[Hongjie Water Service] Several suggestions for optimizing the operation of RO concentrated water

What is DT-RO water treatment process

The DT-RO membrane does not require any form of pre-treatment, and can directly treat the leachate to meet the discharge standards required by the owner.

For the treatment of urban household waste leachate, if it is to meet the national first level emission standards, a two-stage DTRO treatment system is generally provided, including a central control system, sand filter, first level reverse osmosis system, second level reverse osmosis system, leachate storage tank, sulfuric acid storage tank, water purification storage tank, cleaning agent storage tank, degassing tower, etc.

When the system is running, pump the leachate from the regulating tank into the sand filter to remove 50% μ Suspended solids above m are removed through a cylindrical filter with a particle size greater than 10 μ The particles of m then enter the leachate storage tank. During the process of entering the storage tank, the acid addition system is activated to adjust the pH value of the leachate in the storage tank to 6-6.5.

When the liquid level in the leachate storage tank reaches the set height, the first stage reverse osmosis system starts, and the leachate is pumped into the membrane group system by a high-pressure plunger pump.

The purified water produced by the first stage reverse osmosis directly enters the second stage reverse osmosis system, and the generated concentrated solution is circulated within the membrane group. After reaching the set recovery rate, it is discharged into the concentrated solution storage tank.

After passing through the second stage reverse osmosis system, the produced purified water is directly discharged or reused after being deodorized by the degassing device. Due to the low concentration of pollutants in the concentrated solution generated here, it can be discharged to the first stage of reverse osmosis for further treatment to improve the water recovery rate of the system. The cleaning of the membrane group is automatically performed by the system based on the pressure difference, and only acidic cleaning agent and alkaline cleaning agent need to be placed in two cleaning agent tanks respectively.

DT-RO membrane is a form of reverse osmosis, which is a membrane component specifically used to treat high concentration wastewater. Its core technology is a disc tube membrane column. Stack the reverse osmosis membrane and hydraulic diversion disc together, fix them with a central pull rod and end plate, and then place them in a pressure resistant sleeve to form a membrane column.

The core of the DT-RO membrane system is a membrane column composed of a disc type membrane, a guide plate, an O-ring rubber washer, a central pull rod, and a pressure resistant sleeve. There are two types of disc tube membrane columns: large membrane columns and small membrane columns. The small membrane column has a diameter of 200 millimeters and a length of 1000 millimeters, with 170 guide plates and 169 membranes;

The large membrane column has a diameter of 214 millimeters and a length of 1400 millimeters, consisting of 210 guide plates and 209 membranes. The diaphragm and guide plate are stacked at intervals, with O-ring rubber washers placed in grooves on both sides of the guide plate. They are threaded together with a central pull rod and placed in a pressure resistant sleeve. Both ends are sealed with metal end plates.

Each component in the membrane column has different functions. The membrane is composed of two concentric annular reverse osmosis membranes, with a layer of filamentous support sandwiched between the membranes. The outer ring of these three layers of annular materials is welded, and the inner ring is opened, serving as the water purification outlet.

The guide plate (replacing the mesh support layer in the coiled membrane) clamps the membrane in the middle, but does not directly contact the membrane, widening the fluid channel; The surface of the guide plate has convex points arranged in a certain way, which cause turbulence in the leachate under high pressure, increasing the permeability rate and self-cleaning function.

The O-ring rubber washer is sleeved on the center pull rod and placed in the grooves on both sides of the guide plate, playing a role in supporting the diaphragm, isolating sewage and purifying water. The purified water flows along the filamentous support in the middle of the membrane to the periphery of the central pull rod and is discharged through the purified water outlet.

Compared with other membrane components, the DT-RO membrane system has the following three obvious characteristics:

Channel width: The channel between the membranes is 2mm, while the membrane components in roll packaging are only 0.2mm.

Short process: The liquid flow on the membrane surface is only 7cm, while the membrane component in roll packaging is 100cm.

Turbulent flow: Due to the effect of high pressure, the leachate hits the convex points on the guide plate and forms high-speed turbulence. Under the erosion of this turbulence, the membrane surface is not easy to settle pollutants.

In the membrane components of roll packaging, the mesh support will trap pollutants, causing contamination of the membrane in the still water zone.

The above three characteristics determine that DT-RO reverse osmosis technology can tolerate high levels of suspended solids and SDI when treating leachate, and in simple terms, it does not clog.

At the same time, these three technical characteristics are reflected in specific practice, making the disc tube membrane technology have the following engineering characteristics:

The membrane group has less fouling, light membrane fouling, and long membrane life. The special structure and hydraulic design of DT-RO make the membrane assembly easy to clean, avoiding scaling and other membrane fouling, thereby extending the membrane life. The diaphragm used for DT-RO can have a lifespan of over 2 years or even longer.

It does not rely on preprocessing and has good stability, safety, and adaptability. Due to the above structural characteristics, the DTRO membrane group can directly treat leachate without pre-treatment.

In specific engineering, pre-treatment systems may or may not be necessary. For systems with pre-treatment, regardless of whether the pre-treatment process is efficient and stable, the reverse osmosis system can stably achieve standard effluent. Meanwhile, as it does not rely on biological treatment, DT-RO reverse osmosis has good adaptability to the leachate at various stages of the landfill site. It has a very reliable processing effect.

So far, there has been no failure in 243 leachate treatment projects in the past decade abroad. The DT-RO pilot equipment has been tested in more than ten garbage disposal plants in five cities in China, and there has been no case where the effectiveness has been affected due to blockage.

As a pioneer in the industry, Hongjie Water always adheres to the business philosophy of integrity, professionalism, and innovation, constantly developing new technologies, exploring new fields, and providing optimized solutions for users. The business field has involved industries such as chemical, food and beverage, bucket/bottled water, semiconductor, electronic appliances, medical and health care, biopharmaceutical, aquaculture and planting, and can provide feasibility study planning and design, manufacturing and installation, engineering construction, engineering management, and after-sales service solutions for a large number of households.