Alkaline Waste Research Articles

Heavy metals in the sediments of Foundry Cove, Cold Spring, New York

The distribution of Cd and Ni in the sediments of Foundry Cove, a shallow embayment of the Hudson River, is determined as a function of distance from an industrial pointsource of Cd-Ni release. Concentrations of Cd and Ni decrease smoothly by 4 and 3 orders of magnitude, respectively, to the cove margin. High values in surface sediments decrease to preindustrial background levels of 2 ppm Cd and 30 ppm Ni at sediment depths of -20 cm. Budget calculations indicate that 20-50 tons of Cd and 10-30 tons of Ni are now present in the sediments of the cove. Cd is less mobile than Ni in the immediate vicinity of the industrial outfall due to the formation of a solid, mixed, calcium-cadmium carbonate phase from the alkaline waste discharge. Cesium-137 activity is useful in defining areas of sediment scour or recent dredging activities. Concentrations of Zn, Cu, and Pb are related to diffuse metal sources common to all recent Hudson sediments, and not to the local source of Cd and Ni. Preindustrial values of Pb, Cu, and Zn are found at approximately twice the depth for which background values of Cd and Ni are found.

Factors affecting pH change in alkaline waste water treatment—III: A dynamic simulation

A description is presented of a simulation model enabling the calculation on a digital computor of pH in an activated sludge reactor operating under dynamic conditions. The pH is considered to be a function of the relative quantities of carbon dioxide and hydroxyl ions in the mixed liquor, both free and combined as bicarbonate and carbonate. This function is calculated for the conditions of temperature and ionic strength prevailing in the experimental reactor used. The simulation program is based on the mass balances of carbon dioxide and hydroxyl ions. The separate factors influencing these mass balances were discussed in earlier work. A new element under dynamic conditions is the behaviour of sludge towards pH changes. Both the buffering capacity and the rate of buffering were measured and approximated by a mathematical description. Experimental results affirming the validity of the model for shock discharges of alkali are presented.

煙道ガスによる廃水処理および洗毛廃水の蒸発処理例

煙道ガスによる廃水処理および洗毛廃水の蒸発処理例

Factors affecting pH change in alkaline waste water treatment—I

The pH of wastewater in various stages of its purification depends mainly upon the equilibria of carbonic acid. Thus relations between pH and the concentrations of carbon dioxide, bicarbonate and carbonate can be formulated. Corrections for the non-ideal character of the sewage are necessary. With some restrictions the concept of alkalinity can be used for these pH relations. Several (bio)chemical and physical processes occurring in biological purification affect the concentrations of carbon dioxide and (bi)carbonate. Processes studied are carbon dioxide desorption, oxidation of organic matter and nitrification. Models are proposed for the calculation of the effluent pH and the values so obtained are compared with the available experimental results.

Resistance to corrosion of certain metallic materials in sulfurous and alkaline waste products of oil refineries

Resistance to corrosion of certain metallic materials in sulfurous and alkaline waste products of oil refineries

陰イオン交換樹脂膜を利用した含銅硝酸廃液よりの銅および硝酸の電解回収

In practical treatment of wast liquor in electroplating baths with conventional equipments, it was very often evident that chemical reactions did not proceed theoretically. The case was very frequent in the disposition of cyanides. It appears that the trouble comes from the inclusion of various kinds of metallic ions in the waste liquor, which prevent noxious substances from decompotition.The present study was carried out as follows: each kind of metallic ions was added to the waste liquor containing 10.0ppm of cyanides and chlorine was introduced into the liquor in alkaline state to determine residual cyanides content.As the results of the above experiment, it was found that Fe and Ni ions remarkably prevented chlorination of alkaline waste, while single inclusion of Zn, Cu Cd, or Cr ion gave no substantial effects.

Fission Product Recovery from Waste Solutions by Solvent Extraction

Increasing industrial, military, and space requirements for certain fission products places emphasis on new and large-scale methods for their recovery from reactor process waste liquors. With recent developments of new organic extractants for these fission products, solvent extraction offers a versatile alternate technology to ion-exchange, precipitation, and crystallization technologies heretofore used for small-scale recoveries.A process flowsheet has been developed for recovery of strontium and mixed rare earths from adjusted Purex 1WW using di(2-ethylhexyl)phosphoric acid (D2EHPA). After addition of tartrate to complex iron and caustic to adjust the pH to 6, strontium and rare earths are coextracted, then co-stripped with HNO3 in the first cycle. In additional D2EHPA extraction cycles, they are isolated as concentrated fractions. The mixed rare earths from this process can be treated by TBP extraction to separate the individual rare earth elements of which promethium and cerium are of greatest interest. Zirconium-niobium also may be recovered with D2EHPA from acidic waste liquors.An amine pretreatment extraction process has been developed which removes nitric acid, iron sulfate, zirconium-niobium, and ruthenium from waste solutions to furnish a feed liquor more amenable to subsequent fission product recovery processes. The separate recovery of ruthenium, zirconium-niobium, and rare earths may also be possible by amine extraction.A process has been developed for recovery of cesium from alkaline waste solutions using substituted phenols. These compounds are selective extractants for cesium, giving high decontamination from other fission products and sodium. They are readily stripped with dilute HNO3.Previous studies have also outlined methods for recovering neptunium, plutonium, and technetium with solvents similar to those described here. When appropriately combined, these developments offer a versatile integrated solvent extraction flowsheet for recovery of all important fission products and other components from waste liquors.

SED Research Report No. 12: Biological Oxidation of Alkaline Wastes

Biological action does occur at pH values of 9 to 11; less oxidation results at high pH values, but capital and operating costs involved with neutralization are eliminated; results include experime...