Khemia Equipamentos Tecnológicos de Efluentes Ltda.
Company bets on the market’s slow technological advance and
develops recovery device for silver used in photographic processes

Evanildo da Silveira

The technician in industrial design Jonny Francisco Ros de Almeida decided to go against the stream. In 2003 he founded Khemia Equipamentos Tecnológicos de Efluentes (Khemia Technological Equipment for Effluents) in order to develop a recovery device of silver from developed films and X-ray prints – whereas common sense says that photo technology has left films behind and migrated to the digital world. That’s what makes someone such as Cláudio Gomma, for instance, question quite frankly the viability of Khemia, which his own company competes with. In the industry since 1972, Gomma owns Reciclage Plásticos e Metais (Reciclage Plastics and Metals – the name is a reference to reciclagem, "recycling" in Portuguese), which manufactures equipment to recover silver and other by-products of film development. “The silver recovery market is withering away at the same rate in which the digital image market is growing,” he assures. “Kodak, for example, has sold its film manufacturing sector do it would dedicate itself exclusively to the digital area.”

Khemia’s owner says he’s aware of that trend. But for the time being he is not afraid of it. In his opinion, before the end of the decade there won’t be in Brazil enough capital to modernize its area of image production and development of photo-sensitive material. “For ten years I’ve been hearing that the film system would disappear; however, when it comes to safety, such as with microfilming, nothing can replace films,” he claims. “That means that there will be many years still before digitalization takes over the entire sector,” he argues.

What motivated Almeida to found Khemia was his activity at Rec Rent Serviços (Rec Rent Services), a company he opened in 1997 whose business was fixing X-ray equipment. Because of it he began to visit hospitals and radiology clinics and learned of the silver recovery business. He also realized that the discharge of the development’s by-products was – and continues to be – a problem for those who work with X-rays. “They couldn’t find equipment to treat their effluents according to what the environmental legislation determines,” he remembers. Reciclage’s Gomma disagrees with him in this topic as well. “Besides our equipment, there can be found in the market a lot of high quality equipment,” he says. “Since the invention of the photo-sensitive film using silver grains, nearly 100 years ago, the recovery of the residues of this metal has existed as well.”

Almeida, however, has reasons to believe that there’s room for Khemia to prosper in the Brazilian market. His arguments convinced the examiners of the Programa Inovação Tecnológica em Pequenas Empresas (Technological Innovation in Small Businesses Program, PIPE), the program that supports innovation in small businesses of the Fundação de Amparo à Pesquisa do Estado de São Paulo (State of São Paulo Research Foundation, Fapesp), to finance the research for improving its silver recovery device. He assures that the device – an automatic electrolytic extractor of heavy metals in effluents, its technical name – is capable of recovering 100% of the silver in the residues of developing solutions, which the other equipment available can’t do. “There are similar devices in the market, but they’re not as efficient as our extractor,” he points out. He believes that it was that differential that ensured PIPE’s loans. Khemia is still headquartered at the Centro Incubador de Empresas Tecnológicas da Universidade de São Paulo (University of São Paulo’s Incubating Center for Technology Companies, Cietec-USP); but it has already hired a specialized bureau to request a patent for the invention.

Silver in development

To understand how the electrolytic extractor operates it’s necessary to know a few things about the development process of black & white films. Photo-sensitive films, such as photographic, X-ray and printing films, are coated with a fine layer of silver grains that are sensitive to light. To “take a picture” means to expose the layer of silver grains to light. But since different objects reflect light differently, the silver grains are submitted to different degrees of exposition – some are more exposed, some are less. It may happen that areas of the layer of silver grains are not sensitized – in that case they turn out dark or black in the photographs.

Once the film is exposed to light the image is imprinted in it, but is still not visible. In order for the image to be seen the film must be “developed.” The most common developers are methol, hydroquinone and phenidone. At a certain point, the developing process must be interrupted or the quality of the image will be affected. In order to do that a compound of acetic acid diluted in water is used.

The disposal of part of the silver from the film takes place on the next phase, fixing – the last chemical bath, which acts in the dark areas and removes from the film the metal that remains sensitive to light. This bath is necessary because the developer makes the image visible only in the areas that have been already sensitized. All the silver grains that were not affected by light continue in the emulsion and maintain their photo-sensitive qualities – in other words, if they are exposed to light, as they almost certainly will, they may be altered. Sodium thiosulfate is the most used fixer, which has basically two functions: to remove the grains that have not been exposed to light and to stabilize the developed image.

In this process the fixer reduces the non-sensitized metal grains to a suspension of atoms, which is eliminated with washing – the last step of the film development process –, in which water is used. The solution made up of the water and the fixer contains the non-sensitized silver left from the image formation process. In the case of the development of X-ray films, for instance, the liquid may have up to 4 grams (.14 oz) of silver per liter. In the case of photographic films, each roll releases an average of .65 grams (.023 oz) of silver. This material is discharged and may have two destinations: the sewage or a process to recover the silver.

Recover to throw away or to reuse

Throwing away the liquids used for the development of films is the least used alternative: silver is a high polluting heavy metal and its release in the environment is prohibited by norms of Brazil’s National Sanitary Surveillance Agency (Agência Nacional de Vigilância Sanitária, Anvisa) and National Council for the Environment (Conselho Nacional do Meio Ambiente, Conama). The regulations determine that developing liquids used in radiology must go through a neutralization process (carried out by qualified professionals) to reach a pH between 7 and 9 — the pH index measures the acidity of chemicals. It’s only after that that they may be discharged into the local sewage. Fixers, in turn, must go through a process of recovery of the silver, as well as other heavy metals that may be present. Even if the user decides to discharge the liquids in the sewage the silver must be removed. That’s why recovery is the most used alternative.

Totally automated

Thus the market for Khemia’s electrolytic extractor is created by the very regulations for discharging those liquids. And the company’s founder assures that its device is capable of recovering 100 percent of the silver found in the residues of developing solutions. It is fully automated, recognizes the presence of the chemicals in the fixers, and is permanently connected to the processing (or developing) machines. The solution containing the silver left from the developing process is taken to a small barrel inside the extractor. In the barrel the silver grains immersed in the solution are submitted to an electrical current; the electrical current gives the recovered metal the format of small scales. This phase of the process, of electrodeposition, recovers 97 percent of the silver.

The remaining 3 percent are recovered through a filter made of ionic resins. Made of polyester, these resins are developed specifically to retain certain products. In the case of Khemia’s extractor, silver ions. “None of the devices available in the market has two silver recovery systems coupled, one electrolytic, the other for ionic exchange,” says Almeida. "Our system’s innovation is the integration and also the use of microprocessors that monitor and control the process, transmitting in real time all the information to a control center.”

Besides recovering the silver, the electrolytic extractor Khemia has developed treats the effluents so that they can be discharged in the environment. This treatment includes neutralizing the residues – increasing the pH to 7, which means that the mixture is not acid nor alkaline. In addition, there’s the treatment of the water that come out from the processors. To prove that the device does everything Almeida claims it does, he is going to try to have it certified by Brazil’s National Institute of Metrology, Standardization and Industrial Quality (Instituto Nacional de Metrologia, Normalização e Qualidade Industrial, Inmetro).

A declining market

Khemia’s business plan does not include manufacturing the electrolytic extractor for sale. “Our idea is to operate in the services area,” explains Almeida. “We’re going to outsource the manufacture of the equipment and rent it to hospitals, printing plants and newspapers, for example. Instead of being paid with money we may have contracts for the silver recovered. Our machine has the capacity to recover one kilogram (2.2 lbs) of silver a month.”

Another expert in this market, radiologist physician Henrique Carrete Jr., of the Colégio Brasileiro de Radiologia e Diagnóstico por Imagem (Brazilian College of Radiology and Diagnostic through Image, CBR) – who also believes that soon there may not be any silver for Khemia to recover –, sees, however, a potential niche for the company. According to him, radiology clinics treat the residues themselves or have them treated in places with environmental licensing that are subjected to control by the official surveillance organs. “Small and mid-size clinics may prefer to send their residues to a specialized company,” he says.

The project submitted to PIPE

Khemia is a Greek word; the word alchemy is supposed to derive from it. Its meaning is associated to making useful something that would otherwise be useless. The larger market the company is part of – environmental sanitation– is new; and it's expanding, not declining. Before applying for PIPE’s financing, the company’s business plan had been approved by Cietec, the incubation center at the University of São Paulo’s campus where Khemia has been headquartered from the start. In the following year, 2004, Fapesp approved the research project “Desenvolvimento de Extratores Eletrolíticos Automáticos de Metais Pesados em Efluentes” (Development of Automatic Electrolytic Extractors of Heavy Metals in Effluents) in Phase I – that is, the money was given for the company to demonstrate the viability of its idea. Khemia received approximately US$ 75,000 in this phase; it bought reagents and equipment – including a silver foundry. Fourteen months later PIPE’s Phase II was approved; it began in August of 2006 and is scheduled to end in August of 2008. This time the project got some US$ 155,000.

The visitor to the company’s room at Cietec sees one of the three prototypes of the extractor that have already been built. It looks like a small beer keg 60 centimeters (23.6 in) by 40 centimeters (15.7 in) on a square platform 60 centimeters long and 12 centimeters (4.7 in) high. The other two prototypes are in experimental operation, one at a microfilming company and another in a hospital.

To get to the prototypes, and to convince Fapesp to finance the project, Khemia looked for know-how at the Instituto Nacional de Pesquisas Nucleares (Institute for Energy and Nuclear Research, Ipen), where Cietec is located. Since the beginning the project’s main researcher has been involved the retired chemist Alcídio Abraão, who, from 1957 to 1992, was a professor in the Department of Mineralogy of what was then called Instituto de Energia Atômica (Institute of Atomic Energy, IEA), today Ipen. In addition to him, Khemia has as a consultant another researcher, electric engineer Carlos Cugnasca, who is a professor at the University of São Paulo’s Polytechnical School (Escola Politécnica da USP), and two fellowship grantees, one of them an electronics technician and the other a foundry technician.

With this small staff the company is developing other projects besides the electrolytic extractor of silver. “Last year we participated in a project with Finep [Financiadora de Estudos e Projetos, Brazilian Innovation Agency/Research and Projects Financing] with equipment to recover chromium,” says Almeida. “We’re also working on the development of a bactericide made with nanoparticles of silver, and, with Ipen researchers, of an absorber to recover ammonia from hen houses and turn it into energy.”