HKUST R&D Projects in Sewage

Treatment

G.H. Chen IWA HK AGM 2016.6.8

Project - I

Large-scale Study on Realization and Application of SANI process in Sewage Treatment in Hong Kong

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      Demonstration-scale Trial (Phase I)

SRUSB NDN Reactor Reactor

Nitrification NH4 ‐ + O2 → NO3 ‐

Autotrophic Denitrification: HS‐ + NO3 ‐ → N2 + SO4 2‐

Sha TinSha STWSTTin W

Sulfate Reduction: H++SO4 2‐ + COD → HS‐ + HCO3 ‐

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Process and Reactor (Phase I) MBBR – Moving Bed Biofilm Reactor

SRUSB – Sulfate Reduction Up‐flow Sludge Bed

Stage B‐nitrogen Post‐Treatment (demo, 25 m3/d)

De‐gritted raw sewage Treated

effluent

(EQ –

Pre‐treatment Stage A‐organic

Process: SANI-MBBR • 1 Fine Mesh sieve (< 5 min)

• 3 SRUSBs (4 h)

• 1 MBBR (7 h)

• 1 Post treatment unit (1 h)

Total HRT ≈ 12 h

removal by SRUSB removal by MBBR By flocculation‐settling integrated system for P removal & Final polishing

feed tank) 4

           

     

 

         

Results - Quality after Post Treatment (Phase I)

Raw sewage

Final effluent (after post treatment)

Parameters SANI Influent* SANI Effluent* After Post Treatment ** Discharge Requirements

BOD5 (mg/L) 172 32 5.6 ≤ 20 (95%tile)

TSS (mg SS/L) 189 64 18.9 ≤ 30 (95%tile)

TN (mg N/L) 48 14 8.9 ≤ 20 (annual average)

NH4 (mg N/L) 36.7 1.1 0.43 ≤ 5 (annual average)

*Since January, 2015 **Since 13 March, 2015 5

          

            

   

  

 

   

                       

                     

                              

               

PST – Primary Sedimentation Tank FST – Final Sedimentation Tank MLE – Modified Ludzack Ettinger process SANI – Sulfate reduction Autotrophic denitrification Nitrification Integrated process

Results – Footprint Saving (Phase I)

Conventional process (MLE)(Shatin STW as example)

PST FSTAeration Biological Treatment

Anaerobic Digestion

HRT total ~ 21 HRT ~ 2 hr HRT ~10 hr HRT ~ 9 hr

SANI process Footprint saving ≈ 30‐40%

Post Treatment FacilityMechanical Aeration

Filter Mesh AnaerobicSRUSB Reactor MBBR Reactor Digestion

HRT ~ 4 hr HRT ~ 7 hr HRT ~ 1 hr HRT total ~ 12 (With further optimization, HRT of SANI‐MBBR is expected to be further reduced to 6

7 hr, then total HRT to 9 hr.)

HRT < 5 min

  

Results - Sludge reduction (Phase I)

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Primary Biological Reactor Final Sedimentation (PST) (SANI v.s. MLE) Sedimentation (FST)

Biological Sludge

(4)

(1) (2) (3)

Primary Sludge

Biological (Secondary) Sludge Reduction comparing with existing SWHSTW and STSTW plant: 60-70%

Overall Sludge Reduction comparing with existing SWHSTW and STSTW plant: 20-30%

Sludge Thickener

Anaerobic Digester

Centrifuge Dewatering

Sludge Incinerator

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Results – Cost and Energy Savings Estimation (Phase I) Primary Biological Reactor Final

Sedimentation (PST) (SANI v.s. MLE) Sedimentation (FST)

Sludge

(4)

(1) (2) (3)

Overall energy saving for whole plant ≈ 10%

(with energy recovery)

Process PST (1)

Biological Reactor (2)

FST (3)

Anaerobic Digester (4)

Total

Construction Cost Saving 0% 25% 50% 50% 25%

Energy Saving 0% 25% 50% 50% 27%

*Simulated results

Overall CO2 emission reduction

≈ 10%

Sludge Thickener

Anaerobic Digester

Centrifuge Dewatering

Sludge Incinerator

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Project - II

Municipal Organic Waste Management by integrating Food Waste Disposal And Sewage Treatment (MOW-FAST)

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Potential Food Waste Treatment in Hong Kong Total Municipal Organic Waste Management by integrating ‐‐‐ a novel system Food Waste Disposal And Sewage Treatment (MOW‐FAST)

Food Waste Disposer (FWD) (it has been practiced at Provident Centre (和富中心）for 20 years) (DFW particle

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To carry out mathematical model‐based evaluationthe impacts on sewage treatment;

                                  

 

   

     

Food Waste Disposer

Food waste with flushing water

wastewater

MOW‐FAST System

Evaluation of digester performance and energy production

Co‐digestion system

Saline Sewer System

Saline Sewage Treatment Plant

Task I. Characterization of DFW, FWD effluent, and the mixture of DFW and wastewater

Task I to be completed soon

Task II. Laboratory experiments and model‐based evaluation of the impacts of DFW on sewer system

Task III. Model‐based evaluation of the impact of DFW on biological wastewater treatment

Task IV. Laboratory study and model‐based evaluation of the impact of DFW on anaerobic digestion

Task V. Engineering feasibility and economic analysis Providing research basis for the policy formulation for proper FWD installation in Hong Kong

Project – III Introduction of New Centers

Chinese National Engineering Research Center (CNERC) for Control and Treatment of Heavy Metal Pollution (Hong Kong Branch) funded by ITC國家重金屬污染防治工程技術研究中心（香港分中心）

Water Technology Center supported by HKUST 香港科技大學 水技術中心

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Background and Goals of CNERC (Hong Kong Branch)

Major Environmental Challenges: Water scarcity intensified by rapid population growth and water quality deterioration

Energy-intensive and space-consuming water treatment practice

Massive production of sludge without sustainable disposal method

The Goals of CNERC are to : Explore economic and sustainable alternative water resources;

Develop sustainable water/wastewater treatment technologies; and

Integrate technology and system innovations to promote new water industry.

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Research Team • 13 internationally recognized researchers from the local universities,

• 3 renowned researchers from the international academic institutions,

• 4 renowned researchers from Mainland China universities,

• 1 honorary advisors from the Chinese Academy of Engineering and

• 2 industrial consultants from the international top companies.

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Collaboration “Good ties boost inno-tech growth”

A platform for international exchanges (國際交流平台) A platform for scientific research (科學研究平台) A platform for technological development (技術研發平台) A platform for knowledge & technology transfer (技術轉化平台) A platform for engineering technical consultation (工程技術咨詢平台)

國際水業市場

提供優質服務打造水業品牌

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Applications

Innovative ideas

Researches & developments Inspiring

new ideas

                                   

                  

                      

              

                     

       

Coming Event… A 25th anniversary Event of HKUST Sponsored by Institute for Advanced

Studies (IAS) and HKUST Organized by CENERC

IAS Summit Hong Kong‐Inventing Today Imaging Future for Water Pollution Control

Supported by IWA , IWAHK?, EPD? WSD? DSD?, HKIE? CIWEM? 20 – 22 October 2016

IAS conference center, HKUST Free of participation (limited to 150)

(Highlight: ~20 world’s and national leaders in water pollution control and treatment)

Call for Lunch/Dinner Sponsors 16

THANK YOU!

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