In industrial circulating cooling water systems, the concentrations of ions such as Ca2?, Mg2?, HCO??, Cl?, SO?2?, and SiO?2?, as well as harmful substances like suspended solids, bio-colloids, organics, and oils, increase continuously due to evaporation during system operation. This leads to issues such as ① scale formation and deposition, ② corrosion, and ③ proliferation of microorganisms (bacteria, fungi, and algae), resulting in slimes and blockages.

Typically, chemical methods are employed, relying on the addition of dispersants, corrosion inhibitors, and biocides to enhance the system's tolerance to concentration multiples (though this also significantly raises harmful substance levels). Additionally, bypass filtration devices are installed to remove suspended solids and reduce turbidity. Large-scale drainage and replenishment with fresh water are used to lower the concentrations of ions like Ca2?, Mg2?, HCO??, Cl?, SO?2?, and SiO?2?, ensuring that harmful substance levels remain within specified permissible limits (refer to the attachment《Industrial Circulating Cooling Water Treatment Design Specifications》GB/T50050-2007). Clearly, a reliable solution involves reducing the concentrations of scale-forming ions (Ca2?, Mg2?, HCO??, SiO?2?) and corrosive anions (Cl?, SO?2?), as well as lowering organic and microbial content, while significantly decreasing drainage and fresh water intake to meet national water conservation and water usage control requirements.

The M⁺FLO magnetic flocculation + chemical method water softening and turbidity removal system, an upgraded version of the European CP-CHE high-efficiency sedimentation + chemical method water softening and turbidity removal system, replaces the high-efficiency sedimentation CP with M+FLO magnetic flocculation, significantly improving treatment efficiency. It efficiently and deeply removes scale-forming ions (Ca2?, Mg2?, SiO?2?, HCO??) and harmful substances such as suspended solids, bio-colloids, insoluble organics, and oils. Only Cl?, SO?2?, and dissolved COD are not significantly removed and can be controlled within permissible limits through limited drainage and fresh water replenishment.

M+FLO Magnetic Flocculation Water Softening and Turbidity Removal System Process:

[Process description]

By-pass circulating water → M⁺FLO Magnetic Flocculation Hardness and Turbidity Removal Water Purification System → Return to circulating water system

Process Description: A typical M+FLO magnetic flocculation + chemical method high-efficiency water treatment system. Divert by-pass circulating water into the M+FLO magnetic flocculation hardness and turbidity removal water purification system, and add Ca (OH)?/NaOH, Na?CO?/CO? in the hardness reaction tank to adjust the pH value and generate calcium carbonate and magnesium hydroxide precipitates. Then, flow into the M+FLO magnetic flocculation system and add coagulant PFS/PAC, magnetic sand, and flocculant PAM for magnetic-enhanced flocculation reaction. Efficiently and deeply capture,  combine calcium carbonate and magnesium hydroxide precipitates and other suspended particles into large and dense magnetic flocs, which settle and clarify rapidly, achieving deep hardness and turbidity removal purification treatment of circulating water. The treated water is returned to the circulating water system. The magnetic sand floc sludge precipitated at the bottom of the tank is sent to the magnetic sludge separation system via the magnetic sludge return pump for magnetic sand recovery and reuse, while the sludge is discharged to the sludge dewatering unit.

Performance and Advantages of the M+FLO Magnetic Flocculation Hardness and Turbidity Removal Water Purification System: Efficient and deep hardness and turbidity removal, with outlet water hardness <50 mg/L, SiO? <5.0 mg/L, suspended solids (SS) <5.0 mg/L, oil content <3.0 mg/L, and turbidity <1.0 NTU. It can also effectively remove heavy metals, fluoride, etc. The cost per ton of water treatment is approximately 0.1-0.7 yuan (mainly related to the dosage of hardness removal agents). It can simultaneously remove hardness and turbidity (or stop adding hardness removal agents for turbidity removal only), significantly reducing the amount of circulating water discharge and makeup water. Compared with traditional sand filtration or fiber filtration and other traditional bypass filtration technologies (only for turbidity removal), it has unmatched high-turbidity influent treatment performance and higher treatment efficiency, with obvious advantages such as low investment, low operating costs, and simple operation and maintenance.

Typical Applications of the M⁺FLO Magnetic Flocculation Hardness and Turbidity Removal Water Purification System: Efficient and economical hardness and turbidity removal technology, suitable for removing Ca2?, Mg2?, HCO??, CO?2?, silicon, turbidity, and oil, etc. The outlet water turbidity can be below 1.0 NTU. Pre-treatment for industrial wastewater desalination reverse osmosis (RO)/direct tension reverse osmosis (DTRO) membranes, mainly targeting the removal of Ca2?, Mg2?, and silicon, etc. industrial circulating water bypass filtration equipment, simultaneously removing hardness and turbidity, significantly reducing the amount of circulating water discharge and makeup water. Water purification treatment for industrial water supply stations, removing Ca2?, Mg2?, HCO??, CO?2?, silicon, turbidity, and oil, etc.

Typical Case of the M⁺FL0 Circulating Cooling Water Bypass Filtration Hardness and Turbidity Removal Water Purification System: Efficient and economical hardness and turbidity removal technology, suitable for removing Ca2?, Mg2?, HCO??, CO?2?, silicon, turbidity, and oil, etc. The outlet water turbidity can be below 1.0 NTU. Pre-treatment for industrial wastewater desalination reverse osmosis (RO)/direct tension reverse osmosis (DTRO) membranes, mainly targeting the removal of Ca2?, Mg2?, and silicon, etc.  industrial circulating water bypass filtration equipment, simultaneously removing hardness and turbidity, significantly reducing the amount of circulating water discharge and makeup water. Water purification treatment for industrial water supply stations, removing Ca2?, Mg2?, HCO??, CO?2?, silicon, turbidity, and oil, etc.

The original bypass cooling water filtration system at Hainan Dongfang Petrochemical used a gravity valveless filter system with a treatment capacity of 180 m3/h. The circulating water quality data was as follows: pH=8.5, SS=48 mg/L, Ca2?=353 mg/L, Mg2?=92 mg/L, HCO??=181 mg/L, SO?2?/810 mg/L, Cl?=310 mg/L, SiO?=76 mg/L. Due to excessively high hardness, scaling in the cooling water system has become increasingly severe, and the high suspended solids content has caused frequent blockages and backwashing of the valveless filters. In December 2019, the system was upgraded to an M+FLO circulating cooling water filtration system for hardness and turbidity removal. After commissioning, the treated water quality showed: Ca2?=22 mg/L, Mg2?=5.0 mg/L, HCO??=43 mg/L, SiO?=6.0 mg/L, turbidity=1.5 NTU. This upgrade significantly improved the quality of the circulating cooling water and reduced the amount of circulating water discharge and makeup water by 60%.

Notes: The M+FLO-LDH magnetic flocculation + chemical desalination and de-hardening water treatment system, combined with the addition of Ca (OH)?, LDH, CO?, PFS/HFO, and PAM chemicals, effectively removes sulfate, chloride, silicate, total salts, calcium, and magnesium hardness. The resulting LDH calcium composite sludge is a non-polluting inorganic calcium 礬 mineral that can be recycled as raw material for mining or cement production. This system is suitable for efficient and economical desalination and de-hardening treatment of industrial wastewater (or circulating water discharge). Its performance and advantages include a total salt removal rate of ~70%, with treated water meeting standards of TDS < 1000 mg/L, Cl? < 150 mg/L, SO?2? < 150 mg/L, SiO? < 5.0 mg/L, hardness < 50 mg/L, and turbidity < 1.0 NTU. The cost per ton of water treated is approximately 1.0-3.0 yuan (mainly dependent on the amount of anions removed). Compared to traditional pretreatment (de-turbidity/de-hardening) + reverse osmosis desalination + evaporation crystallization processes, this system offers advantages such as simpler processes, lower investment and operating costs, and intelligent automatic operation. However, its desalination depth is less than that of reverse osmosis (RO/DTRO).