Monitoring the Performance of Anaerobic Ponds in the Treatment of Abattoir Wastewater

Transcription

1 Monitoring the Performance of Anaerobic Ponds in the Treatment of Abattoir Wastewater Dr Bernadette McCabe National Centre for Engineering in Agriculture, USQ MINTRAC QLD Environment Network Meeting 14 th March, 2012

2 Presentation Outline Anaerobic Ponds Design principals and operation Churchill Abattoir background Historical wastewater treatment Upgrade to covered anaerobic ponds Overview of monitoring program

3 Anaerobic Ponds Used as a secondary treatment of abattoir wastewater High BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand) removal efficiency ~90% Low operational costs ISSUES Odour emissions Biogas contains high % CH 4

4 Anaerobic Process

5 Anaerobic Pond Design Almost always uses historical organic loading approaches Design pond area, A (Ha) Where S i = influent BOD (mg/l) Q av = average influent (ML/d) L BOD =historical BOD loading (kgbod/ha.day)

6 Churchill Abattoir: Background Process from cattle per week Churchill Abattoir kill cattle for on-site processors who bone out and value add the beef. Water usage is about 200 ML per year with nearly the same volume of recycled water used to wash cattle. Primary solids separation system removes paunch from the waste stream. Paunch solids are about 90 cu m per week. Secondary treatment consists of several anaerobic lagoons and a 120 x 80 x 2 m aerobic lagoon. Irrigate crops as the final wastewater disposal method.

7 Recirculating Rubble Drain WV WV Pond Layout at Churchill Abattoir C D E WV I/O WV WV Breather I/OI/O B A Inflow 1 Inflow 2 Shallow Settlement Drains Scale: approx. Source: Captured: June 2010

8 Cover construction and installation

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10 Project Background Lack of information on how to design and cover ponds Lack of historical data Necessary to determine design criteria Monitoring CA ponds can be potentially used to establish optimal design and operating principles

11 Project outline Project overview Anaerobic pond research Performance Decomposition process Well organised Consistent Clear 1. Water quality Cross reference evidence to terms/concepts introduced in why and how sections to help flow and tighten focus Format/frame around Sludge studies Biogas production Introduce what you do and why you needed to implement specific L & T approaches e.g. are you addressing a certain need or problem? 2. Quality and quantity

12 Recirculating Rubble Drain WV WV 1. Monitoring Water quality C D E WV Pond study: monitoring key parameters such as Daily flow Climate and temp Inflow and outflow effluent characteristics B Shallow Settlement Drains A I/O WV WV Breather I/OI/O Inflow 1 Inflow Scale: approx. Pond Effluent Start End Parameters A Inflow & outflow 17/06/ 26/10/ B Inflow & Outflow 17/06/ 26/10/ E Outflow 10/08/ 26/10/ TSS, alkalinity, NH 3 -N, TKN, FOG, COD, BOD, VA. ph, EC, ORP, temperature

13 Comparison with typical abattoir raw waste water Parameter mg/l BOD COD FOG TSS Total N NH 4 -N Total P VFA Alkalinity Typical abattoir raw waste water 1 (all meats) Churchill Abattoir (Beef) 5 month intensive monitoring average Average

14 Removal efficiencies of the 5-pond system Pond A (uncovered) Pond B (covered) Pond E (uncovered) Parameter Units Inflow Outflow % Inflow Outflow % Outflow % Red n Red n Red n Daily flow m 3 /d HRT Days Temperature C ph ph units ORP mv EC µs COD mg/l COD loading kg COD/m 3 /d BOD mg/d BOD loading kg BOD/m 3 /d TSS mg/l Alkalinity mg/l NR* NR* NH 3 -N mg/l TKN mg/l FOG mg/l VFA (as acetic acid) mg/l NR* NR*

15 Changes in BOD, COD, TSS and FOG loads in the influent and effluent of uncovered pond A

16 Changes in BOD, COD, TSS and FOG loads in the influent and effluent of covered pond B Avereage flow rate (m 3 /h) Temperature ( C) Jul Jul Jul Aug Pond B flow rates and temperature Aug Aug Aug Aug Date Sep Sep Sep Sep Oct Flow rate Influent temperature Effluent temperature Oct Oct Oct

17 Organic loading rates of ponds A and B based on pond volume Month Flow rate (KL/d) Pond A (uncovered) HRT (d) OLR (kgcod/ m 3 /d) Flow rate (KL/d) Pond B (covered) HRT (d) OLR (kgcod/ m 3 /d) July August September October

18 2. Biogas quality Measure biogas quantity and quality from the covered ponds operating at above minimum performance: CH 4, CO 2, H 2 S, & NH 3 -N Assess the potential use of biogas as bioenergy fuel Average onsite biogas composition from covered pond B Average organic loading rate O 2 (%) CO 2 (%) CH 4 (%) H 2 S (ppm) (kgcod/m 3 /day)

19 Biogas composition from Covered Pond B

20 Current status of ponds Source: Captured: July

21 Plant initiative installation of DAF to remove FOGs Important to get this component in place prior to covered pond design Dissolved air floatation system Removes oil and grease and suspended solids Will improve final effluent quality Reduces likelihood of damage to cover of covered anaerobic pond Reduces the need for desludging

22 Current monitoring : Pre DAF vs. Post DAF installation Monitoring data of waste water without DAF treatment has provided baseline data C/f this data against DAF treated waste water can be used to assess the efficiency of the system in breaking down organic matter and generating methane when FOGs are removed

23 Acknowledgements Financial support from Meat and Livestock Australia (MLA) and Australian Meat Processor Corporation (AMPC) Mike Spence, Company Engineer CA NCEA Project team members: Pam Pittaway, Talal Yusaf, Craig Baillie & Peter Harris Input from other NCEA staff: Steve Rees, Rick Cameron, Victor Skowronski and Phil Szabo