The process of soil stabilization is a fundamental requirement before road infrastructure development is possible. Different binding materials have been used worldwide as soil stabilizers. In this study, water treatment waste (i.e., alum sludge (AS)) was used as a soil stabilizer. Alum sludge can work not only as a low-cost soil stabilizer but also can solve the problem of waste management at a large scale. Utilization of alum waste can be a sustainable solution and environmentally friendly exercise. Thus, in consideration of the pozzolanic properties of alum, it was applied as a binder, similar to cement or lime, to stabilize the soil with the addition of 2%, 4%, 6%, 8%, and 10% of dry soil by weight. To analyze the resulting improvement in soil strength, the California Bearing Ratio (CBR) test was conducted in addition to three other tests (i.e., particle size analysis, Atterberg’s limits test, and modified proctor test). The soil bearing ratio was significantly improved from 6.53% to 16.86% at the optimum level of an 8% addition of alum sludge. Furthermore, the artificial neural networks (ANNs) technique was applied to study the correlations between the CBR and the physical properties of soil, which showed that, at 8% optimum alum sludge, maximum dry density, optimum moisture content, and plasticity index were also at maximum levels. This study will help in providing an eco-friendly soil stabilization process as well as a waste management solution.

An investigation into two non-toxic natural coagulants abundantly growing in different countries, cactus (Opuntia spp.) and okra was performed on monthly river water samples (one-year period). The studied case was the Euphrates river/Al-Mashroo canal/Iraq. Six statistical models were interpreted and tested describing the residual turbidity after Coagulation-Flocculation for the three studied cases (Optimum-Coagulant-Dose, Optimum-Flocculator-Velocity-Gradient and Optimum-Flocculation-Time). According to the environmental parameters recorded during the study and the statistical analyses, two facts were concluded. The first fact was that controlling the Optimum-Flocculator-Velocity-Gradient of the Coagulation-Flocculation process gave the highest contribution ratio of the models. The second fact was that the most significant environmental parameter (statistically) in the Coagulation-Flocculation process was the initial turbidity. This was proved for the two natural coagulants under study. Also, from the results of the study, it was concluded that the two natural coagulants were of similar coagulation-flocculation properties, and they were competent for turbidity removal.

None. Applied manuscript is a letter to the editor.

Wearable sensors are the technology of the future and will become an integral part of daily life. These sensors can monitor the physical activities and biochemical information of an individual, organ functions, and environmental changes. A wearable sensor may comprise a sensing element, electrodes, substrate, power unit and data processing unit. Selectivity, sensitivity and reliability of a wearable sensor depend on the sensing element, electrodes and substrate, which can be designed/fabricated with a suitable material. A variety of materials including carbon materials, conductive polymers, metal oxides, metals, elastomers, and nanomaterials have been used depending on the applications of the sensor. In this review, we will summarize the recent developments regarding the use of advanced materials for applications in wearable sensor technologies.