Detecting Water Constituents Unique to Septic Tanks as a Wastewater Source in the Environment by Nontarget Analysis: South Florida's Deering Estate Rehydration Project Case Study

The present study has generated a workflow based on nontarget analysis (NTA) with Compound Discoverer Ver 3.1 to characterize a set of source-discriminating compounds identified in water samples from locations in South Florida (USA), particularly those describing a freshwater environment (Everglades based), urban impacted areas (septic tank driven), and coastal (Biscayne Bay) endmembers in and around the Charles Deering Estate property in the Village of Palmetto Bay. Waters from an interconnected managed canal system were assessed to evaluate the influence of localized emissions. Septic tank effluents influence the water in many Southeast Florida environments due to their diminished onsite treatment capacity based on the limestone-dominated geology and canal systems providing a relatively unobstructed connection pathway. Through a combination of high-resolution mass spectrometry and statistical analyses, a set of tracers and indicators was determined (azelaic acid, decanophenone, galaxolidone, methyl violet, monoolein, metoprolol, and 1-stearoylglycerol). Tentatively identified compounds were generally assigned to various categories such as dyes, personal care products, and pharmaceuticals. The NTA Compound Discoverer Ver 3.1 compound data (presented as principal component analysis and Kendrick mass defect plots) showed apparent differences between wastewater-influenced sites and non-wastewater-influenced sites along with the ranked "Top10" compounds found at each location. Waters from different locations were also compared using the presence of sucralose to further inform the NTA. The most septic-influenced site contained 3594 ± 94 ng/L of sucralose with concentrations declining steadily and reaching the lowest concentrations in Biscayne Bay of 122 ± 94 ng/L. The sucralose concentrations provided further evidence of septic influence on this system. Sucralose was determined to be a conservative tracer between the freshwater and coastal sources and complementary to other probable unique tracers of septic tank effluent identified by the NTA. Environ Toxicol Chem 2022;41:1165-1178. © 2022 SETAC.

A review of sustainable biodiesel production using biomass derived heterogeneous catalysts

The production of biodiesel through chemical production processes of transesterification reaction depends on suitable catalysts to hasten the chemical reactions. Therefore, the initial selection of catalysts is critical although it is also dependent on the quantity of free fatty acids in a given sample of oil. Earlier forms of biodiesel production processes relied on homogeneous catalysts, which have undesirable effects such as toxicity, high flammability, corrosion, by-products such as soap and glycerol, and high wastewater. Heterogeneous catalysts overcome most of these problems. Recent developments involve novel approaches using biomass and bio-waste resource derived heterogeneous catalysts. These catalysts are renewable, non-toxic, reusable, offer high catalytic activity and stability in both acidic and base conditions, and show high tolerance properties to water. This review work critically reviews biomass-based heterogeneous catalysts, especially those utilized in sustainable production of biofuel and biodiesel. This review examines the sustainability of these catalysts in literature in terms of small-scale laboratory and industrial applications in large-scale biodiesel and biofuel production. Furthermore, this work will critically review natural heterogeneous biomass waste and bio-waste catalysts in relation to upcoming nanotechnologies. Finally, this work will review the gaps identified in the literature for heterogeneous catalysts derived from biomass and other biocatalysts with a view to identifying future prospects for heterogeneous catalysts.

Catalysis of glycerol acetylation on solid acid catalyst: a review

Biodiesel is a substitute fuel that is environmentally friendly, biodegradable, and sustainable. The need for biodiesel continues to increase. Biodiesel is made through the process of transesterification of triglycerides and alcohol. Glycerol is a side-effect of biodiesel products with a capacity of 10% of the total weight of its production. Glycerol is the simplest glyceride compound and has several functions as a primary ingredient in chemical production. Through acetylation, glycerol is converted to a material that has a higher sale value. Both homogeneous and heterogeneous catalysts are the acetylation approach to achieve the desired product, namely acetyl glycerol esters (mono-, di- and triacetin). However, in the process, the catalyst’s type and characteristics significantly affect the yield and conversion of the product and the deactivation or reusability of the catalyst, which can inhibit the catalyst’s utilization and effectiveness; therefore, it must be studied further. Besides, the parameters that affect the reaction will also be assessed.

Functionalising hydrothermal carbons for catalysis – investigating solid acids in esterification reactions

Through a simple and controllable synthesis, the properties of acid functionalised carbon-based catalysts can be directed, demonstrating activity reflective of carbon support preparation conditions.

Development of catalyst complexes for upgrading biomass into ester-based biolubricants for automotive applications: a review

Biomass-derived oils are recognised as the most promising renewable resources for the production of ester-based biolubricants due to their biodegradable, non-toxic and metal adhering properties. Homogeneous acid catalysts have been conventionally used in catalytic esterification and transesterification for the synthesis of ester-based biolubricants. Although homogeneous acid catalysts encounter difficulty during phase separation, they exhibit superior selectivity and good stereochemistry and regiochemistry control in the reaction. Consequently, transition metal complex catalysts (also known as homogeneous organometallic catalysts) are proposed for biolubricant synthesis in order to achieve a higher selectivity and conversion. Herein, the potential of both homogeneous transition metal complexes and heterogeneous supported metal complexes towards the synthesis of biolubricants, particularly, in esterification and transesterification, as well as the upgrading process, including hydrogenation and in situ hydrogenation-esterification, is critically reviewed.

The study on continuous denitrification, desulfurization of pyrolusite/activated coke hybrid catalyst

The SO₂ removal and regeneration of ACP improved its NO removal activity, while the denitrification had almost no effect on the desulfurization. The metal sulfate of ACP-Rn showed catalytic activity for NO reduction although there is also a reverse effect.

Sulfonated multi-walled carbon nanotubes for biodiesel production through triglycerides transesterification

Effective solid acid catalysts play a key role to produce high-quality biodiesel through triglyceride transesterification.

Efficient biodiesel production via solid superacid catalysis: a critical review on recent breakthrough

Biodiesel produced from triglycerides and/or free fatty acids (FFAs) by transesterification and esterification has attracted immense attention during the past decades as a biodegradable, renewable and sustainable fuel.

Direct synthesis of dimethyl ether from CO2 hydrogenation over Cu–ZnO–ZrO2/SO42−–ZrO2 hybrid catalysts: effects of sulfur-to-zirconia ratios

Methanol can be dehydrated to form DME over sulfated zirconia catalysts via pathway I, if the sulfur content is low, and pathway II, if the sulfur content is high.

Catalytic upgrading of α-angelica lactone to levulinic acid esters under mild conditions over heterogeneous catalysts

α-Angelica lactone was identified as a better candidate than levulinic acid for the heterogeneously catalysed preparation of levulinic acid esters.

Catalytic acetoxylation of lactic acid to 2-acetoxypropionic acid, en route to acrylic acid

We present an alternative synthetic route to acrylic acid, starting from the platform chemical lactic acid and using heterogeneous catalysis.

p-Sulfonic acid calix[n]arenes: the most active and water tolerant organocatalysts in esterification reactions

¹H NMR experiments showed that p-sulfonic acid calix[n]arenes were more water tolerant and active than monomeric organocatalysts in esterification reactions.

A sulfated ZrO2 hollow nanostructure as an acid catalyst in the dehydration of fructose to 5-hydroxymethylfurfural

Mesoporous hollow colloidal particles with well-defined characteristics have potential use in many applications. In liquid-phase catalysis, in particular, they can provide a large active surface area, reduced diffusion resistance, improved accessibility to reactants, and excellent dispersity in reaction media. Herein, we report the tailored synthesis of sulfated ZrO2 hollow nanostructures and their catalytic applications in the dehydration of fructose. ZrO2 hollow nanoshells with controllable thickness were first synthesized through a robust sol-gel process. Acidic functional groups were further introduced to the surface of hollow ZrO2 shells by sulfuric acid treatment followed by calcination. The resulting sulfated ZrO2 hollow particles showed advantageous properties for liquid-phase catalysis, such as well-maintained structural integrity, good dispersity, favorable mesoporosity, and a strongly acidic surface. By controlling the synthesis and calcination conditions and optimizing the properties of sulfated ZrO2 hollow shells, we have been able to design superacid catalysts with superior performance in the dehydration of fructose to 5-hydroxymethyfurfural than the solid sulfated ZrO2 nanocatalyst.