Integrated Advanced Technologies for the Remediation of Industrial Wastewaters. Case studies

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1 Integrated Advanced Technologies for the Remediation of Industrial Wastewaters. Case studies Isabel ller, PhD CIEMAT- Plataforma Solar de Almería Tabernas (Almería), Spain

2 Industrial Wastewater remediation Possible treatments? Conventional processes are hampered by industrial wastewater recalcitrant nature. Advanced xidation Processes (APs) are efficient but they are not economically acceptable for application to large-scale effluents treatment. Adequate remediation strategy? Integrated physic chemical biological techniques can ameliorate the drawbacks of individual processes and improve the overall treatment efficiency. A combined treatment line for a particular industrial wastewater remediation must be investigated: Physic chemical pre treatment. Advanced xidation process (Solar photo Fenton process or ozonation). Toxicity and biodegradability assessment. Combination with advanced biological treatment after biodegradability enhancement. Finally a economic evaluation of the treatment line must be performed. 2

3 Solar APs for industrial wastewater remediation There is no sense in using solar photocatalytic processes for complete mineralization of recalcitrant industrial wastewaters containing hazardous nonbiodegradable pollutants. High operating and investment costs. The use of photocatalysis as a pre-treatment can be justified if the intermediates resulting are readily degraded by microorganisms. The use of photocatalysis as a post-treatment is justified when industrial wastewater is not toxic and presents low biodegradability from the beginning. Toxicity and biodegradability tests are highly important for effluents partially treated by photocatalysis as more toxic or recalcitrant degradation products could be generated during the process. Highly confidence toxicity results will be obtained when using at least two different bioassays.

4 Solar APs for industrial wastewater remediation Industrial WW characterization: TC, CD, BD, main inorganics, contaminants (LC-MS/GC-MS) Toxic (>5%) TXICITY on-toxic or partially toxic (<5%) EVALUATI F BIDEGRADABILITY 2: Biodegradable. CD>Guideline 1 AP EVALUATI F BIDEGRADABILITY DURIG AP 1: Partially or not biodegradable TC>5 mg/l TC<5 mg/l DILUTI AD EVALUATI F BIDEGRADABILITY 2 BILGICAL TREATMET 1 AP 2 1 EVALUATI F BIDEGRADABILITY DURIG AP 2 BILGICAL TREATMET 1 AP 2 EVALUATI F BIDEGRADABILITY DURIG AP BILGICAL TREATMET CD and toxicity<guideline DISCHARGE Biorecalcitrant compounds AP CD and toxicity<guideline DISCHARGE ller et al., Sci. Tot. Env. 49, 211

5 Physic-chemical pre-treatment Stabilize industrial wastewater and enhance the efficiency of the subsequent oxidation treatment Lab scale assays performed in a Jar-test apparatus for optimization Pre-treatment performed in pilot scale plant Jar-test equipment with 6 positions (VA) for coagulation/flocculation assays at lab scale. Designed to process 1 m 3 /h of wastewater. Sand filter (75 µm). Two micro-filters (25 µm and 5 µm). 5

6 Toxicity and biodegradability tests Respirometric tests BM T respirometer (Surcis S.L.): Acute toxicity and short term biodegradability assays on conventional activated sludge 1L capacity vessel. Temperature and ph control system. Zahn Wellens test Long term biodegradability test: D t Ct - C B 1-1 CA - CBA 6

7 Combination Chemical and biological oxidation. Pilot plants Solar photo Fenton at pilot plant scale CPC solar photo reactor. Irradiated surface = 3 m² V T = 8 L; V i = 44.6 L Batch mode operation. zonation at pilot plant scale 1 L zonation system with a thermic ozone destructor (> 3ºC). Inlet and outlet detectors of 3 in gas phase. perating conditions: 1 L/h air; 5% level of 3 production: inlet concentration of 3.5 g/h 3. Immobilized Biomass Reactor (IBR) at pilot plant scale 2L total volume. Reception (2 L) and decantation (4 L) for continuous mode. ph and oxygen dissolved automatic control systems. Data acquisition and monitoring by a SCADA system. 7

8 Remediation of industrial WW containing pharmaceuticals. IBR-AP H Parameter Amount ph 3.98 Conductivity 7 ms.cm -1 TC 775 mg.l -1 CD 342 mg.l -1 alidixic acid 45 mg.l -1 TSS.47 g.l -1 Cl g.l P 4.1 g.l -1 S g.l -1 a + 2 g.l -1 Ca 2+.2 g.l -1 8

9 Remediation of industrial WW containing pharmaceuticals. IBR-AP TC (mg/l) IITIAL CDITIS (solar photo-fenton) alidixic acid: 39 mg/l Initial TC: 822 mg/l [acl]: 6.5 g/l TC H 2 2 consumed alidixic acid (mg/l) t 3W (min) t 3W (min) Total degradation of the nalidixic acid at 35 minutes (illumination time) (65 mm H 2 2 ) 28% of the initial TC was removed H 2 2 consumed (mm) TC (mg/l) IITIAL CDITIS (Biotreatment) alidixic acid: 38 mg/l Initial TC: 725 mg/l [acl] : 4.3 g/l H 4 + : <.1 mg/l 3- : <.1 mg/l ph: 6.6 TC alidixic acid Time (days) 96% of the initial TC was removed alidixic acid persists after biological treatment (~15 mg/l) alidixic acid (mg/l) 14/38

10 Remediation of industrial WW containing pharmaceuticals. IBR-AP 1 8 % TC reduction AP IBR Biotr. time = 4 days t 3w = 35 min; H 2 2 = 65 mm (elim.xa) IBR AP Biotr. time = 4 days t 3w = 21 min (elim. XA)!!! H 2 2 = 12 mm (elim. XA)!!! 1

11 Remediation of industrial WW containing pharmaceuticals. IBR-AP LC-TF-MS chromatograms H Initial wastewater H P2 Cl P17 IBR IBR + photo-fenton H H P5 XA H H H H H H P3 H P11 H P34 P22 H H H H H P4 P27 P7 H H H H P9 H P14 H H P12 H H P15 H H H P6 H P1 H o DPs P13 H Retention time (min) 11

12 Remediation of industrial WW containing pesticides. AP-IBR demo scale Industrial wastewater DC : 48 mg/l on-biodegradable pesticides Solar Photo-Fenton 2 mg/l Fe 2+ / ph: % mineralization. DC f : 27 mg/l 21 mm H 2 2 consumed. Biodegradable compounds Biological treatment (IBR) DC : 3 mg/l 1.5 days of biotreatment. 75 % mineralization. DC residual : 75 mg/l Decontaminated water DC: 75 mg/l 12

13 Remediation of WW from agro-food industry. IBR-AP Agro food WW characterization (citrus processing plant) DC: 1.2 to 2.3 mg L 1 CD: 2.4 to 4.7 g L 1 Total itrogen: 3.5 to 163 mg L 1 Turbidity: TU Pesticides (µgl -1 ) Influent (µgl -1 ) Effluent (µgl -1 ) Adsorbed in the biofilm (µgl -1 ) % Degradation ACP IMZ TBZ

14 Landfill Leachate treatment Landfilling is the most widespread method for municipal solid waste (MSW) disposal (95% solid residues worldwide). Results from percolation of rainfall, degradation of the organic fraction and other compounds transfer. Complex nature which depends of age, precipitation, seasonal weather variation, waste type and surrounding population. Is a great threat to environment and human health. 14

15 Landfill leachate: Physic-chemical pretreatment ph adjustment (final ph=5) H2S4 (96%) Fe³+ dosage (FeCl3 6H₂) [Fe]final=56 mg/l Coagulation/Flocculation Settling ph adjustment (final ph=3) LL before and after pre-treatment ph Turbidity (TU) CD (mg/l) DC (mg/l) [Fe]t final (mg/l) 7 57 Biodegradability.1.1 Toxicity(%I) % 11.2% H2S4 (96%) 15

16 Landfill leachate: Solar photo-fenton treatment a) Physic-chemical pre-treatment step. b) Solar photo-fenton process. 1, a) b) DC/DC,8 H Is solar photo-fenton process able to improve biodegradability? Acute toxicity (I%= 4). Good biodegradability was reached for 4% mineralization (consumption of 35.5 g H₂₂/L). DC/DCo,6,4,2, Quv (kj/l) 7% of DC removal after 7 min of irradiation time. Total H 2 2 consumption of 12 mm (4 g/l). Required accumulative energy was 11 kj/l H2 2 (mm) Toxicity (I%) Toxicity Biodegradability AS H 2 2 consumption (g/l) AS, Biodegradability 16

17 Landfill leachate post-treatment by IBR 1 8 DC H Adaptation stage (several feeding cycles with MWTP influent and partially photo treated LFL) Feeding with partially photo treated LFL DC (mg/l) Inoculation with active sludge H + 4, - 3, - 2 (mg/l) t (days) 17

18 Landfill leachate treatment: Economic assessment Preliminary economic assessment: In solar driven systems the most important investment cost is the CPC field. Solar photo Fenton design point: mineralization degree of 27% (final DC=8.3 g/l). QUV=137 kj/l CPC collector surface of 685 m². Leachate design flow of 4 m 3 /day (365 days/year of operation) Industrial grade reagents. perating costs % over total costs /m 3 % Total reagents consumption Electricity consumption.1.2 Labour requirement CPC solar field and auxiliary facilities Total costs

19 Cork boiling wastewater remediation Processing of cork slabs includes a boiling step for improving physicchemical characteristics. High water consumption: 4 L/ton of cork. 6-3 boiling cycles per batch of water. Cork boiling wastewater characterization Pollutant load: umber of boiling cycles Cork s agglomeration state Liquid-solid ratio Wastewater containing: corkwood extracts (phenolic acids, 2,4,6-trichloroanisole, chlorophenol, tannic fraction), suspended solids, etc. Low efficiency of conventional treatments. 19

20 Cork boiling wastewater physicchemical pre-treatment 2

21 Cork boiling wastewater physicchemical pre-treatment Acute toxicity (% inhibition) Short term biodegradability (DQb/DQ) Raw wastewater 63. %.8 Pre-treated with FeCl 3.5 g L -1 + ph %.3 Pre-treated with FeCl 3.75 g L -1 + ph 1 + QUIFLC 98.5 g L %.12 Pre-treated with FeCl 3.75 g L -1 + ph 1 + QUIFLC 61.5 g L %.16 Pre-treated with Ca(H) 2.75 g L %.14 21

22 Cork boiling WW: Solar photo-fenton compared to ozonation post-treatment 7 % DC elimination 22

23 Cork boiling wastewater: posttreatment by IBR 1 st inoculation with activated sludge 2 nd inoculation with activated sludge 7 Batch 1 Feeding with pre-treated CBW: Biomass adaptation Batch 2 Batch 3 Batch 4 Feeding with pre-treated CBW Batch 1 Batch 2 Batch DC T Turbidity 8 12 DC (mg/l) T (mg/l) 8 Turbidity (TU) Time (Days) Adaptation phase: Pre-treated Cork Boiling Wastewater (CD=5 3 mg/l) + MWWTP influent (CD end = 5 mg/l). Feeding: Pre-treated Cork Boiling Wastewater (6 mg/l). 23

24 Cork boiling wastewater: posttreatment by IBR Lab-scale assays for chronic toxicity evaluation on activated sludge from MWWTP - Two flaks (9 ml activated sludge + 1 ml de pre-treated cork boiling WW) under continues agitation and aeration through several days. - Assessment of the activated sludge activity by means of the oxygen uptake rate, UR. Day Flask 1 Flask 2 DC (mg L -1 ) UR (mg L -1 h -1 ) End of assay DQ b (mg L -1 ) End of assay

25 Combination F/APs

26 Combination F/APs Two alternatives: 1. 1 Direct treatment, CF=1 2. Concentrate treatment, CF=4 or 1 2 1

27 Combination F/APs r = kc 15 Photo-Fenton A 2 Model compounds at different realistic C in natural water. Fe (II),.1 mm, H 2 2, 25 mg L -1, natural ph Flumequine Carbamazepine Concentration ( g/l) Fenton foxacin Sulfamethoxazole Carbamazepine Flumequine Ibuprofen B H 2 2 consumption C H 2 2 consumption (mg/l) Sulfamethoxazole Ibuprofen floxacin t 3W (min)

28 Combination F/APs Fe (II),.1 mm 8 Fenton-like Photo-Fenton 12.2 mm EDDS H 2 2, 25 mg L -1 atural ph C ( g/l) 6 4 CF=1 CF=4 CF= C ( g/l) times less with EDDS!!! 2 HC CH t 3W (min) HC H H Ethylenediamine-,'-disuccinic acid (EDDS) CH Fe(III)-L + hν [Fe(III)-L]* Fe(II) + L

29 Combination F/APs perational requirements for attaining 95% of pharmaceuticals degradation present in F concentrates (CF=4 and 1) when solar photo-fenton and photo-fenton like Fe(III)-EDDS complex were applied. CF=1 no F. CF H 2 2 consumed (gm Solar photo-fenton 3 ) Q uv (kj L -1 ) t(min) / CPC / / /12.4 surface (1) Solar photo-fenton like Fe (III)-EDDS complex H 2 2 consumed (gm - 3 ) Q uv (kj L -1 ) / / /2.7 t(min) / CPC surface (1)

30 Concluding remarks After physic-chemical pre-treatment Physic-chemical pre-treatment usually improves significantly industrial wastewater characteristics for facing its complete remediation and possible reuse. Best results are usually provided by Fe³+. After ozonation treatment Toxicity should show slight decrease. Better results in biodegradability enhancement. Possible combination with advanced biological treatment for complete wastewater remediation. After solar photo-fenton process Pre-treatment step did not improve photo-treatment s efficiency for cork boiling wastewater. Toxicity reduction and biodegradability enhancement allow its combination with a subsequent advanced biological treatment. Advanced biological treatment before or after chemical oxidation step Specific industrial wastewater showing low toxicity levels and partially biodegradable could face an advanced biological treatment as the first step. ormally for those wastewater with high organic load and containing small concentrations of recalcitrant pollutants. 3

31 Concluding remarks (II) The current lack of data for comparison of solar photocatalysis with other technologies definitely presents an obstacle towards an industrial application. Therefore, it is necessary: Give sound examples of techno-economic studies. Assessment of the environmental impact: life cycle analysis (LCA). To lead their application on industry it will be critical processes can be developed up to a stage, where the technology: can be compared to other processes. can demonstrate its robustness, i.e. small to moderate changes to the wastewater inlet stream do not affect the plant s efficiency and operability strongly. is predictable, i.e. process design and up-scaling can be done reliably. gives additional benefit to the industry interested on this technology application (e.g. giving the company the image of being green ). 31

32 Acknowledgments Unidad de Tratamientos Solares de Agua (Solar Treatment of Water Research Group). Plataforma Solar de Almería (CIEMAT). areas/tsa/index.php