A sensitivity analysis of a single extraction well from deep geothermal aquifers in the Cheshire Basin, UK

Deep hot sedimentary aquifers (HSAs) are targeted for geothermal exploitation in the Cheshire Basin, UK. In this study, a single extraction well targeting the Collyhurst Sandstone Formation was modelled on MATLAB coupling heat and fluid flux. The Collyhurst Sandstone Formation in the Crewe area of the Cheshire Basin is expected to be found at a depth of 2.8 to 3.5 km, and was chosen as an area for geothermal exploration due to the high demand for energy.Model results suggest that low-enthalpy, deep geothermal systems with thick HSAs are affected by both geological and engineering parameters. The results of this study highlight that the thermal gradient, hydraulic conductivity, production rate, length and position of the well screen are the key parameters capable of affecting the success and viability of any single well scheme. Poor planning during exploration and development can hinder the productivity of any single well scheme and these parameters must be considered to fully understand the risk. Engineering parameters, such as the length of the well screen, can be used during well planning to mitigate geological risks in the aquifer, whilst the results presented can also be used as a guide for energy potential under varying conditions.

Evaluation of Element Mobility in River Sediment Using Different Single Extraction Procedures and Assessment of Probabilistic Ecological Risk

In this manuscript, samples of Kupa River sediments were examined using three different extraction agents. The aim of this study was to evaluate the applicability of single extraction procedures to investigate the bioavailability and mobility of major and trace elements (Al, As, Ba, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Si, Sr, Ti, V, and Zn) from river sediment. Two forms of studied elements were evaluated: mobile, the most toxic element form (extraction with 1 M CH3COONH4 and 0.01 M CaCl2) and potentially mobilized form (2 M HNO3 extraction). The estimation of the ecological risk, with the application of the probability distribution of RI (potential ecological risk index) values, is yielded with the help of the Monte Carlo simulation (MCS). Ammonium acetate is proved to be a better extraction agent than calcium chloride. A positive correlation between the content of all extracted elements with nitric acid and the total element content indicates that 2 M HNO3 efficiently extracts all studied elements. Results showed anthropogenic sources of cadmium and copper and high barium mobility. The MCS suggests that risk of Cr, Cu, Ni, Pb, and Zn was low; As and Cd posed a lower and median ecological risk in the studied areas.

Investigation of nikel(II) complexing with 2,6-dimerkapto-4-methilphenol and aminophenols

Complexing of nickel(II) with 2,6-dimercapto-4-methylphenol (DMMP) and hydrophobic amines was studied using physicochemical methods. Hydroxyl-containing amines-aminophenols (AP) were used as a hydrophobic amine. On the part of aminophenols, 2 (N, N-dimethylaminomethyl)-4-methylphenol (AP1), 2 (N, N-dimethylaminomethyl)-4-chlorophenol (AP2), and 2 (N, N-dimethylaminomethyl)-4-bromophenol (AP3) were used. Mixed-ligand complexes were formed in a weakly acidic medium (pHopt 4.6–6.4). Ni(II) is recovered by chloroform by 98.6–99.5% in the form of a mixed-ligand complex (MLC) per single extraction. The optimal conditions for the formation and extraction of these compounds are 1.12 × 10-3 mol/L concentration of DMMP and 0.88 × 10-3 mol/L – AP. Changing the concentration of the reagents does not change the composition of the complexes. MLC of Ni(II) with DMMP and AP are stable in aqueous and organic solvents and do not decompose within three days and for more than a month after extraction. The ratio of reacting components in MLC corresponds to Ni (II): DMMP : AP = 1 : 2 : 2. in the formation of MLC, the coordinating ion is Ni2+. Complexing proceeds with the displacement of a proton from a DMMP molecule. Maximum light absorption is observed at λ = 520–530 nm. The molar coefficients of light absorption are (3.78-3.95) × 10 4. Based on the obtained data photometric methods for the determination of nickel in various industrial and natural objects were developed.