JESS at thirty: Strengths, weaknesses and future needs in the modelling of chemical speciation

Abstract

The current status of the software package JESS (Joint Expert Speciation System), which has been developed over the last 30 years, is described. Chemical speciation models of seawater and of metalion complexation in human blood plasma are used as large equilibrium systems to explore the present capabilities of the code and database. Strengths of JESS are considered to be (a) the power and flexibility of its command-driven programs, (b) the size, generality and openness of its reaction database, (c) its automatic facility to achieve thermodynamic consistency, and (d) its ability to partition chemical reactions to model kinetic constraints. A special feature of JESS is its ability automatically to generate a complete, stand-alone FORTRAN program for any particular chemical equilibrium model that has been developed. Weaknesses of JESS include the lack of a graphical user interface, the resulting effort required in familiarisation, and certain limitations regarding pressure and temperature corrections in concentrated solutions. However, the most troublesome issuescommon to all 'ion-association' frameworks -are due to inadequacies in the thermodynamic data available from the literature and to persistent deficiencies in the fundamental theory of concentrated electrolyte solutions. Accordingly, work on JESS has commenced to construct a global parameterisation facility using both reaction data and the physicochemical properties of strong electrolytes in aqueous solution (including solubilities) intended to improve model function testing and to provide even better mechanisms for data harmonisation.

Investigation of complexation and solubility equilibria in the copper(I)/cyanide system at 25 °C

“…A value of log β 1 = 16.34 at I = 1 M(NaCl) and t = 25°C was estimated using the JESS software (May, 2015) and used to process the independently-measured potentiometric data sets of Akilan and Solis. Values of log β 1 = 16.41 and 16.68 were estimated in the same manner for I = 3 and 5 M (NaCl) respectively.…”

Metal release from stainless steel in biological environments: A review

“…131 Predictions of the chemical speciation of released Fe, Cr, Mn, and Ni [using the JOINT EXPERT SPECIATION software, JESS, version 8.3 (Ref. 133)] from stainless steel grade AISI 304 (surface area to solution volume ratio of 1 cm À1 ) are presented in Fig. 2 (based on measured released metal FIG.…”

Comparison of different surface disinfection treatments of drinking water facilities from a corrosion and environmental perspective

“…The Joint Expert Speciation System (JESS, (May 2015)) was used to model the chemical speciation of iron species in the different solutions. As input values, 1.8 mM Fe 3+ , a temperature of 25°C, atmospheric pressure, 0.782 mM CO 3 2− , 0.0771 mM K + , 0.499 mM SO 4 2− , and 0.499 mM Mg 2+ were used for all cases, while the concentrations of Na + , Ca 2+ , Cl − , the pH, and the redox potential were varied as shown in Table 1.…”