Zero-emission DTRO is a form of reverse osmosis. It is a membrane assembly specially used to treat high-concentration sewage. Its core technology is disc-tube membrane column. The reverse osmosis membrane and hydraulic guide plate are stacked together, fixed with a central tie rod and end plate, and then placed in a pressure-resistant casing to form a membrane column. DTRO overcomes the shortcomings of general reverse osmosis systems that are prone to clogging when treating leachate, making the system more stable and lower in operating costs.   The application of zero-emission DTRO disc-tube reverse osmosis membrane treatment technology in power plant water treatment in my country has entered the stage of gradual promotion. It has the advantages of high raw water treatment quality, wide application range, economic and environmental protection, and easy maintenance and management. The application of DTRO disc-tube reverse osmosis technology can better solve various water resource problems through efficient purification of unconventional water sources. In water-scarce areas with large energy demand, DTRO disc-tube reverse osmosis technology is a general technology for solving the "water problem", and has the advantages of clean production with less land and no other pollution, which helps to break through the ecological and environmental bottleneck for the further development of local economy.   The desalination rate and salt permeability of zero-emission DTRO disc-tube reverse osmosis membrane elements:   The principle of desalination rate is to remove the percentage of soluble impurities from the system influent through the DTRO reverse osmosis membrane. The salt permeability refers to the percentage of soluble impurities in the influent that pass through the membrane. The relationship between them is described by the following expression:   Desalination rate = (1-salinity of produced water/salinity of influent) × 100%   Salt permeability = 100%-desalination rate   The desalination rate of the membrane element is determined when the membrane is manufactured. The desalination rate depends on the density of the ultra-thin desalination layer on the surface of the membrane element. The denser the desalination layer, the higher the desalination rate and the lower the water production. The removal rate of reverse osmosis for different substances is mainly determined by the structure and molecular weight of the substances. The removal rate of high-valent ions and complex monovalent ions can exceed 98%. The removal rate of monovalent ions such as sodium ions, potassium ions, and chloride ions is lower, but it also exceeds 95%. The removal rate of organic matter with a molecular weight greater than 100 can also reach more than 98%, but the removal rate of organic matter with a molecular weight less than 100 is lower.   Storage of zero-emission DTRO disc-tube reverse osmosis membrane elements:   (1) The membrane elements are tested for water flow before leaving the factory, and are stored in a 1% sodium sulfite solution, and then vacuum-packed in oxygen-isolating bags.   (2) The membrane elements must always be kept moist. Even when they need to be temporarily opened to confirm the quantity of the same package, they must be opened without damaging the plastic bag, and this state should be kept until use.   (3) The membrane elements are best stored at a low temperature of 5~10℃. When storing in an environment where the temperature exceeds 10°C, choose a well-ventilated place and avoid direct sunlight. The storage temperature should not exceed 35°C.

The TUF device is a type of tubular membrane with a filtration accuracy of 50nm. It is mainly used in the process of wastewater softening to separate solids and liquids. The membrane component adopts a unique tubular support structure, and the membrane layer is fully anchored or chemically bonded to the sintered porous plastic. The component is designed as a cross-flow filtration mode, and its filtration pore size range belongs to the microfiltration and ultrafiltration range. In addition, the POREX tubular membrane component has excellent chemical resistance, temperature resistance and friction resistance.   Technical features of TUF device: 1. Remove heavy metals (Ca2+, Mg2+, Ba2+, Sr2+)   2. A recovery rate of 10 to 20 times or more can be obtained   3. The strongest, durable and washable membrane on the market   4. Super strong chemical resistance PH 0-14   5. Friction resistance, suitable for solid-liquid separation of coarse particles   6. Microporous membrane, providing excellent filtered water quality and low SDI (generally less than 0.5 NTU)   7. Large channel, cross-flow circulation, allowing high solid load, no pre-treatment required   8. Components are specially designed for wastewater treatment, with a service life of 5-10 years

The treatment effect of the disc-tube reverse osmosis DTRO system does not depend on the pretreatment process. The open flow channel can treat wastewater containing more colloids and suspended solids. The membrane component has a short flow path and a wide flow channel. The special hydraulic conditions make the liquid form turbulence in the membrane column, which greatly reduces the scaling, pollution and concentration polarization of the membrane surface.   Daily maintenance precautions for DTRO membranes: 1. Regularly check the water quality of landfill leachate The water quality of landfill leachate fluctuates greatly, and the raw water quality needs to be regularly analyzed and checked during the treatment process   2. Regularly check the water quality of the single membrane module DTRO membrane modules are all in parallel mode. During normal operation, the conductivity of the produced water generally does not change much. If the conductivity of the produced water is found to increase during operation, the conductivity of the produced water of the single membrane module can be checked. If the conductivity is higher than the conductivity of the discharge, the single membrane module can be isolated and disassembled for inspection. Generally, the O-ring is detached or If the membrane is damaged, the performance of the membrane assembly can be restored after replacement   3. Regular cleaning DTRO membrane assemblies will inevitably be contaminated during operation, so they need to be cleaned. The cleaning method is generally chemical cleaning. The DTRO membrane cleaning agent can be used for online cleaning to restore the flux. During the cleaning process, the temperature is generally controlled at 35°C, and the cycle soaking is carried out. The chemical cleaning time is generally 2 hours. If the contamination is particularly serious, the cleaning time can be appropriately extended. The cleaning process is a professional maintenance process, and the operator needs to strictly follow the cleaning operation procedures to ensure the service life of the membrane assembly.

The main applications of nanofiltration water treatment equipment in sewage treatment are as follows: 1. Softening: Membrane softening water mainly uses the selective permeability of nanofiltration membranes for ions of different valence states to soften water. While removing hardness, membrane softening can also remove turbidity, chromaticity and organic matter, and its effluent water quality is significantly better than other softening processes. Moreover, membrane softening has the advantages of no need for regeneration, no pollution, simple operation, and less land occupation, and has obvious social and economic benefits.   Membrane softening is very common in the United States. In the past 10 years, new softening water plants in Florida have adopted membrane softening to replace conventional lime softening and ion exchange processes. In recent years, with the continuous improvement of nanofiltration performance and the continuous decline in the price of nanofiltration membrane components, membrane softening has been superior to or close to conventional methods in terms of investment, operation, and maintenance.   2. Used to remove organic matter in water: In addition to softening, nanofiltration membranes are mostly used for decolorization, removal of natural and synthetic organic matter (such as pesticides), trihalomethanes, disinfection byproducts (trihalomethanes and haloacetic acids) and their precursors and volatile organic matter in drinking water treatment, to ensure the biological stability of drinking water, etc.   3. Removal of trihalomethanes: Studies have shown that nanofiltration membranes can remove most of the toxic and harmful organic matter and Ames mutagens in water, making the mutagenicity ratio MR values ​​of TA98 and TA100 strains less than 2 at each test dose, and the Ames test results are negative. Further research will examine the interception characteristics of nanofiltration technology for endocrine disrupting substances in drinking water to provide a basis for safe drinking water.   4. Removal of disinfection byproducts and their precursors: Disinfection byproducts mainly include trihalomethanes (THMs), haloacetic acids (HAAs) and possible trichloroacetaldehyde hydroxide (CH). Foreign scientific and technological workers have conducted extensive research in this regard. The average retention rates of nanofiltration membranes for the precursors of these three disinfection byproducts are 97%, 94% and 86% respectively. By selecting appropriate nanofiltration membranes, the quality of drinking water can meet higher standards for safe drinking water quality.   5. Removal of volatile organic compounds (VOCs): It has a high removal rate for trace volatile organic compounds in drinking water.   6. Application in piped drinking water: Nanofiltration can intercept ions with a valence of more than two and other particles, and only water molecules and some monovalent ions (such as sodium, potassium, and chloride ions) are passed through. Nanofiltration can be used to produce direct drinking water, and a certain amount of ions are still retained in the effluent, and the treatment cost can be reduced.

1) Check whether the safety protection device is complete, safe, flexible, accurate and reliable.   2) Check the screws and tighten them to prevent them from falling off during use; check the operating handles of the transmission system and the correct position of the electrical switches without looseness.   3) Check whether the lubrication device is complete, intact, reliable, the oil circuit is unobstructed, and the oil mark is eye-catching, and lubricate and refuel various transmission parts.   4) Check whether various pipelines and pipe fittings are intact, without running, bubbling, dripping, leaking or seeping.   5) Check the integrity of the equipment and whether the parts and accessories are missing. Various tools and accessories should be neatly placed and stored in order.   6) Clean all parts of the equipment to make the equipment clean inside and outside. The sliding guide rails and joints should be free of oil, rust, dust and debris, so that the paint can see the original color and the iron can see the light.   7) The operating post must achieve "one flat", "two clean", "three visible" and "four no", among which: "one flat" means the area around the workshop is flat; "two clean" means the glass, doors and windows are clean, and the ground passages are clean; "three visible" means the shaft can see light, the bottom of the ditch can be seen, and the original color of the equipment can be seen; "four no" means no oil stains, stagnant water, debris, and garbage.

Treatment process: MBR (membrane bioreactor) is a combined process that combines biological treatment with membrane separation. A hollow fiber membrane assembly is placed in the bioreactor. The filtration hollow fiber membrane is an ultrafiltration membrane (UF) with a pore size range of 0.04μm, which is mainly used to intercept suspended liquids and organic matter. Its characteristics can maintain a certain concentration of microorganisms in the bioreactor and purify sewage.   MBR integrated equipment uses membrane bioreactor (MBR) for sewage treatment and reuse. It has all the advantages of membrane bioreactor: good effluent quality, low operating cost, strong system impact resistance, small amount of sludge, high degree of automation, etc. In addition, as an integrated equipment, it has a small footprint and is easy to integrate. It can be used as a small sewage reuse equipment or as a core treatment unit of a larger sewage treatment plant (station). It is one of the hot spots in the current sewage treatment research field and has broad application prospects.   Working principle: Membrane bioreactor (MBR) process is a new wastewater treatment technology that organically combines membrane separation technology with biotechnology. It uses membrane separation equipment to intercept the activated sludge and macromolecular organic matter in the biochemical reaction tank, eliminating the need for a secondary sedimentation tank. The concentration of activated sludge is greatly increased, the hydraulic retention time (HRT) and the sludge retention time (SRT) can be controlled separately, and the refractory substances continue to react and degrade in the reactor.   Therefore, the membrane bioreactor (MBR) process greatly enhances the function of the bioreactor through membrane separation technology. Compared with traditional biological treatment methods, it is one of the most promising new technologies for wastewater treatment.