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Cyanide is extremely toxic to both human and aquatic life and exists as a contaminant in soils and groundwater at decommissioned gasworks sites due to past industrial practices. This included the processing and disposal of gas purification wastes which contained cyanide. The biodegradability of cyanide at gasworks sites in south‐eastern Australia is investigated to determine the viability of in situ bioremediation. Two study sites show cyanide concentrations in groundwater of up to 5,300mg/L CN (total) in the vicinty of these sites. Laboratory experiments using column microcosms indicate both aerobic and anaerobic biodegradation of cyanide in water. Rates of degradation are typically first order with degradation microbiologically driven and are not simple oxidation‐reduction reactions. The rate of degradation is variable, depending on the existence of microbes, concentration and temperature. Even though both sites have cyanide contamination, only one requires remediation. In situ bioremediation is possible at this site thus providing an acceptable outcome to both site owner and the environment.

This paper aims to study peroxymonosulfate (PMS) activation in the ultraviolet (UV)/ozone process for toxic cyanide degradation from aqueous solution by a novel and simple method.

Photocatalytic degradation of cyanide (CN^-) was carried out using a bench-scale photoreactor. Optimization of the UV/ozone process for the highest removal of cyanide was obtained. The effect of parameters such as ozone concentration, PMS concentration, temperature, cations (Cu²⁺, Co²⁺ and Fe²⁺), cyanide concentration, anions (bicarbonate, carbonate, chloride, nitrite, nitrate and sulfate [SO42−]) and scavengers (ethanol [EtOH], humic acid, TBA and NaN₃) was investigated for CN- degradation.

Complete removal of 50 mg/L cyanide was obtained in 4 min in an ozone/UV/PMS process. The cyanide removal increased from 49.3% to 100% by adding the persulfate dosage up to 100 mg/L. The effect of various cations (II) on the cyanide degradation was enhanced in the order Cu²⁺ > Co²⁺ > Fe²⁺. Hydroxyl radical based on different radical quenchers such as salicylic acid proved as the main oxidizing radical for oxidation. The application of ozone/UV/PMS to treat wastewater containing cyanide shows high degradation efficiency.

The ozone/UV/PMS system could be a process for degradation and detoxification of cyanide.

This study provided a simple and effective method for degradation of cyanide from aqueous solution. This method was applicable to protect environment from a huge amount of toxic cyanide wastewater produced by different industrial processes.

The PMS activation is done via a simple and effective method, which is carried out with the ozone/UV system. There are two main innovations. One is that the novel catalytic role of bimetallic ions in the ozone reaction with cyanide and the further decomposition of intermediate products is investigated. The other is that the optimized conditions were obtained for the removal of cyanide as a water contaminant. Furthermore, predominant oxidizing species by PMS activation are identified.

The choice of electrodeposited silver solely because of its corrosion resistance is infrequent since a thick deposit to overcome porosity is necessary. Nevertheless, its anti‐corrosive properties are important in the very many applications in which it is used where this is not the first consideration. This article discusses modern techniques in plating which result in quicker plating times for a given thickness and describes methods for the reduction of tarnish. Trends and developments are reviewed.

A highly selective cyanide phenoxazine-based fluorescence chemosensor POH was created to detect cyanide (CN) ions.

A malonitrile was added to a phenoxazine fluorophore to make this widely available chemosensor. By fluorescence spectroscopy, the sensor POH showed turn-off fluorescence emission for CN with 2:1 binding stoichiometry in CH₃CN/H₂O (90:10 v/v) medium.

The detection limits for CN were 9.8 × 10⁻⁹ M, which were much lower than WHO standards. NMR and FT-IR investigations backed up the suggested sensor POH mechanism.

The detection CN method should be applicable in a number of situations, where the CN anion for fresh water and drinking water has to be quickly and accurately analyzed.

Sour water condensates are aqueous condensates which contain different concentrations of aggressive compounds such as HCl, H2S, CO2, NH3, cyanides, etc. These condensates which can be fairly corrosive are encountered in a variety of refinery processes ranging from atmospheric distillation units to hydrodesulphurisers and sour water strippers. This paper deals with the mechanism of corrosion by these condensates and the factors influencing corrosion in several typical refinery units. In addition, methods for corrosion prevention and control are also discussed.

Efforts to avoid low‐temperature hydrogen attack at a new fluid catalytic cracking unit of the Richfield Oil Corporation, Wilmington, Calif., have been successful as a result of corrosion prevention in the design stage and corrosion control during operation. When the unit was shut down recently after more than a year of successful and continuous operation it was found to be in excellent condition. The following is the first half of a paper presented before the American Petroleum Institute's Refining Division last year and before the National Institute of Corrosion Engineers' Annual Meeting this year. The authors describe the different forms of hydrogen damage and the prevention steps that were taken. Preliminary evaluation by hydrogen probes, painted‐can tests and chemical analyses were employed to detect any hydrogen penetration taking place before the routine shut‐down enabled

AN AIR‐COMPRESSOR FOR STARTING The difficulties and uncertainties encountered in starting the average aero‐engine by direct cranking are too well‐known to need elaboration. The trend towards high powers and the inaccessibility of some engines adds to these difficulties. Starting by means of compressed carburetted air is a great advance over the earlier method, and the use of a motor‐driven air compressor (ground equipment) makes engine starting the certainty it should be. This essential ground equipment is not always available in the case of forced landings, and, in any case, it is advisable to have the aircraft so equipped that it is independent of outside aid, provided this can be done for a reasonable addition of weight.

Possibly the largest user of industrial gold plating is the electronics industry, which demands plating of the highest quality and reliability. In order to ensure these vital requirements considerable research and development work has been undertaken in the past and is still in progress. In this article the author surveys some of the latest techniques resulting from these investigations.

Early this year (CORROSION TECHNOLOGY, March issue) we published the first part of a paper presented before the American Petroleum Institute's Refining Division and also the National Institute of Corrosion Engineers, describing the different forms of hydrogen damage and the prevention steps that were taken at the new fluid catalytic cracking unit of the Richfield Oil Corporation. At that time we announced that we hoped to publish more of this interesting paper, brought up to date. This, then, completes the work of Messrs. Neumaier and Schillmoller and describes protective steps that have been taken at the fluid unit gas plant, the evaluation of these steps, monitoring and the use of organic inhibitors.