62 results about "Mixed liquor suspended solids" patented technology

A system for enhancing an activated sludge process that includes at least one aeration tank subsystem for receiving a flow a wastewater and for introducing dissolved oxygen to a population of microorganisms to promote growth of biological flocs in a mixed liquor defined by a concentration of mixed liquor suspended solids. A weighting agent impregnation subsystem includes an impregnation tank for mixing the mixed liquor, virgin weighting agent, and recycled weighting agent to impregnate the weighting agent into biological flocs suspended in the mixed liquor to form weighted biological flocs. A flocculant injection port located downstream from at least one aeration tank for introducing a flocculant to the mixed liquor for enhancing settling and thickening of the weighted biological flocs and for providing agglomeration of non-impregnated biological flocs and/or partially impregnated biological flocs with weighted biological flocs. At least one clarifier separates and collects the weighted biological flocs from the mixed liquor to provide a secondary effluent and a settled sludge. A return activated sludge subsystem recycles the majority of the settled sludge to the at least one aeration tank. A weighting agent recovery subsystem removes and shears the remaining settled sludge and recovers the weighting agent therefrom and reintroduces the weighting agent to the at least one aeration tank. A wasting subsystem wastes the remaining sludge of the weight agent recovery subsystem to control the population of the microorganisms in the mixed liquor.

A wastewater treatment process is provided that entails both a biological or activated sludge process and a ballasted flocculation process. A first stream of wastewater is directed to a biological system for biologically treating the wastewater. The biological treatment process produces a first effluent and a first sludge. In cases where the biological system is an activated sludge process, the first sludge is recycled. A second stream of wastewater is directed to a ballasted flocculation system. The second stream of wastewater can be a stream independent of the first stream of wastewater or can be derived from the wastewater passing through the biological system. Sludge in the form of activated sludge or mixed liquor from the biological system is mixed with a second stream of wastewater in the ballasted flocculation system for the purpose of biologically treating the second stream of wastewater. Forming a part of the ballasted flocculation system is a settling tank that produces a second effluent and a second sludge. The second sludge is routed to a separator where granular material that forms a ballast in the process is separated and recycled. To effectively remove suspended solids from the wastewater passing through the ballasted flocculation system, the second sludge recycle rate is controlled or maintained at a flow rate of about 15% and higher of the influent flow rate to the ballasted flocculation system. Furthermore, as the mixed liquor suspended solids (MLSS) concentration increases from, for example, 1000 mg/l to about 4000 mg/l, the recycle rate of the second sludge may be varied from about 15% to about 40% of the influent flow rate to the ballasted flocculation system.

Methods and apparatus for treating wastewater are described, one method embodiment including the steps of flowing a mixed liquor suspended solids to a high rate clarification stage, forming a clarifier effluent, a first waste activated sludge stream, and a return waste activated sludge stream. The high rate clarifier effluent stream then flows to a membrane stage that includes a membrane media, producing a membrane reject (retentate) stream and a treated effluent (permeate) stream. Optionally, the methods include routing a screened raw wastewater to an anaerobic and/or aerated anoxic stage and introducing a gas comprising oxygen to the wastewater during the aerated anoxic stage, and optionally allowing the product of this stage to flow to an aeration stage prior to the high rate clarification stage.

The invention discloses an integral controller applied to an aeration tank for sewage treatment. The integral controller comprises a central processor and an analog input circuit, an on-off input circuit, a dissolved oxygen control output circuit, a backwash control output circuit, a communication module, a parameter setting key, a keyboard, a display module, a remote fault alarm circuit, a temperature and humidity data acquisition circuit, a calendar clock module, a network interface circuit, an SD card storage module and a power supply module. The integral controller disclosed by the invention realizes control on dissolved oxygen of a blower by a combination mode of relative input parameters such as dissolvent oxygen content, oxidized reduction potential, mixed liquid suspended solid, suspended solid, water temperature, pipeline pressure, air flow rate and the like, simultaneously realizes intelligent control on backwash, and organically combines the two control processes to optimize the treatment, thereby really fulfilling the aims of ensuring water quality and fully saving energy, and the integral controller not only has the characteristics of quite low cost, strong function, high energy conservation and easiness in popularization, but also is convenient to install and debug.

The invention discloses a method for improving precipitation performance of filamentous bulking sludge. The method comprises the steps of 1), crushing and screening organics, such as corn, wheat, sorghum and rice; 2), measuring the concentration of activated sludge in a biological reaction tank such as an aeration tank and a precipitation tank, and quantifying filamentous bacteria for the bulking sludge; 3), putting into the filamentous bulking sludge according to the weight ratio for preparing the screened organics per gram of the sludge or the weight ratio for preparing the organics per meter of the length of each filamentous bacterium; 4), keeping other conditions in the biological reaction tank unchanged, and increasing stirring; and 5), measuring the MLSS (mixed liquor suspended solid) value and the SVI (sludge volume index) value in the biological reaction tank, so that the improvement of the precipitation performance of the filamentous bulking sludge is achieved. The method can enable the filamentous bacteria causing sludge bulking to grow in adhering and twining manners and change a spreading growing manner of the filamentous bacteria, so that the filamentous bacteria grow densely, the problem that solids and liquid are hard to separate is solved, and the effluent quality of sewage treatment is improved.

A method for regulating and controlling sludge quality in membrane bioreactor belongs to the technical field of biological treatment for waste water. In the invention, simulation waste water is taken as treating object, the EPS content in the sludge is regulated and controlled by sequencing batch operation instead of continuous operation of the traditional MBR process so as to change settlement performance and hydrophobicity of the sludge and delay membrane pollution. The water discharged by the MBR system arrives at first-level A standard of pollutant discharge standard of the national town sewage treatment plant and quality standard for city sewage recycling-city water use; the suspended solid concentration MLSS in the mixed liquid in the MBR is 8.4-13.0 g/L; the volatile solid concentration VSS is 4.7-10.4 g/L; the relative hydrophobicity of the sludge is 66.5-88.6%; the sludge volume index SVI is 32.2-40.7 mL/gMLSS; and the total weight of ecto-polymer of sludge EPS is 19.3-26.5 mg/gVSS. The method has simple operation, low operation cost, good stability, low residual sludge yield, good water quality and high theoretical value, thereby being capable of being applied in engineering practice.

A high-ammonia-nitrogen wastewater treatment method adopts a mechanical grating groove, an oil separation tank, a regulating reservoir, a carbon source tank, efficient combined floatation, a CASS (Commanded Active Sonobuoy System) reactor, a Roots blower, a CASS reflux pump, a middle pond, an MBBR (Moving Bed Biofilm Reactor) contact oxidation pond, a secondary sedimentation tank, an alkali tank, a monitoring pool, an accident pool, a silt pool and a silt filter system. The high-ammonia-nitrogen wastewater treatment method adopts on-line pH (Potential of Hydrogen), COD (chemical oxygen demand), NH3-N (ammonia nitrogen),, MLSS (Mixed Liquor Suspended Solids), DO (Dissolved Oxygen) and ORP (Oxidation Reduction Potential) monitors and a liquid indicator as supplements. The treatment method mainly aims at pollutants including organics of NH3-N, TN, COD (BOD5) (Biochemical Oxygen Demand 5), SS (suspended solids) and oil type pollutants. The pretreatment on the oil type pollutants and the SS is conducted in a way of oil separation and floatation. The principle of removing the NH3-N by a biochemical method is that nitration and denitrification are conducted through a two-stage biochemical treatment process, the ammonia nitrogen is converted to nitrite nitrogen and nitrate nitrogen by the nitration, then a carbon source is supplied to conduct the denitrification so as to convert the nitrate nitrogen to nitrogen, and therefore, denitrification in a true sense is achieved. The high-ammonia-nitrogen wastewater treatment method can be applied to treatment of industrial wastewater containing methyl alcohol, synthesis ammonia, urea, ammonium nitrate, carbonic acid hydrogenous amine and the like.

The invention discloses a method for improving treatment efficiency of a sewage plant by utilizing a bypass sludge activity enhancing technology. The method comprises the following steps of: enabling sewage after primary pretreatment to pass through a main biological tank for secondary treatment and then flow into a secondary sedimentation tank, performing sludge-water separation in the secondary sedimentation tank, discharging supernatant fluid of the secondary sedimentation tank or enabling the supernatant fluid to be subjected to follow-up advanced treatment, conveying activated sludge concentrated by the secondary sedimentation tank to a bypass biological tank through a sludge reflux pump and a pipeline, and enabling the activated sludge to reflux to the water inlet end of the main biological tank after aerobic, anoxic and anaerobic biochemical process treatment in the bypass biological tank. According to the method disclosed by the invention, the total amount of the activated sludge in the sewage plant can be greatly improved by simply transforming (combined building) the existing biological tank or only newly building a small-volume bypass biological tank (separate building), and the total retention quantity of MLSS (mixed liquor suspended solids) of the biological system disclosed by the invention can be improved by 18%-100% in comparison with the process in the prior art. The method disclosed by the invention is suitable for not only new building of sewage plants, but also upgrade and standard-raising transformation of the existing sewage plants; and the method disclosed by the invention has the advantages of high efficiency, low consumption and low investment.

The invention discloses an energy-saving and consumption-reduction stable operation device and a method for enhancing aerobic granule sludge. The device comprises a water inlet unit, a reactor main body, an aeration unit, a water outlet unit and a time control unit, wherein the time control unit is a programmable automatic time controller, and comprises a time control switch and a liquid level meter probe; the time control switch controls a cyclic process of reactor operation; and water inflow is controlled by the liquid level meter probe via electrical signal conduction. An operation cycle is divided into water inlet, standing, aeration, settling and water outlet stages; sludge is inoculated; MLSS (mixed liquor suspended solid) is inoculated as 4-6g/L; an inlet water matrix is town sewage; COD (chemical oxygen demand) concentration of inlet water is 300-800mg/L; a height-diameter ratio of 4-8 and a drainage ratio of 30-70% are adopted; the operation cycle is 4-6h; the settling time is 5-15min; and the aeration time is 3-5h. According to the device and the method, the aerobic granule sludge which is large in granule size, high in settling velocity, stable in structure and rich in flora can be formed, and the problems of high aeration energy consumption, easy sludge bulking in an operation process, unstable long-time operation of a system and the like in the prior art are solved.

The invention provides a method for rapidly culturing autotrophic nitrogen removal granule sludge under conditions of low substrate concentration and high ascending velocity and belongs to the technical field of biological sewage treatment. The method provided by the invention comprises the following steps of: crushing a small amount of anaerobic ammonia oxidation granule sludge, uniformly mixing the crushed anaerobic ammonia oxidation granule sludge with common anaerobic fermentation sludge and aerobic activated sludge and charging the obtained mixture into an upflow anaerobic sludge blanket (UASB) reactor. Artificially synthesized low-ammonia-nitrogen wastewater (total nitrogen is 30-50mg/L) is taken as inflow of the UASB, a continuous flow operation mode is adopted, the ascending velocity of the UASB is 4-7m/h constantly, and culturing is carried out for 50-80 days, so that the high-efficiency autotrophic nitrogen removal granule sludge is obtained. The granule sludge prepared by adopting the method is higher in content of anaerobic ammonia oxidation bacteria, is applicable to treatment of low-ammonia-nitrogen wastewater and is a wastewater biological treatment product with a wide market prospect, wherein the content of anaerobic ammonia oxidation bacteria in the granule sludge is 1.36*10<8>copy/g-MLSS (mixed liquor suspended solids); and when the granule sludge is added into an autotrophic nitrogen removal reactor, the total nitrogen removal rate of the reactor and operation stability of the reactor can be effectively improved, and the problems that urban sewage quantity is high and the autotrophic nitrogen removal granule sludge is easy to run off are solved.

A method and system for controlling dissolved oxygen levels in a secondary treatment system of a wastewater treatment facility that can employ a membrane bioreactor in which oxygen introduction into mixed liquor is controlled to prevent bulking and minimize generation of extra cellular polymeric substances. The control is exercised by insuring that dissolved oxygen levels within the mixed liquor do not fall below a minimum system level at which microorganism stress would occur. This is done by setting a minimum dissolved oxygen level control point equal to a sum of the minimum system level and an adjustment factor determined on the basis of oxygen uptake rate and time delays inherent in sensing oxygen levels and changes thereof within the mixed liquor. The minimum system dissolved oxygen level can be continually calculated on the basis of an inferred food to mass ratio that would vary with sensed mixed liquor suspended solids.

The invention relates to a biological treatment method for wastewater in adipic acid production, which adopts anaerobic + A/O coupling and comprises the following steps: (1) pretreatment: adjusting the pH of raw water to be 6-6.5, and adding coagulants and coagulant aids for coagulation and sedimentation; and delivering the wastewater into a mixing tank after precipitation to supplement trace elements and inorganic phosphorus, and making the nutrition of the mixed wastewater comply with the requirement that the ratio of CODCr to P is (200-300):1; (2) anaerobic treatment: making the pretreatedwastewater subject to anaerobic reaction with the water temperature of 35 DEG C plus or minus 2.5 DEG C and the VFA (volatile fatty acid) concentration of less than 10mmol/L; and adjusting the pH of the added water to make the pH of the anaerobic effluent 8.0-8.5; (3) A/O treatment: adding the wastewater into an A/O reactor after anaerobic treatment to supplement inorganic phosphorus with the ratio of CODCr to N to P being 100:5:1; and controlling the pH value to be 7.0-9.0 at the room temperature, and the MLSS (mixed liquor suspended solids) value to be above 3000mg/L, and thus discharging the water after precipitation and satisfaction of standards.

The invention provides an online measuring device for specific oxygen uptake rate (SOUR) of activated sludge in a sewage treatment system. The online measuring device is characterized by comprising a pre-aeration unit, an SOUR metering unit, a biomass metering unit, and a data control and calculation unit, wherein the pre-aeration unit comprises a first electric control valve, a first water pump, a second water pump, a pre-aeration tank and an aeration system, wherein the SOUR metering unit comprises a second electric control valve, a third electric control valve, an airtight breathing chamber, a dissolved oxygen meter and an electromagnetic stirrer, the biomass metering unit comprises a fourth electric control valve, a fifth electric control valve and an active micro-biomass online detection system, and the data control and calculation unit comprises a data acquisition card, a computer and a software program system. According to the online measuring device, the total active micro-biomass in the activated sludge system is adopted for replacing mixed liquor suspended solids (MLSS) or mixed liquor volatile suspended solids (MLVSS) in a conventional SOUR calculation method so as to accurately measure the SOUR of the activated sludge.

The invention provides a method for treating COW-DM sewage with high chemical stability and biodegradation difficulty. The method comprises the following steps in sequence: catalytic ozonation, A/O (anaerobic/oxic) tank biochemical reaction and sludge-water separation, and the emission standard is met finally, wherein 30-50 ppm of a solid catalyst is added in a catalytic ozonation reaction process, the height of the solid catalyst is 3-4 m, pH is 7-9, the temperature is 25-30 DEG C, the solid catalyst adopts metal or metal oxide supported on a carrier, the retention time for catalytic ozonation is 1-1.5 h, the ozone contact time is 20-30 min, the A/O tank biochemical reaction adopts an A tank and an O tank, the DO (dissolved oxygen) of the A tank is smaller than 0.5 mg/L, pH is 6.5-7.5, the DO of the O tank is 1.5-4.0 mg/L, pH is 7-8, MLSS (mixed liquor suspended solids) is controlled to be 3-6 g/L, the temperature is 20-35 DEG C, the retention time is 6-10 h, denitrification is performed in the A tank, and the required carbon source proportion BOD (biochemical oxygen demand)/TN (total nitrogen) is larger than 4.

The invention discloses a town sewage treatment system which comprises a water inlet tank, a sedimentation tank, an oxidation ditch, a disinfection channel, a water outlet and a control system. The town sewage treatment system is characterized in that the water inlet tank, the sedimentation tank, the oxidation ditch, the disinfection channel and the water outlet are sequentially connected with treated sewage; the control system controls the valve distribution of the water inlet tank, the sedimentation tank, the oxidation ditch, the disinfection channel and the water outlet through detection equipment and a relay unit; an H2S probe and a level sensor are arranged in the water inlet tank; an SS (suspended solid) probe and a PH (potential of hydrogen) probe are arranged in the sedimentation tank; an MLSS (mixed liquor suspended solid) probe and a dissolved oxygen probe are arranged in the oxidation ditch; and a PH probe and a COD (chemical oxygen demand) probe are arranged in the disinfection channel. The invention combines manual control and automatic control, facilitates the operation, saves the energy, lowers the cost, greatly facilitates the maintenance and repair, has a wide application range and can meet the requirements for sewage treatment of various scales.

The invention provides a method for biosynthesis of a hydroxybutyric acid and hydroxycaprylic acid co-polymer from sludge. Aerobic domestication is performed on the activated sludge with sodium laurate used as a carbon source. Each domestication period is 12-36 h and adopts the running manner of water inlet, aerobic aeration, sludge discharging, sedimentation and water outlet. Preferably, the total time from stopping of aerobic aeration to re-aeration each time does not exceed 30 min. In each period, sampling is performed before sludge discharging, MLSS (mixed liquor suspended solids), the pH value and DO (dissolved oxygen) are tested, and after the values are stabilized, sludge domestication is completed. After sludge domestication is stabilized, the next step of a test for synthesis of the hydroxybutyric acid and hydroxycaprylic acid co-polymer from the sludge can be conducted. Production of a biochemical product with the higher added value from a cheap substrate, namely, the activated sludge, can be a new way for recycling of the sludge.