Treatment costs

The whole problem is best dealt with by not making 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. 

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.)...

Figure 5.9 shows an example of the efficiency of these products. The reductions of CFPP and pour point can easily attain 6 to 12°C for concentrations between 200 and 600 ppm by weight. The treatment cost is relatively low, on the order of a few hundredths of a Franc per liter of diesel fuel. In practice, a diesel fuel containing a flow improver is recognized by the large difference (more than 10°C) between the cloud point and the CFPP. 

A comparison of overall treatment costs (purchase and refining) for several crude oils enables the refiner to establish his feedstock requirements and to satisfy the market needs under the most economical conditions. 

Injection of produced water is not a new idea, but the technique has met resistance due to concerns about reservoir impairment (solids or oil in the water may block the reservoir pores and reducing permeability). However, as a field produces at increasingly high water cuts, the potential savings through reduced treatment costs compared with the consequences of impairment become more attractive. 

When low boiling ingredients such as ethylene glycol are used, a special provision in the form of a partial condenser is needed to return them to the reactor. Otherwise, not only is the balance of the reactants upset and the raw material cost of the resin increased, but also they become part of the pollutant in the waste water and incur additional water treatment costs. Usually, a vertical reflux condenser or a packed column is used as the partial condenser, which is installed between the reactor and the overhead total condenser, as shown in Figure 3. The temperature in the partial condenser is monitored and maintained to effect a fractionation between water, which is to pass through, and the glycol or other materials, which are to be condensed and returned to the reactor. If the fractionation is poor, and water vapor is also condensed and returned, the reaction is retarded and there is a loss of productivity. As the reaction proceeds toward completion, water evolution slows down, and most of the glycol has combined into the resin stmcture. The temperature in the partial condenser may then be raised to faciUtate the removal of water vapor. 

Poly(ethylene glycol) (PEG) molecules attached to adenosine deaminase (ADA) have been used in patients exhibiting symptoms of the severe combined immunodeficiency syndrome (SCID) caused by ADA deficiency. The modified enzyme has a plasma half-life of weeks as compared to the unmodified enzyme (minutes) (248). PEG-L-asparaginase has induced remissions in patients with non-Hodgkin s lymphoma (248). However, one disadvantage of PEG-enzyme treatment is its expense, ie, a year s treatment costs about 60,000 (248). 

In many cases, this wastewater has environmental implications and incurs treatment costs. In addition, wastewater may wash out valuable unused raw materials from the process areas. It is very important to know how much wastewater is going down the drain, and what that wastewater contains. The wastewater-flows from each imit operation, as well as from the process as a whole, need to be quantified, sampled, and analyzed. 

Use the material balance for each unit operation to pinpoint the problem areas associated with a process. The material-balance exercise may have brought to light the origin of wastes with high treatment costs, or may indicate which wastes are causing process problems in which operations. The material balance should be used to set priorities for long-term waste reduction. 

In many cases, it is appropriate to compare the waste treatment costs under existing conditions with those associated with the waste-reduction option. The size of a treatment plant and the treatment processes required may be altered significantly by the implementation of waste-reduction options. This should be considered in an economic evaluation. 

Calculate the annual operating costs for the existing process that needs waste treatment, and estimate how these costs would be altered by the introduction of waste-reduction options. Tabulate and compare the process and waste-treatment operating costs for both the existing and proposed waste-management options. If there are any monetary benefits (such as recycled or reused materials or wastes), then these should be subtracted from the total process or waste-treatment costs as appropriate. The expanded cost-analysis scheme discussed in Chapter 8 is appropriate to include at this point in the process. 

Fresh-water usage and influent to biotreatment facility are decreased by 7.2 kg/s. The value of fresh water and the avoidance of treatment cost are additional benefits. 

Cost of wash water including heating = 9/m3 Wastewater treatment cost = 2/m3... 

An economic externality exists whenever the wellbeing of some individual is affected by the economic activities of others without particular attention to the welfare of that individual. For example, smog-related illnesses such as bronchitis and exacerbated cases of childhood asthma have been blamed, to some extent, on the emissions of nitrogen oxides from automobiles and large fossil-fuel-burning power plants. These illnesses have high treatment costs that are not... 

Sopt = optimum stripping factor, where treatment costs are a minimum, referenced to costs of utilities, maintenance, depreciation, labor. As economic conditions change one may need to adjust Sopj, see Reference 143. 

In addition to the treatment costs, it should be remembered that provision of treatment plant occupies site space, which may be more profitably used, and that the penalties for infringements of the consent standards are increasing. 

Medium more expensive than water (but no treatment costs). 

Assess the cost factors applicable, in terms of fan, pump cost, price of land, maintenance and treatment costs. 

Medium recycling is required to save water, save unused nutrients, and save cm waste treatment costs (spent medium contains unused organic nutrients and so would otherwise have to be treated to reduce BOD). 

The perceived need to keep external and internal treatment costs in line with either the output of the boiler or its original capital cost in other words, if it is a small boiler it does not require much in the way of water treatment, which is seldom true ... 

Acid addition is commonly used to convert bicarbonates into the more soluble sulfate salts to reduce the alkalinity of the RO RW, which in turn modifies the brine reject water LSI. Sometimes it is required to maintain the pH level within membrane limits. Additionally, it may be used in conjunction with a reduced dosage of antiscalent chemical to reduce the overall chemical treatment costs. 

Solomon DJ, Hogan AJ (1992) HIV infection treatment costs under Medicaid in Michigan. Public Heaith Reports 197 461-468... 

CBO (hemogiobin/hemalocril pialeiet (daily) Drug treatment cost per unit... 

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