Enhanced Implications on Turbidity Removal from Natural Stone Wastewater by Binary Mixtures

Area of Science:

• Water treatment
• Colloid and surface chemistry
• Environmental engineering

Background:

• Mineral fines' settling rate is influenced by their surface charge.
• High surface charges cause repulsion, hindering rapid settling.
• Low surface charges promote agglomeration and faster settling, reducing treatment chemical needs.

Purpose of the Study:

• To evaluate the effectiveness of coagulant and flocculant mixtures for turbidity removal.
• To compare the performance of binary mixtures against single-agent use.
• To investigate treatment efficacy in an acidic pH range (pH 2-6).

Main Methods:

• Turbidity removal tests were conducted using various valence coagulants and flocculants.
• Experiments focused on acidic pH conditions (pH 2-6).
• Performance of single coagulants/flocculants was compared with binary mixtures.

Main Results:

• Single FeCl3 (80 mg/L) at pH 4 achieved ≤98% turbidity removal.
• Single nonionic flocculant (0.50 mg/L) at pH 2 achieved ≥99% turbidity removal.
• FeSO4/nonionic flocculant mixtures at pH 4 yielded ≤98% removal; FeCl3/anionic flocculant mixtures at pH 2 yielded ≥99% removal.

Conclusions:

• Coagulant and flocculant mixtures can effectively remove turbidity, particularly in acidic conditions.
• Specific binary mixtures demonstrated high efficiency, comparable to or exceeding single-agent treatments.
• Optimizing coagulant/flocculant combinations and pH is crucial for efficient mineral fines removal.