Coagulation solids

The word curdling comes from curd, the coagulated solid formed by adding acid or rennet to milk. Curds are the precursors of most cheeses. 

The second-stage (ammonia removal) effluent contained unacceptable levels of F and P and had to be subjected to third-stage lime treatment. This raises the pH from 8.5 to 11.4 and produces an effluent with concentrations of F and P equal to 25 and 2 mg/L, respectively. The hydraulic design parameters were a 15 min reaction time and a 265 gpd/ft (10.8 m /m /day) clarifier overflow rate. The resulting precipitated solids underflow concentration was 0.6% by wt. In all three stages, an anionic polymer was used to aid coagulation, solids settling, and effluent clarification. 

This equation shows why, for example, aggregated droplets in an emulsion cream faster than individual droplets, and why coagulated solids in a suspension usually sediment faster than individual particles (in both cases the effective radius is larger). 

In some suspensions, very fine colloidal sohds are present and are very difficult to coagulate. In these cases, it is typically necessary to adjust for coagulation mixing intensity and time to obtain coagulated solids that are more amenable to flocculation. 

Sorption to Coagulation Solids in Drinking Water Treatment. 162... 

Electrochemical reactions at the electrodes produce very fine H2 and O2 gas bubbles and highly chemically reactive hydroxyl (OH ) and superoxide (H02 ) radicals. The gas bubbles promote the flotation of coagulated solids and coalesced hydrocarbons, etc. The hydroxyl and superoxide radicals cause precipitation of hydroxides of heavy metals and the breakdown of many soluble organic molecules. 

Equalization + Coagulation -Solids Separation + Neutralization Equalization + Coagulation -Solids Separation + Neutralization Equalization -t-Coagulation -Solids Separation- -i-Neutralizadon... 

Worldwide use of activated silica sols, new modifications involving use of NajSiF, plus silicate, and new applications in sewage treatment have been summarized by Middleton (196). Large-scale use in coagulating solids from water in Chicago has been described by Vaughn (197). 

With suspension polymerization, reactor fouling is sometimes a problem. In such cases, it can be helpful to have a small gap between the outer baffle edge and the reactor wall. That may reduce accumulation of coagulated solids at the wall-baffle junction. 

Emulsion of Liquid Paraffin and Phenolphthalein, B.P.C. Contains 50 per cent of liquid paraffin, emulsifying agent, flavouring, and 0 34 per cent w v of phenolphthalein. The assay for liquid paraffin is the same as above except that the ethereal extracts are washed first with 15 ml 0-5N sodium hydroxide and then with 15 ml water. 1 to 2 mg of phenolphthalein may be absorbed in the coagulated solids. 

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