Wastewater

McWong is closely involved in projects that are owned by Baosteel Group.The wastewater treatment plant is built to treat the wastewater produced from multiple steel making process lines. The wastewater produced from different process lines is first pretreated before entering into the main wastewater treatment plant. Once entering the main wastewater treatment plant, the system prepares the wastewater to meet the reuse water standards and the Shanghai discharge standard. Most of the treated wastewater from this system is currently being reused while the excess effluent water is discharged to the ShiDongKou sewage treatment plant. Reusing the wastewater at this system has been a great success for the Pugang Iron and Steel Co.

The design capacity of WWTP is 14000m³/d.

First, the influent wastewater flows through a screen and then into the main equalization basins. There is a submersible mixer in the equalization basins to prevent settlement of suspended solids. Second, a lift pump is used to pumps the wastewater into a Micro-Vortex Flocculation Reactor (MVFR). Coagulants and polymers are added at the influent pipe of MVFR, the effluent water from MVFR then flows via gravity into a V-shaped sand filter, and where the effluent from the sand filter flows into clean water tank and is ready for reuse or discharge.

The sludge at the bottom of the MVFR is pumped into sludge thickener. Backwash water from the sand filters flow back to the equalization basins for treatment; VFDs are used in the water reuse pumps to control the speed of the pump. When the water level in the clean water tank is at a high level, the discharge gate valve will open to discharge the excess water to the local sewer. The sludge processed from the sludge thickener is sent to a filter press for dewatering.

The entire wastewater treatment plant is controlled remotely using instrumentation and a central PLC control system.