When metals are applied to surfaces, water is used as flushing medium, thus coming into contact with heavy metals such as copper, lead, tin, zinc, nickel, or chromium.
In the dissolved form, these heavy metals are harmful to the environment. They have to undergo a cleaning process prior to biological treatment. Copper, for example, is highly toxic to organic organisms, depending on the concentration. Heavy metals must therefore be re-converted into an unsoluble form and removed from the effluent. This process is known as heavy-metal precipitation.
For discharge of the effluent into the normal municipal sewage system, the pH must be adjusted to a required value – which requires neutralization of the wastewater.This can be carried out in batch treatment plants or in continuous-flow systems.
Precise pH adjustment is also vital for efficient heavy-metal precipitation. Our OKO-tech treatment plants measure the pH in the feed line and in the outlet and adjust it to the target value required. In the presence of complexing agents, hydroxidic precipitation will not be sufficient for reliably meeting the limits for heavy metals. We will use highly effective precipitants based on inorganic and organic sulfides in this case. For highly complexed heavy metals such as electroless nickel, we prefer to use our evaporators for effluent-free production, thus generating metal-containing concentrates for subsequent recycling.
We are happy to help by using our longstanding practical expertise for the complex processes within the electrical industry. We design and manufacture one-stop turnkey waste water treatment plants.