Investigation, remediation, and environmental development in port areas

Transcription

1 Investigation, remediation, and environmental development in port areas Strategic Approaches and Technical Aspects Patrick Jacobs*, Daniela Lud, Simon Bos 6 november 2004 Tauw Powerpoint-presentatie versie 4.0 1

2 Port areas as economic factors Main gateways for national economies: networks of rail tracks, roads, canals and rivers connecting the sea with the hinterland. Worldwide, about 95 % of cargo transported by ship. Hubs of a wide array of commercial and industrial activities. Ports are crucial factors for the local, regional and national economic well-being. Photo: Port Authority of Algeciras Bay

3 Example: dry bulk loading operations Dry bulk spilling Dust Washout and runoff Fuel/ oil Anti fouling BULK CARRIER LOADING OPERATION Trucks, railways, Industries STOCKPILING Ballast water Dredging & Dumping

4 Approaches to sustainable environmental improvement Management plans plansto to minimize the the contaminant emission of of the the port port and and related related operations Optimized investigationand and risk risk assessment tools tools for for sediment pollution Novel Novel conceptsfor for remediation and/or and/or dredging and and disposal of of contaminated sediment

5 Management Concepts

6 Project examples Manganese recycling with sulfuric acid (by-product) extraction Feasibility study / pilot testing Metal extraction from hazardous waste using waste heat and chemicals from a cluster of industrial sites Desktop study, functional design Ferrochromite reduction with synthesis gas (by-product) Market investigation Lab testing

7 Investigation/ Risk assessment

8 Lines of evidence in ecological risk assessment of contaminated sediments Nature / extent of contamination Benthic diversity Bioavailability, bioaccumulation, and adverse effects on aquatic organisms Stability of sediment and contaminants Risks posed to aquatic biota and resources

9 Nature / extent of contamination: Novel investigation techniques

10 Medusa detection probe

11 Medusa sediment surveying

12 Case study: Dredging project in The Netherlands Klasse Klasse Klasse Klasse Klasse 0 0 Main cost factor: handling contaminated dredged material Sediment hazard classes 1 4

13 Medusa pollution mapping Klasse Klasse Klasse Klasse Klasse 0 0 Highly resolved dredging plan Cost savings: EUR

14 Case study: Ore-loading port Saldanha Harbor (RSA) ore handling plant Republic of South Africa ore jetty Saldanha Harbor

15 Conceptual sediment assessment model Known extent of contmination: Ecotox Chemistry Ecology Contaminant analysis Ecotoxicological test battery Ecotox yes response no Detailed analysis Chemistry Class I and II classification Class II-III until IV Special analyses Advanced bio-tests Ecological analysis Stop Analyses Action Modified after Ahlf et al. (2002)

16 Risk assessment of contaminated sediments Mercury in sediments is of major concern Methylation of mercury and Accumulation in the food chain Good estimate of Hg and MeHg in biota/fish is crucial for risk assessment Calculations with models (SERAFM, PHREEQC) show: site specific data are needed HgII MeHg

17 Case example: MeHg determines risk Calculated human exposure for total Hg as anorganic Hg is about 3 times lower than calculated exposure for total Hg as anorganic Hg and MeHg 1,2 1 Hazard Index 0,8 0,6 0,4 0,2 0 Hg as HgII Hg incl. MeHg

18 Case example: MeHg determines risk If fish consumption is an important exposure route for the site, organic forms of mercury need to be taken into account in the risk assessment 1,2 1 Hazard Index 0,8 0,6 0,4 0,2 0 Hg as HgII Hg incl. MeHg

19 Sediment and dredged material handling Capital dredging Maintenance dredging Remediation dredging In-place approaches

20 Handling options In-Place Dredging MNR MNR Treatment Containment In-situ In-situ capping Confined underwater disposal/ capping Land Land disposal Beneficial use use Bioremediation Physical separation Immobilization Chemical extraction Chemical treatment Biological treatment Immobilization Thermal treatment

21 Underwater disposal options unrestricted disposal capped disposal dredged material cap ring dike subsediment disposal artificial island

22 Disposal site Ijsseloog (The Netherlands)

23 Disposal site Ijsseloog (The Netherlands) Dimensioning and design of subsidence basin and sediment disposal Logistics, routing, process instrumentation, acceptance criteria Monitoring of the sediment depot The Netherlands Germany 870 m

24 Model design for underwater disposal site Sediment with heavy metals from abandoned ore mining area Capped disposal with Active Capping Sedimenteinbau unter Wasser, z. B. mittels Pump- u. Fördersystem und Schüttrohr Ton-, Schluff- Abdeckung, 0,5 GOK, 92 m NN Sohle Wiederherstellung, 45 m NN Sohle Abgrabung, 30 m NN Abandoned gravel pit Lower River Rhine, Germany

25 Contour plot flooding/ underwater diposal backfilling river

26 3-D geochemical model (PHAST / WPHAST) flooding/ underwater diposal backfilling river

27 After 0 years: calculated copper concentration Sand cap Active cap (zeolite) Contaminated sediment

28 After 50 years: calculated copper concentration Sand cap Active cap (zeolite) Contaminated sediment

29 After 500 years: calculated copper concentration Sand cap Active cap (zeolite) Heavy metal release into surface water

30 Site specific accelerating factors Advective groundwater flow Porewater flow by compaction Gas bubbles pouring upwards (channel forming) Contaminant transport by colloidal phases Sequestration by complexing agents

31 Site specific accelerating factors And what happens when the near-by lignite mining operation maintains the groundwater table depression for pit dewatering Thank you!