Waste liquids treatment

Figure 3.7 Flow sheet of alkali waste liquid treatment.

Figure 3.8 Scheme of waste liquid treatment unit. Nittetu Chemical Ei neering Co., Tokyo 174-0041, Japan. 

Fig. 11. Layout of a2o dye manufacturing plant. 1, storage tanks for liquid starting materials 2, storage dmms for solid starting materials 3, dia2oti2ation vessel 4, coupling component vessel 5, ice machine 6, coupling vessel 7, isolation vessel 8, filter presses 9, filtrate to waste liquor treatment plant 10,...

Three-phase fluidized bed reactors are used for the treatment of heavy petroleum fractions at 350 to 600°C (662 to 1,112°F) and 200 atm (2,940 psi). A biological treatment process (Dorr-Oliver Hy-Flo) employs a vertical column filled with sand on which bacderial growth takes place while waste liquid and air are charged. A large interfacial area for reaction is provided, about 33 cmVcm (84 inVirr), so that an 85 to 90 percent BOD removal in 15 min is claimed compared with 6 to 8 h in conventional units. 

Dissolution Forms a liquid waste for treatment as in Table 1 7.4... 

It was quite recently reported that La can be electrodeposited from chloroaluminate ionic liquids [25]. Whereas only AlLa alloys can be obtained from the pure liquid, the addition of excess LiCl and small quantities of thionyl chloride (SOCI2) to a LaCl3-sat-urated melt allows the deposition of elemental La, but the electrodissolution seems to be somewhat Idnetically hindered. This result could perhaps be interesting for coating purposes, as elemental La can normally only be deposited in high-temperature molten salts, which require much more difficult experimental or technical conditions. Furthermore, La and Ce electrodeposition would be important, as their oxides have interesting catalytic activity as, for instance, oxidation catalysts. A controlled deposition of thin metal layers followed by selective oxidation could perhaps produce cat-alytically active thin layers interesting for fuel cells or waste gas treatment. 

First, handling of highly concentrated acids, including hydrofluoric acid, especially at elevated temperatures, is very dangerous and requires use of special equipment and appropriate training of personnel. Second, the required amount of fluorine (or HF) is well above the amount needed based on the interaction stoichiometry. This results in large amounts of liquid waste, the treatment of which is very expensive. 

Mannich polymers Cationic, solution polymer flocculants with a MW of 5 to 8 M. Very high viscosity at only 4 to 8% active strength solution liquid. A hydrolyed polyacrylamide, it is very useful for general municipal waste water treatment. The dose rate normally is 200 to 300 ppm or more. 

Recent research development of hydrodynamics and heat and mass transfer in inverse and circulating three-phase fluidized beds for waste water treatment is summarized. The three-phase (gas-liquid-solid) fluidized bed can be utilized for catalytic and photo-catalytic gas-liquid reactions such as chemical, biochemical, biofilm and electrode reactions. For the more effective treatment of wastewater, recently, new processing modes such as the inverse and circulation fluidization have been developed and adopted to circumvent the conventional three-phase fluidized bed reactors [1-6]. 

RO can recover metals, antifreeze, paint, dyes, and oils in the retentate while generating cleaned up wastewater permeate for disposal. RO is also used to reduce the volume of waste liquids (e.g., spent sulfite liquor in paper manufacturing). Wastewater treatment application removals of 95 percent TOC, > 90 percent COD, > 98 percent PAH compounds, and pesticides > 99 percent have been seen [Wilhams et al., chap. 24 in Membrane Handbook, Sirkar and Ho (eds.), Van Nostrand, 1992]. 

Di-ft-octylphthalate, including waste containing di-n-octylphthalate, is classified as a hazardous waste product by EPA. Generators of waste containing this contaminant must conform to EPA regulations for treatment, storage, and disposal (see Chapter 7). Rotary kiln or fluidized bed incineration methods are acceptable disposal methods for these wastes. Liquid injection incineration may also be used (HSDB 1995). 

The development of liquid-membrane extraction has been mainly in the fields of hydrometallurgy and waste-water treatment. There are also potential advantages for their use in biotechnology, such as extraction from fermentation broths, and biomedical engineering, such as blood oxygenation. 

Now, from its essential notion, we have the feedback interconnection implies that a portion of the information from a given system returns back into the system. In this chapter, two processes are discussed in context of the feedback interconnection. The former is a typical feedback control systems, and consists in a bioreactor for waste water treatment. The bioreactor is controlled by robust asymptotic approach [33], [34]. The first study case in this chapter is focused in the bioreactor temperature. A heat exchanger is interconnected with the bioreactor in order to lead temperature into the digester around a constant value for avoiding stress in bacteria. The latter process is a fluid mechanics one, and has feedforward control structure. The process was constructed to study kinetics and dynamics of the gas-liquid flow in vertical column. In this second system, the interconnection is related to recycling liquid flow. The experiment comprises several superficial gas velocity. Thus, the control acting on the gas-liquid column can be seen as an open-loop system where the control variable is the velocity of the gas entering into the column. There is no measurements of the gas velocity to compute a fluid dynamics... 

The main fields of application for directed crystallization as a purification (separation) technology are organic-chemical separation and purification (2), fruit juice or liquid food concentration (3.4, waste water treatment (1) ... 

Ozone decay. Is it necessary to know the ozone decay rate (exactly) in waste water treatment studies No, not in every case. Often the reactions of ozone with organic compounds occur in the liquid film (fast reactions), so that cL is (approx.) zero and ozone decay cannot occur. Generally, measure the dissolved ozone concentration cj B 3.2, B 4... 

The continuous-flow set-up can use either a reaction, similar to semi-batch, to remove the oxygen transferred or two reactors in series. The ozone or oxygen is removed from the liquid in the first reactor by stripping or vacuum degassing and then it flows into the absorber. After having passed through the absorber, the liquid can be recycled or discharged. More information on full-scale application of this method in municipal waste water treatment plants can be found in Redmon (1983) and ASCE (1991). 

In many cases, this type of reactor provides the best way of carrying out a reaction between gaseous and liquid reactants in contact with a solid catalyst or an inert packing. That is the reason why these reactors are widely used in chemical and petrochemical industries as well as in biotechnology and waste water treatment. Reviews of all the applications have been published recently (1,2). 

Gas/liquid contacting is frequently encountered in chemical reaction and bioprocess engineering. For reactions in gas/liquid systems (oxidation, hydrogenation, chlorination, and so on) and aerobic fermentation processes (including biological waste water treatment), the gaseous reaction partner must first be dissolved in the liquid. In order to increase its absorption rate, the gas must be dispersed into fine bubbles in the liquid. A fast rotating stirrer (e.g. a turbine stirrer), to which the gas is supplied from below, is normally used for this purpose (see the sketch in Fig. 34). 

Surface aeration is usually employed for slow reactions or for batch processes. It can be used in semicontinuous systems when it is desirable to recirculate the gas from the headspace. This is frequently the case in hydrogenation and is referred to as dead-end hydrogenation. In this system, gas is fed continuously to the reactor at the rate at which hydrogen is being consumed no compression costs to overcome the static head of liquid or external recirculation is needed. Feeding gas from the headspace may be preferred when there is a possibility of plugging sparger holes with reaction products. Surface aerators are also extensively used for waste-water treatment. There are two types of surface aerators the brush aerator, and the most commonly used turbine aerator. 

The surface aerator has been used for decades in biological waste-water treatment with H < 4 m. For various sizes of turbine stirrers whose disks were positioned exactly in the surface of the liquid, the mass-transfer coefficient can also be related as... 

Fig. 12.19. Flow diagram for the manufacture of acrylic fiber (1) acrylonitrile (2) tank farm (3) polymerizer (4) comonomer and catalyst (5) centrifuge (6) waste liquid (7) dried polymer (8) grinding (9) polymer storage (10) dissolver (11) filter (12) solvent plant (13) spinnerette (13w) wet spinning (13d) dry spinning (14) roller dryer (15) additional treatment (16) crimper (17) cutter (18) acrylic fiber bale.

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