Photographic Waste Research Articles

Characterization of a Bacterium (A-1) That Decomposes Ferric Chelate of EDTA in Photographic Processing Waste Solutions(PROSEEDINGS OF 24TH SYMPOSIUM ON TOXICOGY AND ENVIRONMENTAL HEALTH)

A Ferric-EDTA(Fe-EDTA)-degrading bacterium, strain A-1 was characterized by its physiological properties. The rate of degradation of Fe-EDTA was measured by the titration method and ion chromatography. The former method has the advantage of allowing a greater number of sample measurements of samples at one time. The rate of degradation of Fe-EDTA was higher in a stationary culture than in a shaked one. The optimum pH for the degradation rate was approximately 8.2. Strain A-1 grew in the presence of various kinds of metal-EDTA chelates, but a Na salt, Mg and Ca chelates of EDTA inhibited the growth. Their MICs (minimual inhibitory concentration) were 0.0045, 0.03 and 0.006%, respectively. These characteristics of strain A-1 have similarities to those of strain B-3, but were different from those of Agrobacterium sp. which were reported by Lauff previously (Appl. Environ. Microbiol., 56, 3346 (1990)). All of the detail taxonomic characters indicate that the isolate strain A-1 belongs to a Pseudomonas sp.

Hydrothermal oxidation of Navy excess hazardous materials

An oxidation system was designed to destroy Navy excess hazardous materials using hydrothermal (supercritical water) oxidation by air in the presence of high pressure, high temperature water. Stone & Webster was contracted by the Defense Advanced Research Projects Agency and the Office of Naval Research to design a very compact, automated shipboard unit. The hydrothermal oxidation system incorporates General Atomics' reversing flow reactor technology. The excess hazardous materials consist of contaminated fuels, hydraulic fluids, lubricants, coolants, paint and photographic wastes. The hydrothermal oxidation technology converts organic components to CO 2 and water and inorganics to mineral acids and oxides at high efficiency in a fully-enclosed processing environment of 870 K and 22.5 MPa.

Clean technology for treatment of photographic wastes and silver recovery

Photographic industry which is extensively used by the medical and film industries heavily depend on silver. The industry produce large quantities of wastewater containing high concentrations of silver compounds. Silver in all forms is regarded as toxic heavy metal and prohibited from discharging into public sewers. Also silver is an expensive commodity and recovery of silver from these wastewaters and recycling improves production cost. Thus makes the process an environmentally friendly operation. This paper gives an insight of an improved silver extraction process developed at the building department of Ngee Ann Polytechnic to effectively recover silver from photographic wastes and to treat the waste water to standards acceptable for disposal, by the Ministry of the Environment.

Eliminating screen printing photographic wastes

Eliminating screen printing photographic wastes

Eliminating screen printing photographic wastes

Eliminating screen printing photographic wastes

Electrocatalytic oxidation of thiosulfate on a modified nickel hexacyanoferrate film electrode

A modified nickel hexacyanoferrate film glassy carbon electrode is prepared by the electrochemical deposition technique. The film is very stable upon voltammetric scanning in the potential range of 1.0 to −0.5 V (vs. SCE) and an oxidation peak occurs at 0.35 V (vs. SCE) (1 mol/l NaNO3). The effects of electrolyte, solvent, coexisting ions and other variables on the voltammetric behaviour of the modified film have been studied. The thickness of the resulting film can be controlled by changing the number of voltammetric cycles and the concentrations of nickel(II) and hexacyanoferrate(III) ions. The film shows catalytic activity towards electrooxidation of thiosulfate with a peak potential +0.5 V (K−-containing media). This oxidation potential of thiosulfate on the modified electrode is shifted negatively by about 550 mV as compared to the naked glassy carbon electrode. For practical application, the modified electrode can be used for the determination of thiosulfate in concentrations from 5.0×10−5 to 1.0×10−1 mol/l. This method has been successfully applied to the determination of thiosulfate in photographic waste effluents.

Separation of silver from waste waters by ion-exchange resins and concentration by microbial cells

Waste waters of film processing plants are rich with silver. Part of the silver is regenerated electrochemically, but the rest (0.5 g) remains in waste waters and is sent to sewers. This is a bad politic from both the environmental (toxic waste waters) and the economical point of view (a waste of silver). In this work, the silver was isolated by ion-exchange resins and then concentrated by microorganisms. For exchange of silver, Ionenaustauscher I, II and IV were used. The batch method was used to obtain a static equilibrium. Silver elution from exchangers is based on silver transformation to a stable cation or anion complex. By varying the ligands, pH and eluent concentrations, optimum elution is found at 1 mol/l Na2S2O3, 1 mol/l NH3, 2 mol/l HNO3 and 1 mol/l (NH2)2CO. The concentration of silver in the eluent is about 50 mg/l. The silver ion uptake from solutions after ion exchange by mixed bacterial culture isolated from photographic waste water drain and pure bacterial cultures Escherichia coli 3009 and Bacillus subtilis 3053. was studied. Experiments were carried out in submerse culture at pH 7 with different Ag+ concentrations (4, 8 and 40 mg/l) on a rotary shaker (100 rpm) at 37°C. At the lower Ag+ concentrations a good growth and simultaneous removal of Ag+ from the solutions was achieved. At Ag+ concentration of 40 mg/l growth and removal of Ag+ by mixed and pure culture differed significantly. Thus mixed bacterial culture grew well and at the same time removed efficiently Ag+ (approximately 90%) from medium. Pure bacterial cultures on the contrary were unable to grow at 40 mg/l Ag+, though their biomass showed to be an effective biosorbent for Ag+ (approximately 80% of Ag+ removal).

DETERMINATION OF CYANIDE COMPOUNDS IN INDUSTRIAL WASTE SOLUTIONS

An analytical method has been developed for determination of cyanide compounds in photographic waste solutions and similar samples. Cyanide compounds in photographic waste solutions were determined accurately by decreasing the distillation temperature to 75 o C and the sample matrix concentration to 1% at the first step of the procedure. Less than 0.1ppm of cyanide compounds, calculated in terms of cyanide ion, was determined in a photographic waste solution by our method, yet 11ppm was determined by the official method of JIS-K0102

Recovering Silver from Photographic Process Wastes

Spent color bleach-fix solution (CBFS), a product of photographic processing operations, is a potential source of silver. Of the extraction reactors used in recovering this silver, the rotating cylindrical electrode (RCE) has an advantage in that it provides improved mass transfer with an extended effective surface area. In addition, the application of a potentiostatic technique allows the silver deposition reaction to take place preferentially, without the formation of silver sulfide. The process consists of prior physical treatment, subsequent chemical reduction of the ferric-EDTA (ethylene diamine tetra-acetic acid) complex present in the CBFS with sodium dithionite (monitored by measuring the redox potential of Fe3+/Fe2+ couple), followed by electrodeposition of silver in a divided cell using a cation exchange membrane. The combined procedure results in increased current efficiency and reduced electrolysis time.

A Photoassisted Process of Depositing Silver from Photographic Fixing Baths or Wastes onto Oxidized Titanium Sheets

AbstractA direct and simple method of silver photoassisted deposition onto thin layers of anodic titanium dioxide is presented. This process, which requires no external electrical bias, can be used for silver recovery from fixing baths or wastes. The main parameters affecting this deposition reaction are studied. In solar lighting, the maximum amount of recovered silver is 0.35 mg.cm-2, after four hours of illumination, which corresponds to an annual recovery yield of about 2.8 kg of silver per square meter of active material.

The Application of Reverse Osmosis to Recover Photographic Processing Wastes

The Application of Reverse Osmosis to Recover Photographic Processing Wastes

A Bleach System for Color Positive and Negative Film that Reduces Waste Treatment Requirements

Federal, state and municipal regulations on the disposal of industrial waste water have stimulated much photographic industry activity where chemical and mechanical methods must be devised to comply with the regulations. Several systems are in use for treating the major problems of photographic waste water. The bleach solution is one of the most troublesome materials to treat because of the presence of heavy metals or cyanides. The concentration of these substances must be reduced to a level of 0.1 ppm. Work is described that has been done to develop and test a bleach formula that contains no chromium, iron or cyanides. A copper halide bleach was found to be attractive because under current regulations permissible levels for copper are 15 times greater than for cyanide or hexavalent chromium. Either cupric bromide or cupric chloride could be used, and the latter was selected for testing because it has a cost advantage. A 21-g/I concentration was found to give bleaching times equivalent to SR27. The replenishing rate is 654 liters per million feet of 35mm Eastman color positive film (5381).

The Treatment of Photographic Waste Water by Ozone (II)

The Treatment of Photographic Waste Water by Ozone (II)

Treatment of Photographic Waste Water by Ozone (I)

Treatment of Photographic Waste Water by Ozone (I)