Brief Introduction to Guiyang Waste Water Treatment Plant Construction Project in Cities and Towns
Located at Xiangxincheng Village in the suburb of Guiyang County seat, Chenzhou City, this facility, daily capacity 60,000 cubic meters, serves the majority of the county seat, the county’s industrial park and the Xincheng plot, covering a population of 140,000. The carrousel oxidation ditch process is adopted in this project, as shown below:
The pretreatment structures like the coarse screens, booster pump chamber, fine screens and sedimentation tank remove the big-size floaters, part of the suspended matters and grains in the sewage water first; the feed water then enters the biological treatment section- the carrousel oxidation ditch, wher_e COD, NH3-N and total P are removed; the outlet water then enters the secondary sedimentation tank for sludge and water separation and clearing, after which the water goes to the disinfection tank for ClO2 disinfection treatment; and in the end, the water is discharged to the Guanxi River nearby. Most of the sludge at the bottom of the secondary sedimentation tank is returned to the oxidation ditch, while a small portion is pumped to the sludge storage tank, and removed and buried in fillings afterwards after dewatering via the belt filtering press.
The designed indexes of quality of water entering the plant are COD 300mg/l, BOD5 160 mg/l, SS 200 mg/l, NH3-N 30 mg/l and TP 3.5 mg/l；while the outlet water quality shall meet Grade-1 B standards of Discharge Criteria of Pollutants for Municipal Waste-water Treatment Plants, specifically: COD ≤60mg/l, BOD5≤20 mg/l, SS ≤20 mg/l, NH3-N ≤8 mg/l and TP ≤1.0 mg/l。Annually, the plant could reduce the discharge of COD by 6,000 tons；BOD by 1,533 tons；SS by 1,971 tons；TN by 110 tons and TP by 27 tons.
Hydrochina Zhongnan Engineering Corporation undertook this project on EPC basis,The Project was started in December, 2008,The Project was checked and accepted by the employer on December 15th, 2009. The Project was checked and accepted by the employer on December 18th, 2010. It was taken over by Guiyang City Construction Investment Company Limited on December 18th, 2011. The warranty period stated in the contract was from December 18th, 2009 to December 17th, 2011.