Raw effluent

Except for treated wastewater, almost all raw effluents contain solid compounds or grease and hydrocarbons responsible for fouling/clogging. As seen previously, on-site measurement is thus preferable, in order to place the instru-... 

Fig. 2.6.9. MS-MS chromatogram (MRM channel m/z 219 — 133) of raw effluent (river water) treated in a Barcelona drinking water treatment plant. Insets product ion scan of NPE2C (A) and NP (B), obtained using argon as collision gas at collision energy of...

One study that has tackled this issue, however, was recently published by de Souza et al. [104], who set up an environmental risk assessment of the 21 intravenous antibiotics most used in an intensive care unit of a hospital in Curitiba (Brazil). They evaluated the RQ, based on PEC, both in the raw effluent and after a dedicated conventional biological treatment. They found that, in the raw effluent from the ward, the environmental risk was high for 15 compounds, medium for 4 and low for 2 similarly, the treated effluent was labelled as high risk in terms of 14 compounds, medium for 5 and low for 2. 

Emmanuel E, Perrodin Y, Keck G, Blanchard JM, Vermande P (2005) Ecotoxicological risk assessment of hospital wastewater a proposed framework for raw effluents discharging into urban sewer network. J Hazard Mater Al 17 1-11... 

Akmehmet, I. and Arslan, I., Application of photocatalytic oxidation treatment to pretreated and raw effluents from the Kraft bleaching process and textile industrial, Environ. Pollut., 103(2-3), 261-268, 1998. 

TABLE 29. Annual Production of Raw Effluents for Mills with Capacity Ranging from 10 to 60 tons FFB Per hour. 

The characteristics of palm oil refinery effluent vary according to the type of refinery operation (chemical or physical refining, fractionation process, etc.), process control, and housekeeping program. It is quite difficult to derive general characteristics for raw effluent. Therefore the choice of treatment system will depend very much on the complexity of the raw effluent, i.e., its flow and characteristics. 

Total fatty matter (TFM) concentrations in the raw effluent can lead to poor performance of the treatment process. Therefore, care should be taken to ensure efficient removal of TFM in the pretreatment (physical/chemical) process. TFM is one of the main contributors to BOD. 

Table 1 shows the variation in the levels of heavy metals in effluent samples collected in the morning and afternoon. EWA and EWB represent morning and afternoon samples, respectively. Table 2 shows the effect of treatment of the effluent with sodium hydroxide during the period of study, with EWA and TEA representing the levels in ppm before and after treatment, respectively. ND represents non-detectable levels by the spectrophotometer. Table 3 shows results obtained when raw effluent, tap water, bore hole water and treated effluent were analyzed for the levels of heavy metals under study. The results show that there are very high levels of zinc in the borehole water. Table 4 shows the analytical results obtained after raw effluent was treated with sodium hydroxide and then compared to the analytical results obtained when lime was used instead of sodium hydroxide in treating the raw effluent. 

Treatment of the raw effluent with both lime and sodium hydroxide reduced the levels of all the metals, and even zinc was reduced to non-detectable levels in some cases (Table... 

The UV/UV-visible method was applied for the determination of total phosphorus from raw effluents. The results were compared with those obtained by atomic absorption analysis as the reference method (Fig. 13). 

Inlet conditions— flow rate and analysis of inlet stream (raw water/raw effluent), concentration of suspended solids, particle size, pH and temperature of inlet stream Outlet conditions desired— flow rate of exit stream, concentration of suspended solids, particle size, pH, dissolved oxygen and temperature Whether the vendor is able to guarantee required performance (flow rate and analysis which should meet specified norms by statutory authorities) without chemical pre-treatment... 

The study by Anderson and Clark [10] of heavy metals removal from the effluent of a medium-sized multi-product dyestuffs company illustrates the progressive development of an effluent control system. Typical concentrations of metals in the raw effluent and the discharge limits set by the water authority are set out in Table 6.5. 

Table 6.5 Typical raw effluent and required metal discharge limits for a multiproduct dyestuffs company in England [10]. ...

The use of excess reactants, diluents, or heat carriers in the reactor design has a significant effect on the flowsheet recycle structure. Sometimes the recycling of unwanted byproduct to the reactor can inhibit its formation at the source. If this can be achieved, it improves the overall use of raw materials and eliminates effluent disposal problems. Of course, the recycling does in itself reuse some of the other costs. The general tradeoffs are discussed in Chap. 8. 

Figure 10.7 Effluent treatment costs should be included with raw materials costs when traded off against separation costs to obtain the optimal recovery. (From Smith and Petela, Chem. Eng., 513 24, 1991 reproduced by permission of the Institution of Chemical Engineers.)...

The best solution to effluent problems is not to produce the waste in the first place, i.e., waste minimization. If waste can be minimized at the source, this brings the dual benefit of reducing waste treatment costs and reducing raw materials costs. 

Single-reaction-step processes have been studied. However, higher selectivity is possible by optimizing catalyst composition and reaction conditions for each of these two steps (40,41). This more efficient utilization of raw material has led to two separate oxidation stages in all commercial faciUties. A two-step continuous process without isolation of the intermediate acrolein was first described by the Toyo Soda Company (42). A mixture of propylene, air, and steam is converted to acrolein in the first reactor. The effluent from the first reactor is then passed directiy to the second reactor where the acrolein is oxidized to acryUc acid. The products are absorbed in water to give about 30—60% aqueous acryUc acid in about 80—85% yield based on propylene. 

Effluent Guidelines and Standards. The Clean Water Act requires specific levels of control for dischargers. These are outlined in the Effluent Guidelines and Standards for various industrial categories. These standards limit the discharge of pollutants, usually in terms of a unit weight of pollutant per unit of either product or raw material, rather than a concentration in the discharge stream, in order to eliminate the use of dilution to meet limits. 

Water reuse is usually a question of the tradeoff between the costs of raw water and the costs associated with treatment for reuse and for discharge. If biological treatment is to be employed, several factors must be considered. These are an increase in concentration of organics, both degradable and nondegradable. This may have a negative effect in terms of final effluent toxicity. An increase in temperature or total dissolved soHds may adversely affect the performance of the biological process. 

A typical reactor operates at 600—900°C with no catalyst and a residence time of 10—12 s. It produces a 92—93% yield of carbon tetrachloride and tetrachloroethylene, based on the chlorine input. The principal steps in the process include (/) chlorination of the hydrocarbon (2) quenching of reactor effluents 3) separation of hydrogen chloride and chlorine (4) recycling of chlorine to the reactor and (i) distillation to separate reaction products from the hydrogen chloride by-product. Advantages of this process include the use of cheap raw materials, flexibiUty of the ratios of carbon tetrachloride and tetrachloroethylene produced, and utilization of waste chlorinated residues that are used as a feedstock to the reactor. The hydrogen chloride by-product can be recycled to an oxychlorination unit (30) or sold as anhydrous or aqueous hydrogen chloride. 

The neutralization process is not energy intensive added heat evaporates water formed in the reaction and water entering the system with the raw materials, which is 50% NaOH. The significant waste effluent contains 10—100 ppm NaCN and must be treated before disposal. 

Residual monomers exhibit a characteristic sharp odor even in subtoxic concentration, due to the very low olfactory threshold. Modem requirements in terms of environmental safeguard have led to significant improvements in the control of polymerization effluents, driving off gases, and residual monomer in the raw polymer. Consequendy, the acryUc elastomers of the 1990s are practically odor-free, and represent a significant improvement over the products of the past. 

Utilities and yard services (boiler plant, refrigeration, compressed air, water supply and treatment, effluents, fire protection, yard piping, yard electrical, yard materials handling, raw and finished-product storage)... 

The fluid being pumped is often not well defined. Terminology like well water, industrial effluent, raw water, boiler feed water, condensate water, etc., is usually the only definition we have of the fluid being pumped. Any of these fluids can contain several concentrations of. solids that cause erosion and wear inside the pump. 

Adhesives and resins are one of the most important raw materials in wood-based panels. Thus, each question concerning the life cycle assessment and the recycling of bonded wood panels does bring into question the adhesive resins used. This includes, for example, the impact of the resin on various environmental aspects such as waste water and effluents, emission of noxious volatile chemicals during production and from the finished boards, or the reuse for energy generation of wood panels. The type of resin has also a crucial influence on feasibility and efficiency for several material recycling processes. 

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