Wastewater generated by the metal processing, electroplating, and electronics industries contains heavy metal ions such as nickel, chromium, copper, and zinc, which are strictly controlled pollutants. The most pressing question for corporate environmental managers is: "How can we effectively and economically remove heavy metals from wastewater?" This article will focus on chemical precipitation and solid-liquid separation technologies.
Chemical precipitation is the most commonly used method for heavy metal removal. Chemical precipitation involves the addition of reagents to convert heavy metal ions into water-insoluble precipitates. Efficient separation of these fine precipitates is crucial. Dissolved air flotation (DAF) systems offer superior performance compared to traditional sedimentation tanks in this regard. The microbubbles generated by DAF systems effectively bind to lightweight flocs with a specific gravity close to that of water, causing them to float, resulting in faster separation and better results. They are particularly suitable for removing hydroxide precipitates.
While inclined plate sedimentation tanks can also be used to settle heavy metal sludge, DAF systems are more adaptable when treating wastewater containing oil or complex complexes. Modular, integrated treatment equipment is an ideal choice for small and medium-sized workshops or production lines requiring quality separation and pretreatment. An integrated treatment equipment for heavy metal wastewater will integrate units such as pH adjustment, reaction, flocculation, dissolved air flotation separation and sludge concentration to achieve automated dosing and control, ensuring that the treated effluent can stably meet the Table III standards.
