were documented. Consequently, a high annual infection risk of 5.50 × 10−2 (0.00 to 48.30 × 10−2), 54.50 × 10−2 (9.10 × 10−3 to 1.00) and 70.50 × 10−2 (3.60 × 10−2 to 1.00) was observed for adults exposed to contaminated irrigation water, adults exposed to contaminated agricultural soil and children exposed to agricultural soil, respectively. This study, therefore, documents a huge public health threat attributed to the high probability of infection in humans exposed to L. monocytogenes in irrigation water and agricultural soil in Amathole and Chris Hani District Municipalities in the Eastern Cape province of South Africa.

The University of Sharjah is a leading educational and research institution in the Gulf region. To stimulate the different aspects of sustainability in education and research as well as to ensure the implementation of sustainability concepts throughout the University campus operations, the concept of sustainability circles is implemented. The University being in hot-arid-zone and mostly surrounded by desert terrain relies on unconventional water conservation programs and initiatives such as the use of innovation & technology, reuse and recycling of water, and awareness campaigns. In line with such programs, the use of potable water is limited for hygiene purposes and wastewater generated within the University is reused after treatment to irrigate the vast green spaces through the most efficient irrigation water application systems. Examples of water conservation practices include use of efficient water devices, reuse of treated greywater for toilet flushing at a selected location, water quality monitoring, preservation to conserve water for its intended use, promoting waterless car wash on the campus grounds etc. On-campus water is also conserved through disseminating knowledge and awareness to the University community and beyond through various sustainability related programs and initiatives organized by Sustainability Office for water conservation and environmental protection.

Continuous vigilance of water quality is essential throughout water supply and storage systems to ensure safe water quality and safeguard consumer health. In the present study, sixty-three sampling locations in Sharjah, UAE, were assessed for possible water quality variations from water supply through utilized water storage tanks in buildings. All investigated physico-chemical parameters were within national water quality guidelines except for free residual chlorine (

Natural Pinus halepensis sawdust has been explored as an alternative biosorbent of heavy metals from aqueous solutions. The effects of pH, adsorbent dose, contact time, metal concentration, and temperature on copper and lead sorption efficiency were investigated through batch experiments. The optimum pH range was 5–8 for Pb and 7 for Cu. Optimum adsorbent dose, achieving almost complete Cu and Pb removal was 10 g/L. Contact times at which maximum metal adsorption was achieved ranged between 5 min to 24 h. An increase in initial metal concentration had varying impacts yet always resulted in increased adsorption capacity. Equilibrium adsorption data were best fitted with Freundlich isotherm for Cu while Pb experimental data fitted equally both Freundlich and Generalized isotherm models. Metal adsorption kinetics was very well described by the pseudo second-order model. Higher metal removal efficiencies and improved equilibrium adsorption capacity were observed at higher temperature. The adsorption process was not spontaneous for Cu, and for Pb at lower temperatures. Adsorption was an endothermic chemical process and the positive values of Δ S suggest an increase in randomness at the solid/liquid interface during adsorption.

Bottled water as well as bottled water dispensers is widely used in the United Arab Emirates as a source of drinking water in residential, commercial, and institutional settings. The quality of such waters is of utmost concern as it has the potential to cause waterborne outbreaks, if (re)contaminated. Besides, bottled water dispensers could act as a source of contamination over time, if not cleaned properly on a regular basis. A cross-sectional study was conducted on 40 water samples collected from public and private bottled water dispensers in the emirates of Dubai and Sharjah. Samples were analyzed for heterotrophic plate count bacteria, fecal and total coliforms, and fungal growth. No total and fecal coliforms were detected in any of the samples. Heterotrophic plate counts (HPC) ranged between 0 and 100 CFU/100 ml, with an overall average of 31 CFU/100 ml. There was no significant difference between the HPC bacterial levels of public and private bottled water dispensers. However, a significant association (p

The biodegradation of naphthalene, 2-methylnaphthalene and phenanthrene was evaluated in marine sediment microbial fuel cells (SMFCs) under different biodegradation conditions, including sulfate reduction as a major biodegradation pathway, employment of anode as terminal electron acceptor (TEA) under inhibited sulfate reducing bacteria activity, and combined sulfate and anode usage as electron acceptors. A significant removal of naphthalene and 2-methylnaphthalene was observed at early stages of incubation in all treatments and was attributed to their high volatility. In the case of phenanthrene, a significant removal (93.83±1.68%) was measured in the closed circuit SMFCs with the anode acting as the main TEA and under combined anode and sulfate reduction conditions (88.51±1.3%). A much lower removal (40.37±3.24%) was achieved in the open circuit SMFCs operating with sulfate reduction as a major biodegradation pathway. Analysis of the anodic bacterial community using 16S rRNA gene pyrosequencing revealed the enrichment of genera with potential exoelectrogenic capability, namely Geoalkalibacter and Desulfuromonas, on the anode of the closed circuit SMFCs under inhibited SRB activity, while they were not detected on the anode of open circuit SMFCs. These results demonstrate the role of the anode in enhancing PAHs biodegradation in contaminated marine sediments and suggest a higher system efficiency in the absence of competition between microbial redox processes (under SRB inhibition), namely due to the anode enrichment with exoelectrogenic bacteria, which is a more energetically favorable mechanism for PAHs oxidation than sulfate.

The present work describes the optimization and validation of a highly selective and sensitive analytical method using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE LC-MS/MS) for the determination of some frequently prescribed pharmaceuticals in urban wastewater received and treated by Sharjah sewage treatment plant (STP). The extraction efficiency of different SPE cartridges was tested and the simultaneous extraction of pharmaceuticals was successfully accomplished using hydrophilic-lipophilic-balanced reversed phase Waters&reg, Oasis HLB cartridge (200 mg/ 6 mL) at pH 3. The analytes were separated on an Aquity BEH C18 column (1.7 &micro, m, 2.1 mm &times, 150 mm) using gradient elution and mass spectrometric analysis were performed in multiple reactions monitoring (MRM) selecting two precursor ions to produce ion transition for each pharmaceutical using positive electrospray ionization (+ESI) mode. The correlation coefficient values in the linear calibration plot for each target compound exceeded 0.99 and the recovery percentages of the investigated pharmaceuticals were more than 84%. Limit of detection (LOD) varied between 0.1&ndash, 1.5 ng/L and limit of quantification (LOQ) was 0.3&ndash, 5 ng/L for all analytes. The precision of the method was calculated as the relative standard deviation (RSD%) of replicate measurements and was found to be in the ranges of 2.2% to 7.7% and 2.2% to 8.6% for inter and intra-day analysis, respectively. All of the obtained validation parameters satisfied the requirements and guidelines of analytical method validation.

The aim of this study is to calculate total cruising route effective doses using three commonly used algorithm codes CARI-6, EPCARD and SIEVERT. Further, the impact of flight cruising duration, altitude and latitude on the estimated effective doses will also be investigated. A total of 24 commercial UAE flight data were collected and retrospectively analysed. CARI-6, EPCARD and SIEVERT codes were used to estimate the total route effective doses per single trip of different destinations including USA, Europe, South Africa, Asia and Australia. Aircraft crew effective doses were shown to significantly increase with flying altitude. A strong significant correlation (0.6469; p < 0.05) was obtained between flight duration and the estimated effective doses, while a moderate insignificant correlation (0.3899; p > 0.05) was obtained with flying altitude for all 24 flights using CARI-6. For flights with the same latitude and duration, all codes gave total effective doses within experimental uncertainties.

Monitoring drinking water, including bottled water, is imperative to safeguarding public health especially where bottled water consumption is high like in the United Arab Emirates (UAE). In this study, radionuclide activity levels of Tritium (3H) and Potassium (40K) were assessed in various brands of bottled water marketed in UAE. Activity level data was used to calculate the annual effective doses (Ed) for different age groups, and the excess lifetime cancer risk (ELCR) for adult males and females in the UAE population. Activity levels for both radionuclides were below the allowable maximum guideline values specified by local and international standards. Calculated total age dependent ingestion doses revealed that adults and lactation age groups received the highest effective ingestion doses. Adult males exhibited a higher ELCR for both isotopes, compared to females. Nonetheless, total radioactive dose for each water brand (0.91–1.47 μSv/yr) as well as for each population group were well below the recommended annual reference dose level of 100 μSv set by World Health Organization. Therefore, bottled water in the UAE is safe from the radiological aspect for investigated radionuclides, and poses no significant radiological exposure and health risk to the public.

The use of lime, bittern and activated carbon were evaluated in the post treatment of tannery wastewater effluent, collected from an existing tannery, after being subjected to medium sized screening and micro-screening. Effluent from an existing tannery was used as the test medium. Jar tests were conducted after raising the pH of the medium to 11.3 ± 0.1 by injecting 5% w/v lime slurry followed by the addition of different doses of bittern as a coagulant. The characteristics of the influent and effluent after the chemical treatment were determined. The clarified effluent was then passed through an activated carbon adsorption column and the various constituents of the effluent were re-measured. The results indicate very good removals of total suspended solids (TSS) (97%), apparent color and turbidity (99%), total phosphorus (87%), and chromium (99.7%). Good removals were also attained for chemical oxygen demand (COD) (71%) and biochemical oxygen demand (BOD) (57%). The addition of lime and bittern increased concentrations of total dissolved solids (TDS) and conductivity by 30% and 36%, respectively. Low arsenic removal was recorded in the range of 56% as a result of combined coagulation with lime, bittern, and activated carbon adsorption. Comparison of coagulation process using bittern, aluminum sulfate and ferric chloride indicated that the three coagulants operate equally well when applied at their optimal pH values.

Laboratory-scale simulated distribution system trihalomethane (SDS-THM) tests were conducted on selected public drinking water sources to predict as well as evaluate trihalomethane formations under controlled laboratory conditions. Varying concentrations of SDS-total trihalomethane at any time (SDS-TTHMT) (2.68–85.78 μg/L) were detected in the two simulated water sources. Evaluating the impact of each test variable on attained SDS-TTHMT levels revealed that for both water sources, the majority of samples exhibited higher SDS-TTHMT levels in the presence of higher chlorine doses. For the two sources, 85 to 87.5 percent of the sample pairs exhibited higher SDS-TTHMT levels at higher incubation temperatures. Incubation periods at which maximum THM levels were attained varied with water source type as well as pH values. All comparable samples exhibited SDS-TTHMT values higher (1.41 and 7.07 folds) than actual surveyed TTHM levels. Statistically, SDST-TTHM showed significant correlations with applied chlorine dose at the 0.05 level, and with TOC, bromides, contact time, and temperature at the 0.01 level. The predictive model, formulated using multiple regression approaches, exhibiting the highest coefficients of determination was logarithmic for the laboratory simulated THM database (r2=0.70; p

The current research aims at developing predictive models for trihalomethane (THM) formation in Lebanon based on field-scale investigations as well as laboratory controlled experimentations. Statistical analysis on field data revealed significant correlations for TTHM with chlorine dose, Specific UV-A, and UV254 absorbing organics. Simulated distribution system-THM tests showed significant correlations with applied chlorine dose, total organic carbon, bromides, contact time, and temperature. Predictive models, formulated using multiple regression approaches, exhibiting the highest coefficients of determination were quadratic for the directly after chlorination (DAC; r 2 = 0.39, p

The current study aims at investigating the efficiency of electrocoagulation for the removal of humic acid from contaminated waters. In parallel, conventional chemical coagulation was conducted to asses humic acid removal patterns. The effect of varying contributing parameters (matrix pH, humic acid concentration, type of electrode (aluminum vs. iron), current density, solution conductivity, and distance between electrodes) was considered to optimize the electrocoagulation process for the best attainable humic acid removal efficiencies. Optimum removals were recorded at pH of 5.0-5.5, an electrical conductivity of 3000 μS/cm at 25 °C, and an electrode distance of 1 cm for both electrode types. With aluminum electrodes, a current density of 0.05 mA/cm2 outperformed 0.1 mA/cm2 yet not higher densities, whereas a current density of 0.8 mA/cm2 was needed for iron electrodes to exhibit comparable performance. With both electrode types, higher initial humic acid concentrations were removed at a slower rate but ultimately attained almost complete removals. On the other hand, the best humic acid removals (∼90%) by chemical coagulation were achieved at 4 mg/L for both coagulants. Also, higher removals were attained at elevated initial humic acid concentrations. Humic acid removals of 90% or higher at an initial HA concentration of 40 mg/L were exhibited, yet alum performed better at the highest experimented concentration. It was evident that iron flocs were larger, denser, and more geometrical in shape compared to aluminum flocs.

Spatial and seasonal changes in trihalomethane concentrations were investigated in various water distribution systems in Lebanon supplied by different water sources. A seasonal sampling program was initiated during which trihalomethanes and various contributing water quality and operational parameters were monitored at points along the distribution system. The majority of samples collected from points within the distribution network exhibited higher trihalomethane concentrations (1–13 folds) when compared to total trihalomethane levels detected in samples collected directly after chlorination. Recorded trihalomethane concentrations in Lebanon were highest in the spring, followed by the summer and winter. Moreover, total trihalomethane concentrations were higher when the abstraction sources were surface waters compared to ground water sources. Also, higher mean trihalomethane values were recorded in chlorinated waters originating from sources subjected to semi-conventional water treatment before the application of chlorine compared to mean trihalomethane values established in chlorinated waters originating from sources subjected to direct chlorination.

This paper examines the need for an interdisciplinary educational approach in environmental engineering and science, discusses the constituents of interdisciplinary environmental education, and addresses its advantages. A case of interdisciplinary environmental education within the Interfaculty Graduate Environmental Sciences Program at the American University of Beiurt is then presented. Specifically, this newly created program is introduced with a description of its structure, content, and performance in terms of mission accomplishment, student enrollment, and marketability of its graduates. Future curriculum development and constraints are also examined.

Water‐related diseases are a human tragedy, resulting in millions of deaths each year, preventing millions more from leading healthy lives, and undermining development efforts by burdening the society with substantial socio‐economic costs. This problem is of great significance in developing countries, where polluted water, water shortages, and unsanitary living conditions prevail. This paper presents a case study on a health‐based socio‐economic assessment of drinking water quality in Lebanon, based on relevant valuation approaches and available country‐specific data. The assessment revealed that the potential health and economic benefits due to water and sanitation improvements can be significant (0.15‐3.35 percent of GDP).

Chemically enhanced wastewater treatment is attracting substantial interest, especially for wastewaters that are not amenable to treatment by conventional biological treatment strategies. Among the currently employed chemical unit processes in wastewater treatment, coagulation–flocculation has received considerable attention for yielding high pollutant removal efficiency. Over the past years, several authors have investigated the role of magnesium ions as a potential coagulant for the chemical clarification of wastewater. This paper presents a comprehensive review of high-pH–magnesium coagulation–flocculation processes in wastewater treatment, describes their applicability and reveals the contribution of such treatment strategies to the chemical clarification of various wastewaters. More importantly, the paper discusses the advantages, disadvantages and process efficiency of high-pH–magnesium coagulation–flocculation in relation to various sources of magnesium ions. The characteristics of sludges produced from lime-based chemical wastewater treatment processes are also discussed. Finally, factors impacting the economics of the process are considered to estimate the costs incurred.

Soluble heavy metals present in water could be deleterious to health, and as a result, their discharge into surface waters has been regulated internationally. Many processes for the removal of heavy metals from water and wastewater have been investigated. Coagulation and precipitation are the processes that have been reported to be most effective in the removal of heavy metals. In this study, seawater liquid bittern (LB), as an inexpensive source of magnesium, added to wastewater alkalized with lime or caustic soda is investigated as a possible coagulant. The experiments covered tests on eight metals: arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc. The lime-LB process culminated in high removals (>90%) for cadmium, chromium, lead, mercury, and zinc and reasonably good removals (71, 82, and 75%) for arsenic, copper, and nickel, respectively. These results were superior to those obtained using the caustic-soda–LB process. The concurrent presence of different metals in solution has been shown to have a minor effect on removal efficiencies for most metals. However, in the case of nickel, removal was appreciably increased by 18.5%. Also, higher concentrations of a single metal showed higher removal efficiencies.

Integrating microbial fuel cell (MFC) into rotating biological contactor (RBC) creates an opportunity for enhanced removal of COD and nitrogen coupled with energy generation from wastewater. In this study, a three-stage rotating bioelectrochemical contactor (referred to as RBC–MFC unit) integrating MFC with RBC technology was constructed for simultaneous removal of carbonaceous and nitrogenous compounds and electricity generation from a synthetic medium containing acetate and ammonium. The performance of the RBC–MFC unit was compared to a control reactor (referred to as RBC unit) that was operated under the same conditions but without current generation (i.e. open-circuit mode). The effect of hydraulic loading rate (HLR) and COD/N ratio on the performance of the two units was investigated. At low (3.05 gCOD g−1N) and high COD/N ratio (6.64 gCOD g−1N), both units achieved almost similar COD and ammonia-nitrogen removal. However, the RBC–MFC unit achieved significantly higher denitrification and nitrogen removal compared to the RBC unit indicating improved denitrification at the cathode due to current flow. The average voltage under 1000 Ω external resistance ranged between 0.03 and 0.30 V and between 0.02 and 0.21 V for stages 1 and 2 of the RBC–MFC unit. Pyrosequencing analysis of bacterial 16S rRNA gene revealed high bacterial diversity at the anode and cathode of both units. Genera that play a role in nitrification (Nitrospira; Nitrosomonas), denitrification (Comamonas; Thauera) and electricity generation (Geobacter) were identified at the electrodes. Geobacter was only detected on the anode of the RBC–MFC unit. Nitrifiers and denitrifiers were more abundant in the RBC–MFC unit compared to the RBC unit and were largely present on the cathode of both units suggesting that most of the nitrogen removal occurred at the cathode.

This study aims to determine the extent of groundwater damage in the Upper Litani River Basin (ULRB) after years of water mismanagement and overfertilization in what is considered to be Lebanon’s largest fertile area. Physical and chemical samples were collected between 2005 and 2010 and analyzed using “The Standard Methods for the Examination of Water and Wastewater” (APHA, AWWA) in order to determine the extent of this pollution. The parameters included pH, ammonia, nitrate, nitrite, sulfate, phosphate, dissolved oxygen, and total dissolved solids.

Thirty-two domestic bottled water brands were analyzed for various physico-chemical as well as bacterial water quality parameters. Recorded results were compared with the Lebanese Standards Institution standards of quality and standards of identity as well as various international water standards for bottled waters. Results showed a widespread in the characteristics of investigated bottled waters, yet the majority met the different bottled water standards for physico-chemical parameters except for pH (4 brands), hardness (2 brands), and calcium (2 brands). All samples showed negative growth for fecal coliforms, yet 18.8% (N = 6) and 59.4% (N = 19) of the samples revealed positive results for total coliforms and heterotrophic plate count at 37°C, respectively. Generated Piper diagrams revealed that the majority of investigated waters are of calcium–magnesium bicarbonate type; some brands were rich in sodium–potassium chloride, and few were of the mixed type. Comparison of the study results with reported label values indicated good agreement with stated pH values but considerable variation for dry residue, Mg, Na, K, Ca, Mg, HCO3, Cl, and SO4. Identification labels showed varying compliance with the Lebanese Standards Institution standards of identity.

The toxicological risks and lifetime cancer risks of trihalomethanes through oral ingestion, dermal absorption, and inhalation exposure from tap water in selected regions in Lebanon are estimated. Existing trihalomethane concentrations do not pose any non-carcinogenic and developmental risks in the exposed population via oral ingestion. Among the three pathways, residents have a higher risk of cancer through oral ingestion than through the other two pathways. The lifetime cancer risk through oral ingestion for dibromochloromethane makes the highest contribution to total risks, followed by bromodichloromethane, bromoform, and chloroform. The total multipathway cancer risk analysis suggests that no cancer risks exist during the summer and winter seasons; however, in the spring the total cancer risks exceeds the USEPA acceptable level of 10−6 by a factor of 10.7.

This paper presents a synopsis of various low-cost techniques employed for the removal of phosphates from water and treated wastewater. Techniques employed include seawater flocculation and coagulation/ flocculation using bittern, adsorption on fluidised raw dolomite bed, and filtration through iron and aluminium coated filter media. Seawater flocculation at a seawater concentration of 10% exhibited highly efficient (>90%) removal of Total Phosphorus (TP) from alkaline oxidation pond effluents. For experiments employing fluidised raw dolomite bed, varying degrees of phosphate adsorption capacities were observed for the different test influents used. Finally, laboratory experiments conducted to determine the efficacy of iron and aluminium coated media in removing low concentrations of phosphates indicated very effective phosphate removals (>90%) when applied to Distilled Water (DW) and synthetic groundwater, and less success when applied to Tap Water (TW) (