79results about How to "Does not affect the processing effect" patented technology

The invention discloses a method for precipitating and stabilizing As from As-containing solution. According to the method, ferrous salt is used as As precipitator; through the air oxidation in the As-containing solution in a weak acid condition, Fe<2+> is oxidized into Fe<3+>; and Fe<3+> reacts with As to generate precipitate with high stability and low As leaching toxicity. The method is simple in technology, and generates the precipitate which is ferric arsenate crystalline compound-scorodite crystal FeAsO4. 2H2O under the conditions that the pH value is 4-6, the temperature is 70-95 DEG C, the molar ratio between Fe and As is 1-1.5, the air flow rate is 120-200L / h and the reaction time is 5-7h; the precipitate As has the leaching toxicity concentration of 1-2mg / L which is lower than the limit value of Identification Standards for Hazardous Wastes-Identification for Extraction Toxicity (GB 5085.3-2007); and the harmless stabilizing treatment for the As-containing solution can be realized.

The invention belongs to the field of sewage treatment and relates to a biological treatment method for high-concentration wastewater with high ammonia nitrogen content, in particular to a biological tannery wastewater treatment system and a treatment method thereof. The biological tannery wastewater treatment system comprises a first-stage gridding aeration tank, a horizontal flow sedimentation tank, a second-stage gridding aeration tank and a radial flow sedimentation tank which are communicated sequentially, wherein the bottom of the horizontal flow sedimentation tank is communicated with a material inlet of the first-stage gridding aeration tank through a backflow pump; and the bottom of the radial flow sedimentation tank is communicated with a material inlet of the second-stage gridding aeration tank through the backflow pump. According to the treatment method, the organic degrading proportion and the denitration function of the system are enhanced by two-stage aeration. The treatment system and the treatment method which are disclosed by the invention has the advantages that the treatment effect is obvious, running maintenance is facilitated, the energy consumption is low, and the treatment cost is low; and obvious economical and beneficial benefits are realized.

The invention relates to a sponge iron-AT (Aluminium Titanate)-PVF (Polyvinyl Fluoride) composite filler and application thereof on water treatment. The composite filler is formed by filling attapulgite composite hydrophilic polyurethane foam of the size of 1.5*1.5*1.5cm and sponge with the grain diameter of 2-5cm at the weight ratio of 1: (4-50). The sponge iron-AT-PVF composite filler has the characteristics of low cost, good water treatment effect, high degrading speed and high removal rate on elements N and P as well as organic matters which are difficult to be degraded in the wastewater. The TN (Total Nitrogen) and TP (Total Phosphorus) indexes in the effluent can be drastically lowered under the aerobic or anaerobic conditions when the composite filler is put into a common biochemical treating pond.

The invention relates to a target signal processing device of an unmanned aerial vehicle evadible system. The target signal processing device comprises a radio frequency receiving-transmitting system, an analog-digital converter, an FFT conversion module, a modulus circuit, a non-phase-coherent accumulation instrument and a CFAR detection circuit, wherein the radio frequency receiving-transmitting system is used for transmitting radio frequency signals to a target, receiving scattered echo signals, and mixing the echo signals with radio frequency signals to obtain beating signals; the analog-digital converter is used for conducting analog-digital conversion on the beating signals to obtain digital signals; the FFT conversion module is used for conducting fast Fourier transformation on the digital signals to obtain spectrograms, processing the spectrograms to obtain frequency values corresponding to peak points, and obtaining initial target distance signals; the modulus circuit is used for conducting modulus on the initial target distance signals to obtain signal amplitude values; the non-phase-coherent accumulation instrument is used for conducting non-phase-coherent accumulation on the signal amplitude values to obtain non-phase-coherent accumulation data; the CFAR detection circuit is used for detecting the non-phase-coherent accumulation data with a constant false alarm detection method to obtain target distance signals. The invention further provides the unmanned aerial vehicle evadible system. By means of the target signal processing device and the unmanned aerial vehicle evadible system, the target signal obtaining accuracy rate is improved, and the sizes of the device and the system are reduced.

The invention discloses a system and a process for sludge in situ decrement enhanced by utilizing metazoan and application of the process. The system comprises an anaerobic zone, an anoxic zone, an oxic zone, a metazoan growing zone and a secondary sedimentation zone. A biochemical system can perform in situ decrement through arranging the metazoan growing zone in the sewage treatment process; and cultivated and domesticated metazoan is continuously added in the metazoan growing zone to enhance organism predation, thereby achieving the purpose of sludge in situ decrement and realizing sludge decrement effect of 50-80% of activated sludge. The process of activated sludge in situ decrement with an efficient biological method is suitable for any activated sludge methods and deformation technologies thereof, such as A<2> / O (anaerobic-anoxic / oxic), A / O (anoxic / oxic), SBR (sequencing batch reactor), MSBR (modified sequencing batch reactor), CASS (cyclic activated sludge System), oxidation ditch, MBR (membrane bio-reactor) and the like, can also be used for a biological treatment technology having a biological carrier, can be used for sludge decrement of a newly-built sewage treatment engineering and can also be used for transformation of a built engineering with extremely low transformation cost.

The utility model relates to a SAR image segment method for the flash annealing based on a MRF, which is characterized in that: 1) The original split field is defined, 2) The local energy of each pixel point in the current split field is calculated; 3) The current pixel point sentinel is changed: firstly, whether a prior dominant sentinel is in the current pixel point neighborhood is determined, if yes, the new sentinel of the current pixel point is marked as the prior dominant sentinel; if no, the sentinel of the current pixel point is changed randomly to get a new sentinel, if the new sentinel calculated energy is lower than that of the current sentinel, the new sentinel is accepted, otherwise a value is randomly selected between 0 and 1, if the possibility rate corresponding to the energy differential value between the new energy and the current energy is larger than or equal to the selected value, the sentinel is accepted, otherwise the new sentinel is not accepted; 4) A global energy in the current state and in the new state is calculated, if the variable value of the global energy is less than a threshold value defined in advanced, the iterative optimization process is over. The utility model has advantages of increasing the processing speed, and facilitating the application of the SAR image segment method based on the analogue annealing in processing system.

The invention provides a treatment device and method of printing and desizing mixed wastewater. The treatment device of the printing and desizing mixed wastewater is characterized by comprising a water collecting regulating tank, a reinforced circulating type efficient anaerobic bioreactor, an aerobic biological contact oxidation tank, a gas-flotation tank, a high-level oxidization tank and an aeration biological filter tank. The treatment device and method disclosed by the invention are especially suitable for treating the high-ammonia-nitrogen high-concentration printing and desizing mixed wastewater generated in printing and desizing processes, a process system disclosed by the invention is adopted to effectively treat the high-concentration high-ammonia-nitrogen wastewater generated by the printing process and high-concentration high-alkaline wastewater generated by the desizing process in printing and dyeing enterprises after the two kinds of wastewater are subjected to flow-dividing and mixing, and also can be combined with a wastewater treatment process for other relatively-low-concentration pollutants in a printing and dying plant to form a complete wastewater treatment system of the enterprise, thereby realizing modifying and upgrading an existing wastewater system.

The invention discloses a comprehensive fresh-keeping method of green tea, belonging to the technical field of tea processing and fresh keeping. The method comprises the following steps of: firstly, putting classified fresh leaves of tea into a microwave dewatering machine to be dewatered; then processing the dewatered and reshaped tea leaves by quenching technology; and finally, carrying out fresh-keeping packaging to the produced finished tea leaves by nanometer packing material. The microwave dewatering and the quenching processing are integrated with nanometer material packaging, so the fresh-keeping quality of the green tea can be obviously improved. The content of free amino acid, tea polyphenols, chlorophyll and vitamin C in the green tea group which is stored at 35 DEG C for 80 days with the comprehensive fresh-keeping method are respectively 5.1%, 10%, 15.3%, and 40.1% higher than that of the same in the common tea group, and the green tea storage quality is greatly improved.

The invention discloses an excess sludge reduction bioreactor with variable aeration and a worm attachment oblique plate, which relates to a bioreactor for excess sludge reduction. The bioreactor solves the problems that that the conventional excess sludge reduction device has low oxygen utilization rate, poor aeration adjustment, easy worm drop, low growth density of worm colony, difficult discharge of inert substances and the like. An automatic gas flow adjustor which is well arranged can automatically adjust the air flow entering a plurality of variable micropore aeration pipes according to the dissolved oxygen concentration of sludge mixed solution in a container, thereby realizing variable aeration for the sludge mixed solution in the container; the dissolved oxygen concentration of the sludge mixed solution can be kept at the maximum dissolved oxygen concentration of the worm sludge reduction through the variable aeration; and a plurality of variable aperture vent holes are uniformly distributed on the variable micropore aeration pipes, and the variable range of the diameters of the vent holes is 0.2 to 0.8 millimeter. The excess sludge reduction bioreactor integrates the worm attachment oblique plate and the variable aeration so as to greatly improve the sludge reduction effect, and the sludge reduction reaches over 90 percent.

The invention relates to a high-quality tea processing method, and also relates to special equipment for key procedures for realizing the method, and belongs to the technical field of tea making. The method of the present invention comprises steps of de-enzyming, shaping and drying in sequence; at least one quenching step is added after the steps of de-enzyming and forming, and the quenching step is to rapidly cool the tea leaves after corresponding steps within 30-120 seconds To 0-20 ℃, keep 1-3 minutes. The special equipment for the key process of the present invention is a quenching machine, which includes a channel-type refrigeration chamber installed on the frame except for the openings at both ends, and the passage of the refrigeration chamber is provided with a circulation system that passes through the refrigeration chamber from the openings at both ends. The conveyor belt, the outer top of the cooling chamber is provided with a refrigerator and a circulation fan, the circulation fan communicates with the refrigeration chamber through the air supply channel and the return air channel, and the heat exchanger of the refrigerator is placed in the return air channel. The method and equipment can not only better protect the color, aroma and taste of the tea, but also increase the content of beneficial substances in the tea.

The present invention relates to a method and device for laminating mainly plate-shaped workpieces with the use of pressure and heat, wherein the workpiece has at least a thermal activation adhesive layer. Firstly, at least one workpiece is supplied to a vacuum cavity of a vacuum laminating press, and the vacuum chamber is divided into a pressure half part and a product half part by an airtight flexible pressing member. In the product half part of the vacuum chamber, the workpiece is laminated with the use of heat, and the product half part is vacuumized, and the pressing member presses the workpiece directly or indirectly against one lower side of the vacuum chamber due to a pressure difference formed by vacuumizing and / or due to loading of the pressure half part of the vacuum chamber by an additional pressure. The vacuum laminating press is started to interrupt the laminating treatment, the workpiece is transferred to the press, and the press is applied by a temperature at or above an activation temperature and / or precipitation temperature of the adhesive layer. The invention is characterized in that a separate foil or foil together with the workpiece brought into the press or foil web guided by the vacuum chamber is utilized as the flexible pressing member.

The invention discloses a handling method about microwave waste water denitrogenation, containing three steps of waster water preconditioning, microwave denitrogenation processing and gas collectiong. Waste water preconditioning is used to adjust and stabilize the water quality of waste water, adjusting waste water's pH value above 10; domestic sewage is not adjusted pH. Microwave denitrogenation can make the ammonia nitrogen in waste water escaped with form of ammonia gas at the action of microwave, reaching denitrogenation effect. Gas collectiong processing is collecting the alkaline air escaped in the microwave processing, avoiding air pollution. This method has the advantages of high ammonia nitrogen removement effect, short processing time, low operation cost, small equipment volume and high automation degree. This method is the same with the waste water containing high concentration ammonia nitrogen, such as coking waste water, garbage infiltration liquid, chemical fertilizers, agricultural chemicals waste water some pharmacy waste water and so on, also adapted for denitrification processing of domestic sewage.

The invention discloses a preparing method of biological sponge iron to dispose effluent, which comprises the following steps: 1. making sponge iron into 2-5cm particle; soaking in the clean water for 4-12h; washing; 2. adding predisposed sponge iron in the biochemical reactor; aerating the disposed effluent with pH value at 6-9 until the sponge iron in the reactor is immersed completely; adding active sludge as inoculating flora; proceeding microbe domestication and fixing reaction under exposing condition; waiting the water quality index of outlet water approaching stable; finishing.

The present invention discloses process of eliminating heavy metals from city sewage and sludge. The heavy metal eliminating apparatus consists of simplified sequencing batch bioreactor, concentrating and settling tank and pH regulating tank, and the simplified sequencing batch bioreactor as the main treating apparatus operates in the simplified process comprising feeding sludge, aerobic reaction, aerobic sludge elimination and feeding sludge. The main reactor has exhaust ratio designed in optimal sludge inoculating amount, and the un-exhausted sludge is used for the next batch. The present invention has short treating period, and the treated sludge has the contents of residual Cu, Zn, Cd, Ni and other heavy metal reaching relevant standard.

An artificial waterweed for treating sewage in-situ is composed of a floating ball, a rope fixed to said floating ball, cleaning leaves connected to said rope, and a weight fixed to lower end of said rope. It features high effect for nutrient-enriched sewage and water.

The invention belongs to the technical field of the dyeing pre-treatment of textile fabric, and particularly relates to a pre-treatment process for the textile fabric. The pre-treatment process for the textile fabric specifically comprises the following steps: singeing; rolling cold-batch working solution; piling; washing in 7-10 grids by hot water, wherein the temperature is 98 DEG C; washing bycold water; and drying. The pre-treatment process is capable of, through a DF-boiling and bleaching agent and other assistants, preparing the continuous, rapid, low-temperature, and low-alkaline efficient pre-treatment working solution, the working solution is extensively applied to a pre-treatment processing technology of textiles, such as pure cotton, polyester cotton, brocade cotton, rayon, non-woven fabric, dacron, and tencel, so the piling time can be reduced from 20-24 hours of a traditional cold-batch process to 2-6 hours, and the refining effect of cotton fabrics and the uniformity ofdyeing are greatly improved. The dye-uptake of the dyeing effect is improved by 10%-20%, and the hand feeling is softer.

The invention discloses a regenerated papermaking wastewater treatment system and a process. The treatment system comprises a physiochemical treatment unit, an anaerobic treatment unit, a biological selection unit, a first aerobic treatment unit, a second aerobic treatment and a sedimentation unit, which are communicated in sequence, wherein the physiochemical treatment unit is provided with a coagulant adding device; the first aerobic treatment unit is provided with a microorganism microbial inoculum adding device; the second aerobic treatment unit is provided with a metazoan culture adding groove; aeration pipe nets which are communicated with air blowing equipment are arranged at the bottoms of the first aerobic treatment unit and the second aerobic treatment unit; and the sedimentation unit is provided with a sewage reflowing pipeline which is communicated with the anaerobic treatment unit and the biological selection unit. The treatment system disclosed by the invention is suitable for the treatment of papermaking wastewater and realizes the low sewage yield of the regenerated papermaking wastewater treatment.

The present invention relates to a method for treating sewage by using coupling field oxidation, and its technological process includes the following steps: firstly, making the sewage undergo the processes of magnetization treatment, primary coagualting reaction and precipitation to remove suspended matter, then feeding said sewage into first coupling field oxidation pool to make oxidation, and making the oxidated water undergo the processes of coagulation reaction, precipitation and secondary coupling oxidation so as to implement said invention. Its coupling oxidation is implemented by using mixed oxidant containing O-, O2, O and O3 in coupling field formed from at least two both of magnetic field, ultrasonic wave and UV light. Said method is good in treatment effect, can effectively remove COD, BOD, SS, N, P, chromaticity and abnormal smell, etc. in the water.

The invention discloses an efficient oxygen supply nano-bubble suspended carrier flowing biochemical bed sewage treatment system which comprises a grille, an anaerobic tank, an anoxic tank, an MBBR nano-bubble biological reaction tank and a secondary sedimentation tank. A high-specific-surface-area suspended carrier suitable for attaching propagation of microbial strains is put in the MBBR nano-bubble biological reaction tank, the MBBR nano-bubble biological reaction tank is connected with a nano-bubble machine using an air source as oxygen and is responsible for nano-bubble delivery towards the MBBR nano-bubble biological reaction tank to form high-density nano-bubble water. The sewage treatment system creatively integrates a nano-bubble technology and a suspended carrier flowing biochemical bed technology, a brand new sewage treatment system and a process are formed, the shortcomings of frequent sludge adding, high-energy-consumption blast aeration, sludge reflux, daily aged sludge treatment and the like existing in an existing activated sludge and wastewater treatment system are overcome, and the sewage treatment system also has the advantages of being simple in operation, stable in operation, large in treatment amount and the like.

The invention discloses a method for precipitating and stabilizing As from As-containing solution. According to the method, ferrous salt is used as As precipitator; through the air oxidation in the As-containing solution in a weak acid condition, Fe<2+> is oxidized into Fe<3+>; and Fe<3+> reacts with As to generate precipitate with high stability and low As leaching toxicity. The method is simple in technology, and generates the precipitate which is ferric arsenate crystalline compound-scorodite crystal FeAsO4. 2H2O under the conditions that the pH value is 4-6, the temperature is 70-95 DEG C, the molar ratio between Fe and As is 1-1.5, the air flow rate is 120-200L / h and the reaction time is 5-7h; the precipitate As has the leaching toxicity concentration of 1-2mg / L which is lower than the limit value of Identification Standards for Hazardous Wastes-Identification for Extraction Toxicity (GB 5085.3-2007); and the harmless stabilizing treatment for the As-containing solution can be realized.

The invention belongs to the technical field of water treatment sludge, and particularly relates to an activated sludge deep dewatering method. The method includes the steps: firstly, extracting sludge (with water content about 99%-96%) in a concentration tank; secondly, adding an appropriate number of amidino-containing cationic high molecular reagents into the sludge and then mixing the reagents with the sludge; thirdly, exhausting the flocculated sludge into a plate-and-frame filter press for filter pressing to obtain a filter cake with the water content lower than 60%. Compared with a conventional sludge deep dewatering method, the activated sludge deep dewatering method has the advantages that the sludge can be conditioned only by adding one organic compound without adding dry base materials such as lime, the water content of the filter cake after filter pressing is lower than 60%, the process is simple, the filter-pressed filter cake has no effect on sludge resource utilization in subsequent incineration and the like, and accordingly the filter cake has a fine practical application prospect.

The invention relates to the field of corrosion and scale inhibitors and discloses a phosphorus-free corrosion and scale inhibitor composition. The composition comprises a polymer A, a polymer B, organic acid and / or organic acid salt and water-soluble inorganic zinc salt; the polymer A is a copolymer of maleic anhydride, allyloxy polyethylene glycol maleic acid monoester and allyloxy polyethyleneglycol sulfonate, and the polymer B is a corrosion inhibition polymer; the weight ratio of the polymer A to the polymer B to the organic acid and / or organic acid salt to the water-soluble inorganic zinc salt is 1:(0.3-6.67):(0.025-1.25):(0.05-1.6). The invention further provides a phosphorus-free corrosion and scale inhibitor and application thereof. According to the phosphorus-free corrosion andscale inhibitor composition, the application amount of the corrosion and scale inhibitor is effectively lowered, and the cost is greatly reduced.

The invention relates to an artificial wetland treatment method and device of pickled food processing wastewater. The artificial wetland treatment method comprises the following steps: (1) inlet water back-flowing and buffering; (2) purifying treatment; (3) sewage treatment, namely infiltrated sewage is collected on a water collection layer positioned on the bottommost part of a treatment pond and enters an effluent water buffer pond through water through holes; (4) back-flowing and salt squeezing. The device constructed according to the artificial wetland treatment method comprises an artificial wetland body, wherein one side of the artificial wetland body is provided with an inlet water buffer pond, and the other side of the artificial wetland body is provided with the effluent water buffer pond; the artificial wetland body positioned between the inlet water buffer pond and the effluent water buffer pond is provided with the treatment pond; the treatment pond is sequentially divided into the water collection layer, a treatment layer, a water distribution pipe, a salt squeezing pipe and salt resistant plants from bottom to top; the treatment layer is filled with multilayer artificial wetland media; the water distribution pipe and the salt squeezing pipe are distributed on the surface of the treatment layer; the salt resistant plants are planted in the artificial wetland media. The artificial wetland treatment method disclosed by the invention has the advantages of wide medium source and low price. The device disclosed by the invention solves the shock problem of fluctuated impact of the water quality and water amount of distributed sewage without continuous and uniform water inflow.

The invention provides a full-die-cutting ultrahigh frequency electronic tag antenna and processing equipment and a processing technology thereof, the full-die-cutting ultrahigh frequency electronic tag antenna comprises an antenna body, and the full-die-cutting ultrahigh frequency electronic tag antenna is characterized in that the antenna body is provided with a chip binding positioning point formed by a die cutting mode and a chip binding point formed by the die cutting mode. According to the invention, the problem of how to avoid applying an etching process to produce the chip binding point and the chip binding positioning point of the ultrahigh frequency electronic tag antenna in the prior art is solved.

The invention relates to the technical field of nitrocellulose membrane preparation, in particular to a preparation process of a nitrocellulose membrane, which comprises the following steps: (1) preparing nitrocellulose membrane slurry; (2) filtering the membrane slurry obtained in the step (1); (3) coating and forming the membrane slurry in the step (2), and preparing a nitrocellulose membrane, namely an NC membrane, by adopting a stepped heating mode; (4) treating the surface of a NC membrane; wherein the surface treatment of the NC membrane comprises the step of treating the surface of the NC membrane through hot water and PBS in sequence; and (5) drying the NC membrane. The preparation process can be applied to production of the NC membrane, bubbles and impurities generated by the NC membrane can be effectively reduced, and the production quality of the NC membrane is improved.

The invention relates to a muddy water separator used for town and country construction and a technology thereof, and belongs to the technical field of sludge treatment. The muddy water separator comprises a water clearing agent tank, a flocculating agent tank, a blending pool, a flocculating pool, an oxidation pool, a water clearing pool and a squeezing mechanism, wherein the water clearing agent tank is communicated with the blending pool. The technology comprises the steps of pumping sludge water ready to be treated into the blending pool and conducting treatment on the sludge water, afterwards, sending the sludge water to the flocculating pool and conducting standing treatment on the sludge water, sending upper-layer sludge water to the oxidation pool and conducting treatment on the upper-layer sludge water, and sending lower-layer sludge to the squeezing mechanism through a sludge entrance to be subjected to dehydration. The muddy water separator used for town and country construction is applicable to desilting in urban construction and river channels, and has the advantages of being trenchless, short in process, convenient to operate, flexible to implement and the like.

The invention discloses an aluminum alloy nickel plating pretreatment method, which comprises cleaning, alkaline micro-etching and acidic neutralization: an acidic neutralization solution is a mixed solution of sulfuric acid and hydrogen peroxide; first zinc immersion: a zinc immersion solution is a mixed solution composed of zinc oxide, sodium hydroxide, lactic acid or / and malic acid and water; stripping: a stripping solution is a low-concentration HNO3 solution; second zinc immersion: the zinc immersion solution is the same as the zinc dipping solution used in the first time; and zinc reduction: a zinc reduction solution comprises glacial acetic acid, succinic acid, lactic acid and malic acid. According to the method, the pollution of zinc ions to a chemical nickel plating solution or anickel electroplating solution is greatly reduced, the service life of the chemical nickel plating solution or the nickel electroplating solution is prolonged, tank replacement of the chemical nickelplating solution or the nickel electroplating solution is reduced, and the binding force of the plating layer is kept at a high level. According to the method, the dosage of chemicals such as phosphate, zinc oxide and nitric acid can be greatly reduced, the waste liquid generated by the method is easier to treat, and the contained heavy metal zinc ions are easy to chemically settle and are separated from the waste liquid.

The invention provides a laser processing system and method for monitoring laser power changes. The laser processing system comprises a high-power laser device, a beam expander, a first beam splitter,a positive lens, a second beam splitter, an integrating rod, an energy detector, a negative lens, a PSD detector, a cutting head and a workpiece table. A laser energy detection system adjusts the emergent power of the high-power laser device, so that the laser power in the laser processing process is kept stable. A position detection system monitors the position change condition of a laser beam emitted by the laser device. The first beam splitter and the cutting head are placed on respective one-dimensional motion platforms correspondingly, and the center of the laser beam is always kept coinciding with the optical axis of the cutting head by driving the first beam splitter to move in the horizontal direction and driving the cutting head to move in the horizontal orthogonal direction. Inthe long-term laser processing process, it is guaranteed that cut materials have good consistency, and the yield of laser processing in industrial application is effectively guaranteed for a long term.

The invention discloses a printing and dyeing waste water treatment system and process with low yield of sludge. According to the invention, an intake pump, a valve, a flowmeter, an anaerobic hydrolysis zone, a biological selection zone and a biologically reinforced predation aerobic sludge reduction zone are successively connected; the anaerobic hydrolysis zone is provided with a diving mixer and a biological filling material carrier, the biological selection zone is provided with a diving mixer, an aeration device is provided at the bottom of the biological selection zone and the biologically reinforced predation aerobic sludge reduction zone, a metazoa culture adding groove is connected with the biologically reinforced predation aerobic sludge reduction zone, the upper part of the biologically reinforced predation aerobic sludge reduction zone is connected with the bottom of a secondary settling tank, the upper part of the secondary settling tank is provided with an outlet pipe, and sludge at the bottom of the secondary settling tank is connected with the bottom of the anaerobic hydrolysis zone and the biological selection zone through a settling zone sludge reflux pump and a sludge pipe. The printing and dyeing waste water treatment process with low yield of sludge in the invention is applicable to all the activated sludge processes and variant processes thereof and can be used for newly building a construction and reconstructing a built construction.

The invention discloses a maintenance-free rural domestic sewage treatment device, and relates to the field of domestic sewage treatment. The maintenance-free rural domestic sewage treatment device comprises a sand settling pond, a pump I, a reactor I, a pump II, a reactor II, a pump III, a drain pipe, an electric control cabinet and a remote monitoring system. The electric control cabinet is connected with the pump I, the pump II and the pump III, the sand settling pond, the pump I, the reactor I, the pump II, the reactor II, the reactor III and the drain pipe are sequentially connected withone another, the reactors are used for accommodating biological carriers, microorganisms can be attached to the biological carriers, and the remote monitoring system is used for monitoring water levelprotection heights of the reactors. The maintenance-free rural domestic sewage treatment device has the advantages that water can be uniformly distributed without dead spaces, can be quickly drainedand re-aerated and can be sufficiently uniformly re-aerated, biological film cultivation procedures can be omitted, the maintenance-free rural domestic sewage treatment device can run in a programmedmanner, and full-automatic unattended operation further can be implemented; the water level protection heights of the reactors can be remotely monitored, so that the biological carriers can be timelyreplaced or cleaned, and the maintenance-free rural domestic sewage treatment device is high in organic load impact resistance.