The study demonstrates the feasibility of using an in situ bacterial treatment to enhance gas release and resource recovery from landfill soil containing lignocellulosic waste. This article is protected by copyright. All rights reserved.

The hydrothermal liquefaction (HTL) of algal biomass is a promising route to viable second generation biofuels. In this investigation HTL was assessed for the valorisation of algae used in the remediation of acid mine drainage (AMD). Initially the HTL process was evaluated using Arthrospira platensis (Spirulina) with additional metal sulfates to simulate metal remediation. Optimised conditions were then used to process a natural algal community (predominantly Chlamydomonas sp.) cultivated under two scenarios: high uptake and low uptake of metals from AMD. High metal concentrations appear to catalyse the conversion to bio-oil, and do not significantly affect the heteroatom content or higher heating value of the bio-oil produced. The associated metals were found to partition almost exclusively into the solid residue, favourable for potential metal recovery. High metal loadings also caused partitioning of phosphates from the aqueous phase to the solid phase, potentially compromising attempts to recycle process water as a growth supplement. HTL was therefore found to be a suitable method of processing algae used in AMD remediation, producing a crude oil suitable for upgrading into hydrocarbon fuels, an aqueous and gas stream suitable for supplementing the algal growth and the partitioning of most contaminant metals to the solid residue where they would be readily amenable for recovery and/or disposal.

Amine scrubbing is a proven technology in the oil and gas industries. Its use in coal fired power plants is not fully understood and the likelihood of solvent degradation is high. Decreased absorption efficiency, undesirable by-products and the environmental impact of their disposal are the main consequences. In the present study, samples of monoethanolamine were thermally degraded, at 160•C for between 2 and 8 weeks, and their CO2 removal capacity deterioration was determined. The findings show that thermal degradation at 160•C for 8 weeks reduced monoethanolamine concentration by 95%, but the remaining solvent still retained 22% of its capacity to remove CO2, probably due to the capacity of some of the degradation products to remove CO2. Therefore, the requirement for monoethanolamine make-up in operational amine scrubbing systems may not be quite as serious as initially believed. A 20% higher MEA loss was determined in the samples with 0.37 initial CO2 loading (mol CO2/mol MEA). 2-Oxazolidone, N-(2-hydroxyethyl)-ethylenediamine and 1-(2-hydroxyethyl)-2-imidazolidinone were identified as the major monoethanolamine degradation products, the latter being indicated as the most stable product with concentrations of up to 17% (v/v). Corrosion (1.95 mm/year) of the stainless steel (type 316) equipment, used during the experiments, was also observed.

We recommend you cite the published version. The publisher's URL is: http://dx.doi.org/10.1016/j.resconrec.2016.08.009Refereed: Yes (no note) Disclaimer UWE has obtained warranties from all depositors as to their title in the material deposited and as to their right to deposit such material. UWE makes no representation or warranties of commercial utility, title, or fitness for a particular purpose or any other warranty, express or implied in respect of any material deposited.UWE makes no representation that the use of the materials will not infringe any patent, copyright, trademark or other property or proprietary rights. UWE accepts no liability for any infringement of intellectual property rights in any material deposited but will remove such material from public view pending investigation in the event of an allegation of any such infringement. This work examines the potential for resource recovery from metalliferous mine wastes in 19 south west England and Wales. It does this through an assessment of the physicochemical 20 composition of several key metalliferous legacy mine waste piles and an analysis of their co-21 location with key cultural, geological and ecological designations. Solid samples were taken 22 from 14 different sites and analysed for metal content, mineralogy, paste pH, particle size 23 distribution, total organic carbon and total inorganic carbon. The majority of sites contain 24 relatively high concentrations (in some cases up to several % by mass) of metals and metalloids, 25 including Cu, Zn, As, Pb, Ag and Sn, many of which exceed guideline concentrations. 26 PLEASE SCROLL DOWN FOR TEXT. Physicochemical composition of wastes and co-located environmental designations atHowever, the economic value of metals in the waste could be used to offset rehabilitation costs. 27Spatial analysis of all metalliferous mine sites in south west England and Wales found that 28 around 70% are co-located with at least one cultural, geological and ecological designation. 29All 14 sites investigated are co-located with designations related to their mining activities, 30 either due to their historical significance (e.g. mining infrastructure), rare species assemblages 31 (e.g. lichens and bryophytes) or geological characteristics (e.g. mineralisation). This 32 demonstrates the need to consider the cultural and environmental impacts of rehabilitation and 33 resources recovery on such sites. Further work is required to identify non-invasive remediation 34 and resource recovery methodologies to allow sites to be rehabilitated at minimal cost and 35 disturbance. 36 37 Introduction 38There are few locations world-wide where historic metal mining is more evident than in 39 mainland Britain. Extensive mining of major ores for metals including copper, lead, tin and 40 zinc at locations such as the Devon Great Consols in south west Devon and Parys Mountain in 41 north west Wales fuelled profound societal and industrial change world-wide (particularly 42 during the Industrial Revolution) but as a consequence created a s...

This paper presents a study of various geochemical humidity-style weathering tests that were carried out on waste mine rock from Avoca, County Wicklow, Ireland. The aim of this paper is to present data that demonstrate some of the geochemical controls on weathering rates together with release rates from laboratory testwork. These data are used to determine the applicability of various interpretations of humidity cell data for prediction of acid rock drainage. Furthermore, within this context the paper offers opinion on common questions related to the use of such tests: should humidity cells be aerated? How long should the test be run for? Is pre-treatment of the samples required? Is inoculation of the samples with iron and sulfur oxidising microbes required? And should these tests really be considered to be accelerated weathering tests?