Washing effluent

Wash effluents from nitration installation can cause problems due to the high nitrophenol concentrations, their high toxicity to sewage bacteric and their general resistance to biodegradation. Electrochemical pretreatment tests in the laboratory showed a reduction in toxicity, and improvement of the color smell, etc. The electrochemical pretreatment is also attractive because of the absence of solid waste coproducts and its ease of operational control, [135]. 

The metals in wash effluents are then extracted by complexation with added resins. A second approach to recovery of metals is to use a flocculant to separate the metals from soil particles following an acid wash. The metals are then concentrated and recovered by sodium hydroxide precipitation. 

Oxalic acid in the feed does not affect the sorption behavior of Cr + and Ni + ions on the cation resin. However, about 75% of the Ni(ll) ions were in the sorption and wash effluents because resin affinity for Ni + ion is lower than that for Cr + and Am + ions. 

Several researchers have investigated the possibilities of membranes for the removal of dispersed water-based ink pigments from wash effluent [121-126]. Generally, membranes, in particular ultrafiltration membranes, have been found to completely remove ink pigments from effluent streams. It has also been observed that the permeate flux and the fouling tendency depend on operational conditions and effluent composition. For instance, coagulation pretreatment [125], feed water acidification [121], and surfactant addition [123] have been found to improve the flux and decrease fouhng. 

Open stage water wash, effluent sewered... 

The major variation in performance among the various dye types was the low initial color rejection for several acrylic process wash effluents. Subsequently it has been found that these rejections can be raised to acceptable levels by increasing the pH slightly. The color rejection is normally high for direct, acid/direct and disperse dye wash water effluents. 

A last application concerning the use of UV spectrophotometry for waste management is the quality control of external wastes, brought on a given centralised treatment plant. Wastes from septic tanks, industrial liquid wastes (high loaded wastewater or process water) or washing effluents (from tanks, for example) can be collected in small amounts by trucks, and brought to a centralised treatment plant. 

Jung J, Yang J K, Kim S H and Yang J W (2008), Feasibility of micellar-enhanced ultrafiltration (MEUF) or the heavy metal removal in soil washing effluent . Desalination, 222,202-211. 

Solute concentration in a wash effluent that is collected over a period and mixed, kg m ... 

Figure 10.1 represents batch washing. The average solute concentration in wash effluent at any time (or wash ratio) can be calculated from the washing curve using the following equation (if washing with a clean wash liquid) ... 

All these process influence the choice of oil-spill countemieasures. Quickly collection of the oil after a spillage and mechanical recovery by sorbents is one of the most important countermeasures in marine oil-spill response. Sorbents are solid products capable of trapping liquid pollutants. Sorbents are used to reduce the spread of a spill of pollutant, fix a pollutant by impregnation to facilitate its, recovery for small spills recover the pollutant from effluents generated, by cleanup operations Alter pollutant that cannot be recovered from, a water mass (channels, rivers, water intakes and washing effluents) [24]. 

Washing water conditioning upstream and/or downstream from the washed filter. Thickening of washing effluents usually by flotation, or by sedimentation if the oil/SS ratio in the raw water is too low-... 

For finishing wash effluents, an increased dissolved BOD5 load and mainly the frequent requirement of achieving low final nonionic detergent concentrations mean biological treatment by medium load activated sludge. Even extended aeration can be used, whereas a trickling filter would suffice for final treatment of the first two effluents. 

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