Treatment scale: the total design scale is 3500m3/d.
2. Design water quality: CODcr =1200mg/l; bo D5 = 800mg/L；
SS = 150mg/L； pH=6~9 .
3. Discharge standard CODcr ≤100 mg/l; bo D5≤20mg/L； SS≤70mg/L；
pH=6~9 .
4, process overview:
Wastewater grid well regulating tank UASB reaction tank SBR reaction tank meets the discharge standard.
5. Project investment: 239,438+10,000 yuan;
6. Project area:1632m2; ;
7. Operating cost: 0.9 1 yuan /m3.
8. labor capacity: 2 persons.
9. Duration: 3 months.
1. Overview
Beer production mainly takes barley and rice as raw materials, supplemented by hops and fresh yeast, and is made by long-term fermentation.
The wastewater produced in the production process of the company mainly comes from the technological processes such as corn cleaning and soaking. Sewage has the characteristics of high pollutant concentration and low pH value. If it is directly discharged into the water body without treatment, it will lead to serious eutrophication, destroy the ecological balance of the water body and cause serious pollution to the environment.
Based on the idea of developing economy to promote the coordinated development of enterprise benefits, pollution control and environmental protection, the leaders and employees of the company decided to entrust a professional environmental protection company with advanced technology, stable operation and reasonable investment to treat its production sewage under the supervision and support of the superior environmental protection department and in accordance with the requirements of national environmental management.
2. Water quality and wastewater quantity
2. 1 design water volume
Design scale of this project: 3500 m3/d, average flow:1.46m3/hr;
2.2 Design water quality
Referring to the data of similar projects and the water quality indicators provided by the owner, the design water quality of this project is determined as follows:
CODCr = 1200mg/L； bo D5 = 700mg/L； SS = 400mg/L；
PH=5~6 .
3. Emission standards
According to the requirements of local environmental protection department, the treated water quality meets the first-class discharge standard of Integrated Pollutant Discharge Standard (GB8978- 1996). Namely:
CODCr≤ 100mg/L； bo D5≤20mg/L； SS≤70 mg/L, PH=6~9.
4. Compilation basis
Relevant information and requirements provided by the owner
Comprehensive discharge standard of pollutants (GB8978- 1996)
Code for Design of Outdoor Drainage (2000 Edition)
Water supply and drainage design manual
Code for Design of Concrete Structures GB500 10-2002
5. Selection and discussion of process scheme
5. 1 wastewater quality analysis
Beer production takes barley and rice as raw materials, supplemented by hops and fresh yeast, and is made by long-term fermentation. Wastewater mainly comes from malt manufacturing, saccharification, fermentation, bottle washing and filling. Beer wastewater is rich in sugar, protein, starch, pectin, alkyd resin, mineral salts, cellulose and vitamins. It is an organic wastewater with moderate concentration and good biodegradability. The wastewater is continuously discharged, and the water quality and quantity fluctuate to some extent.
5.2 Process Selection
Beer wastewater belongs to medium-high concentration organic wastewater, which has good biodegradability, but its production is seasonal and its discharge is discontinuous, especially for ground washing water, and its water quantity and concentration fluctuate greatly. The factory collects the wastewater from each workshop together, and because of the low inorganic load, it is not suitable for the requirement of "anaerobic+aerobic" method commonly used in China to treat raw water COD >: 6000 mg/L.
Beer wastewater contains a lot of organic carbon, but less nitrogen source. In the traditional biochemical treatment, its nitrogen content is much lower than BOD: n: 100: 5 (mass ratio), which makes some breweries adopt the traditional activated sludge method, and the treatment effect is very poor, even without supplementing nitrogen source. After comparison of various schemes, CASS method was determined to treat beer wastewater.
In the aerobic unit, after a comprehensive comparison between the membrane method and the ordinary activated sludge method, we think that compared with the membrane method, CASS method has the same total investment and operating cost because it saves the sedimentation tank, but when applied to engineering, CASS method is more stable and reliable and has a long service life. Compared with ordinary activated sludge process, SBR process has more obvious advantages in investment and operation cost, so we choose CASS process.
Circulating activated sludge system (CASS) is a new technology developed on the basis of SBR process and oxidation ditch process. CASS pool is the core of the system. Most pollutants in sewage are degraded and removed here. It concentrates the biological reaction process and the mud-water separation process in the same pool. CASS reaction tank is divided into biological selection zone, facultative zone and aerobic zone. The basic function of the selection area is to prevent sludge bulking, the dissolved organic matter in sewage can be adsorbed and removed by sludge particles through enzyme reaction, and the nitrate in the returned sludge can be denitrified in this selection area; In the facultative zone, there is a little aeration, which is basically in an anoxic state. Organic matter is preliminarily degraded in this area, and some nitrate nitrogen can also be removed. Aerobic zone, namely aeration zone, mainly carries out nitrification and degradation of organic matter, and also carries out nitrification and denitrification. CASS tank is a batch reactor, in which aeration and non-aeration processes are repeated. Sewage is treated according to certain cycles and stages, and each cycle consists of the following stages: water intake/aeration/sludge reflux stage-completing the biodegradation process; Non-aeration/sedimentation stage-realizing mud-water separation; Decapitation/excess sludge removal stage-discharging supernatant; Idle stage-restore the activity of activated sludge.
? The above stages constitute a cycle of operation. According to the amount and concentration of sewage, its operation mode can take the form of 6 cycles/day, 4 cycles/day and 3 cycles/day, and the operation time of each cycle is 4, 6 and 8 hours respectively. In the process of circulation, firstly, water filling, aeration and sludge reflux are carried out, and the water level in CASS tank gradually rises from the initial design lowest water level to the highest design water level with the inflow of water. When aeration and mixing have passed for a certain time, aeration is stopped, activated sludge is flocculated under static conditions, and mud-water separation is carried out. After settling, the supernatant is discharged by moving the decanter on the weir surface, and the water level is restored to the designed lowest water level, and then the operation is repeated. In order to ensure the system to operate under the best conditions, sludge must be discharged regularly. The discharge process of excess sludge is generally carried out after precipitation, and the sludge concentration can be as high as10g/L. The discharge amount of excess sludge is far less than that of traditional activated sludge treatment process.
5.3 process flow chart
Grille slag blower
Beer wastewater grid machine sump lift pump adjustment pool CASS reaction pool contact pool
The mud cake is transported to the screw pump mud storage tank of the sludge dehydrator.
Figure 1 block diagram of sewage treatment process
5.4 Description of process flow
After coarse impurities are removed from the wastewater through the grid, it enters the water collection tank and is lifted by the water pump into the CASS reaction tank, so that most pollutants in the wastewater are degraded and removed in the tank. The wastewater is treated biochemically here, and the treated wastewater is discharged into the contact pool, disinfected and discharged into the water body. Excess sludge from CASS reaction is discharged into sludge storage tank, pumped into sludge concentration dehydrator by sludge pump for dehydration, and the dehydrated dry sludge is transported abroad, and the water filtered by filter press returns to the water collection tank.
5.5 Prediction of treatment effect
Sewage enters the CASS pool from the regulating pool, and then comes out from the CASS pool. CASS tank removed almost all pollutants, and the results are shown in Table 4.
Table 1 inlet and outlet water quality and removal rate of main structures
Water quality: influent mg/L, effluent mg/L, removal rate%.
CODcr 1200 450 63 in biological selective adsorption zone of CASS pond
BOD5 700 200 7 1
SS 400 180 55
Aerobic zone CODcr 450 200 56
BOD5 200 150 15
SS 180 140 22
Main aeration zone CODcr 200 70 65
BOD5 150 30 80
SS 140 70 50
Contact battery CODcr 80 40 50
BOD5 30 10 67
Pages 70 and 30
The total removal rate is above CODcr 1200 70 94.
BOD570010 above 98
SS 400 30 is higher than 92.
6. Electrical automatic control
6. 1 power distribution
The total installed capacity of the sewage treatment station is about 2 19.87kW, of which the running power is about134.0kw. The power line is routed to the power distribution cabinet in the sewage treatment station.
6.2 Automatic control system
The sewage treatment station adopts PLC automatic control and local button box manual control. There is a change-over switch on the console, which is automatically controlled by PLC according to the pre-programmed program when the change-over switch is in the automatic position; When the changeover switch is in the manual position of the local button box, it can be manually controlled by the machine.
Each lift pump can be controlled by an automatic control system according to the liquid level. When the amount of sewage in the pool is small, one pump runs or runs intermittently; when the amount of sewage in the pool is large, two pumps run or one of them runs intermittently to avoid pump damage or sewage overflow caused by insufficient flow of a single pump.
The CASS tank adopts PLC and electric valve to automatically switch the working state according to time control, so as to realize a series of actions such as water intake, aeration, decanting, etc., so that the two tanks can automatically operate alternately, and can also be switched to manual state according to the situation, and the operating state of the two tanks can be adjusted through human intervention.
7. List of main building structures and equipment
7. 1 List of main buildings (structures)
No. Structure (Building) Name Process Size (M) Number of main design parameters
1 collecting well L*B*H=2.0×2.0×4.0 Total volume: 16m3.
Structural form: 1 underground concrete block.
2 l * b * h between grids = 3.0× 2.0× 3.0. Total volume: 18m3.
Structural form: 1 semi-ground reinforced concrete block
2 Adjustment tank L*B*H= 16.2×9.0×4.5 Total volume: 656m3.
Structural form: 1 semi-ground reinforced concrete block
3 CASS reaction tank L*B*H= 19.0×9.0×5.0 Total volume: 855m3.
Structural form: semi-ground reinforced concrete
Volume load:
0.24 kg BOD/m3 km2
4 Sludge storage tank L*B*H=4.0x3.0x3.0 Total volume: 36m3
Structural form: semi-ground reinforced concrete
HRT = 16hr 1 block
5 contact battery L*B*H=6.0x3.0x3.0 Total volume: 54m3
Structural form: semi-ground reinforced concrete
HRT = 1 5min1block
6. Construction area of sludge dewatering machine room: 27m2 Structural form: 1 brick-concrete structure.
7 Building area: 60m2 Structure: 1 Brick-concrete structure.
Note: This design does not include the fence, ground greening and road hardening in the station area.
7.2 List of major equipment
Serial number equipment name equipment model main parameters unit quantity remarks
1 mechanical fine grating RAG-500 grating strip gap 10mm
Power: 0.37kW set 1 stainless steel.
2 sewage pump CT-5-11-100 power: 1 1kW is equipped with two autotransformers.
3 submersible agitator QJB 15/4 power: 15kw 2 units.
4 sewage pump CT-5-11-100 power: 1 1kW, 2 sets with autotransformer.
5 Sludge reflux pump CT-5 1.5-65 Power: 1.5kW, 4 sets with autotransformer.
6 blower SSR200 air volume: 32m3/min
Motor power: 45kW, 3 2 for use, 1 standby.
7 aerator kki215/d90/set1200, including air support and pipe fittings.
8 decanter XPS-560 decanting capacity of 560 m3/h 2 sets.
9 Sludge pump
10 concentration, pressure filtration and dehydration machine
1 1 electronic control system/1including electrical instruments.
8. Project investment estimation and economic and technical analysis
8. 1 project investment estimation
8. 1. 1 civil engineering investment estimation
Table 8. 1 Civil Engineering Investment Estimation Table
Order Name Unit Quantity Type Quantity Specification Total Price Remarks
No. (m) (ten thousand yuan)
1 grid Jing Zuo 1 2.5× 1.0×3.0 0.56 reinforced concrete
2. Collecting well seat 1 2.0×2.0×4.0 1.20 reinforced concrete
3 Adjustment slot seat116.2× 9.0× 4.5 49.20 Reinforced concrete
4 CASS reaction tank seat 2 16.0×9.0×5.0 54.00 reinforced concrete
5 Sludge storage tank seat 1 4.0×3.0×3.0 2.70 reinforced concrete
6 Sludge dewatering machine room m2 1 27 2. 16 Brick-concrete structure
7 Workshop m2 1 60 4.80 Brick-concrete Structure
8 Subtotal (T 1) 1 14.62
8. 1.2 equipment investment estimation
Table 8.2 Estimation Table of Equipment Investment
Serial number equipment name equipment model unit quantity unit price total price remarks
1 5 sets of mechanical fine grid bg4820-0/0.97 0.97 stainless steel
Two sewage pumps CT-5 1.5-65 sets 20.4 1.82 including autotransformer.
3 sludge pump CT-5 1.5-65 sets 1.3 1.3 1
4 sewage pumps CT-52.2-80 2 0.46 0.92 including autotransformer
6 sludge pump CT-52.2-80 2 sets 0.46 0.92 including autotransformer.
7 Two sets of underwater blowers WRC-100 5.1KLOC-0/0.20 including silencers and other supporting accessories.
8 sets of aerators KKI2 15/D90 400 0.02 6.00 including air branch pipes and fittings.
9 200m3/h decanter 2 4.76 9.52
10 screw pump I- 1B2' 1.38 0.38
XMY25/6300 sets 1 1 belt filter press 1 2.86 2.86 with accessories.
12 dosing system /2 sets 2.47 4.94 including metering pump.
13 electronic control system/set11601160 includes electrical instruments.
T2 Subtotal 157.48
8. 1.3 total investment estimation of the project
Table 8.3 Estimated Total Investment of the Project
No. The project name is called square expense reserve bill.
(ten thousand yuan)
A civil engineering 1 14.62
Two. Process equipment 157.48
Equipment supporting, transportation and miscellaneous expenses (II) ×3% 4.72
Four. Installation project (II) × 13.5% 2 1.26
5. Total direct cost of this project (1)+(2)+(3)+(4) 211.64.
Intransitive verb Direct cost tax of this project (V) × 3.4% 5.55438+0
7. Indirect cost of this project
1 engineering design fee (V) ×5% 10.58
2. Engineering debugging training fee (5) ×5% 10.58 including technical training.
3 The total indirect cost of this project is 1+2 2 1. 16.
Eight engineering tax [(7) ]×5.6% 1. 19
The estimated total investment of this project is (5)+(6)+(7)+(8) 23888+0.
Remarks:
1. The total investment of this project only includes the sewage treatment station;
2. The budgetary estimate of civil engineering investment does not include other ancillary facilities and measures except the main structure, and the budgetary estimate shall be subject to the construction drawing;
3. The standard discharge outlet shall be solved by the owner according to the requirements of the local environmental protection department;
4. Laboratory instruments shall be purchased by the owner according to the needs of the project;
8.2 Operating cost analysis
8.2. 1 Operating cost calculation
Electricity bill
The installed capacity of this project is about 2 19.87kW, of which the operating power is 134.0kW, the electricity fee is calculated at 0.62 yuan /kW, and the treated water is calculated at 3500 m3/d;
E1=134.0× 24× 0.62 ÷ 3500 = 0.57 yuan /m3 sewage.
(2) Medical expenses
The daily dosage of PAM is 5.95kg, and the unit price is 30 yuan/kg;
The dosing cost is 0.05 yuan /m3 sewage.
(3) Labor cost
Per capita wages and benefits are calculated by 20 yuan/day/person, and the quota is 3, then
E3 = 20× 3 ÷ 3500 = 0.02 yuan /m3 sewage.
(4) Water consumption
The amount of tap water used for dispensing and testing is about 20 tons per day, and the cost per ton of water is about 2.0 yuan, so the daily water fee is about:
E3 = 20× 2.0 ÷ 3500 = 0.0 1 yuan /m3 sewage.
(5) The total operating expenses are:
E4 = e1+E2+E3 = 0.57+0.05+0.02+0.01= 0.65 yuan /m3 sewage (excluding depreciation and maintenance fees).
8.2.2 Economic Benefit Analysis
According to the accounting, the biogas output is about 2250m3/d, calculated by calorific value, each 10000m3 is equivalent to 8 tons of standard coal, and each ton of standard coal is calculated by 400 yuan, so the annual benefit of biogas is about:
2250× 365×10-4× 8× 0.04 = 262,800 yuan/year.
8.3 Project Implementation Plan
Project implementation schedule
Engineering stage 1 1 month 1 February1month, February and March.
feasibility study
Construction document design
Civil Engineering
assembling work
9. Quality assurance
9. 1 Ensure that the treated water meets the discharge standard;
9.2 The treatment system runs stably, safely and reliably;
9.3 according to the environmental protection model project design, achieve high quality engineering quality standards;
9.4 Lifelong paid service; Provide free technical advice for life.
Table 8.2. 1 Power Consumption List
Serial Number Equipment Name Power (kW) Running Time (H) Unit Quantity Remarks
1 mechanical fine grid 0. 12kW 6 sets 1
2 sewage pumps 1.5kW 24, 2 for use 1 standby.
3 sludge pumps 1.5kW 2 1.
4 sets of 2.2kw sewage pumps, 24 sets, 2 for use 1 standby.
5 Sludge pump 2.2kW 1.5h 2
6 underwater blowers 1 1kW 18h 2.
7 decanter 1. 1kW 3h 2
8 screw pumps 2kW 3 sets 1
9 belt filter press 4.0kW 3 sets 1
10
SBR is the abbreviation of sequencing batch reactor, which is usually called sequencing batch activated sludge process in China. From 65438 to 0969, the Dutch National Institute of Health Engineering changed the continuous flow oxidation ditch for treating hospital sewage into intermittent operation, and achieved remarkable results. Inspired by this, scholars all over the world began to study and develop the intermittent activated sludge process. 1979, American R. Irvine and others put forward SBR process for the first time according to the test results.
In recent years, with the rapid development of monitoring and testing technology and the successful development of special equipment decanter for SBR process, as well as the application of electric valve, pneumatic valve, electromagnetic valve, water level gauge, mud level gauge and automatic timer, especially computer automatic control system, monitoring means tend to be automatic, and the advantages of SBR process are fully exposed, which has aroused widespread concern and can be quickly popularized and applied.
SBR process is simple, without secondary sedimentation tank, intermittent (or continuous) water inflow and intermittent drainage. Complete the five processes of water feeding, reaction, precipitation, decanting and idle in a single reaction tank.
Compared with the traditional activated sludge process, SBR process has the following process characteristics:
1. The technological process is simple and the investment is low.
2. The biochemical reaction has large thrust and strong treatment capacity. The research shows that the activated sludge in SBR reactor has high biological activity, and its microbial ribonucleic acid (RNA) is 3 ~ 4 times that of ordinary activated sludge. In SBR reactor, with aeration, organic matter (F) gradually decreases, while biological solid (M) gradually increases, sludge load (F/M) decreases with time, biochemical reaction advances in time, and F/M gradient reaches the ideal maximum, which has strong pollutant removal ability.
3. Sludge bulking will not occur, and the operation effect is stable. Sludge bulking is mostly caused by excessive reproduction of filamentous bacteria. Most filamentous bacteria, such as gymnosperms, are specialized aerobic bacteria. In the SBR reaction tank, the anoxic or anaerobic environment in the precipitation decanting stage alternates with the aerobic environment in the reaction stage, which can effectively inhibit the excessive reproduction of obligate aerobic bacteria, thus forming biological flocs with flocculating microorganisms as the main body, without sludge bulking, and the operation effect is stable.
4. It can resist impact load and has high operation flexibility.
5. After stopping ventilation for 5 minutes. SBR method, the precipitation is carried out in an ideal static state, and the separation effect of mud and water is good.
5.5 Analysis of wastewater treatment effect
The treatment effect of each process stage is predicted as follows:
Table 5-2: Treatment Effect Analysis Table
Unit total treatment rate of UASB reactor and SBR reactor in vertical sedimentation tank
Water inlet, water outlet, water inlet and water outlet.
CODcr mg/L 12000 & lt； 10000 10000 & lt； 1000 1000 & lt； 100 >99%
BOD5 mg/L 8000 & lt 7000 7000 & lt 400 400< 20 > 99.7%
Suspended solid mg/L 2500 & lt 750 750< 500 700< 70 > 97%