Batch tests, sedimentation

A batch test on the sedimentation of a slurry containing 200 kg solids/m3 gave the results shown in Figure 5.14 for the position of the interface between slurry and clear liquid as a function of time. 

Batch tests (i. e., tests on individual waste materials) are conducted with the provided solid suspensions (e.g., soils such as Woodburn, Sagehill, and Olyic, as well as two bottom sediment samples) prepared with previously air-dried solids (i. e., soils and bottom sediments), ground to a uniform powdery texture for mixing with the eluates from the 24-h batch leaching test of the different SWMs/COMs. The concentrations of eluates in solution were designed to evaluate the capability of different environmental solids to adsorb available contaminants. The solid particles were fully dispersed with the aqueous phase to achieve complete adsorption. Common practice is to use a solid solution ratio of 1 g 4 ml [ 1 ], together with proper tumbling of the samples at a constant temperature (e.g., at least 24 h in a constant temperature environment of 20°C). 

ISO/DIS 14592. (1999) Water quality - Evaluation of the aerobic biodegradability of organic compounds at low concentrations in water. Part 1 Shake flask batch test with surface water or surface water/sediment suspensions (22.11.1999)... 

Most of the difficulties encountered in the development of a sound deagn basis for sedimentation units handling type lU and IV systems, centre on the problem of app g batch test information to continuous separatioa Ckapter 7 presents a review of these methods and their plication to the ecffication of continuous sedimentation equ ment. Obvious, the use of continuous, small-scale darffierHMckeners provides a sounder technical base for process scale-up to industrial itize [Khatib and Howell, 1979],... 

A sorption isotherm is completed for each solid particle type and SWMs/ COMs. A range of solid to solution concentrations (i.e., solid solution) was chosen for each solid phase and waste material leachate (e.g., 50-250 mg/l),with about five data points per range. All control and test samples were performed in duplicate. The solution used in the isotherms was prepared by a 24-h batch leaching experiment with the solid test material and distilled water. The material controls consisted of the test material leachate without the solid phase particles. Chemical analyses, expressed either as TOC or as individual organic compound (e.g., aliphatic and aromatic compounds) concentrations relative to the organic carbon content of the SWM/COM, revealed the actual concentrations of various organic constituents in the leachates. Solid phase controls were also prepared for each of the test soils/sediments in order to determine the concentrations of the constituents leached from the solid phase alone. 

The sorption behavior of 11 PAH compounds (a training set, Table 11) on various solid phases (e.g., three soils and two sediments) with different properties to relevant sorption (e.g., organic carbon content, clay content, pH, cation exchange capacity CEC Table 12), was determined by batch equilibrium studies [1]. Batch equilibrium tests were designed to determine rates of equilibrium sorption under conditions of high mixing and high surface areas of the solid particles (see Chap. 3). 

ASTM. 1987a. Standard test method for 24-h batch-type measurement of containment sorption by soils and sediments. ASTM, D 4646, American Soriety for Testing and Materials, Philadelphia, PA pp. 120-123. 

American Society for Testing and Materials, Standard Test Method for 24-Hour Batch-Type Measurement of Containment Sorption by Soils and Sediments, Philadelphia, PA, 2001. 

Some of the more obvious areas definitely requiring test work are filtration, sedimentation, spray, or fluidized bed or any other kind of solids drying, extrusion pelleting, pneumatic and slurry conveying, adsorption, and others. Even in such thoroughly researched areas as vapor-liquid and liquid-liquid separations, rates, equilibria, and efficiencies may need to be tested, particularly of complex mixtures. A great deal can be found out, for instance, by a batch distillation of a complex mixture. 

The purpose of this work was to optimize mixing, various pretreatment (coagulation and sedimentation) and filtration processes, utilizing artificial asbestos suspensions containing asbestos levels of the order of 5.10 ° to 10 f/1. At first, tests were carried out through a batch process to obtain the optimum conditions which were then applied to the pilot plant. Also, the pilot plant effectiveness was evaluated for asbestos fiber removal. 

Many properties of liquid paints can be measured with considerable accuracy. Samples must be homogeneous. They must also be sufficiently large to be representative for a given batch. Impurities and permanent material defects (e.g., skin formation, a hard sediment, or gelling of the paint) can be detected. The most common investigations to which a sample is subjected before starting the tests are described in ISO 1513. Only those tests that are important for paint storage, transportation, and application are described here. 

Batch Settling and Sedimentation Velocities. A batch settling test on a slurry... 

Although comprehensive descriptions of equipment selection are given in this chapter the specifics of data analysis and equipment simulation are presented elsewhere. Chapter 4 provides practical methodologies, theories and principles that underpin the analysis of filtration, jar sedimentation and expression tests. Chapters 6 and 7 respectively present extensive descriptions of batch and continuous filter simulations, however, an introduction to simulation is described here. 

Consider a plant which is required to process five separate feeds in batches at rates equivalent to 15 m h At the current stage of process specification it is not clear whether the prime objective for the separation of two of the feeds is solids dewatering or washing. Sedimentation and filtration tests have been performed on small samples of the slurries and analysed using... 

Moncrieff A.G., 1964. Theory of thickener design based on batch sedimentation tests, Trans IMM, 73, 729-759. 

---