Chlorine decay behavior is significantly variable since it depends on the quality of water and the condition of a distribution system. The effect of various parameters on the bulk chlorine decay kinetics in water samples collected from the Zai water treatment plant in Jordan has been examined. These parameters are reaction time, temperature, TOC, and free chlorine dose. An empirical equation describing the abovementioned effects has been derived. The general trend of chlorine decay decreases upon time and can fairly be represented by first-order decay kinetics. An increase in the value of temperature and TOC parameters has proportional effects on the decay of bulk chlorine. However, the data show that the decay constants were found to be inversely proportional to the initial chlorine concentration. A general correlation for the calculation of bulk chlorine decay rate constant as a function of the parameters in question of this study has been proposed. Consequent predictions are in good agreement with the observed results in this study.

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Deep eutectic solvents (DESs) are a class of green and tunable solvents that can be formed by mixing constituents having very low melting entropies and enthalpies. As types of materials that meet these requirements, plastic crystalline materials (PCs) with highly symmetrical and disordered crystal structures can be envisaged as promising DES constituents. In this work, three PCs, namely, neopentyl alcohol, pivalic acid, and neopentyl glycol, were studied as DES constituents. The solid–plastic transitions and melting properties of the pure PCs were studied using differential scanning calorimetry. The solid–liquid equilibrium phase diagrams of four eutectic systems containing the three PCs, i.e., L-menthol/neopentyl alcohol, L-menthol/pivalic acid, L-menthol/neopentyl glycol, and choline chloride/neopentyl glycol, were measured. Despite showing near-ideal behavior, the four studied eutectic systems exhibited depressions at the eutectic points, relative to the melting temperatures of the pure constituents, that were similar to or even larger than those of strongly nonideal eutectic systems. These findings highlight that a DES can be formed when PCs are used as constituents, even if the eutectic system is ideal.