SOLVIA IoniX is a line of electrochemical technologies for streams that a scheme of settling, biology and filtration does not fully handle: the concentrate of membrane systems, effluent carrying odour and colour, the hard-to-oxidise organics left after the biological stage.
SOLVIA IoniX brings together electrochemical units meant for streams that yield poorly both to mechanical and to biological treatment: a high salt load, hard-to-oxidise organics, colour, sulphides and odour, residual COD, ammonium nitrogen, the concentrates left by membrane treatment. Such treatment acts on the pollutant neither by carrying it into sludge nor by biological breakdown, but through controlled oxidation-reduction processes — what changes is the chemical state of the substance.
The units work on their own or enter a common scheme: pre-treatment of a difficult effluent, polishing after the biological stage, treatment of reverse osmosis concentrate, oxidation of residual organics, abatement of odour, correction of the oxidation-reduction regime, electrochemical precipitation of particular pollutants, preparation of the water for the stages that follow. Replacing every other method with a single solution is not the intention here: electrochemistry is placed where it makes technological sense, and a working plant is modernised without being rebuilt.
Biological treatment copes with domestic sewage and with part of the organic load, but it has bounds. Beyond them lie hard-to-oxidise organics, colour, sulphides, elevated COD, wash water, industrial effluent of unsteady composition and compounds that resist biological breakdown. An unsteady composition stands apart in that list: standard solutions work on it with less predictability.
An electrochemical block in such a scheme does not replace the biological process but stands behind it as a polishing stage, strengthening the result where biology has reached its practical limit. After the biological stage there remain odour, residual colour, hard-to-oxidise organic compounds, sulphides, elevated COD, micropollutants and unsteady figures at the outlet — that remainder is what gets treated. The treatment tells above all on industrial and mixed effluent.
The treatment is carried by separate functional loops so that different processes do not run in one zone. The anodic loop is directed at oxidation: hard-to-oxidise organics, colour, odour, sulphides and particular micropollutants, and with them the oxidising potential of the medium is raised. The cathodic loop works with reduction reactions — a shift of pH and redox potential, conditions for the precipitation of particular components, preparation of the stream for the stages that follow.
Odour at treatment works, at sewage pumping stations and in holding tanks comes from reducing conditions and the formation of hydrogen sulphide. Oxidising the sulphides and shifting the oxidation-reduction regime change not the perception of the odour but the conditions in which it forms, and electrochemistry is therefore considered here alongside aeration, nitrate stabilisation, sorption and pH control rather than as a measure of its own.
The trouble of a working plant is often concentrated in a single stream or unit: reverse osmosis concentrate, water from a backwash, a stream carrying odour or heightened colour, residual COD after biology, a local industrial discharge, a side stream of high salinity. Replacing the plant outright does not match such a case, while rebuilding aeration tanks, clarifiers and reservoirs can be too costly or too difficult technically.
The electrochemical loops are assembled into an external module tied into the existing system on a side stream. The module takes part of the flow, treats it and returns it to the system or sends it on to the next stage of treatment. The main vessels are left as they are, and the retrofit reaches the stream that calls for it rather than the whole plant. A site where the treatment works are built and running while one stream stays troublesome is the principal case for such a connection.
Reverse osmosis cleans the water but produces a concentrate in which salts, organic substances and other pollutants accumulate. Such a stream is hard to discharge: raised salinity and conductivity, accumulated poorly degradable substances, the need for separate treatment or for dilution, costly disposal. The pollutants in it are gathered at high concentration, and that changes the conditions of treatment against those of the feed water.
The set of stages is chosen by the composition of the concentrate: electrochemical oxidation of the organic load, anodic treatment, cathodic precipitation of particular components, sorption or filtration afterwards, blending with other streams once quality has been checked, integration into the membrane scheme. The same order — first make a difficult pollutant more controllable by concentrating it, then treat it in that controlled form — is considered for compounds that are hard to remove as well, and special anode materials and ion exchange stages may be applied to them.
The regime of treatment follows the water and not the type of the site: the composition of the effluent, salinity, conductivity, pH, the content of chlorides, sulphates and sulphides, COD and BOD, ammonium nitrogen, colour and toxicity to the biology, and also the possibility that by-products form. In operation pH, redox potential, conductivity, current, voltage, flow, temperature, pressure, level and the quality of the treated stream are watched; at large sites that watching is gathered into a control cabinet, remote monitoring or SCADA.
For a difficult effluent the order of verification is a pilot trial on the real water of the site. A pilot shows the abatement of odour, the change of COD and of colour, the behaviour of the sulphides, the shift of redox potential and pH, the energy use, the steadiness of the process, the quality of the water after treatment, the need for filtration afterwards and the scope for scaling up. A laboratory assumption about an industrial effluent or a concentrate is confirmed on the site itself.
SOLVIA IoniX brings together a number of SOLVIA's own engineering developments in the electrochemical treatment of wastewater, in the treatment of concentrates and in the retrofit of working treatment plants. The technological solutions of the platform are being developed within the developer's patent strategy; particular ones concern external retrofit modules, anodic and cathodic loops, and the treatment of difficult streams, of concentrates and of pollutants that are hard to remove. Design particulars, the parameters of the electrode materials, the treatment regimes and the control algorithms are not disclosed in open materials.
Tell us about your site — our engineer will prepare a process design, a specification and a quotation within one business day.