Long-term reverse osmosis tests were conducted with electroplating wastes on a new membrane referred to as NS-100. This membrane consists of a polyurea layer, formed by the reaction of tolylene diisocyanate with polyethylenimine, deposited on a porous polysulfone support film. The membranes were tested as liners within 0.5411. diameter fiber glass tubes. A total of 2360 hr of continuous reverse...

The total reconstitution of copper-zinc superoxide dismutase by stoichiometric addition of the metals to completely metal-free apoprotein is described. Reconstitution has been monitored by electron paramagnetic resonance (EPR) and absorption spectroscopy, enzymic activity, and acrylamide gel el%ctrophoresis. Under the same conditions, it has been possible to prepare highly active enzymes with c...

BACKGROUND A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(II)SO(4 )so...

Cyanide heap leaching is the predominant technology used in processing low-grade gold ores. During closure of a heap leach operation, residual cyanide must be removed from the process and waste solutions, as well as the heap. Biological cyanide oxidation is a proven, economical technology for destroying cyanide in process and waste waters and spent heaps. The use of biological cyanide degradati...

water resource scarcity, population growth, pollution of surface and groundwater by discharging toxic wastewater and subsequent diseases may raise the necessity of reusing and treatment of wastewater. cyanide is one of the toxic materials which can be found in some industrial wastewaters. strict laws set by international bodies have forced industries to work on developing efficient cyanide remo...

Phytoremediation counts as a major method for future which essentially needs resistance to contaminating agents. We pretreated the plants (Salix babylonica, as a model plant in phytoremediation of polluted waters) by sodium cyanide (0, 3 and 5 mg CN- L-1) to induce resistance with regard to acclimation and then examined their resistance to higher concentrations of cyanide. Accordingly, some of ...

samples of the waste rock obtained from marofengin south africa ground 60, 70 and 80% passing 75µm were leached with cyanide in bottle roll tests. the results obtained showed that the percentage gold dissolution depends more on the ore size consists than on the cyanide concentration with the highest average dissolution rates of 88.75, 94.34 and 95.90% found at 600, 500 and 500 ppm, for 60, 70 a...