Advanced Treatment of Municipal Sewage
Decolorization and COD Reduction of Printing and Dyeing Wastewater
Removal of Heavy Metals from Electroplating Wastewater
Recycling of Papermaking / Mining Wastewater
Frequently Asked Questions
What is Compound Poly Aluminium Chloride (CPAC) and how does it differ from standard PAC?
CPAC is an enhanced coagulant formulated by combining standard Poly Aluminium Chloride (PAC) with additional components such as iron salts, activated carbon, diatomite, or polyacrylamide. Unlike single PAC, which is effective only within a pH range of 6–9, CPAC extends the applicable range to pH 4–11 and delivers improved performance in decolorization, heavy metal removal, and sludge reduction.
What types of wastewater is CPAC most suitable for treating?
CPAC is highly versatile and suitable for treating municipal sewage, printing and dyeing wastewater, electroplating wastewater, coal washing and mining wastewater, food processing wastewater, and papermaking black liquor. Its modular compounding design allows the formula to be adjusted based on specific water quality characteristics.
How effective is CPAC in removing heavy metals from industrial wastewater?
CPAC can be compounded with sulfides to complex heavy metals such as Cr⁶⁺ and Cu²⁺ found in electroplating wastewater, combined with iron salts to promote netting and precipitation. This synergistic approach achieves a significantly high heavy metal removal rate, making it suitable for industries with strict discharge standards.
Does CPAC produce less sludge compared to standard PAC?
Yes. The composite components in CPAC, such as diatomite, enhance the compactness of flocs formed during the coagulation process. As a result, sludge volume is reduced by approximately 20%–30% compared to single PAC treatment, which in turn lowers the cost and effort required for subsequent pressure filtration and sludge disposal.
What should be done before applying CPAC to a wastewater treatment system?
Prior to application, it is essential to conduct a comprehensive water quality test to determine the pH level, COD concentration, and heavy metal content of the wastewater. Based on these test results, the CPAC formula can be adjusted accordingly — for instance, increasing the iron salt proportion for acidic wastewater — to ensure optimal treatment performance.
What are the storage requirements for CPAC products?
Liquid CPAC should be stored in sealed containers in a cool environment with a temperature not exceeding 30°C, and has a shelf life of 12 months. Solid CPAC should be stored in a dry location with relative humidity not exceeding 60% to prevent moisture absorption and caking, which could affect product performance.
BS Water
