Introduction
Tianjin TEDA is an important national economy development area in Tianjin city, north China. The WWTP in TEDA was built in December 1999, whose designed scale is 100,000m3/d. MOTIMO cooperated with TEDA WWTP to build the recycled reclaimed water project, using CMF system From 2003. The inlet water of the system is the standard produced water of TEDA WWTP, and the CMF permeation goes into RO desalination system.

 Scope of Work
MOTIMO has undertaken and completed CMF system design, UF membrane manufacture, equipment installation and commissioning.

 General Information

• The project phase one (5,000 m³/day) completed by MOTIMO has been operated well since 2003.
• The project phase two (5,000 m³/day) completed by MOTIMO has been operated well since 2005.
• The project phase three (20,000 m³/day) completed by MOTIMO has been operated well since 2008.
• MOTIMO will start the project phase four (20,000 m³/day) in the near future.
• MOTIMO membrane has been replacing the original famous UF membrane step by step these years.
• The CMF permeate is treated by RO system directly and the final permeate is supplied for Toyota, BHE thermal power and other factories in TEDA.

 Membrane Information

MOTIMO UOF-4 membrane modules (material PVDF, effective membrane area 40m3, pore size 0.03μm) were used in the CMF system, which is composed of 14 skids MT-CMF-50, with 50 membrane modules each skid and totally 700 membrane modules. Each skid runs independently producing constant flow of water.
The average membrane flux is 53LMH (peak instantaneous flux is 65LMH), water quality meets the RO inlet water requirements.
  

 Process
Fourteen skids MT-CMF-50 with totally 700 membrane modules.
Control system consists of PLC, project control computer, on-site instrumentation, automatic valves, and remote monitoring computer with both manual and automatic functions.
Backwash System serves for MT-CMF-50 skids periodically.
Dosing system prepares for the chemicals during backwash or chemical cleaning.
Cleaning system can keep regular chemical cleaning for the CMF to ensure the excellent recovery rate of membrane flux.
Air supply system consists of air compressor and gas storage tank, supplying gas to membrane air scrubbing and pneumatic instrument.

CMF Layout

 
 

Table 1 CMF system permeate quality

No.	Item	Unit	Index
1	PH		6.9
2	Temperature	°C	12-25
3	COD	mg/L	43
4	BOD5	mg/L	<2
5	Turbidity	NTU	0.09
6	SS	mg/L	<1
7	TN	mg/L	<10
8	T-P	mg/L	<0.2
9	Coliform	pcs/L	None
10	Total bacteria	pcs/mL	0
11	Residual chlorine	mg/L	<1
12	Conductivity	ms/cm	3250
13	Dissolved solid	mg/L	2106

Table 2 CMF system operation parameters

No.	Item		Content
1	Operation flux per square meter		Max 65LMH Average 53LMH
2	Maximum inlet water pressure		0.2MPa
3	Maximum TMP		0.15MPa
4	Temperature		12~25°C
5	Water flow/circulation method		Cross flow
6	Maximum backwash water quantity		75LMH
7	Control method		Stable flow
8	Air consumption		5.0m3/h·module
9	Air wash pressure		≤0.05MPa
10	Backwash water consumption	water and air	0.5m3/h.·module
11		water only	2.5m3/h·module
12	Backwash water pressure		≤0.05MPa
13	Backwash time	water and air	40s
14		water only	50s
15	CEB period		24 h

Conclusion
Theimplementation of the project can achieve the water resource utilization, thus the discharge of wastewater can be greatly reduced and the surrounding environment is significantly improved. We can know from practical application of the project that MOTIMO’s CMF system has been advanced and it is a reliable technology, which plays an important role in making wastewater become resources. From the actual operation data, the technical and economic indicators have reached the design requirements, and achieved good economic and social benefits. In the course of the project operation, MOTIMO positively know the site’s work needs, and carried out the after-sales service seriously and responsibly.