Cost of Effluent Treatment

The main advantage offered by this bath is the reduction of the cost of effluent treatment 34 however, the low metal content means that stricter day to day analytical control of the bath contents is required. Thus the process is probably viable only if laboratory facilities are available in the same plant. To some extent the disadvantages may be overcome by a compromise move to a medium cyanide-medium metal bath. 

With regard to the environment, the intensified plant of the future will be much less obtrusive, with the distillation and absorption towers of our present chemical complexes being replaced by more compact and inconspicuous equipment, which may be hidden by the boundary tree line. In addition, the cost of effluent treatment systems will be less, allowing tighter emission standards to be reached economically. The economic incentive to produce commodity chemicals in large centralised plant complex is likely to diminish or disappear with the application of PI. Thus distributed manufacture in smaller plant will be both feasible and economic, thereby avoiding the need to distribute hazardous material on the public transport system. 

Cost figures provided here are "order-of-magnitude" estimates, and are representative of charges typically assessed to the client by the vendor, exclusive of profit. The total annual cost to operate a 12-module filtration unit ranges between 314,180 and 1,209,700, depending on whether effluent treatment and costs are considered, the flow rate through the unit, the cleanup requirements, and the cost of effluent treatment... 

The costs per 1,000 gal is dependent on the flow rate, the duration of the project, whether concentrate disposal is being considered, and the cost of effluent treatment and disposal. These ranges are shown below and are based on a one year project. 

High water usage is not sustainable and increases the cost of effluent treatment Recycle process water back through the fermentatimi... 

The operating costs entail raw material costs and effluent treatment costs. Only scenarios 1 and 3, i.e. fixed outlet concentration with and without reusable water storage, are considered. The additional information provided for the case study pertains to the mass ratios between raw material streams and freshwater. In process 1, 1 kg of water (aqueous phase) is required to wash 3 kg of raw material stream (organic phase) to the desired specification. In process 2, 1 kg of water is required for every 2 kg of raw material stream. These requirements are dictated by mass transfer. 

The cost of ChemOx treatment depends on the specific application. Factors that influence cost include specific contaminants to be removed, concentration of contaminants in the effluent, amount or flow rate of water to be treated, discharge requirements, and geographical location. The vendor states that they will provide cost estimates for specific applications (D17705T, p. 4). 

Cost of Filtration Treatment at Various Flow Rates with or without Effluent... 

Eliminate continuous catalyst promoter addition lower cost of construction materials and elimination of effluent treatment systems... 

Recent developments in material science, electrochemical reactor design, and electrocatalysis have led to an increasing number of electrolytic applications in the area of effluent treatment. These developments have allowed electrochemical treatment processes to become competitive with physicochemical and biological processes, in terms of both capital and operating costs. Some cost-competitive cases of electrochemical pollution control have appeared in the literature over the past several years [1-6]. 

Improving the Performance of Effluent Treatment Plant (GG175), helps companies to consider their effluent systems as an integral part of their plant operations which can lead to reduced waste and treatment costs,... 

Another example could be the cooling or condensation of particulate laden gases or vapours. It is possible to cool the hot gas or condense the vapours by direct contact with a cold liquid, usually water. Although this might eliminate particulate fouling of a cooler and the associated cleaning costs, it could generate other costs for effluent treatment or the need to separate the condensate from the coolant phase. The latter may not be a problem if the two liquids are immiscible. 

As both radiation-curing and plasma affect only the outer surface of the fabric, only a minimum of chemicals are needed. The cost is low because of a shorter processing time and (partial) reduction of effluent treatment (Samanta et al., 2014). Both techniques have been compared using conventional methods regarding the process medium, water and energy requirement, time required, consumption of chemicals, and cost. 

The advantages of physical compared to chemical refining are improved product yield in many cases reduced refining costs both in plant and processing elimination of soapstock splitting reduction of effluent treatment costs. 

The paper industry pulp biobleaching, pitch control, manufacture of mechanical pulps with low energy cost, and effluent treatment. 

Pulp washing is a key process stage in all types of pulp mill. Poor washing conditions may lead to higher water and chemical consumption, reducing the effectiveness of effluent treatment and chemical recovery operations. All these factors tend to increase production costs and effluent problems. 

Additional separation and recycling. Once the possibilities for recycling streams directly, feed purification, and eliminating the use of extraneous materials for separation that cannot be recycled efiiciently have been exhausted, attention is turned to the fourth option, the degree of material recovery from the waste streams that are left. One very important point which should not be forgotten is that once the waste stream is rejected, any valuable material turns into a liability as an effluent material. The level of recovery in such situations needs careful consideration. It may be economical to carry out additional separation of the valuable material with a view to recycling that additional recovered material, particularly when the cost of downstream effluent treatment is taken into consideration. 

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 capital cost of most aqueous waste treatment operations is proportional to the total flow of wastewater, and the operating cost increases with decreasing concentration for a given mass of contaminant to be removed. Thus, if two streams require different treatment operations, it makes no sense to mix them and treat both streams in both treatment operations. This will increase both capital and operating costs. Rather, the streams should be segregated and treated separately in a distributed effluent treatment system. Indeed, effective primary treatment might mean that some streams do not need biological treatment at all. 

The high cost of coal handling and preparation and treatment of effluents, compounded by continuing low prices for cmde oil and natural gas, has precluded significant exploitation of coal as a feedstock for methanol. A small amount of methanol is made from coal in South Africa for local strategic reasons. Tennessee Eastman operates a 195,000-t/yr methanol plant in Tennessee based on the Texaco coal gasification process to make the methyl acetate intermediate for acetic anhydride production (15). 

Caro s acid is finding increasing appHcation ia hydrometaHurgy, pulp bleaching, effluent treatment, and electronics. There are several appHcations of Caro s acid ia hydrometaHurgy. It is usually made on-site by either the isothermal or the adiabatic process. The latter method is preferred because its capital cost is less and the system is safer due to the fact that the product is used as soon as it is made. 

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. 

Ozone (O3) is a powerful oxidant, and application to effluent treatment has developed slowly because of relatively high capital and energy costs compared to chlorine. Energy requirements for ozone are in the range of 10 to 13 kWh/lb... 

Temperature and Humidity When adsorption, absorption, or condensation is employed, the lowest inlet gas temperature is desirable. Adsorbent and absorbent capacities generally increase with the decreasing gas temperature. High waste-gas temperatures may preclude the use of adsorption or condensatit)n due to the cost of chilling. Thermal and catalytic oxidation benefit from a hot effluent gas stream, as that reduces the supplementary fuel requirement. In biological treatment, a waste-gas temperature of near 37 °C is ideal. 

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