WO2018101892A1

WO2018101892A1 - Advanced biological treatment method for slaughterhouses wastewater

Info

Publication number: WO2018101892A1
Application number: PCT/TR2016/050470
Authority: WO
Inventors: Abdullah SAGHIR; Abdulhafez ABDULHAFEZ
Original assignee: Hasan Kalyoncu Universitesi
Priority date: 2016-11-29
Filing date: 2016-11-29
Publication date: 2018-06-07
Also published as: TR201619150A2

Abstract

The invention relates to a device and a method of treatment waste water from slaughterhouses, which enables production of biogas and soil compost and reuse of treated waste water for washing the squares and or irrigation.

Description

ADVANCED BIOLOGICAL TREATMENT METHOD FOR SLAUGHTERHOUSES

WASTEWATER

Subject of the Invention

The invention relates to a device and a method of treatment wastewater from slaughterhouses, which enables production of biogas and soil compost and reuse of treated wastewater for washing the squares and irrigation.

The State Of Art

The wastewater discharged from the industries of the high organic load is considered one of the most important reasons of environment pollution in the world, if has not been treated properly.

The wastewater is the reason of pollute the ground water and environment pollution in the case of discharged to natural lands, and to the sewer systems without treatment or insufficient treatment which cause increase in organic loads which insert to treatment plant of wastewater.

This could lead to get operation problems during investment plants and reduce treatment produce, so industrial wastewater treatment is considered the most important things to get clean environment reflect on different humanity sectors .

The wastewater from slaughterhouses has high organic load so it is considered so pollution. In addition, slaughterhouses are used big quantity of water, for example: a slaughterhouse in a country uses about 300 m³/day. So it is so important finding new active techniques to treatment slaughterhouses wastewater which enables reused treated water in washing processes or in irrigation. Also, it should be interest of production soil composed, and generate bio-gas from processes of treatment pollutant water, at the time whole world interest of production alternative energy. Also, by this technique CH₄ gas can be generated which has high economic value .

In state of art, there are many application to overcome these problems but they have many disadvantages about efficient work.

Although the patent number CN2015207630 (U) is about "Device for chicken is slaughtered production line wastewater reclamation and recycles", the device used membrane technology, and sand filters due to these reasons the device differs from our application which consists of full biological treatment.

Although the patent number MX2009014232 (A) is about " Plant and process for treating slaughterhouse wastewater ", but it used anaerobic filter and SBR (Subsequent Batch Reactor) and did not focus on phosphorus removal or recycling treated wastewater, so due to these reasons this patent differs from our application which used UASB, Anoxic oxic tank and final settling tank and focuses on nitrogen and phosphorous removal and recycling treated wastewater.

The patents number EP0218896 (Al), (Bl) and CH665138 are about " Process for the preliminary treatment of organic slaughterhouse waste" they only focus on" preliminary treatment" and used chemical material in treatment , so they differ from our application which did not use any chemical materials in treatment and focused on advanced biological treatment not only preliminary treatment" .

The patent number CN105198170 (A) is about " Advanced treatment apparatus for pond high-ammonia-nitrogen culture wastewater" it focused on wastewater from culture and used wetlands , so it differs from our application which does not use wetlands in treatment and focuses on slaughterhouse wastewater whose characteristic differs from characteristic culture wastewater.

The patent number CN104909517 (A) is about "Industrial production wastewater advanced treatment device", the device comprises an anoxic-anaerobic-aerobic bio membrane bioreactor and two ozone- floating bed biological tanks, so this device differs from our application which use sequence biological stages: UASB - anoxic - aerobic and final settling tank, our application is full biological treatment and does not use Ozone .

The patent number KR20150031553 (A) is about "Plants for advanced treatment of wastewater for improving phosphorous removal efficiency and method for treating wastewater using thereof", this patent used sequence biological stages: first anoxic - an anaerobic reactor- an aerobic - a second anoxic, a membrane separator and a treated water tank , so it differs from our application which uses sequence biological stages: UASB - anoxic - aerobic and final settling tank, our application is full biological treatment and not use membrane.

The patent number CN204237680 (U) is about "Advanced industrial wastewater treatment system", used chemical and biological process such as flocculation, so it differs from our application which uses only biological processes.

The patent number CN104129890 is about "Device and method for enhanced biochemical process for advanced treatment of high ammonia nitrogen industrial wastewater", focused on domestic wastewater its characteristics: PH6-9, COD<1000mg/l, BOD₅ <300mg /l, SS<250mg /l, Ammonia <400mg/l.

In our application we focused on very high polluted wastewater which has the following characteristics: PH:6~9, COD≤5310mg/l, BOD5≤2761mg/l, SS≤323mg/l, Ammonia ≤323mg/l, so the device scope differs from our application scope, the processes in this device also differ from our application.

The patent number CN105481190 (A) is about " Control method and device for advanced nitrogen and phosphorus removal treatment by coupling denitrifying phosphorus removal with partial nitrification and anaerobic ammonia oxidation", this device focuses on domestic wastewater , and the control method comprises the following steps : SBR reactor; BAF reactor to then the mixed effluent enters a UASB so the scope and sequence processes of the control method and devic differ from our application scope.

Detail Description of the Invention

New treatment method had been discovered which considered hybrid pattern from three treatment methods :

-Up-flow anaerobic sludge blanket process in UASB reactor (5) (Up- Flow Anaerobic Sludge Blanket reactor)

-A²/0 method (Anaerobic Anoxic Oxic Method)

-VIP method (Virginia Initiative Plant Method)

The plan of UASB reactor (5) is shown in Figure 1 in detail.

A²/0 and VIP methods are considered perfect methods in what related to high removal organic pollutants and high removal of phosphorus and nitrogen.

In these methods we can get biogas, sludge to be used as fertilizer and reusing treated wastewater in washing the slaughterhouses yards and irrigation.

It is replaced anaerobic part by UASB reactor (5) to get useful anaerobic biology treatment characteristics in UASB reactor (5) reduce sludge quantity and to reduce necessary aeration energy aeration tank (11) .

The research is discussed the study of biology treatment in UASB reactor (5) in what related of slaughterhouses wastewater followed by anoxic tank (8) then followed by aeration tank (11) and finally followed by final settling tank (12) .

The experiments showed that there is possibility to get high removal efficiency to all pollutants in hydraulic retention times in parts of treatment laboratory as follows :

UASB reactor (5) :24 hours, anoxic tank (8) : 12 hours, aeration tank (11) :24 hours, and final settling tank (12) : 3 hours at least, in (27+1)° temperature in anoxic tank (8) and aeration tank (11), with returned sludge flow from final settling tank (12) to entrance of the anoxic tank (8) approximately 100% from the flow of raw wastewater and mixed liquid flow from aeration tank (11) to entrance of the anoxic tank (8) approximately 300%, we get removal efficiency of different parameters as following: Νθ3^~ , PC ^3~ , H4⁺ ,TSS ,TDS ,TS , BODs , COD respectively : 93%- 83.6% - 73% - 91.2% - 47.9% -52.9 % -96.9% - 97.3%. These results are shown in the Table 1.

Table 1: the percentages of pollutants removing the within hydraulic retention times (24, 12, 24, and 3) hours in UASB reactor (5) followed by the anoxic tank (8), then an aeration tank (11) and final settling tank (12) respectively:

Table 2 : The results of treatment compatible with the hydraulic retention times in UASB reactor (5), the anoxic tank (8), the aeration tank (11) and the final settling tank (12) 24, 12, 24, 3 hours in respectively:

By this technique CH₄ gas can be generated which has high economic value, in addition, we can treat slaughterhouses wastewater to reuse it in washing processes factory and irrigation.

By this application we can get quantity of sludge which has some of nitrogen, full of phosphorus and nitrogen which could be used as soil composed, the treated wastewater by this application can be recycled in slaughterhouse again, this new technique is suitable for Islamic countries and for slaughterhouses which do their process in Islamic manner.

The Technical Description of the Invention:

The return activated from final settling tank (12) to the beginning of the anaerobic stage in A²/0 method causes overload of phosphorus on this stage, so in the invention we return activated sludge flow from final settling tank (12) to the beginning of anoxic tank (8) only, so the returning of activated sludge flow to the anaerobic tank (11) was cancelled in our application.

The return flow of mixed liquor flow in the VIP method from the end of anoxic stage to the beginning of anaerobic lead to anaerobic stage become with dissolved oxygen and go deviate from anaerobic conditions so the anaerobic stage will be less efficiency in decompose of the combined phosphorus with organic matter, in the invention return flow recycle 1 was cancelled. UASB reactor (5) has proven good performance as a treatment for anaerobic and simplicity of operation and the possibility to benefit from bio-gas, which can be collected from above so in our the our new method for slaughterhouse wastewater treatment we used it as anaerobic stage, to get the facility integrated treatment is the removal of COD, BOD₅, N, P043^~ and TSS, the plan of invented treatment method is shown in figure .

The research is discussed the study of biology treatment in UASB reactor (5) in what related to slaughterhouses wastewater followed by anoxic tank (8) then followed by aeration tank (11) and finally followed by final settling tank (12) .

Technique and Mechanic Description of the Invention:

1-UASB reactor (5) :

The raw slaughter wastewater come from the feeding tank of raw wastewater (1) by a small feeding dosing pump (2) on a pipe called as first pipe (3) to UASB reactor (5) which is a cylinder where wastewater flow from down to up with so slow vertical velocity about 0.08m/hour, where we keep on hydraulic retention time of polluted water which will be treated about 24 hours.

The first pipe (3) has a small feeding dosing pump (2) and is used for carrying wastewater from raw wastewater tank to the UASB reactor (5) .

Also, the system of UASB reactor (5) has pipe for discharge gases (17) to tank for gas receiving (18) in order to discharge gases from the UASB reactor (5) system. There is also a dome for gas separating (4) that is shown on the figure of longitudinal section plan for the experimental device. Around the UASB reactor (5) there is heated water by heater with thermostat (6) and a pipe for drawing sludge ( 7 ) .

In addition, there is a chance to take samples from the UASB reactor (5) system. This process can be conducted by valves for taking samples (10) shown in the figure 6. 2-Anoxic tank (8) :

The wastewater comes from the top of UASB reactor (5 ) to the anoxic tank (8) . Its dimension are 80cm: height ,20cm: width and 20cm: length, it has closed top and there is a slow mixer (9) at the top of the tank to do the mixing with return flows a part of the activated sludge from the final settling tank (12) which come to the entrance of the anoxic tank (8) by the pipe for sludge (14) and first dosing pump (15), and a part of the mixed liquor flow from the aeration tank (11) to the entrance of the anoxic tank (8) as well by the pipe for mixed liquid (13) and dosing pump (16) . In addition, the flow rate of the return from the aeration tank (11) to anoxic tank (8) is three times of the flow rate of the return from final settling tank (12) to anoxic tank (8) . In other words, the flow rate of active sludge from the final settling tank (12) to the aeration tank (11) is 100% or equal t the inflow slaughter wastewater. As shown in figure 5, the rate of inflow slaughter wastewater is Q and the mixed liquor flow from aeration tank (11) to the anoxic tank (8) is 3Q while the flow rate of active sludge from the final settling tank to the aeration tank is Q or 100% from Q.

While pipe for mixed liquid (13) is used to carry mixed liquid from aeration tank (11) to anoxic tank (8) and has second dosing pump

(16), pipe for sludge (14) are used to carry sludge from final settling tank (12) to anoxic tank (8) and has first dosing pump

(15) .

In addition, in order to control the hydraulic retention times in anoxic tank (8) and to carry wastewater from anoxic tank (8) to aeration tank (11), more than one anoxic tank control valves (22) are used between anoxic tank (8) and aeration tank (11) .

The anoxic tank (8) is necessary for reducing N03^~ and Ν0₂ ^~ to 2 gas which go off the wastewater as shown in this equation:

N0₃ ^~→N0₂ ^~→ NO→N₂0→N₂ 3- Aeration tank (11) :

The mixture in the anoxic tank (8) moves into the aeration tank

(11) where needed quantity of air exhaust in the bottom of aeration tank (11) by air diffusers (20) which take the air by air pump (21) to make bio oxidation to organic and carbonic compounds, and to make oxidation NH3 compounds to nitrate and niter compounds .

This mixture stays in the aeration tank (11) about 24 hour (based on flow of enter water to the starting point of treatment ), in this tank the final reduction to carbonic and organic compounds is done , as a result COD and BOD₅ reduce, and oxidation NH₃ to nitrate and niters to leave return water in anoxic tank (8) .

Also, in aeration tank (11) phosphate compounds become established, at the starting point of bacteria cells which will discard from it with precipitate Bio-mass in the bottom of final settling tank

(12) .

The experimental device was shown in figure 5, figure 6, which construct according to mentioned fundamentals of design. As shown in the figure, there are air pump (21) and air diffusers (20) in the system. Also, there is a pipe called as final pipe for wastewater (19), in order to carry the wastewater from the aeration tank (11) to final settling tank (12) . This final pipe for wastewater ( 19 ) has more than one aeration tank control valves (23) for the hydraulic retention time controlling in the aeration tank (11) and carrying treated wastewater from aeration tank (11) to final settling tank (12).

There is also a connection between aeration tank (11) and anoxic tank (8) with pipe for mixed liquid (13), as mentioned above.

4- Final settling tank (12) :

Final settling tank (12) has a cylindrical shape with a conic bottom to collect the sludge, its top diameter was 60 cm, and total height of sludge and water in it was 37 cm, the final settling tank (12) receives water for aeration tank (11) by final pipe for wastewater (19) . Also, there is a connection between final settling tank (12) and anoxic tank (8) by pipe for sludge (14) .

A- The comparison according to the removing BOD₅:

The comparison between the treating method suggested in our research and the other treatment methods relating to the efficiency of removing the BOD₅ is illustrating in table 3 :

Table 3 : The comparison between the treating method suggested in our research and the other treatment methods relating to the efficiency of removing the BOD₅ . B-The comparison according to the removing of phosphorus expressed PO₄ ³- :

The comparison between the treating method suggested in our research and the other treatment methods relating to the efficiency of removing the P04^3~ is illustrating in table 4.

Table 4 : comparison between the treating method suggested in our research and the other treatment methods relating to the efficiency of removing the PO4³ ' .

C- The comparison according to removing Ammonia Nitrogen

The comparison between our suggested treatment methods with the other biological treatment methods in terms of the efficiency of removal the Ammonia nitrogen is illustrated in table 5.

The treatment

The minor traditional method suggested

Removes less than 10%

treatment 73% in this research has better results

-The biological The treatment process method suggested

Removes (40 - 70) %

- Bacterial 73% in this research has assimilation better results

Table 5 : The comparison between the treating method suggested in our research and the other treatment methods relating to the efficiency of removing the H₄ ⁺.

D- The comparison according to the removing of nitrate:

The comparison between our suggested treatments with the other biological treatment methods in terms of the efficiency of removing Nitrate Nitrogen is illustrated in the following table:

Table 6 : comparison between the treating method suggested in our research and the other treatment methods relating to the efficiency of removing the N03^~ . A plan for the invented treatment method showed the hydraulic retention times and returned flow and temperature degree in the tanks is shown in Figure 5 .

It is recommended to use this method of treatment and use the treated water in washing the slaughterhouse yards after being sterilized or in irrigating the woody trees and industrial crops .

It is recommended to use the biological gas results from treatment of slaughterhouse wastewater by the anaerobic methods, which obtains a financial benefit that reduce the consumption of electricity in the slaughterhouse.

Explanation of the Given Figures

Figure 1: Plan of UASB Reactor

Figure 2: Plan for A²/0 Method

Figure 3: Plan for VIP Method

Figure : The Plan of Invented Treatment Method

Figure 5 : The Plan for the Invented Treatment Method Showed the Hydraulic Retention Times and Retuned Flow and Temperature Degree in the Tanks

Figure 6: Longitudinal Section Plan for the Experimental Device

Figure 7 : Plan the Experimental Device Design

References

1. Feeding tank of raw wastewater

2. Small feeding dosing pump

3. First pipe

4. Dome for gas separating

5. UASB reactor

6. Heated water by heater with thermostat

7. Pipe for drawing sludge

8. Anoxic tank

9. Slow mixer

10. Valves for taking samples

11. Aeration tank

12. Final settling tank

13. Pipe for mixed liquid

14. Pipe for sludge

15. First dosing pump

16. Second dosing pump

17. Pipe for discharge gases

18. Tank for gas receiving

19. Final pipe for waste water

20. Air diffuser

21. Air pump

22. Anoxic tank control valves

23. Aeration tank control valves

Claims

1. A method for treatment of slaughterhouse wastewater, characterized in that it comprises the steps of;

a. introducing the raw wastewater from the feeding tank of raw wastewater (1),

b. transporting the raw wastewater to UASB reactor (5) by first pipe (3) ,

c. treating the wastewater in UASB reactor (5) about 24 hours, d. transporting the mix liquid from the top of the UASB reactor (5) to anoxic tank (8),

e. treating the mix liquid in anoxic tank (8) about 12 hours with stirring by a slow mixer (9),

f. transporting the mix liquid from anoxic tank (8) to aeration tank (11) by anoxic tank control valves (22),

g. providing air exhaust to the aeration tank (11) by air diffusers (20) and air pump (21),

h. treating the mix liquid in aeration tank (11) about 24 hours, i. transporting the mix liquid to final settling tank (12) from aeration tank (11) by final pipe for wastewater (19) and aeration tank control valves (23),

j. treating the mix liquid in final settling tank (12) at least 3 hours ,

k. getting out of treated wastewater from final settling tank (12) .

The method according to claim 1, wherein the biological gases is collected to a tank for gas receiving (18) by a dome for gas separating (4) and a pipe for discharge gases (17), in the step

3 . The method according to claim 1, wherein the mix liquid in anoxic tank (8) is stirred from down to up with vertical velocity about 0.08 m/h, in the step (e) .

The method according to claim 1, wherein a part of the mixed liquor from the aeration tank (11) is returned to the entrance of the anoxic tank (8) by pipe for mixed liquid (13) and second dosing pump (16), in the step (h) .

The method according to claim 1, wherein a part of the activated sludge from the final settling tank (12) is returned to the entrance of the anoxic tank (8) by pipe for sludge (14) and first dosing pump (15), in the step (j) .

The method according to claim 4 and 5, wherein the flow rate of the return of mixed liquor from the aeration tank (11) to anoxic tank (8) is three times of the flow rate of the return of activated sludge from final settling tank (12) to anoxic tank

The method according to claim 1, wherein the temperature maintained about (30+1) °C during the UASB reactor (5) stage, the step ( c) .

8. The method according to claim 1, wherein the temperature is maintained about (27+1) °C during the anoxic tank (8) and aeration tank (11) stages, in the step (e) and (h) .

A device for treatment wastewater from slaughterhouses, which enables production of biogas and soil compost and reusable treated wastewater, characterized by comprising;

a feeding tank of raw slaughterhouse wastewater (1) where the raw wastewater comes from,

a UASB(up-flow anaerobic sludge blanket) reactor (5) as an anaerobic stage ,

an anoxic tank (8) for removal of ammonium ions from wastewater by reduction of nitrate and nitrite ions to nitrogen gases,

an aeration tank (11) for removal of organic pollutants and phosphorus ,

a final settling tank (12) for removal of microorganisms and solids from treated wastewater physically.

10. The device according to claim 9, wherein the UASB reactor (5) comprises heated water by heater with thermostat (6) around the

UASB reactor (5), a pipe for drawing sludge (7) and valves for taking samples (10).

The device according to claim 9, wherein it comprises a dome for gas separating (4), a pipe for discharge gases (17) and a tank for gas receiving (18) for collection of biological gases from UASB reactor (5) .

The device according to claim 9, wherein the anoxic tank comprises a slow mixer (9) at the top of the anoxic tank (8) mix liquid.

The device according to claim 9, wherein the aeration tank (11) comprises air diffusers (22) to provide air exhaust in the bottom of aeration tank (11) and air pump (21) which gives the air.

The device according to claim 9, wherein it comprises a first pipe (3) to carry wastewater from feeding tank of raw wastewater (1) to UASB reactor (5) and a small feeding dosing pump (2) on the said first pipe (3) .

15. The device according to claim 9 wherein it comprises more than one anoxic tank control valves ( 2) for controlling the hydraulic retention time in anoxic tank 8 ) and for carrying wastewater from anoxic tank (8) to aeratio tank (11) .

The device according to claim 9, wherein it comprises more than one aeration tank control valves (23) for controlling the hydraulic retention time in the aeration tank (11) and carrying treated wastewater from aeration tank (11) to final settling tank (12) and also final pipe for wastewater (19) for carrying treated wastewater from aeration tank (11) to final settling tank (12) . The device according to claim 9, wherein it comprises a pipe for mixed liquid (13) and second dosing pump (16) for carrying mixed liquid from aeration tank (11) to anoxic tank (8) .

18. The device according to the claim 9, wherein it comprises a pipe for sludge (14) and first dosing pump (15) for moving the sludge from settling tank (12) to anoxic tank (8) .

The use of the device according to claims 9 to 18 for washing the slaughterhouse yards and irrigating the woody trees and industrial crops .

The use of the device according to claims 9 to 18 for reducing the consumption electricity in slaughterhouses with the production of biological gases.