Increased functionality of methyl oleate using alkene metathesis

A series of alkene cross-metathesis reactions were performed using a homogeneous ruthenium-based catalyst. Using this technology, a variety of functional groups can be incorporated into the bio-based starting material, methyl oleate. Trans-stilbene, styrene, methyl cinnamate and hexen-3-ol have all been shown to give desirable products. Using this technology, aromatics, alcohols or additional esters can be incorporated into the products. For example, the cross-metathesis reaction of methyl oleate with methyl cinnamate by the second-generation Grubbs catalyst showed 70% conversion of methyl oleate into products where half of the observed products contain an aromatic group and over one-third of the products contain an α,β-unsaturated methyl ester. This promising green route is versatile, and with an appropriate selection of starting materials, it is applicable to the synthesis of polymer precursors, industrial fluids or any other application where the upgrade of natural oils is necessary.     

Studies on process optimization of biodiesel production from waste cooking and palm oil

This work investigated the optimisation of biodiesel production from waste cooking oil (WCO) and palm oil using a two-step transesterification process for WCO and base catalysed transesterification for palm oil. Transesterification reactions were carried out to investigate the effects of prepared catalyst CaO, methanol/WCO and methanol/palm oil ratio and temperature on the yield of biodiesel. A series of experiments were conducted to determine the best conditions for biodiesel production, using methanol/oil ratio between 4:1 and 11:1 and contact time varying between 2 and 4 h. Biodiesel yield of around 90 and 70% was obtained for palm and waste cooking oil at the methanol/oil ratios of 6:1 and 8:1 at temperature of 60 °C for reaction time of 4 h using prepared CaO as catalyst. The physicochemical properties of palm and WCO biodiesel were carried out using standard methods, while the fatty acid profile was determined using gas chromatography. The investigation concludes that biodiesel obtained from palm and waste cooking oil was within the specified limit.     

大九湖泥炭藓湿地对磷、铜污染物净化作用的模拟研究

在大九湖泥炭藓沼泽湿地采用野外实地模拟方法,就泥炭藓湿地对铜、磷两种污染物的净化能力进行了研究。结果表明,磷污染物浓度分别为10,100,1 000 mg/L时,两小时后泥炭藓湿地对该污染物的净化率分别为939%,695%,663%;同样的浓度梯度下,对铜污染物的净化率分别为1000%,976%,880%。泥炭藓湿地对污染物具有很强的净化能力,其泥炭层部分在湿地净化污染物中起到重要作用。利用拟一级动力学模型、修改上限的拟一级动力学模型、拟二级动力学模型、Elovich模型、双常数速率模型、抛物线扩散模型等6个模型对泥炭藓湿地的净化进行动态研究,其中后4个模型均可模拟湿地净化的动态过程。长期预测以拟二级动力学模型为最佳。     

Speciation of 210Po and 210Pb in air particulates determined by sequential extraction

Speciation of (210)Po and (210)Pb in air particulates of two Syrian phosphate sites with different climate conditions has been studied. The sites are the mines and Tartous port at the Mediterranean Sea. Air filters were collected during September 2000 until February 2002 and extracted chemically using different selective fluids in an attempt to identify the different forms of these two radionuclides. The results have shown that the inorganic and insoluble (210)Po and (210)Pb (attached to silica and soluble in mineral acids) portion was found to be high in both sites and reached a maximum value of 94% and 77% in the mine site and Tartous port site, respectively. In addition, only 24% of (210)Pb in air particulates was found to be associated with organic materials probably produced from the incomplete burning of fuel vehicle and similar activities. Moreover, the (210)Po/(210)Pb activity ratio in air particulates was higher than that in all samples at both sites and varied between 3.85 in November 2000 at Tartous port site and 20 in April 2001 at the mine area. These activity ratios were also higher than the natural levels. The (210)Po/(210)Pb activity ratio was also determined in each portion resulting from the selective extraction and found to be higher than that in most samples. The sources of (210)Po excess in these portions are discussed. Soil suspension, which is common in the dry climate dominant in the area, sea water spray and heating of phosphate ores were considered; polonium is more volatile than the lead compounds at even moderate temperature. Furthermore, variations in the chemical forms of (210)Po and (210)Pb during the year were also investigated. However, the results of this study can also be utilized for dose assessment to phosphate industry workers.     

Synthesis of biodiesel from chicken’s skin waste by homogeneous transesterification

ABSTRACT

Poultry skin waste is considered to be a promising source of biodiesel. However, this source presents an environmental threat as it is being discharged into landfills without any treatment. We studied the feasibility of biodiesel production from poultry skin waste. Two-step extraction of lipids from chicken’s skin was developed and gave 97.5% yield using the optimum time and temperature. Esterification was then optimised to remove free fatty acids (FFA) where the ideal parameters were 65 °C during 30min with a molar ratio of methanol to oil of (1:3) and 1% of H₂SO₄. The third step was the transesterification which was performed using 60 °C and 300–600 rpm agitation for 1 h, with 1% basic catalyst and 1:3 (molar ratio) of methanol to oil. The biodiesel (FAME), was characterised using gas chromatography coupled with mass spectrometry (GC-MS) followed by chemical and physical analyses such as iodine number, acid number, flash point and cetane number. The total conversion was obtained using above conditions and most of the studied proprieties of produced biodiesel meet the EN14214 standard. This is an extremely encouraging result, offering a good source of biodiesel by valuing poultry skin waste.     

Inhalation threshold of toxicological concern (TTC) — Structural alerts discriminate high from low repeated-dose inhalation toxicity

The threshold of toxicological concern (TTC) of a compound represents an exposure value below which the associated human health risk is considered negligible. As such, this approach offers assessing the risk of potential toxicants when little or no toxicological information is available. For the inhalation repeated-dose TTC, the goal was to derive structural alerts that discriminate between high- and low-toxic compounds. A further aim was to identify physicochemical parameters related to the inhalation-specific bioavailability of the compounds, and to explore their use as predictors of high vs low toxicity. 296 compounds with subacute, subchronic and chronic inhalation toxicity NOEC (no-observed effect concentration) values were subdivided into three almost equal-sized high-, medium- and low-toxic (HTox, MTox, LTox) potency classes. Whereas the derived 14 HTox and 7 LTox structural alerts yield an only moderate discrimination between these three groups, the high-toxic vs low-toxic mis-classification is very low: LTox-predicted compounds are not HTox to 97.5%, and HTox-predicted compounds not LTox to 88.6%. The probability of a compound being HTox vs LTox is triggered further by physicochemical properties encoding the tendency to evaporate from blood. The new structural alerts may aid in the predictive inhalation toxicity assessment of compounds as well as in designing low-toxicity chemicals, and provide a rationale for the chemistry underlying the toxicological outcome that can also be used for scoping targeted experimental studies.     

Determination of parabens and benzophenone-type UV filters in human placenta. First description of the existence of benzyl paraben and benzophenone-4

UV filters and parabens (PBs) are chemicals used in daily personal care and hygiene products to protect materials and humans from the adverse effects of UV radiation and to preserve the integrity of the formulation, respectively. Several studies highlight their widespread environmental occurrence and endocrine disrupting effects. However, little is known about human exposure to these compounds. The objective of this study was to investigate the exposure of human embryos and foetuses to endocrine disrupting UV filters and PBs.Placentas from volunteer mothers in Barcelona were collected at delivery after informed, written consent by the pregnant women. UV filters and parabens were analysed by liquid chromatography-tandem mass spectrometry. The excellent performance of the method allowed measuring the target compounds in human placental tissue at low ng/g fresh weight level. The detection frequency of the selected compounds was in the range 17–100%. Benzophenone-1, methyl paraben, butyl paraben and benzyl paraben were detected in all samples. The highest measured concentration corresponded to methyl paraben, 11.77 ng/g fresh weight. Reported concentrations of benzophenone-4 and benzyl paraben constitute the first evidence about their accumulation in placenta. The results obtained corroborate that foetuses are exposed to a wide diversity of UV filters and PBs via the placenta.     

Viability of solar photovoltaics as an electricity generation source for Jordan

Viability of solar photovoltaics as an electricity generation source for Jordan was assessed utilising a proposed 5 MW grid‐connected solar photovoltaic power plant. Long‐term (1994–2003) monthly average daily global solar radiation and sunshine duration data for 24 locations – distributed all over the country – were studied and analysed to assess the distribution of radiation and sunshine duration over Jordan, and formed an input to the RetScreen Software for evaluation and analysis of the proposed plant's electricity production and economic feasibility. It was found that depending on the geographical location, the global solar radiation on horizontal surface varied between 1.51 and 2.46 MWh/m²/year with an overall mean value of 2.01 MWh/m²/year for Jordan. The sunshine duration was found to vary, according to the location, between 8.47 and 9.68 hours/day, with a mean value of 9.07 hours/day and about 3311 sunshine hours annually for Jordan. The annual electricity production of the proposed plant varied depending on the location between 6.886 and 11.919 GWh/year, with a mean value of 9.46 GWh/year. The specific yield varied between 340.9 and 196.9 kWh/m², while the mean value was 270.59 kWh/m². Analysis of the annual electricity production of the plant, the specific yield, besides the economic indicators, i.e. internal rate of return, simple payback period, years to positive cash flow, net present value, annual life cycle saving, benefit/cost ratio, and cost of energy – for all sites – showed that Tafila and Karak are the most suitable sites for the solar photovoltaic power plant's development and Wadi Yabis is the worst. The results also showed that an average of 7414.9 tons of greenhouse gases can be avoided annually utilising the proposed plant for electricity generation at any part of Jordan.     

Partitioning of radionuclides and trace elements in phosphogypsum and its source materials based on sequential extraction methods

Phosphogypsum is a waste produced by the phosphate fertilizer industry. Although phosphogypsum is mainly calcium sulphate dihydrate, it contains elevated levels of impurities, which originate from the source phosphate rock used in the phosphoric acid production. Among these impurities, radionuclides from 238U and 232Th decay series are of most concern due to their radiotoxicity. Other elements, such as rare earth elements (REE) and Ba are also enriched in the phosphogypsum. The bioavailability of radionuclides (226Ra, 210Pb and 232Th), rare earth elements and Ba to the surrounding aquatic system was evaluated by the application of sequential leaching of the phosphogypsum samples from the Brazilian phosphoric acid producers. The sequential extraction results show that most of the radium and lead are located in the "iron oxide" (non-CaSO4) fraction, and that only 13-18% of these radionuclides are distributed in the most labile fraction. Th, REE and Ba were found predominantly in the residual phase, which corresponds to a small fraction of the phosphate rock or monazite that did not react and to insoluble compounds such as sulphates, phosphates and silicates. It can be concluded that although all these elements are enriched in the phosphogypsum samples they are not associated with CaSO4 itself and therefore do not represent a threat to the surrounding aquatic environment.     

Efficiency of locally available filter media on fluoride and phosphate removal for household water treatment system

Since conventional water treatment is not affordable in developing countries,looking for locally available and alternative treatment options is mandatory.Removal of fluoride and phosphate can be achieved by designing appropriate filtration media from different materials such as sand,calcined clay,pumice,scoria and bone char.This study was designed to determine the removal efficiency of these locally available filter media with respect to detention time and pH.The filtration apparatuses(tank)were filled separately with stone,gravel with grain size 0.6-4.75 mm and 40 cm deep,sand(ES=0.15-0.35 mm and UC=1.5-3),calcined clay,pumice,scoria and bone char with grain size 0.25-0.5 inch.Water samples were prepared using glass bottles with fluoride concentrations of 6 and 8 mg/l and phosphate concentration of 4 mg/1.Laboratory analysis was carried out before and after filtration to determine the removal efficiency of each medium.It was found that the highest removal of fluoride was achieved by bone char(89.65%),followed by pumice(82.4%).However,bone char has rather increased the concentration of phosphate by 63.8%.Sand was the most efficient media to remove phosphate,managing to remove by 70%.Therefore,it is an attractive option to use these locally available,environmental friendly and appropriate technologies for efficient removal of both fluorine and phosphate at the household or community water treatment level.     

Passive sampling: A cost-effective method for understanding antibiotic fate,behaviour and impact

The occurrence of antibiotics in the environment has raised much concern in recent years. Understanding their release, fate and behaviour in the environment is vital to assess potential risks. In this study, a novel passive water sampler – diffusion gradients in thin-films for organics (o-DGT) – was employed to assess the occurrence and removal of antibiotics in two waste water treatment plants (WWTPs) — one in China and the other in the United Kingdom (UK). Of the targeted compounds, 11 of 19 were detected in the Chinese WWTP (ND—200 ng/L) and 10 of 40 were found in the UK plant (ND—1380 ng/L). Florfenicol, lincomycin, ofloxacin and roxithromycin were most abundant in the Chinese WWTP (influent), while anhydrous erythromycin, ciprofloxacin, trimethoprim, ofloxacin and sulfapyridine were the most abundant in the UK influent samples. Estimated Chinese and UK consumption data are used to interpret the results. Neither of the WWTPs was very effective at removing antibiotics: ~ 40–50% (overall) was removed by the two plants, with the rest being discharged into the receiving rivers. This is the first study using o-DGT to assess the occurrence and removal of antibiotics in WWTPs. o-DGT is a useful, cost-effective tool to assess WWTP performance and can highlight the effectiveness of treatment steps, which can be applied to wastewater based epidemiology studies.     

Pollutant exposures and health symptoms in aircrew and office workers: Is there a link?

Sensory effects in eyes and airways are common symptoms reported by aircraft crew and office workers. Neurological symptoms, such as headache, have also been reported. To assess the commonality and differences in exposures and health symptoms, a literature search of aircraft cabin and office air concentrations of non-reactive volatile organic compounds (VOCs) and ozone-initiated terpene reaction products were compiled and assessed. Data for tricresyl phosphates, in particular tri-ortho-cresyl phosphate (ToCP), were also compiled, as well as information on other risk factors such as low relative humidity.A conservative health risk assessment for eye, airway and neurological effects was undertaken based on a “worst-case scenario” which assumed a simultaneous constant exposure for 8 h to identified maximum concentrations in aircraft and offices. This used guidelines and reference values for sensory irritation for eyes and upper airways and airflow limitation; a tolerable daily intake value was used for ToCP. The assessment involved the use of hazard quotients or indexes, defined as the summed ratio(s) (%) of compound concentration(s) divided by their guideline value(s).The concentration data suggest that, under the assumption of a conservative “worst-case scenario”, aircraft air and office concentrations of the compounds in question are not likely to be associated with sensory symptoms in eyes and airways. This is supported by the fact that maximum concentrations are, in general, associated with infrequent incidents and brief exposures. Sensory symptoms, in particular in eyes, appear to be exacerbated by environmental and occupational conditions that differ in aircraft and offices, e.g., ozone incidents, low relative humidity, low cabin pressure, and visual display unit work. The data do not support airflow limitation effects. For ToCP, in view of the conservative approach adopted here and the rareness of reported incidents, the health risk of exposure to this compound in aircraft is considered negligible.     

The ecological effects of trichloroacetic acid in the environment

Trichloroacetic acid (TCAA) is a member of the family of compounds known as chloroacetic acids, which includes mono-, di- and trichloroacetic acid. The significant property these compounds share is that they are all phytotoxic. TCAA once was widely used as a potent herbicide. However, long after TCAA's use as a herbicide was discontinued, its presence is still detected in the environment in various compartments. Methods for quantifying TCAA in aqueous and solid samples are summarized. Concentrations in various environmental compartments are presented, with a discussion of the possible formation of TCAA through natural processes. Concentrations of TCAA found to be toxic to aquatic and terrestrial organisms in laboratory and field studies were compiled and used to estimate risk quotients for soil and surface waters. TCAA levels in most water bodies not directly affected by point sources appear to be well below toxicity levels for the most sensitive aquatic organisms. Given the phytotoxicity of TCAA, aquatic plants and phytoplankton would be the aquatic species to monitor for potential effects. Given the concentrations of TCAA measured in various soils, there appears to be a risk to terrestrial organisms. Soil uptake of TCAA by plants has been shown to be rapid. Also, combined uptake of TCAA from soil and directly from the atmosphere has been shown. Therefore, risk quotients derived from soil exposure may underestimate the risk TCAA poses to plants. Moreover, TCE and TCA have been shown to be taken up by plants and converted to TCAA, thus leading to an additional exposure route. Mono- and di-chloroacetic acids can co-occur with TCAA in the atmosphere and soil and are more phytotoxic than TCAA. The cumulative effects of TCAA and compounds with similar toxic effects found in air and soil must be considered in subsequent terrestrial ecosystem risk assessments.     

Three Dimensions of Social Media Messaging Success by Environmental NGOs

Studies show that NGOs persist in using social media to impart unidirectional messages rather than taking advantage of the participatory nature of networked media. Fear of a loss of message control may be at the heart of NGOs’ desire to keep social media messages on track. The current study examines the success of an environmental NGO in keeping its social media messages under control using quantitative content analysis of an NGO-promoted hashtag, #climatemarch, during a United Nations conference on climate change in 2015. Three dimensions of social media message success – volume, topic/valence, and participants – are proposed.     

An analysis of the environmental pressure exerted by the eucalyptus-based kraft pulp industry in Thailand

The study reported here focuses on the environmental pressure exerted by large-scale eucalyptus-based kraft pulp industry in Thailand. The objective of this study was to identify the most important sources of greenhouse gases, acidifying and eutrophying compounds and tropospheric ozone precursors, human toxicity compounds and solid waste associated with the kraft pulp industry. To this end, we performed an environmental systems analysis of the kraft pulp industry system in which we distinguished between two subsystems: the eucalyptus forestry subsystem and the kraft pulp production subsystem. The results indicate that the environmental pressure is caused by the kraft pulp production subsystem rather than by the eucalyptus forestry one. The chemical recovery unit was found to be the most important source of carbon dioxide (CO₂) and sulfur dioxide (SO₂) and responsible for more than one-half of the emissions of greenhouse gases and acidifying compounds from eucalyptus-based kraft pulp production in Thailand. Biomass combustion in the energy gene ration unit is an important source of nitrogen oxide (NO _x ) and carbon monoxide (CO) which in turn are responsible for over 50% of the emissions of tropospheric ozone precursors. About 73% of the eutrophication is caused by biological aerobic wastewater treatment emitting phosphorus (P). With respect to the eucalyptus forestry, only fertilizer use in eucalyptus plantations is a relevant source of pollution through the emission of nitrous oxide (N₂O) and phosphate (PO ₄ ³⁻ ).     

Reuse of mining wastewater in agricultural activities in Jordan

A pilot study was completed in the Al-Abyad area near phosphate mining activity in Jordan. Six plots of 50 m² each were planted with two types of plant species (Zea mays spp. and Medicago lupulina spp.) and irrigated using three types of water (fresh groundwater, mine wastewater, and hydride water consisting of 50% fresh and 50% mine wastewater) to investigate the suitability of utilizing mine wastewater for food production in the area. Water, soil and plant sampling was completed for each plot over different time intervals and analyzed for heavy metal (Cr⁺⁶, Ni⁺², Zn⁺² and Pb⁺²) in addition to major ionic composition of the water used for irrigation. Crop yield was estimated at the end of the experiment. Plots irrigated with mine wastewater showed slightly higher heavy metals concentrations and soil salinity during the experiment period was higher for plots irrigated with mine wastewater compared to plots irrigated with fresh water, and it was uniform through the upper 45 cm of the soil profile due to the high amount of irrigation water used during the experiment. Crop yield was inversely proportional to salinity as an increase of salinity by 2-folds resulted in reducing yield by almost 50%. However, no risk of heavy metals contamination was found in plants and soil. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Human exposure to endocrine disrupting chemicals and fertility: A case–control study in male subfertility patients

BackgroundDioxins, PCBs, chlorinated pesticides, brominated flame retardants, bisphenol A, triclosan, perfluorinated compounds and phthalates are known as endocrine disrupting chemicals (EDCs).ObjectivesThe aim of our study was to investigate whether higher exposure to EDCs is associated with increased subfertility in men.MethodsWe measured biomarkers of exposure in 163 men, recruited through four fertility clinics. According to WHO guidelines, we used a total motility count (TMC) of 20 million as cut-off value. We assigned patients to the case group when two semen samples – collected at least one week apart – had a TMC < 20 and to the control group when both samples had a TMC ≥ 20. To estimate the risk of subfertility and alteration in sex hormone concentrations we used multivariable-adjusted analysis, using logistic and linear regressions, respectively.ResultsFor an IQR increase in serum oxychlordane, the odds ratio for subfertility was 1.98 (95% CI: 1.07; 3.69). Furthermore, men with serum levels of BDE209 above the quantification limit had an odds of 7.22 (1.03; 50.6) for subfertility compared with those having values below the LOQ. Urinary levels of phthalates and triclosan were negatively associated with inhibin B and positively with LH. Urinary bisphenol A correlated negatively with testosterone levels.ConclusionsOur study in men showed that internal body concentrations of endocrine disrupting chemicals are associated with an increased risk of subfertility together with alterations in hormone levels. The results emphasize the importance to reduce chemicals in the environment in order to safeguard male fertility.     

Comparision of China’s volatile organic compound pollution management: a computable general equilibrium approach

The public health and ecological impacts of volatile organic compound (VOCs) pollution have become a serious problem in China, arousing increasing attention to emissions control. In this context, this paper analyses the effectiveness of VOC reduction policies, namely pollution charges and environmental taxes at the national and industrial sector levels. It uses a computable general equilibrium model, which connects macroeconomic variables with VOC emissions inventory, to simulate the effects of policy scenarios (with 2007 as the reference year). This paper shows that VOC emissions are reduced by 2.2% when a pollution charge equal to the average cost of engineering reduction methods – the traditional approach to regulation in China – is applied. In order to achieve a similar reduction, an 8.9% indirect tax would have to be imposed. It concludes that an environmental tax should be the preferred method of VOC regulation due to its smaller footprint on the macroeconomy. Other policies, such as subsidies, should be used as supplements.     

Nail polish as a source of exposure to triphenyl phosphate

Triphenyl phosphate (TPHP) is primarily used as either a flame retardant or plasticizer, and is listed as an ingredient in nail polishes. However, the concentration of TPHP in nail polish and the extent of human exposure following applications have not been previously studied. We measured TPHP in ten different nail polish samples purchased from department stores and pharmacies in 2013–2014. Concentrations up to 1.68% TPHP by weight were detected in eight samples, including two that did not list TPHP as an ingredient. Two cohorts (n = 26 participants) were recruited to assess fingernail painting as a pathway of TPHP exposure. Participants provided urine samples before and after applying one brand of polish containing 0.97% TPHP by weight. Diphenyl phosphate (DPHP), a TPHP metabolite, was then measured in urine samples (n = 411) and found to increase nearly seven-fold 10–14 h after fingernail painting (p < 0.001). To determine relative contributions of inhalation and dermal exposure, ten participants also painted their nails and painted synthetic nails adhered to gloves on two separate occasions, and collected urine for 24 h following applications. Urinary DPHP was significantly diminished when wearing gloves, suggesting that the primary exposure route is dermal. Our results indicate that nail polish may be a significant source of short-term TPHP exposure and a source of chronic exposure for frequent users or those occupationally exposed.     

Parametric uncertainty analysis on hydrodynamic coefficients in groundwater numerical models using Monte Carlo method and RPEM

Groundwater resources are the only source of water in many arid and semi-arid regions. It is important to manage these resources to have a sustainable development. However, there are many factors influencing the accuracy of the results in groundwater modeling. In this research, the uncertainty of two important groundwater model parameters (hydraulic conductivity and specific yield) were considered as the main sources of uncertainty in estimating water level in an unconfined aquifer, in Iran. For this purpose, a simple method called Rosenblueth Point Estimate Method (RPEM) was used to assess groundwater modeling parametric uncertainty, and its performance was compared with Monte Carlo method as a very complicated and time-consuming method. According to calibrated values of hydraulic conductivity and specific yield, several uncertainty intervals were considered to analyze uncertainty. The results showed that the optimum interval for hydraulic conductivity was 40% increase–30% decrease of the calibrated values in both Monte Carlo and RPEM methods. This interval for specific yield was 200% increase–90% decrease of the calibrated values. RPEM showed better performance using the evaluating indices in comparison with Monte Carlo method for both hydraulic conductivity and specific yield with 43% and 17% higher index values, respectively. These results can be used in groundwater management and future prediction of groundwater level.