Introduction of JOGMEC's latest R&D of mining pollution control techniques

Transcription

1 Introduction of JOGMEC's latest R&D of mining pollution control techniques 7 th February, 2014 JOGMEC Seminar on Exploration and Mine Pollution Control Kazunori HATSUYA Planning Division Metals Environment Management Department Japan Oil, Gas and Metals National Corporation (JOGMEC)

2 Outline 1. Functions of JOGMEC in the field of mine pollution control 2. Acid mine drainage treatment with iron oxidizing bacteria 3. Drainage treatment with sulfate reducing bacteria 4. Drainage treatment by phytoremediation (accumulate by plant) Aim Operating Matsuo sulfur mine (1953) Current Matsuo neutralization plant and surrounding The Matsukawa R.(left) polluted by drainage from Matsuo mine (1974) Current Matsukawa R. share our experience and technology for sustainable development of African mining sector! 2

3 Outline 1. Functions of JOGMEC in the field of mine pollution control 2. Acid mine drainage treatment with iron oxidizing bacteria 3. Drainage treatment with sulfate reducing bacteria 4. Drainage treatment by phytoremediation (accumulate by plant) Aim Operating Matsuo sulfur mine (1953) Current Matsuo neutralization plant and surrounding The Matsukawa R.(left) polluted by drainage from Matsuo mine (1974) Current Matsukawa R. share our experience and technology for sustainable development of African mining sector! 3

4 Measures for mine pollution control Generation mechanism of acid drainage Pyrite FeS 2 + 7/2O 2 + H 2 O Fe SO H + Sulfate ion Measures against acid drainage generation / treatment Plug sealing Protection channel Soil covering and grass planting Neutralization 4

5 Current situation of drainage treatment in Japan Neutralization tank Flowchart of general acid drainage treatment Matsuo neutralization plant (Administrated by JOGMEC) 200km Mines practicing drainage treatment Suspended or abandoned mine with owner (55) Abandoned mine without owner (24) Thickener Sludge dam 5

6 Functions of JOGMEC in the field of mine pollution control JOGMEC 1. Technical support Research and consulting, Support of construction works, Administration of treatment plant, Education, Information providing 2. Research and development Mine pollution control technologies 3. Financial support Management of the mine pollution control reserve and fund Loan for mine pollution control construction 4. International cooperation Holding of technical seminar and hosting of trainees Mine administrators Local government The administrator of ownerless mine Mining company Mining right owner Mining countries Grant Government of Japan 6

7 JOGMEC s R&D of mining pollution control technologies 1970~ Technology for vegetation at dams Technology for closure of tunnel 1980~ Technology for returning sludge into underground caves Technology for agglomeration of sludge 1990~ Mine drainage treatment technology using sulfate reducing bacteria Centralized management technology for drainage from plural mines Mine drainage treatment technology using coal ash Technology for economical use of energy in mine drainage treatment 2000~ Treatment technology for B, F and Sb in mine drainage Sludge reduction technology (using iron oxidizing bacteria) Passive treatment (using sulfate reducing bacteria, phytoremediation) 7

8 Outline 1. Functions of JOGMEC in the field of mine pollution control 2. Acid mine drainage treatment with iron oxidizing bacteria 3. Drainage treatment with sulfate reducing bacteria 4. Drainage treatment by phytoremediation (accumulate by plant) Aim Operating Matsuo sulfur mine (1953) Current Matsuo neutralization plant and surrounding The Matsukawa R.(left) polluted by drainage from Matsuo mine (1974) Current Matsukawa R. share our experience and technology for sustainable development of African mining sector! 8

9 Acid drainage treatment with iron oxidizing bacteria Current flow Calcium Calcium 処理原水 AMD 処理原水 AMD Carbonate 炭カル Carbonate 炭カル (ph1.8 (ph1.8) (ph1.8 前後 (ph1.8) ) 前後 ) AMD AMD 原水槽 storage 原水槽 storage tank tank Fe: more than 300m g/l, as Fe2+ SO 4 :more than 2000mg/L Iron oxidizing Calcium 処理原水 AMD bacteria Calcium Carbonate 炭カル処理原水 AMD (ph1.8 (ph1.8) 前後 (Fe) 2+ Fe 3+ ) Carbonate 炭カル (ph1.8 (ph1.8) 前後 ) Slaked 消石灰 Slaked 消石灰 lime lime 放流放流 Overflow release Overflow release バクテリア回収槽 Bacteria バクテリア回収槽 Bacteria Solid-liquid recovery recovery (~ph6.5) (ph7.5) separation tank tank (~ph6.5) (ph7.5) tank 殿物 Dewatered ( スラリーを脱水 sludge ) Sludge 殿物繰返し recycling 殿物 Dewatered ( スラリーを脱水 sludge ) Sludge 殿物繰返し recycling Proposed flow (Bacterial oxidation and two step neutralization) Slaked 消石灰 lime Slaked 消石灰 lime Over flow ph:7.4, Fe: 0m g/l To reduce the volume of sludge and the amount of neutralizer バクテリア回収槽 Bacteria recovery 固液分離槽 Solid-liquid liquid Overflow AMD 原水槽 storage Ion 酸化槽 oxidazing ph 放流脱鉄槽 control tank Neutralizing 中和槽 tank separation tank release tank バクテリア回収槽 Bacteria recovery 固液分離槽 Solid-liquid liquid Overflow AMD 原水槽 storage (ph2.5 tank 前後 ) (ph3.5) tank (ph7.0) (ph7) Ion 放流酸化槽 oxidazing ph 脱鉄槽 control tank Neutralizing 中和槽 tank separation tank release (ph2.5) (ph3.5) tank Fe 主体殿物 Sludge Al 主体殿物 Sludge (ph2.5 tank 前後 ) (ph3.5) tank バクテリア着床泥の返泥 Sludge with bacteria ( 砒素の共沈 (Fe, (ph7.0) As) (ph7) ) 中和泥の返泥 Sludge ( 資源化 (Al) ) (ph2.5) (ph3.5) Fe 主体殿物 Sludge Al 主体殿物 Sludge Ion oxidation 鉄酸化工程中和工程バクテリア着床泥の返泥 Sludge process with Neutralizing bacteria ( 砒素の共沈 (Fe, As) process ) 中和泥の返泥 Sludge ( 資源化 (Al) ) 9

10 Test result of acid drainage treatment with iron oxidizing bacteria Cake volume (m3 / year) 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1, Sakoda et al. (2014, in press) Small scale test 4,607 Conventional system (the record of 2005 fisical year) Precipitation in Ca(OH)2 neutralizing Precipitation in bacteria oxidizing 1,558 1,315 Proposed process (an estimate) On-site test Sludge cake The achievements of on-site test Amount of neutralizer: 19.8% down Volume of sludge: 37.6% down Running cost: 18.4~31.1% down 10

11 Outline 1. Functions of JOGMEC in the field of mine pollution control 2. Acid mine drainage treatment with iron oxidizing bacteria 3. Drainage treatment with sulfate reducing bacteria 4. Drainage treatment by phytoremediation (accumulate by plant) Aim Operating Matsuo sulfur mine (1953) Current Matsuo neutralization plant and surrounding The Matsukawa R.(left) polluted by drainage from Matsuo mine (1974) Current Matsukawa R. share our experience and technology for sustainable development of African mining sector! 11

12 Active treatment versus Passive treatment Active treatment Active treatment is the improvement of water quality by methods which require ongoing inputs of artificial energy and/or (bio)chemical reagents Passive treatment Passive treatment is the deliberate improvement of water quality using only naturally-available energy sources (e.g. gravity, microbial metabolic energy, photosynthesis), in systems which require only infrequent (albeit regular) maintenance in order to operate effectively over the entire system design life Mine Water: Hydrology, Pollution, Remediation Paul L. Younger et al. Merits of passive treatment Dramatically reduce the cost of water treatment Maintenance almost-free Reduce labor cost Using natural purifying effect Reduce running cost (chemicals, electricity etc.) Harmony with natural landscape Demerits of passive treatment Difficulties in securing the stability of purification capability Purification capability is affected by the change of temperature and quality of drainage Severe water quality management is required under the principles of compliance of water effluent standard 12

13 Some types of passive treatment Anoxic limestone drain (ph neutralization) inhibit precipitation of Fe 3+ oxide (Fe 3+ oxide covers the limestone and prevents ph neutralization) require Fe 2+ oxidation in later process anaerobic Close Under R&D by JOGMEC Anaerobic wetland PRB (permeable reacting barrier) (sulfate reduction by bacteria) Use limestone Require chemicals heavy metals are precipitate as Use bacteria sulfide sterilized at acid condition Not require chemicals inactive at low temperature (below 15 ) require nutrition (organic carbon) Oxic limestone drain (ph neutralization, Fe 2+ oxidation) easy chemical reaction, easy installation Fe 3+ oxide precipitate on the surface of limestone and prevents ph neutralization aerobic Open Aerobic wetland (iron oxidization by bacteria) Fe 2+ Fe 3+ at low ph small amount of heavy metals are co-precipitate with Fe 3+ oxide 13

14 Model of passive treatment by wetland ph neutralization Removal of suspended solids Oxidation and precipitation of Fe 2+ Precipitation and filtration of Zn, Cu etc. Abandoned mine Drainage (limestone) (gravity settling) (iron oxidizing bacteria) (sulfate reducing bacteria) Treated water Natural river Limestone drain Settlement tank Aerobic wetland Anaerobic wetland Artificial aerobic wetland in northern Japan (Hokkaido Research Organization) Artificial anaerobic wetland in northern Japan (Hokkaido Research Organization) 14

15 Mechanism of anaerobic bioreactor Brown rice Rice husk (MOFF) Procurable on site Cost almost nothing 15

16 Current tests of anaerobic bioreactor treatment Demonstration test Laboratory test In JOGMEC s Metals Technology Center From 2008 Litter-scale column On site test Near abandoned mine From 2009, for neutral ph drainage From 2013, for acid drainage Litter~Cubic meter-scale column 16

17 Curried out Litter-scale column Influent Water Quality (C mine): test 8.0 for drainages from 7 different ph : 3.3~3.8 mines Zn : 12.5 ~ 19.0 mg/l Cu : 6.0 ~ 12.0 mg/l 6.0 Pb : 0.7 ~ 1.5 mg/l Cd : 0.15~0.25 mg/l SO4 2- : 200 mg/l Heavy metals are continuously removed 4.0 from drainages 50 5 Influent water (test 3.0 period: 1~2 years) Treated water National effluent standard days 17 days days ph Laboratory test of anaerobic bioreactor treatment Zn conc. S 2- (mg/l) conc. (mg/l) Cu conc. (mg/l) SO 4 2- conc. (mg/l) Cd conc. (mg/l) Pb conc. (mg/l) ph Zn conc. (mg/l) S 2- conc. (mg/l) Cu conc. (mg/l) SO 2-4 conc. (mg/l) ph Cd conc. (mg/l) S 2- conc. (mg/l) SO 2- Cu conc. 4 conc. (mg/l) (mg/l)

18 Laboratory test of anaerobic bioreactor treatment Freeze and cut SEM Ingredient of column Sulfur Upper part 0-5cm 5~10cm 0-15cm 0-25cm 0-35cm Lower part Zn Cd Cu Acid soluble metals 金属量 in column (mg) ingredient (mg) Zinc Copper Small sulfide metals (μm-size) were observed in Heavy metals are promptly precipitated at injection side column ingredient 18

19 On site test of anaerobic bioreactor treatment for neutral ph drainage Old tailing dam Active Treatment Plant Temporary Storage Tank Magnetic Valve Influent Water Quality: ph : 6.0~7.8 Zn : 0.8 ~ 2.0 mg/l Cd : 0.03~0.15 mg/l SO4 2- : 150~280mg/L Mine water storage tank (300L) ph:5.91 Cd:0.103mg/L SO 4 2- :250mg/L Indoor Organic ingredient Reactor1 (1000L) Flow rate: 200mL/min each Reactor2 (1000L) Reactor3 (1000L) Storage Tank(1000L) Return to Existing Active Treatment Facility Treatment Tank1~3(300L) Reactor 1 Reactor 2 Reactor 3 Rice husk Rice husk Rice husk & Composted bark with cow manure Residence time 12.5 ~ 50 hours 50 hours 50 hours 25 hours ~ 原水中継槽 ~ ~ 試験建屋正面 ~ ~ 試験建屋内部 ~ ~ 建屋裏 ~ ~ 建屋側面 ~ 手前タンク : 原水槽処理槽 1~3 貯水槽後方タンク : 反応槽 1~3 ( 右上 : 充填されている活性炭 ) Test site Reactor Section of reactor 19

20 On site test of anaerobic bioreactor treatment for neutral ph drainage Reactor 1 Reactor 2 Reactor 3 Organic ingredient Rice husk Rice husk Rice husk & Composted bark with cow manure Residence time 12.5 ~ 50 hours 50 hours 50 hours 25 hours Rice husk Composted bark with cow manure HRT: (HRT: Hours of residential time) HRT: Zn and Cd concentration of influent and effluent of reactor 3 during >1000 days Heavy metals are continuously removed in all reactors (test is ongoing) 20

21 On site test of anaerobic bioreactor treatment for acid drainage Influent Water Quality: ph : 3.3~3.5 Zn : 15 ~ 20 mg/l Cd : 0.05 mg/l Pb : 0.08 mg/l Cu : 5 ~ 10 mg/l SO4 2- : 350 ~ 400 mg/l Test site (northern Japan) Receiving tank and reactors Colum size: 35L Main ingredient: Rice husk, limestone, mud HRT: Hours of residential time Heavy metals are continuously removed in reactors despite low temperature (test is ongoing) 21

22 Outline 1. Functions of JOGMEC in the field of mine pollution control 2. Acid mine drainage treatment with iron oxidizing bacteria 3. Drainage treatment with sulfate reducing bacteria 4. Drainage treatment by phytoremediation (accumulate by plant) Aim Operating Matsuo sulfur mine (1953) Current Matsuo neutralization plant and surrounding The Matsukawa R.(left) polluted by drainage from Matsuo mine (1974) Current Matsukawa R. share our experience and technology for sustainable development of African mining sector! 22

23 Mechanism of phytoremediation by hyperaccumulator Examples of hyperaccumulator Evaporation / Diffusion Decomposition / Transformation / Accumulation Move to aerial part Stimulate microorganism Removal Absorption Arabis gemmifera (for Zn, Cd) Funaria hygrometrica (for Pb, Au) Discharge Stabilization Mechanism of phytoremediation (Sakakibara, 2013) Phytoremediation is the direct use of green plants and their associated microorganisms to stabilize or reduce contamination in soils, sludges, sediments, surface water, or ground water. (US PEA) Eleocharis acicularis (for heavy metals) From 2013, JOGMEC conducts joint study of phytoremediation with national institutes / universities. 23

24 Example of on site test of phytoremediation Ehime University launched on site test of phytoremediation for mine drainage by using E. acicularis. Floating cultivation method Adsorb heavy metals directory from water (Sakakibara, per comm) JOGMEC and Ehime Univ. jointly conduct on site test at other abandoned mines. 24

25 Example of on site test of phytoremediation Drainage: ph : 3.3~5.6 Fe : 4.6 ~ 2.5 mg/l Cu : 0.1 mg/l Pb : ~ mg/l Zn : 6.7 ~ 2.5 mg/l As : ~ mg/l Cd : 0.03 ~ 0.01 mg/l Al : 11 ~ 2 mg/l E. Acicularis promptly accumulates heavy metals Change of heavy metal concentration of E. acicularis soaked in acid drainage during 27 days (in October 2013) (Sakakibara, per comm) 25

26 Thank you for your attention! 26