Electro-Dewatering of Wastewater Sludge: Influence of the Operating Conditions Using the Response Surface Methodology

Transcription

1 ElectroDewatering of Wastewater Sludge: Influence of the Operating Conditions Using the Response Surface Methodology Dr. Akrama Mahmoud ENSGTILaTEP Bâtiment d Alembert. Rue Jules FerryBP Pau France European Conference on Fluid Particle Separation (ECFPS) 57 October 2010, LyonFrance

2 . Conventional Dewatering System: 57 October 2010, Lyon, France Pressure MDW Initial Wastewater Sludge Free water Solids Bound water Cation ion Akrama Anion ionmahmoud (ECFPS) Piston Filter medium Filter Press Belt Press S f : 1535% 57 October 2010, Lyon, France

3 ELECTRODEWATERING How it works? Free water Solids Pressure EDW Anode Current S f : 3055% Anode 57 October 2010, Lyon, France Bound water Cation ion Anion ion Piston Filter medium Cathode Cathode Advantages: High efficiency in liquid/solids separation; Ability to avoid the blockage of the filter media; Low energy consumption compared to thermal drying.

4 EXPERIMENTAL SET UP Anode () Akrama9 Mahmoud (ECFPS) 57 October 2010 Second, Lyon, France Cake Cathode () (1): Filtration/compression cell (2): Electronic scale (3): Computer and data acquisition (4): Movement sensor (5): DC power supply (6): Digital multimeter (7): Filtrate collector (8): Teflon piston (9) Electrodes Activated sludge S in ~0.5% Conditioning Initial Suspended Sludge Stage ➊ Feed Filtration/Compression Electrically Compression (MDW) 1Floculation S in ~2.53% 2Batch drainage 57 October 2010, Lyon, France P ( kpa) t=t 0 Δt 1 =2 h t=t 1 Δt 2 =2 h t=t 2 Stage ➋ (EDW) P ( kpa) (1050 V) 57 October 2010, Lyon, France Stage ➌ Laboratoryscale of EDW device

5 RESULTS AND DISCUSSION Texte Filtrate mass (g) (I) (III) (II) (v) Starting of EDW Filtration/Compression Stage ➋ Electrically Compression Stage ➌ MDW Time (s) (50 V, 400 kpa) EDW Dry solids content (%) V (1200 kpa) 50 V (1200 kpa) 30 V (1200 kpa) 20 V (1200 kpa) 50 V (600 kpa) 40 V (600 kpa) 30 V (600 kpa) 20 V (600 kpa) 50 V (200 kpa) 40 V (200 kpa) 30 V (200 kpa) 20 V (200 kpa) S f =42% Starting of EDW The corresponding power consumption: kwh/kg (additionally water removed) 57 October 2010, Lyon, France 57 October 2010, Lyon, France Time (s) 800 s 4100 s MDW

6 RESULTS AND DISCUSSION Analysis of the RSM design B : Voltage A : Pressure AB BB AA B : Voltage AA BB A : Pressure AB Reference line (a): The final dry solids content Standardized effect Reference line (b): The energy consumption calcultaed per the additional mass of water removed Standardized effect Energ Final dry solids content (%) kwh/kg (additionally water removed) Response surface Surface de réponse 10estimée 2 0,6 0,5 0,4 0,3 0,2 0,1 Pressure (kpa) Presuure Voltage (V) Voltage Pressure (kpa) S f (%) S 0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 57 October 2010, Lyon, France kwh/kg (additionally Ene water rg removed) 0,0 0,1 0,2 0,3 0,4 0,5 57 October 2010, Lyon, France Voltage (V)

7 Energy Consumption Trend Energy consumption (kwh/kg water removed) Dryness (%) CONCLUSIONS Thermal Drying to 1.2 kwh/kg water removed 57 October 2010, Lyon, France Final dry solids content (%) 10 to 12% 30 to more than 55% Sludge cake before the EDWprocess 200 kpa (ii) 200 kpa (iii) 400 kpa (i) 400 kpa (ii) 400 kpa (v) 600 kpa (i) 600 kpa (ii) 600 kpa (iii) 600 kpa (v) 1200 kpa 57 October 2010, Lyon, France Sludge cake after the EDWprocess Energy efficient Electrodewatering requires less than 10 and 25% of the theoretical thermal drying energy for the low and moderate voltages cases, respectively. High dryness By changing the operating parameters, a dryness of 30 to 55% or greater can be achieved.

8 THANKS FOR YOUR ATTENTION CONTACT INFORMATION Dr. Akrama Mahmoud ENSGTILaTEP Bâtiment d Alembert. Rue Jules FerryBP Pau France