1d:T79c,# Dimensionless Distribution Coefficient This function computes the natural logarithm of dimensionless distribution coefficient (Kd) from adsorption equilibrium data across temperatures, and non-temperature treatments, if any. This function prepares the foundational input required for thermodynamic parameter analysis. ```r LnKd(V, m, MW.Ad, M.Ad, Non_T_trt, T_trt, Rep, IGC, Ce) ``` ## Arguments - `V`: Volumn of water in litre - `m`: Mass of the adsorbent in gram - `MW.Ad`: Molar weight of the adsorbate in gram per mole - `M.Ad`: Molarity of the solvent in mole per litre(55.5 for water) - `Non_T_trt`: Non-temperature treatment - `T_trt`: Temperature treatment - `Rep`: Replication - `IGC`: Initial graded concentrations of the adsorbate in milligram per litre - `Ce`: Equilibrium concentration of the adsorbate in milligram per litre ## Returns * qe_i: Absorbed amount in milligram per kg * Kd_i: Distribution coefficient * lnKd_i: Natural logarithm of Kd * Mean_lnkd: Average of lnKd ## Examples ```r V <- 0.02 # in litre m <- 2 # in gram MW.Ad <- 75 M.Ad <- 55.5 Non_T_trt <- c(0,0,0,0,0,0,1,1,1,1,1,1) T_trt <- c(1,1,1,2,2,2,1,1,1,2,2,2) Rep <- c(1,2,3,1,2,3,1,2,3,1,2,3) IGC <- c(2,4) Ce2 <- c(0.030, 0.031, 0.032, 0.033, 0.034, 0.035, 0.030, 0.031, 0.032, 0.033, 0.034, 0.035) Ce4 <- c(0.030, 0.031, 0.032, 0.033, 0.034, 0.035, 0.030, 0.031, 0.032, 0.033, 0.034, 0.035) Ce <- data.frame(Ce2, Ce4) my.LnKd<- LnKd(V, m, MW.Ad, M.Ad, Non_T_trt, T_trt, Rep, IGC, Ce) ``` ## References Roy, A., Manjaiah, K. M., Datta, S. P., Rakshit, D., Barman, M., Ray, P., Golui, D., Raza, M. B., Tigga, P., Mondal, S., Vishwanath, Meena, S., & Meena, P. (2025). Effect of Low-Molecular-Weight Organic Acids and Silicon on Arsenic Adsorption and Desorption in a Paddy Soil of Bengal Delta Plain: Insights from Thermodynamics and Equilibrium Modeling. Water, Air, & Soil Pollution, 236(6), 344. https://doi.org/10.1007/s11270-025-07963-7

LnKd function