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AGFA and the EnvironmentGary Barber
A G F A Gevaert Pty Ltd
PO Box 164 BELMONT
WA 6104 AUSTRALIA.
Care for the environment is one of the greatest concerns of our modern society. Government, industrial companies and private citizens are daily confronted with the many aspects of this complex problem.
They have to ensure that the load on the environment is minimised at the source, and that their products or packaging can either be recycled after use or be destroyed without any further burden on the environment.
During this presentation I will attempt to address issues directly affecting NDT in terms of film and chemistry technologies and these will include;
Broadly speaking, legislation relating to environmental pollution can be divided into three areas;
With NDT film processing, we can more or less exclude air pollution and ground pollution by solids and concern ourselves only with water pollution. Depending on the outlets into which the wastewater is drained, we encounter various regulations. Generally speaking the regulations for urban sewers are usually less stringent than those for surface or ground water. Urban sewers often depend on the type and capacity of the municipal treatment plant, if you have the luxury of working in this type of civilised environment compared to that of a pipeline in remote circumstances or even offshore.
It is important to note that whilst we should be aware of responsible waste disposal, NDT is regarded as only a very small polluter in the overall scheme of things. But this is no reason to be complacent when PHYSICAL POLLUTION FACTORS are present in our everyday work activities. In addition to the colour, smell and lack of clarity of wastewater, the temperature is penalised in particular. However, the temperature of NDT waste water does not normally exceed 35oC, nor is abnormal hindrance to be expected from the smell or colour of the water.
MECHANICAL POLLUTION FACTORS are affected by various legislations which impose restrictions concerning the amount of solid components that may be suspended in waste water but NDT waste contains only a negligible amount of solids so we can almost completely disregard this factor.
The acidity of the discharged water however is an important parameter which may affect us. It is easy to check and although the pH VALUE of individual baths can deviate from the regulations (between 6 and 9), the pH value will almost always lie within the limits with a normal combined discharge from a processor as a result of mutual neutralisation of the various baths. I will elaborate on this aspect later in the presentation.
OILS, FATS and INFLAMMABLE products may not be present in wastewater but as it is in a diluted form and neither explosive or flammable where NDT is concerned we need not take any action.
However CHEMICAL POLLUTION FACTORS do come into play and the three important classes of pollutants should be distinguished between;
TOXIC COMPONENTS that are present in photographic processing include METALS, being various metal ions in fairly small concentrations, but because of the risk of disturbing the biological balance in biochemical treatment units, they may not be discharged in too high a concentration into sewers connected to a water treatment plant. Therefore when processing NDT film attention must be paid in particular to the recovery of silver.
As Ag+-ion, it is toxic for most micro organisms and fish. However, given that adequate precautions and sensible processing conditions prevail, the chance that silver will cause problems in the wastewater is small. The silver is present in the rinsing water is in the form of a thiosulphate complex. This chemical compound has considerably less toxic properties than the free silver ion.
In addition, silver ions form salts with chloride, bromide and, in particular, sulphide ions which are very difficult to dissolve. The silver ions present are then rapidly deposited as almost insoluble salts. Because various legislations do not take these facts into account, it is advisable to remove the silver before discharge and we will discuss this later.
The discharge of PHENOLS is subject to restrictions. Hydroquinone which is generally used as a black and white developer is actually a phenol derivative. It is quickly degraded in an adapted biological treatment plant. With direct discharge into a watercourse, the concentration of this developing agent should be kept sufficiently low.
AMMONIACAL NITROGEN - for rapid fixing, large quantities of ammonium ions are used. The chance of free ammonia being formed is small. This can only occur in an alkaline environment, which is not attained in the wastewater. In a biological treatment plant, these ions will be partly degraded.
To obtain a highly concentrated processing solution ORGANIC SOLVENTS are sometimes used. Chlorinated hydrocarbons are not used. In ready to use baths and in the waste water the dilution is so great that only traces of solvents are still present and are rapidly degraded in a treatment plant.
You will note that much emphasis and mention has been made of treatment plants and whilst many NDT organisations have direct connection, if you are not connected to a sewer but discharge directly into a surface water course, including septics, it is more than likely that your legislator will require treatment and actions within your organisation, in accordance with the strict regulations for discharge to avoid or at least minimise pollution.
The most direct way of ensuring that water pollution is no longer a problem is to use non-polluting chemicals. Every photographic industry regards it as its duty to carry out a great deal of research into this problem. The first object of this is to find replacement solutions which avoid the use of products that cause serious pollution. As long as the processing of silver halide materials with liquid chemicals continues to exist, the use of reducing baths will have to be taken into account.
Other means will have to be used to counteract the pollution caused by these ingredients or to keep it within reasonable limits. The most obvious are;
The most polluting effect of a particular chemical product is in proportion to the concentration in which it is present in the water. The official limits are expressed in the form of maximum permissible concentrations. The problem of process control can also be regarded as the searching for ways of staying below the permissible or problematic concentration.
The solution for keeping the concentration of pollutants low by diluting with extra amounts of water is an obvious one. However, the increasing scarcity of pure water is one of the main problems in the present struggle for better environmental protection. With this solution, the remedy is probably worse than the problem. It should be clearly stressed that with the extra addition of diluting water, the absolute quantity of contaminating substances which is discharged is NOT reduced. What can be achieved as a result is that the discharge satisfies the regulations. It means however that a larger volume has to be treated by the central purification plant. Extra dilution is usually forbidden by law.
Until now, the chemical balance is maintained in traditional processing sequences by replenishment. This means that in every processing solution, part of the liquid is regularly replaced by a replenisher liquid. The concentration of chemicals is thus restored and the waste products and the ingredients introduced by the film are kept at an acceptable level. Water pollution can be prevented with the exact addition of the prescribed replenishment quantities. Over replenishment leads to greater environmental pollution. In the long term we at AGFA are striving towards systems for which minimum quantities of chemicals are sufficient.
Selected discharge depending on local circumstances, it is sometimes preferable to collect the overflow of certain processsing liquids and to have them collected and disposed of by suitably qualified and specialised companies. In fact, here in Australia there are a number of just such companies operating - not just in a disposal capacity but also in the field of silver recovery.
Silver Recovery and it is up to you decide on just how this is done in your establishment, is a necessary measure which every consumer of NDT film should take. Silver recovery is not only necessary for pollution reasons, but the scarcity of silver makes it irresponsible to allow this valuable metal to be lost. In addition, the relatively high cost of silver ;means that recuperation can be an economically profitable process. So, where to from here? Environmental policy varies greatly from country to country and region to region, and furthermore is sometimes very unclear. The present German directive (Anhang 53) relating to industrial radiography lays down the maximum amount of silver freight in the waste water of a processor to 50mg Ag/m2 of processed film for film consumption between 3000 and 30,00m2 per year. We (AGFA NDT) have taken this German directive of 50mg Ag/m2 as a target, since we expect that this directive has the greatest chance to become the future European legislation.
In order to reduce the silver freight, the solution must be sought in a drastic reduction in the silver content of the fixer bath. Accordingly, we have developed an approach for complying with ecological legislation in a step-by-step process. One of the first steps was the introduction of Silver fix, which considerably reduces the concentration of silver in the fixer. We have however gone further with the recent launch of the STRUCTURIX NDT S eco, a film processor with cascade fixing, which when installed in the 5 minute cycle, forms the basis for the "Supreme eco Film System" in which film, chemistry and processor are all carefully matched and tailored to ensure the best ecological results in terms of;
It should be realised that the NDT S eco is a high capacity machine and experience in this region tells me that a small to medium capacity machine is more the order of the day. And, strangely enough, AGFA has recognised this as well. So for the majority of us, APCNDT is the first opportunity to view, in the flesh, the recently released STRUCTURIX NDT M eco. Its a smaller version of the NDT S eco and occupies a minimal amount of space in either a lab or mobile darkroom. It processes sheet film as well as roll film up to 5m in length. It lives up to expectations ecologically with;
A CASCADE fixing system is an entirely new concept for processing x-ray films. This new processor is built with two successive fixing tanks replenished on the counterflow principle. The result is nothing less than revolutionary in terms of the amount of silver in the wash water. The cascade fixing principle is basically very simple; the exposed film is first developed in the dev tank and then washed in the intermediate wash tank.
The film is then 100% fixed in the first fixer tank and rinsed in the second fixer tank. Since fixer replenishment is carried out in the 2nd fixer tank, the concentration in this tank remains very low. There is also very little carry over of silver into the water tank, so that the wastewater complies with the most stringent standards.
The "cascade fixing" system ensures that the amount of silver in the wash water is only 40 mg/m2, thus remaining well within the limit of <50mg/m2 previously discussed.
ASTM E94 states; " To produce a satisfactory radiograph, the care used in making the exposure must be followed by equal care in processing. The most careful radiographic techniques can be nullified by incorrect or improper darkroom procedures".
No, I haven't changed the subject! Mainly because incorrect or improper darkroom procedures can not only lead to sub optimal film results but can lead to contamination of chemicals with subsequent ecological consequences.
Therefore if you are not using, for instance, the AGFA designed set of practical, dedicated tools for the radiographer or darkroom assistant to control and to prove compliance of your sytem then chances are you may be doing both your organisation and the environment a grave disservice.
In case you are not aware these tools include;
Simple tools to assist in quality control and contribute to responsible ecological and environmental film processing activities.
AGFA views ecological concerns as a fundamental obligation to ensure optimal processing, and therefore subscribes to the principles of "RESPONSIBLE CARE", a worldwide commitment by the chemical industry with respect to the environment. When it comes to ecology, I hope that today's presentation gives you an insight into the commitment we are showing to this cause.
In recent years, the feeling of responsibility concerning environmental protection has increased considerably. The other side of industrialisation and increasing prosperity is becoming more and more obvious. The rapidly progressing pollution process can only be slowed down if everyone is personally aware of this evolution and, in particular, if governments, trade and industry work together more effectively.
Today's presentation is intended for users of NDT materials and contained information on the effect WE have on environmental pollution. Please take heed so that we all can, collectively and as individuals, calculate the nature and extent of the potential pollution we can produce, and how we can take the necessary measures to avoid contributing to further downgrading of our children's future environment.
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