Conventional Treatment Systems

Clay - The use of elay based floeculating agent(s) in eonjunetion with a strong metal preeipitator has proven sueeessful in many wastewater treatment applieations where the objeetives are aimed at metals removal. Clay based floeeulants eleans the wastewater and in some eases replaees multistage conventional treatment system and saves the traditional operational difficulties of treatment with several chemicals such as metal hydroxide precipitation, coagulant, floeeulants and other methods. Commercial clay-based floeeulants usually consist of bentonite and other... 

Coal Slurries - Two component treatments prove to be effective on a commercial scale for coal slurry flocculation. The use of encapsulated floccuiant suspended in a counter charged floccuiant provides the robusmess of traditional dual component systems, but with additional performance advantages, which include reduction in filter cake moisture content and an increased throughput rate. Figure 5 illustrates the typical filter cake moisture content obtained by a conventional treatment system compared to the encapsulated treatment system using coal tailings as the substrate. 

Three categories of regulatory limitations apply to wastewater discharge from industrial facilities such as oilfields and petroleum refineries [20]. The first category includes effluent limitations, which are designed to control those industry-specific wastewater constituents deemed significant from the standpoints of water quality impact and treatability in conventional treatment systems. In the United States, these limitations are the EPA Effluent Guidelines, issued under Public Law 92-500. 

The SRS demonstration showed when natural gas was added to air sparging, cleanup would normally take 10 years to reach acceptable levels (95%) using conventional systems could be achieved in about 4 years to undetectable levels. Such a difference would result in a 1.5 million savings over conventional treatment systems for just the SRS demonstration (D118127, p. 4). 

A major deficiency of conventional treatment systems is their inability to make use of a single-process separation for aU the dissolved constituents on a molecular or ionic level. Membrane processes operate at ambient temperature and offer one-step separation for all the dissolved constiments on molecular or ionic level without any need for further chemical addition. Table 29.2 gives the application of different membrane processes for diverse contaminants. 

Membrane systems give a compact and modular constmction, which occupies less floor space in comparison to the conventional treatment systems. This becomes extremely attractive in the land-scarce countries such as Japan and Singapore. 

The overall costs for a VFO unit can be lower than the costs of conventional liquid fuel treatment plants. The U.S. Department of Energy conducted a survey that showed that the costs of operating a liquid fuel treatment system over a 20-year period is approximately 0.50 MMBtu... 

Microparticulate Systems - Although dual combination treatment systems comprising microparticles and flocculants have been used in the paper industry since the 1980s, it is only recently that there has been a general trend for paper mills to switch from conventional single component systems to dual systems. 

Membrane processes also offer other advantages over conventional treatments. They reduce the number of unit processes in treatment systems for clarification and disinfection and increase the potential for process automation and plant compactness. Designers also thought membrane plants could be much smaller than conventional plants of the same capacity and, given their modular configuration, could be easily expanded. Additionally, these plants would produce less sludge than conventional plants because they wouldn t use such chemicals as coagulants or polymers. 

Hydrochloric acid in combination with chlorine dioxide can be used as a treatment fluid in water-injection wells that get impaired by the deposition of solid residues [332,333]. The treatment seems to be more effective than the conventional acidizing system when the plugging material contains iron sulfide and bacterial agents because of the strongly oxidative power of chlorine dioxide. Mixtures of chlorine dioxide, lactic acid, and other organic acids [1172,1173] also have been described. 

If conventional treatment fails, unresolved diaper rash can also lead to secondary bacterial infections. Staphylococcus aureus and streptococci are the most likely pathogens responsible for these infections and require treatment with systemic antibiotics.3 37 While topical protectants may be used as an adjunct in treatment, suspected bacterial infections should always be referred to a physician for accurate diagnosis and the selection of an appropriate antibacterial regimen.34 Figure 62-7 shows a useful algorithm for the effective treatment of diaper dermatitis. 

The economics for this project are presented in comparison to the previous operating situation with essentially no waste treatment, and to estimated costs if a conventional precipitation and neutralization waste treatment system had been installed without modifying the manufacturing process itself. 

Figure 6.4 shows an example of an existing plating facility and its conventional reduction-precipitation wastewater treatment system in New Britain, TN.15... 

FIGURE 6.4 Conventional reduction-precipitation wastewater treatment system. 

The treatment efficiency of this system (Figure 6.6) is much higher than that of the conventional reduction-precipitation wastewater treatment system (Figure 6.4).15... 

FIGURE 6.6 Innovative flotation-filtration wastewater treatment system using conventional chemicals. 

The treatment efficiencies of the two innovative flotation-filtration wastewater treatment systems (Figures 6.6 and 6.7) are expected to be higher than those of the conventional reduction-precipitation system. 

The innovative flotation-filtration wastewater treatment system (Figure 6.6) using conventional chemicals has the highest flexibility and best performance. When desirable, the innovative chemical FeS or equivalent can also be used. 

The primary distinguishing feature of the improved activated sludge treatment system is that high-rate DAF is the secondary clarifier for separation of suspended solids from the activated sludge aeration basin effluent, as opposed to secondary sedimentation alone in a conventional activated sludge system. 

A typical overloaded conventional complete-mix activated sludge treatment plant (shown in Figure 27.11) has been described in Section 27.3.3. The same conventional treatment plant can be improved by the addition of a secondary flotation clarifier (shown in Figure 27.12). Some advantages of the improved activated sludge system are mathematically presented below. 

Due to the higher amounts of organic pollutants in the food industry wastewater, conventional biological treatment systems can be used. 

---