Kieran Nolan

Treatment options for wastewater effluents from pharmaceutical companies

In recent years, concerns about the occurrence and fate of active pharmaceutical ingredients, solvents, intermediates and raw materials that could be present in water and wastewater including pharmaceutical industry wastewater has gained increasing attention. Traditional wastewater treatment methods, such as activated sludge, are not sufficient for the complete removal of active pharmaceutical ingredients and other wastewater constituents from these waters. As a result, complementary treatment methods such as membrane filtration, reverse osmosis and activated carbon are often used in conjunction with the traditional methods for treatment of industrial wastewater. Most of the literature published to date has been on the treatment of municipal wastewater. However, there is a growing body of research that looks at the presence of active pharmaceutical ingredients in industrial wastewater, the treatment of these wastewaters and the removal rates. This article, reviews these treatment methods and includes both traditional methods and advanced oxidation processes. The paper concludes by showing that the problem of pharmaceuticals in wastewaters cannot be solved merely by adopting end of pipe measures. At source measures, such as replacement of critical chemicals, reduction in raw material consumption should continue to be pursued as the top priority.

Peer Reviewed: Calixarenes: Designer Ligands for Chemical Sensors

These cup-shaped molecules can form inclusion complexes with a wide range of guest species.

The potential for a suite of isotope and chemical markers to differentiate sources of nitrate contamination: A review

Nitrate is naturally found within the environment as part of the nitrogen cycle. However, anthropogenic inputs have greatly increased nitrate loads within ground and surface waters. This has had a severe impact on aquatic ecosystems and has given rise to health considerations in humans and livestock. Therefore, the identification of nitrate sources is important in preserving water quality and achieving sustainability of our water resources. Nitrate sources can be determined based on the nitrate nitrogen (N) and oxygen (O) isotopic compositions (δ(15)N, δ(18)O). However, sewage and manure have overlapping δ(15)N and δ(18)O values making their differentiation on this basis problematic. The specific differentiation between sources of faecal contamination is of particular importance, because the risk to humans is usually considered higher from human faecal contamination (sewage) than from animal faecal contamination. This review summarises the current state of knowledge in using isotope tracers to differentiate various nitrate sources and identifies potential chemical tracers for differentiating sewage and manure. In particular, an in depth review of the current state of knowledge regarding the necessary considerations in using chemical markers, such as pharmaceuticals and food additives, to differentiate sewage and manure sources of nitrate contamination will be given, through an understanding of their use, occurrence and fate, in order to identify the most suitable potential chemical markers.

Parallel microflow photochemistry: process optimization, scale-up, and library synthesis.

A novel, multimicrocapillary flow reactor (MμCFR) was constructed and applied to a series of sensitized photoadditions involving 2(5H)-furanones. The reactor allowed for rapid and energy-, time-, and space-efficient sensitizer screening, process optimization, validation, scale-up, and library synthesis.

From Conventional to Microphotochemistry: Photodecarboxylation Reactions Involving Phthalimides

A series of acetone-sensitized photodecarboxylation reactions involving phthalimides have been investigated using conventional and microphotochemistry. Both, intra- and intermolecular transformations were compared. In all cases examined, the reactions performed in microreactors were superior in terms of conversions or isolated yields. These findings unambiguously prove the advantage of microphotochemistry over conventional photochemical techniques.

Photosensitized addition of isopropanol to furanones in a 365 nm UV-LED microchip

The DMBP-sensitized addition of isopropanol to furanones was studied in a novel LED-driven microchip reactor. Complete conversions were achieved after just 2.5 to 5 min of irradiation with 6 × 365 nm high-power LEDs. The results were compared to analogous experiments using a conventional batch reactor.

Synthesis of Juglone (5-Hydroxy-1,4-Naphthoquinone) in a Falling Film Microreactor

Photooxygenation of 1,5-dihydroxynaphthalene to Juglone was studied in a falling film microreactor. Moderate conversion rates of up to 31% were achieved after just 160 s of exposure to visible light. In contrast, batch reactions gave much lower conversions of up to 14% after a prolonged time period of 10 min. The difference in performance is explained by the superior light penetration in the microfilm and the large gas—liquid contact area.

Photooxygenations in a bubble column reactor

A novel column reactor was constructed and successfully applied to dye-sensitized photooxygenation reactions in aqueous alcohol solutions. The air flow pattern within the narrow glass column could be controlled via the size of the air inlet capillary. Using a 500 μm capillary, a slug flow pattern was realized which allowed for superior mass transfer and light transparency within a thin solvent layer. These features subsequently gave higher conversion rates and isolated yields.

Development of a calix[4]arene sensor for soft metals based on nitrile functionality.

The current work is amongst the first to examine the potential usefulness of the nitrile functional group in potentiometric analytical sensors for soft metals. Nitrile functionality has hereby been incorporated into a calix[4]arene skeleton to give a series of new cation selective hosts. The analytical sensing behaviour of these hosts was examined by Ion Selective Electrode (ISE) based potentiometry. In all cases a preference for soft metals was observed, explained primarily in terms of soft–soft compatibility between calix[4]arene nitrile hosts and metal guests in combination with a classical ‘lock and key’ best fit mechanism. Hosts 2, 3 and 4 showed very strong responses towards Hg(II) ions, with Ag(I) being the main interferant. The introduction of electron delocalising aromaticity proximal to the nitrile functionality was thought to reduce the availability of negative charge for cation coordination, apparently affecting the Hg(II) cation in particular. An acute fall in Hg(II) response coupled with the emergence of Ag(I) as the primary ion was observed for 7 and 8.

An SPE LC-MS/MS method for the analysis of human and veterinary chemical markers within surface waters: an environmental forensics application.

In this study, the use of co-occurring discriminators of sewage and manure was assessed as a potential way to disentangle sewage and manure sources. A suite of human and veterinary derived chemical markers, which includes pharmaceuticals and compound such as food additives, has been identified for this purpose. The suite was selected in such a manner as to provide additional source characterisation, e.g. differentiating raw versus treated sewage inputs. An SPE-LC-MS/MS method was developed and validated for the determined suite of chemical markers with a detection limit of up to 50 pg L(-1). This represents one of the lowest limits of detection for pharmaceuticals reported in literature. To illustrate the suitability of the proposed method to differentiate sewage and manure inputs to surface water bodies, results from surface water samples collected at monitoring sites corresponding to specific land use types within Ireland are discussed.