On1 May, a national standard for water treatment reagent came into force. Yuri Rulev Head of the Aluminium Chemistry Sector at the Aluminium Association, and Olga Bogomazova, Vodokanal Reagents Director General, will tell us about the development of the new regulatory document, specifics of the water treatment process, the new industry standard and its impact on aluminium consumption, as well as benefits from the new standard for water and wastewater treatment plants.
IDEA AND STANDARD
The importance of the drinking water quality is obvious to everyone. After all, the liquid flowing from the tap in the kitchen, as once said Mikhail Zhvanetsky, "is for the most important, internal use."
The adopted standard gained particular importance because for the first time it unified the requirements for the production of aluminium polyoxychloride from various raw materials in one document: waste, secondary aluminium and low-quality (especially imported) raw materials are no longer acceptable for tap water treatment. In addition, according to Rosstandart, the document provides for the ongoing and expanded incoming control of quality of the aluminium polyoxychloride coagulants, which can reliably prevent the ingress of impurities into the treated tap water.
The Aluminium Association initiated the development of the standard. “Our Aluminium 099 Technical Committee contacted the chairman of the Water Quality 343 Technical Committee, who welcomed the idea,” says Yuri Rulev, Head of the Aluminium Chemistry Sector. “We developed the standard on the basis of our market analysis and foreign standards.” The product manufactured by Vodokanal Reagents – a member of the Association from Yekaterinburg – became the benchmark for the quality requirements of aluminium polyoxychloride set out by the new GOST (industry standard).
WATER TREATMENT LESSONS
Olga Bogomazova, General Director of Vodokanal Reagents, explains that the companies used to work using their own technical specifications. They developed the TSs and applied for their registration in Rosstandart. Therefore, now we have many technologies for manufacturing oxychloride, namely using hydrate, pure aluminium or secondary raw materials. In the latter case, used engines and oiled chips can be also involved in the process...
But why is it bad to use reagents from recycled materials for water treatment? Olga Bogomazova states three main negative factors: the risk of re-pollution, high energy and labour costs, lack of material homogeneity and the presence of harmful impurities in the coagulant.
The new standard prevents the use of low-quality secondary materials
The mass fraction of the 13th element in the low-quality secondary material is not as high as in pure aluminium, which results in the increased content of harmful substances that can pollute the water again. According to Olga Bogomazova, when buying a product from recycled materials, the customer eventually buys up to 20-25% of the sediment. It'll cost more in the end.
In addition, the use of coagulants from recycled materials in wastewater plants causes frequent filter contamination. In case of using reagents with pure aluminium, the filter should be washed once every 4-5 months, while with recyclables, it must be washed up to several times a week. And the filtered water may contain harmful impurities in the amounts exceeding the permissible values. That’s how re-contamination occurs: the dirt in the coagulant can remain on the filters and get into the water.
And let's bear in mind that breakdowns and failure of expensive pumps and membrane filters often occur because of such harmful impurities.
To prevent sedimentation during the barbotage (in French, barbotage is mixing – loading products into a container for storing coagulants with a constant air supply), the solution must be continuously stirred, and this is a very energy- and labour-intensive process.
If past experience is any guide, the producer of coagulant from recycled materials is extremely rarely able to work with one trusted counterparty - the suppliers are different and their raw materials have different quality. “Today it is an 18-percent product, tomorrow it is 16-percent one...” says Olga Bogomazova. “The employees constantly have to measure the dosage, which also increases labour costs.”
RUSSIAN CONTRIBUTION
Compared with sulphate that was used in Soviet times, aluminium polyoxychloride is a relatively new reagent. It was developed in Japan in the early 90s, and came to Russia in the late 90s – early 2000s. Nowadays it is becoming more and more popular. Thanks to its undeniable advantages, polyoxychloride outperformed aluminium sulphate: it has better performance (especially at low temperatures), longer shelf life, less aggressive properties and better solubility.
There has been a long overdue need to develop a regulatory document. Moreover, other countries – for instance, the European Union, Malaysia, and China – already have polyoxychloride standards. Russian developers mainly applied the experience of their European colleagues and their on the EN8-83 standard adopted by the EU. But Russia did not just borrow foreign ideas, our experts introduced many innovations into it.
“The key difference between our standard and the European one is that we set out the quality requirements for both liquid and dry products. Thus, we covered all possible products. And at the same time, the new standard expressly states that the use of recycled materials is unacceptable,” explains Yuri Rulev.
CUI BONO?
According to Yuri Rulev and his colleagues from TC 343, if before the adoption of the standard, only those who produced polyoxychloride from low-quality cheap materials were able to gain profits, now the final customers – the water and wastewater treatment plants will have the best it.
We can already say that the introduction of a new GOST will have a positive impact on the cost of water treatment. After all, the better the reagent, the less amount of it is required. Therefore, companies planning to purchase polyoxychloride under the new GOST will be able to save some money.
Aluminium polyoxychloride manufactured from primary metal shows good performance at low temperatures.
Of course, there are those who consider the new standard to be a threat to their position in the market. These companies manufacture oxychloride from recycled materials. In response to their claims, the Aluminium Association and the Russian Water Supply and Sanitation Association mention that the application of this standard is not mandatory. However, it was introduced in the best interests of the main customers – the water treatment plants, and the market will have to adapt to their interests.
WHAT'S NEXT?
According to the Head of the Aluminium Chemistry Sector, the main objective now is to inform customers about the new GOST. He counts on the assistance of the Russian Association of Water Supply and Sanitation with their various promotion events, including the famous All-Russian Water Congress.
The adopted standard will be expanding the scope of its application. It is expected to become the basis for an interstate standard, and the new ISO is currently being developed.
There is also a possibility, though remote, of developing a technical regulation for water treatment. Such document will provide a comprehensive assessment of the water treatment efficiency for a long period. According to Yuri Rulev, this technical regulation will accelerate the transition from obsolete sulphate to aluminium polyoxychloride and allow customers to save money by applying the best available technologies.
PLUS 50 PERCENT
As for the possible increase of aluminium consumption following the adoption of the new standard, there is only preliminary data so far. It is clear that in the beginning the level of transition to aluminium oxychloride will be low.
Olga Bogomazova estimates the capacity of the coagulation market (including all the reagents for water treatment – sulphate, aluminium oxychloride, and ferric chloride) at 350 thousand tons per year. Of these, about 65 thousand tons account for oxychloride. Around 2 thousand tons of primary aluminium per year are now used for the production of aluminium polyoxychloride – both dry and liquid. The new GOST may increase this volume up to 3-4 thousand tons. Therefore, the demand for aluminium in this segment will grow by 50%.