Katherine Huddersman

Part 1. Production of a modified PAN fibrous catalyst and its optimisation towards the decomposition of hydrogen peroxide

This paper describes the novel and innovative use of a mixture of hydrazine and hydroxylamine to prepare one of the first solid state Fenton’s catalysts where the active site does not leach out and is therefore reusable enabling industrial take-up. It resulted in an ongoing series of papers, 4 grants totalling £2million, and the award or filing of 5 patents. The catalyst is in field trials with Severn Trent Water for the removal of microcontaminats to meet new EU legislation. A similar process applied to low-value wool fibres (as patented by KDH) is likely to result in improved rural sustainability.

Highly selective bromination of toluene in a bromine-oxirane-zeolite system

Abstract The liquid-phase bromination of toluene in a zeolite—bromine—oxirane system has been studied. This system increases selectivity toward the para -bromotoluene isomer due to two factors: first, the oxirane deactivates the sites located on the external surface of the zeolite and, second, a bromine—oxirane complex is formed that is less active and bulkier than is bromine. Using this method, 98% pure para -bromotoluene can be obtained. The catalyst system is deactivated rapidly, presumably due to epoxide polymerization.

Investigation of the mechanical and physico-chemical properties of a modified PAN fibrous catalyst

This paper was the first confirmation that the metal catalyst was located on the exterior surface of the fibre and the first to obtain an understanding of the number and nature of atoms around the active site by an EXAFS study at the international Synchrotron Source at Daresbury. Characterisation of the mechanical strength of the catalyst showed that it was good enough for industrial applications as detailed above.

Pilot-Scale Removal of Trace Steroid Hormones and Pharmaceuticals and Personal Care Products from Municipal Wastewater Using a Heterogeneous Fenton’s Catalytic Process

The pollution of water sources by endocrine disrupting compounds (EDCs) and pharmaceutical and personal care products (PPCPs) is a growing concern, as conventional municipal wastewater treatment systems are not capable of completely removing these contaminants. A continuous stir tank reactor incorporating a modified polyacrylonitrile (PAN) catalyst and dosed with hydrogen peroxide in a heterogeneous Fenton’s process was used at pilot scale to remove these compounds from wastewater that has undergone previous treatment via a conventional wastewater treatment system. The treatment system was effective at ambient temperature and at the natural pH of the wastewater. High levels of both natural and synthetic hormones (EDCs) and PPCPs were found in the effluent after biological treatment of the wastewater. The treatment system incorporating the modified PAN catalyst/H2O2 decomposed >90% of the EDCs and >40% of PPCPs using 200 mgL−1 H2O2, 3 hr residence time. The estrogenic potency EE2-EQ was removed by 82.77%, 91.36%, and 96.13% from three different wastewater treatment plants. BOD was completely removed (below detection limits); 30%–40% mineralisation was achieved and turbidity reduced by more than 68%. There was a <4% loss in iron content on the catalyst over the study period, suggesting negligible leaching of the catalyst.

Antimicrobial activities of hydrogen peroxide and its activation by a novel heterogeneous Fenton’s‐like modified PAN catalyst

Aims:  To investigate the potential activation of hydrogen peroxide by a novel catalyst, reducing the concentration of hydrogen peroxide required and the time taken for microbial inactivation.

Mycobactericidal activity of hydrogen peroxide activated by a novel heterogeneous Fentons‐like catalyst system

To investigate the potential activation of hydrogen peroxide by a novel catalyst, reducing the concentration of hydrogen peroxide required and the time taken for mycobactericidal activity. The mycobactericidal properties of an iron‐based novel heterogeneous‐modified polyacrylonitrile (PAN) catalyst in combination with hydrogen peroxide were examined against Mycobacterium chelonae using a modified version of the European suspension test. Mycobactericidal activity was significantly increased when the modified PAN catalyst was combined with hydrogen peroxide. The 0·5% w/v hydrogen peroxide and 2‐g catalyst system resulted in average Log reductions of >5·80 for Myco. chelonae at 30‐min exposure at room temperature. This was a significant increase in activity (P < 0·01) compared to 0·5% w/v hydrogen peroxide alone. This study has expanded on previous work and knowledge of the modified PAN catalyst and hydrogen peroxide system, by providing evidence for mycobactericidal activity when the novel PAN catalyst is combined with hydrogen peroxide.

Novel Fibrous Catalyst in Advanced Oxidation of Photographic Processing Effluents

A novel fibrous catalyst was used to destroy the pollutants in Kodak Non-Silver-Bearing (NSB) photographic processing effluents with high chemical oxygen demand (COD) value. The oxidation activity of the catalyst was evaluated in terms of COD reduction of the effluent. The effects of concentrations of hydrogen peroxide and effluent, amount of catalyst, reaction time and temperature on the COD reduction were studied. In addition, the combination of catalysis with UV treatment on the COD reduction of the effluent was also investigated. Based on the experimental results, room temperature is preferred for the catalytic oxidation of NSB effluent. It was found that COD reduction of the effluent depends on the amount of hydrogen peroxide added to the feed in relation to the mass of catalyst used. Significant COD reduction (up to 52%) is achieved after 4 hours of catalytic treatment. Extending the duration of catalysis up to 24 hours gives further slight decrease in COD value.

Maleic acid oxidation using a heterogeneous modified polyacrylonitrile (PAN) fibrous catalyst.

Abstract The effectiveness, kinetics and mechanism of oxidation of maleic acid in solution using a novel modified polyacrylonitrile (PAN) catalyst/hydrogen peroxide system was studied. The modified PAN catalyst contains immobilised Fe3+ and its reaction with hydrogen peroxide generates reactive hydroxyl radicals according to Fenton’s reaction. The effects of the amount of the modified PAN catalyst, hydrogen peroxide concentration, pH and temperature on the oxidation rate of maleic acid were investigated. The oxidation products were also determined and a reaction pathway proposed and degree of mineralisation investigated. A 95% conversion of maleic acid was achieved in 3 h and 65% TOC removed in 2 h under optimum conditions - temperature of 19 °C, with 19.59 mM H2O2 initial concentration, pH of 3.36 and 1.5 g of modified PAN catalyst. The activity of the catalyst was similar within the pH range of 3-. The pseudo first order rate constant for the oxidation of maleic acid using the modified PAN catalyst/H2O2 system was 2.2 × 10-4 min-1. A reaction mechanism has been proposed, and the main routes of the oxidation process were through formic and acetic acids.

Conversion of solid waste to activated carbon to improve landfill sustainability

Heterogeneous composite wastes from landfills were evaluated as precursors for the generation of activated carbon (AC). A single-step chemical activation process was applied involving irradiation with microwave energy and impregnation with KOH. The average percentage yield of AC from active landfill precursor was higher than that from closed landfill for all depths sampled. Increase in impregnation ratio and irradiation power decreased the average percentage yield for both landfill precursors (active: 38.1 to 33.1%; closed: 42.1 to 33.3%). The optimum pH range for adsorption of methylene blue was pH 6–7, while adsorption increased with increase in temperature over the range 30 to 50°C. Carbonyl and hydroxyl groups were the major functional groups on the surface of AC. The properties of the AC are potentially suitable for the removal of cationic dyes and pollutants. AC generated from the landfill composite was comparable to that from other biomass being managed through AC generation. This is the first report to demonstrate the possible reuse of landfill composite as AC. The reuse option of landfill composite could provide a means of sustainable management of landfilled municipal waste.

Integrated Approaches to Soil Contamination Monitoring

1Technological Educational Institute of Crete, 3 Romanou Chalepa, 73133 Chania, Greece 2Hellenic Agricultural Organization-DEMETER, Department of Soil Science of Athens, Institute of Soil and Water Resources, 1 Sofokli Venizelou Street, Lykovrisi, 141 23 Attiki, Greece 3De Montfort University, The Gateway, Leicester LE1 9BH, UK 4School of Engineering, University of Basilicata, Viale dell’Ateneo Lucano 10, Potenza, Italy 5Rutgers University, 101 Warren Street, Newark, NJ 07102, USA