I. What is the sewage regulator?
Sewage regulator refers to: in sewage treatment, used to regulate the flow of incoming and outgoing water structures.
Mostly used in factories sewage station, industrial park sewage plant.
II. Sewage regulator, is it important?
Very important! Especially industrial wastewater, changing conditions, uneven water quality and unstable water, easy to reduce the overall effect of sewage treatment, and can not give full play to the design load of the treatment equipment.
The setting of the regulating tank can make the wastewater unaffected by changes in peak flow or peak concentration of wastewater.
III. What are the specific roles of the sewage regulating tank?
Regulating pool can be summarised as three major roles, respectively: regulating water quantity + balanced water quality + pretreatment.
Specifically, the role of regulation is mainly reflected in the following aspects:
1. Provide a buffer capacity of the sewage treatment load, to prevent drastic changes in the load of the treatment system;
2. to reduce fluctuations in the flow of sewage into the treatment system, so that the dosing rate of chemicals used in the treatment of sewage is stable and suitable for the capacity of the dosing equipment;
3. in controlling the pH value of the sewage and stabilising the water quality, the neutralisation capacity of different sewages themselves can be utilised to reduce the consumption of chemicals in the neutralisation process;
4. preventing high concentrations of toxic substances from entering directly into the biochemical treatment system;
5. when the factory or other systems temporarily stop discharging sewage, it can still continue to input sewage to the treatment system to ensure the normal operation of the system.
IV. What are the classifications of the regulating tank?
According to the type of regulating pool can be divided into 2 categories, water quantity regulating pool and water quality regulating pool.
Five. How to understand the water regulator?
Water regulation is relatively simple, generally only need to set up a simple pool, to maintain the necessary volume of regulating pool and make the water uniform can be.
Wastewater treatment in the simple water regulation in two ways: one for the line of regulation, inlet water is generally used gravity flow, water pumps to enhance the highest water level in the pool is not higher than the design level of the water intake pipe, the lowest water level for the dead water level, the effective depth of water is generally 2 ~ 3 m. The other is outside the line of regulation, regulating the pool is located in a bypass, when the sewage flow rate is too high, the excess sewage with a pump into the regulating pool when the flow rate is below the design flow rate, and then from the regulating pool back to the pool. When the flow rate is lower than the design flow rate, and then from the adjustment pool back to the catchment well, and sent to the subsequent treatment.
Outside the line of regulation compared with the line of regulation, the regulation pool is not subject to the height of the water intake pipe, construction and drainage is more convenient, but the amount of water to be regulated need to be lifted twice, consuming power. Generally designed for in-line regulation.
Six. How to understand the water quality adjustment pool?
The task of water quality regulation is a different time or different sources of sewage mixing, so that the outflow of water quality is more uniform, in order to avoid subsequent treatment facilities to withstand excessive impact load.
1. Addition of power regulation: addition of power is in the regulating pool, the use of additional impeller mixing, blower air mixing, pump circulation and other equipment for mandatory regulation of water quality, its equipment is relatively simple, good operating results, but high operating costs.
2. Differential flow mode regulation: the use of differential flow mode of forced regulation, so that different times and different concentrations of sewage water quality of their own hydraulic mixing, this way basically no running costs, but the equipment is more complex.
Seven. Why do some regulating pool also need to get aeration equipment?
The main role of the regulator is to regulate the amount of water and water quality, but because the water into the regulator also contains a certain amount of suspended solids, the regulator does not add mixing equipment will make the suspended solids precipitation, reduce the regulator volume, plus aeration equipment is mainly for the purpose of mixing, aeration mixing than the mechanical mixing of maintenance is small, an investment of less, easier to achieve. In addition some sewage plants can improve the biochemistry of sewage through pre-aeration.
What is the impact of excessive chlorine ion content in sewage biochemical treatment and the elimination of countermeasures?
Microorganisms grow well under equal osmotic pressure, such as microorganisms in the mass of 5 ~ 8.5g / L NaC1 solution; in low osmotic pressure (p (NaC1) = 0.1g / L), a large number of solution water molecules penetrate into the body of the microorganisms, microbial cell expansion, severe rupture, resulting in the death of microorganisms; in the high osmotic pressure, (p (NaC1) = 200g / L), microbial Under high osmotic pressure, (p(NaC1)=200g/L), a large number of water molecules in the body seeped out of the body (i.e.: dehydration), so that the cells undergo plasmic wall separation.
Microbial unit structure is the cell, the cell wall is equivalent to semi-permeable membrane, in the chlorine concentration is less than or equal to 2000mg / L, the cell wall can withstand the osmotic pressure of 0.5-1.0 atmospheric pressure, even if coupled with the cell wall and cytoplasmic membrane has a certain degree of toughness and elasticity, the cell wall can withstand the osmotic pressure will not be greater than 5-6 atmospheric pressure.
But when the concentration of chloride ions in aqueous solution in 5000mg / L or more, the osmotic pressure will increase to about 10-30 atmospheric pressure, in such a large osmotic pressure, microbial water molecules will be a large number of water molecules penetrate into the solution outside the body, resulting in the loss of cellular water and the occurrence of plasmalemma wall separation, and in severe cases, microbial death. Engineering experience data show that: when the concentration of chlorine in the wastewater is greater than 2000mg / L, the activity of microorganisms will be suppressed, COD removal rate will be significantly reduced; when the concentration of chlorine ions in the wastewater is greater than 8,000mg / L, it will result in the expansion of the sludge volume, the water surface of the flooding of the large number of bubbles, microorganisms will be killed one after another.
Inhibit the performance of sludge activity
When the biochemical system chlorine ion concentration drastically sudden change, sludge carbonation performance and nitrification performance will be weakened quickly or even disappear, resulting in a significant decrease in COD removal rate, nitrification process nitrite accumulation, even if you improve the dissolved oxygen in the sewage, the effect is not obvious. That is to say, the activated sludge has a certain tolerance to the concentration of chloride ions, and when the concentration of chloride ions exceeds a certain value, the degradation capacity of the system decreases until the system loses the treatment capacity.
The sudden change of chloride ion is more disturbing to the system than the gradual change of chloride ion. The rate of organic matter degradation decreases as the chloride ion rises, so low F/M (nutrient to activated sludge ratio by mass) is more suitable for the treatment of wastewater containing chloride ions.
Chloride ions altered the composition of microorganisms in the sludge and changed the sedimentability and effluent SS of the sludge, leading to severe sludge loss, decrease in the concentration of activated sludge, increase in the sludge index, and decrease in the 30-minute settling rate.
The results of activated sludge microscopic examination showed that the low salinity showed that the biological phase in it was relatively rich, with a wide variety of filamentous bacteria, bacterial colloid and protozoa, and the activated sludge particles were very large, the bacterial colloid was closed, and the flocs had a certain degree of compactness. With the increase of chlorine ion concentration of incoming water, when the chlorine ion mutation from the original 150mg / L to 1000mg / L, filamentous bacteria and protozoa basically do not exist, and the bacterial colloid becomes more dense, at this time the flocs become small, unusually tight. The degradation of organic matter in sewage mainly depends on the common action of a large number of microorganisms in sewage, and the increase of chlorine ions leads to the reduction of the number of genera in microorganisms in activated sludge, which leads to the decrease of organic matter degradation rate.
Sewage biochemical treatment system in the chlorine ion content over how much will have an impact on microorganisms
1. With the increase of salinity, the growth of activated sludge is affected. Its growth curve changes in: the adaptation period becomes longer; logarithmic growth period growth rate becomes slower; deceleration of the duration of the growth period becomes longer;
2. Salinity enhances the respiration of microorganisms and cell lysis;
3. salinity reduces the biodegradability and degradability of organic matter. So that the removal rate and degradation rate of organic matter decreased. Although the extension of aeration time can improve the removal efficiency of organic matter, but over a certain period of time, with the increase in the aeration time of organic matter removal rate rises slowly. On economic considerations, by extending the aeration time to improve the removal rate of high salt organic matter is not desirable;
4. Inorganic salts make the sedimentation of activated sludge to strengthen. With the increase of salinity, the sludge index decreases;
5. domestication of activated sludge for treatment of high-salt effluents is a necessary tool for the success of the treatment system. The domestication of activated sludge is the process of adapting the microbial metabolism to the high salinity environment and allowing salt tolerant bacteria to proliferate.
How to eliminate the effect of chloride ions?
1. Domestication of activated sludge
By gradually increasing the chlorine ion content of biochemical feed water, microorganisms will balance the intracellular osmotic pressure or protect intracellular protoplasm through their own osmotic pressure regulating mechanisms, which include gathering low molecular weight substances to form a new extracellular protective layer, regulating their own metabolic pathways, changing the genetic composition, etc. Therefore, normal activated sludge can be adapted to the high salinity environment in a short time.
Therefore, normal activated sludge can be domesticated for a certain period of time to treat high-chlorine ion wastewater within a certain chlorine ion degree range. Although activated sludge can improve the chlorine ion tolerance range of the system and improve the treatment efficiency of the system through domestication, the microorganisms in the domesticated activated sludge have a limited tolerance range for chlorine ions and are sensitive to changes in the environment. When the chlorine ion environment changes suddenly, the adaptation of microorganisms will disappear immediately. Domestication is only a temporary physiological adjustment of microorganisms to adapt to the environment and does not have genetic characteristics. The sensitivity of this adaptation is very unfavourable to sewage treatment.
The domestication time of activated sludge is generally 7-10d, domestication can improve the degree of tolerance of sludge microorganisms to salt concentration, the reduction of activated sludge concentration in the early stage of domestication is due to the increase of salt solution is toxic to microorganisms, so that some microorganisms die, which is shown as a negative growth, and microorganisms adapted to the environment begin to reproduce in the late stage of domestication, so the concentration of activated sludge increases. Taking the removal of COD by activated sludge in 1.5% and 2.5% sodium chloride solution as an example, the removal of COD in the early and late stages of domestication were 60% and 80% and 40% and 60% respectively.
2. Dilution of wastewater with high chloride ion concentration
In order to reduce the concentration of chloride ions in the biochemical system, the influent water can be diluted so that the chloride ions are lower than the value of the toxic domain, and the biological treatment will not be inhibited. Its advantage is that the method is simple, easy to operate and manage; the disadvantage is that it increases the scale of treatment, infrastructure investment and operating costs. For Yangli wastewater plant, due to the large amount of water and continuous operation, even through the online instrumentation measured at a certain time the high concentration of chloride ions, but the operability of targeted dilution is poor. Therefore, this method is more suitable for factories and enterprises that produce wastewater with high chloride ion concentration.
3. Choose a reasonable process
For different concentrations of chloride ion content to choose different treatment processes, appropriate choice of anaerobic process to reduce the range of chlorine ion concentration in the aerobic section of the back sequence.
4.Increase DO in biochemical system
Appropriately increase the dissolved oxygen in the biochemical system to ensure the activity of activated sludge.
5. Discharge the remaining sludge
Increase the discharge of the remaining activated sludge to ensure that the sludge grows in the logarithmic growth period, in order to improve the removal efficiency of pollutants.
6. Adding nutrient source
The metabolism of sludge is accelerated when dissolved oxygen is increased. In order to ensure the metabolism of sludge, we should make sure that the nutrition is sufficient, and if necessary, we can add certain nutrient sources to ensure the activity of sludge.
| Phosphonates Antiscalants, Corrosion Inhibitors and Chelating Agents | |
| Amino Trimethylene Phosphonic Acid (ATMP) | CAS No. 6419-19-8 |
| 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP) | CAS No. 2809-21-4 |
| Ethylene Diamine Tetra (Methylene Phosphonic Acid) EDTMPA (Solid) | CAS No. 1429-50-1 |
| Diethylene Triamine Penta (Methylene Phosphonic Acid) (DTPMPA) | CAS No. 15827-60-8 |
| 2-Phosphonobutane -1,2,4-Tricarboxylic Acid (PBTC) | CAS No. 37971-36-1 |
| 2-Hydroxy Phosphonoacetic Acid (HPAA) | CAS No. 23783-26-8 |
| HexaMethyleneDiamineTetra (MethylenePhosphonic Acid) HMDTMPA | CAS No. 23605-74-5 |
| Polyamino Polyether Methylene Phosphonic Acid(PAPEMP) | |
| Bis(HexaMethylene Triamine Penta (Methylene Phosphonic Acid)) BHMTPMP | CAS No. 34690-00-1 |
| Hydroxyethylamino-Di(Methylene Phosphonic Acid) (HEMPA) | CAS No. 5995-42-6 |
| Salts of Phosphonates | |
| Tetra sodium salt of Amino Trimethylene Phosphonic Acid (ATMP•Na4) | CAS No. 20592-85-2 |
| Penta sodium salt of Amino Trimethylene Phosphonic Acid (ATMP•Na5) | CAS No. 2235-43-0 |
| Mono-sodium of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP•Na) | CAS No. 29329-71-3 |
| (HEDP•Na2) | CAS No. 7414-83-7 |
| Tetra Sodium Salt of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP•Na4) | CAS No. 3794-83-0 |
| Potassium salt of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP•K2) | CAS No. 21089-06-5 |
| Ethylene Diamine Tetra (Methylene Phosphonic Acid) Pentasodium Salt (EDTMP•Na5) | CAS No. 7651-99-2 |
| Hepta sodium salt of Diethylene Triamine Penta (Methylene Phosphonic Acid) (DTPMP•Na7) | CAS No. 68155-78-2 |
| Sodium salt of Diethylene Triamine Penta (Methylene Phosphonic Acid) (DTPMP•Na2) | CAS No. 22042-96-2 |
| 2-Phosphonobutane -1,2,4-Tricarboxylic Acid, Sodium salt (PBTC•Na4) | CAS No. 40372-66-5 |
| Potassium Salt of HexaMethyleneDiamineTetra (MethylenePhosphonic Acid) HMDTMPA•K6 | CAS No. 53473-28-2 |
| Partially neutralized sodium salt of bis hexamethylene triamine penta (methylene phosphonic acid) BHMTPH•PN(Na2) | CAS No. 35657-77-3 |
| Polycarboxylic Antiscalant and Dispersant | |
| Polyacrylic Acid (PAA) 50% 63% | CAS No. 9003-01-4 |
| Polyacrylic Acid Sodium Salt (PAAS) 45% 90% | CAS No. 9003-04-7 |
| Hydrolyzed Polymaleic Anhydride (HPMA) | CAS No. 26099-09-2 |
| Copolymer of Maleic and Acrylic Acid (MA/AA) | CAS No. 26677-99-6 |
| Acrylic Acid-2-Acrylamido-2-Methylpropane Sulfonic Acid Copolymer (AA/AMPS) | CAS No. 40623-75-4 |
| TH-164 Phosphino-Carboxylic Acid (PCA) | CAS No. 71050-62-9 |
| Biodegradable Antiscalant and Dispersant | |
| Sodium of Polyepoxysuccinic Acid (PESA) | CAS No. 51274-37-4 |
| CAS No. 109578-44-1 | |
| Sodium Salt of Polyaspartic Acid (PASP) | CAS No. 181828-06-8 |
| CAS No. 35608-40-6 | |
| Biocide and Algicide | |
| Benzalkonium Chloride(Dodecyl Dimethyl Benzyl ammonium Chloride) | CAS No. 8001-54-5, |
| CAS No. 63449-41-2, | |
| CAS No. 139-07-1 | |
| Isothiazolinones | CAS No. 26172-55-4, |
| CAS No. 2682-20-4 | |
| Tetrakis(hydroxymethyl)phosphonium sulfate(THPS) | CAS No. 55566-30-8 |
| GLUTARALDEHYDE | CAS No. 111-30-8 |
| Corrosion Inhibitors | |
| Sodium salt of Tolyltriazole (TTA•Na) | CAS No. 64665-57-2 |
| Tolyltriazole (TTA) | CAS No. 29385-43-1 |
| Sodium salt of 1,2,3-Benzotriazole (BTA•Na) | CAS No. 15217-42-2 |
| 1,2,3-Benzotriazole (BTA) | CAS No. 95-14-7 |
| Sodium salt of 2-Mercaptobenzothiazole (MBT•Na) | CAS No. 2492-26-4 |
| 2-Mercaptobenzothiazole (MBT) | CAS No. 149-30-4 |
| Oxygen Scavenger | |
| Cyclohexylamine | CAS No. 108-91-8 |
| Morpholine | CAS No. 110-91-8 |
| Other | |
| Sodium Diethylhexyl Sulfosuccinate | CAS No. 1639-66-3 |
| Acetyl chloride | CAS No. 75-36-5 |
| TH-GC Green Chelating Agent (Glutamic Acid,N,N-diacetic Acid, Tetra Sodium Salt) | CAS No. 51981-21-6 |