The development of slow-release chemical oxidants for sub-surface remediation is a relatively new technology. Our objective was to develop slow-release persulfate-paraffin candles to treat BTEX-contaminated groundwater. Laboratory-scale candles were prepared by heating and mixing Na(2)S(2)O(8) with paraffin in a 2.25 to 1 ratio (w/w), and then pouring the heated mixture into circular molds that...

BACKGROUND Hairdressers are at risk for occupational respiratory diseases, but the risk factors, causal agents, and underlying mechanisms are not completely defined. AIM To describe the features of a large group of hairdressers consecutively referred to our center for suspected occupational asthma (OA) over an 8-year period, the type of occupational respiratory diseases, the etiologic agents,...

Remediation of hydrocarbon contaminated soils can be performed both in situ and ex situ using chemical oxidants such as sodium persulfate. Standard methods for quantifying persulfate require either centrifugation or prolonged settling times. An optimized soil extraction procedure was developed for persulfate involving simple water extraction using a modified disposable syringe. This allows cons...

The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 7...

OBJECTIVE Hairdressers have an increased risk for airway symptoms especially when using hair-bleaching powder containing persulfate. To minimize exposure, dust-free bleaching powder (DFP) has been made available. We studied the effects of regular powder (RP) or DFP on the airway symptoms of hairdressers with hair-bleaching associated rhinitis. METHODS Twelve hairdressers each performed three ...

The chloric acid method is most commonly used to obtain accurate and reproducible measurements of iodine and remove interfering substances. Unfortunately chloric acid is a potential hazard, requiring an explosion-proof hood, among other precautions. We have developed a simple, convenient, and economic method for measuring urinary iodine by using 1 mol/L ammonium persulfate, a nonexplosive, nonh...

Simple and reliable procedures have been developed for analyses of N03 , total N, and organic N in fresh waters. N03is determined by second-derivative UV spectroscopy. Total N and organic N are determined based on secondderivative analyses of N03following persulfate digestion. Resolution of organic N determinations was increased by using ion-exchange resins to remove N03from samples with high c...