Polybrominated diphenyl ethers (PBDEs) are widely detected in coastal wetlands but their remediation is still difficult. In this study, different carbon sources, namely formate, acetate, pyruvate, lactate, succinate, methanol and ethanol, were added to mangrove sediments contaminated with BDE-47, a common PBDE congener, to enhance its degradation. After 2-month incubation, all carbon addition significantly enhanced degradation percentages. The residual BDE-47 percentage significantly correlated with the abundance of total bacteria and Dehalococcoides spp. The addition of methanol, acetate and succinate also achieved significantly higher degradation rates and shorter half-lives than sediments without carbon amendment at the end of 5-month incubation, although degradation percentages were comparable between sediments with and without extra carbon. The degradation pathway based on the profiles of degradation products was also similar among treatments. The results indicated the stimulatory effect of extra carbon sources on BDE-47 degradation in contaminated sediments was carbon- and time-specific.

PURPOSE OF REVIEW: Cyanobacteria, commonly known as blue-green algae, are often seen as a problem. Their accumulation (bloom) in surface water can cause toxicity and aesthetic concerns. Efforts have been made in preventing and managing cyanobacterial blooms. By contrast, purposeful cultivation of cyanobacteria can create great opportunities in food, chemical and biofuel applications. This review summarises the current stage of research and the socio-economic impacts associated with both the problems and opportunities induced from the presence of cyanobacteria in surface water. RECENT FINDINGS: Insightful knowledge of factors that trigger cyanobacterial blooms has allowed for the development of prevention and control strategies. Advanced technologies are utilised to detect, quantify and treat cyanobacterial biomass and cyanotoxins in a timely manner. Additionally, understanding of cyanobacterial biochemical properties enables their applications in food and health industry, agriculture and biofuel production. Researchers have been able to genetically modify several cyanobacterial strains to obtain a direct pathway for ethanol and hydrogen production. Cyanobacterial blooms have been effectively addressed with advances technologies and cyanobacterial research. However, this review identified a knowledge gap regarding cyanotoxin synthesis and the relevant environmental triggers. This information is essential for developing measures to prevent cyanobacterial blooms. Additionally, this review affirms the promising opportunities that cyanobacteria offer in the food, cosmetics, pigments and agriculture. Biofuel production from cyanobacterial biomass presents an immense potential but is currently constrained by the cultivation process. Thus, future research should strive to achieve effective mass harvesting of cyanobacterial biomass and obtain a profound understanding of cyanotoxin production.

Comparative studies were developed with regard to the criteria emissions of THC - total hydrocarbons, CO - carbon monoxide and NOx - nitrogen oxides, and BTEX (benzene, toluene, ethyl benzene and xylenes). Three four-stroke motorcycles were fuelled with E22 fuel (gasoline with 22% of ethanol). One flex fuel motorcycle was also fuelled with E100, 100% Hydrated Reference Ethanol, and with E61 (61% of ethanol). Criteria emissions were quantified using traditional measurement techniques based on the European Directive 97/24/EC (EURO protocol). To determine the BTEX emissions, gas chromatography coupled with mass spectrometry was employed. All motorcycles were equipped with a catalyst (TWC) used to reduce the amount of toxic emissions in the exhaust gases. To evaluate the performance of the catalyst, one motorcycle was tested with and without the device. One motorcycle was tested according to two different test protocols, namely, the ECE/TRANS/180 WMTC, also known as the Worldwide Motorcycle Test Cycle, and the EURO protocol. The main results were that toluene emissions were more prevalent than other aromatics. The tests with and without the catalyst showed that after the catalyst was employed the conversion efficiencies for benzene, toluene, ethyl benzene and xylene were 52.3%, 84.0%, 85.0%, and 86.0%, respectively. The results regarding the flex fuel motorcycle show that BTEX emissions decrease with an increase of ethanol in the mixture. Comparing the EURO and WMTC protocols, it was observed that the WMTC protocol generates lower emissions compared to the EURO protocol; however, NOx showed the opposite trend of BTEX.

Effectiveness of oil spill dispersants containing lecithin/Tween 80 (L/T) blends in ethanol was measured as a function of L:T ratio, surfactant:solvent ratio, solvent composition, and dispersant:oil ratio (DOR) using baffled flask dispersion effectiveness tests. Optimal L:T ratios are between 60:40 and 80:20 (w/w); at higher L:T ratios, effectiveness is limited by high interfacial tension, while at lower L:T ratios, insufficient lecithin is present to form a well-packed monolayer at an oil–water interface. These optimal L:T ratios retain high effectiveness at low DOR: 80:20 (w/w) L:T dispersant is 89% effective at 1:25 DOR (v/v) and 77% effective at 1:100 DOR (v/v). Increasing surfactant:solvent ratio increases dispersant effectiveness even when DOR is proportionally reduced to keep total surfactant concentration dosed into the oil constant. Replacing some of the ethanol with octane or octanol also increases dispersant effectiveness, suggesting that ethanol's hydrophilicity lowers dispersant–oil miscibility, and that more hydrophobic solvents would increase effectiveness.

Desulfurization of liquid fuels mitigates the amount of noxious sulfur oxides and particulates released during fuel combustion. Existing literature on oxidative-adsorptive desulfurization technologies focus on sulfur-in-fuel removal by various materials, but very little information is presented about their desorption kinetics and thermodynamics. Herein, we report for the first time, the mechanism of sulfur desorption from neutral activated alumina saturated with dibenzothiophene sulfone. Batch experiments were conducted to examine the effects of agitation rate, desorption temperature, sulfur content, and eluent type on sulfur desorption efficiencies. Results show enhanced desorption capacities at higher agitation rate, desorption temperature, and initial sulfur content. Desorption efficiency and capacity of acetone were found to be remarkably superior to ethanol, acetone:ethanol (1:1), and acetone:isopropanol (1:1). Desorption kinetics reveal excellent fit of the nonlinear pseudo-second-order equation on desorption data, indicating chemisorption as the rate-determining step. Results of the thermodynamics study show the spontaneous (ΔG° ≤ −2.08 kJ mol⁻¹) and endothermic (ΔH° = 32.35 kJ mol⁻¹) nature of sulfur desorption using acetone as eluent. Maximum regeneration efficiency was attained at 93% after washing the spent adsorbent with acetone followed by oven-drying. Scanning electron microscopy, Fourier transform infrared, and X-ray diffraction spectroscopy analyses reveal the intact and undamaged structure of neutral activated alumina even after adsorbent regeneration. Overall, the present work demonstrates the viability of neutral activated alumina as an efficient and reusable adsorbent for the removal of sulfur compounds from liquid fossil fuels.

Propylene glycol (PG) is widely used in the foods, pharmaceuticals, oil industry, animal feed, cosmetics and other industries. Because of the existence of a chiral carbon center, PG forms R (Rectus)- and S (Sinister)-enantiomers. Currently, the toxicity study of its R-, S-enantiomers is still very scarce. In this study, we have assessed the developmental toxicity and neurotoxicity of the R-, S-, and RS-PG enantiomers in zebrafish larvae. We found that exposure to R-, S-, and RS-PG enantiomers did not significantly affect the basic developmental endpoints of embryos or larvae (i.e., embryonic movement, hatching, mortality, malformation, heartbeat, body length), indicating that R-, S-, and RS-PG exposures did not exhibit the basic developmental toxicity in zebrafish larvae. The toxicity of three enantiomers was lower than that of ethanol, and there was no significant difference between them. However, R-, S-, and RS-PG exposures with high doses could significantly change the eye diameter and locomotor activity of larval zebrafish, indicating that R-, S-, and RS-PG enantiomers of high doses could potentially exhibit the neurotoxicity and ocular developmental toxicity in zebrafish larvae. Therefore, the potential neurotoxicity and ocular developmental toxicity of R-, S-, and RS-PG enantiomers for infants and toddlers should be considered.

Increasing awareness about sustainability has compelled the recent researchers to explore different methods for evaluation. Conventionally the sustainability of a process was majorly dependent on the economics feasibility. Recently need of incorporation of environmental and social concerns in overall sustainability assessment has been realized. Authors in their prior work has published a framework for performing sustainability assessment of biomass processing enterprises. The present work is on selection of sugarcane valorization pathways based on the sustainability index using the same framework. Six alternative routes are compared based on their economic, environment and social criteria. Life cycle assessment of each process is performed as per ISO 14040/44 to evaluate the environmental criteria. Integrated method of value function (MIVES) is used for consolidation of different indicators and criteria. Amongst the process alternatives considered for assessment, 1G2G ethanol route is observed to have highest sustainability index (0.864) owing to relatively lower environmental impact whereas first generation butanol production route (1GRS) had the least sustainability index of 0.090 on account of decreased yield and less products. Sensitivity analysis performed on the model showed no significant change in the ranking of the alternatives.

In order to reduce the transmission of pathogens, and COVID-19, WHO and NHS England recommend hand washing (HW) and/or the use of hand sanitizer (HS). The planetary health consequences of these different methods of hand hygiene have not been quantified. A comparative life cycle assessment (LCA) was carried out to compare the environmental impact of the UK population practising increased levels of hand hygiene during the COVID-19 pandemic for 1 year. Washing hands with soap and water was compared to using hand sanitizer (both ethanol and isopropanol based sanitizers were studied). The isopropanol-based HS had the lowest environmental impact in 14 out of the 16 impact categories used in this study. For climate change, hand hygiene using isopropanol HS produced the equivalent of 1060 million kg CO₂, compared to 1460 million for ethanol HS, 2300 million for bar soap HW, and 4240 million for liquid soap HW. For both the ethanol and isopropanol HS, the active ingredient was the greatest overall contributing factor to the environmental impact (83.24% and 68.68% respectively). For HW with liquid soap and bar soap, there were additional contributing factors other than the soap itself: for example tap water use (28.12% and 48.68% respectively) and the laundering of a hand towel to dry the hands (10.17% and 17.92% respectively). All forms of hand hygiene have an environmental cost, and this needs to be weighed up against the health benefits of preventing disease transmission. When comparing hand sanitizers to handwashing with soap and water, this study found that using isopropanol based hand sanitizer is better for planetary health. However, no method of hand hygiene was ideal; isopropanol had a greater fossil fuel resource use than ethanol based hand sanitizer. More research is needed to find hand hygiene sources which do not diminish planetary health, and environmental impact is a consideration for public health campaigns around hand hygiene.

Aegle marmelos (L.) Correa belongs to the family Rutaceae is generally known as “bael fruit tree” occuring across the south Asian countries. The current investigation screened the main derivatives from crude ethanolic extracts of the Bael tree leaf and evaluated activity effects on the larvae and adults of Aedes aegypti (L.) Dengue vector mosquito and a non-target aquatic predator. The GC-MS results showed that the peak area was found to be profound in N-methyl-1-adamantaneacetamide (N-M 1a) followed by oleic acid (OA) with 63.08 and 11.43% respectively. The larvicidal activity against the fourth instar larvae and the crude Ex-Am showed prominent mortality rate (93.60%) at the maximum dosage of 100 ppm. The mortality rate of N-M 1a and OA was occurred at 10 ppm (97.73%) and 12 ppm (95.4%). The repellent activity was found to be prominent at crude Ex-Am (50 ppm) as compared to the pure compounds (N-m 1a and OA) with maximum protection time up to 210 min. The non-target screening of Ex-Am, N-M 1a, and OA on mosquito predator Tx. splendens showed that they are scarcely toxic even at the maximum dosage of 1000 ppm (34.13%), 100 ppm (27.3%), and 120 ppm (31.3%) respectively. Thus, the present investigation clearly proved that the crude Ex-Am and their major derivatives Nm 1-a and OA showed their acute larval toxicity as well as potential mosquito repellent against the dengue mosquito and eco-safety against the mosquito predator.