Mine Drainage Treatment ith Li t d C twith Limestone and Compost

Case Study: Machacamarca Municipality

Takayuki Iwanaga (09M51420)y g ( )Niwa Laboratory

Department of Civil Engineering

Boli iaBolivia

Geo-environmental Engineering May,2010

1General Information

JAPANJAPAN

Plurinational State of Bolivia

Capital cities: La Paz (Administrative); Sucre (Judicial)

Area: 1 098 581km2 (Water: 1 29%)Area: 1,098,581km (Water: 1.29%)

Population: 9,775,246 (2009 est.)

Languages: Spanish (Official), g g p ( ),Quechua, Aymara and Guarani

Ethnic groups: 30% Mestizo, 30% Quechua 25% Aymara 15% WhiteQuechua, 25% Aymara, 15% White

GDP Per capita: $1,723 (2009est.)www.cia.gov

2Mega-Diverse Country

2560mt

3660mt

416mt

3Environmental Problems

• Water pollution and water management

• Air pollution

• Deforestation

• Land degradation and soil erosiong

• Loss of biodiversity

4Mining Activities and Water Pollution

Mining activitiesAfter a long period of recession the Bolivian mining sector has reactivated due to increase of mineral prices in 2006.

Western Bolivia most mines produce acid t ith hi h t t f hwater with a very high content of heavy

metals.

Cooperative and small-scale mining inCooperative and small scale mining, in which more than 70,000 families work, is particularly polluting.

Damage to population’s health and productive activities such as agriculture within the area of influence of pollution.

Mitigation measures and modern mine

acid water

gdrainage treatment technologies are expensive for cooperative and small-scale mining workers.

5Pollution Mitigation Project

Thuska Uma ProjectFinancial support by PIEB

(Started in 2008)

• Reduce the pollution in Huanuni river andthe area ecosystems.

• Development of mine drainage treatmenttechnologies with passive and activemethods in order to recover water to use Pilot plantfor irrigation.

Machacamarca

Pilot plant

Machacamarca

6What is Active and Passive Treatment?

Active Treatment

It is the conventional waste water engineering applied to mine waters.

Younger et al. (2002):

“Active treatment is the improvement of water quality by method which

Artificial energy: Electrical power for pumping, mixing, aerating, etc.

require ongoing inputs of artificial energy and/or (bio) chemical reagents”

Reagents: Alkaline liquids or solids (e.g. calcium hydroxide, sodium hydroxide), organic polymers (for coagulation/ flocculation, etc.) or pressurized gases.

Inverse Osmosis

Using semipermeable membrane of sheep

7What is Active and Passive Treatment?

Passive Treatment

Pulles et al. (2004):( )

“A water treatment system that utilizes naturally available energy sourcessuch as topographical gradient, microbial metabolic energy, h t th i d h i l d i l b t i f tphotosynthesis and chemical energy and requires regular, but infrequent

maintenance to operate successfully over its design life”

Reducing and alkalinity producing system (RAPS)

•Organic material serves as theOrganic material serves as the nutrient source for iron- and suphate-reducing bacteria.

N t li th idit i

Permeable organic matter Compost of sheep - Llama

•Neutralize the acidity in a limestone layer.

•Alkaline addition in RAPS is Limestone drain

Gated discharge

Pipe

dominated by the limestone dissolution pathway.

8Implementation of Treatment Plant

Influent

Compost

Semipermeable membrane

Water pump

Limestone

Inverse osmosis EffluentDeposit “Lamela”

Passive treatment Active treatment

Laboratory Pilot plant

9Test Results of Passive Treatment

Concentration Logarithmic [mg/lt]

(Treated water)

www.pieb.com.bo

pH of water before and after treatment

(Max. allowable, Class C) (Cadmium) (Iron) (Zinc) (Nitrogen) (Sulphate) (Sulfides)

Days

(pH LMP, class C)

(pH Treated water)

(Projection, pH)

Polynomial (pH Treated water)

10Conclusions

• The present combined passive and active mine drainage treatment technology can stabilize the pH level of water and reduce heavy metals.

• Construction and operation of mine drainage treatment plant do not use sophisticated technologies.

• Materials which is use to treat mine water can be found in the local area.

• The proposed mine drainage treatment technology is cheaperThe proposed mine drainage treatment technology is cheaper than using only an active treatment.

11References

• www sida se/PageFiles/2826/Environmental policy brief Bolivia pdfwww.sida.se/PageFiles/2826/Environmental policy brief Bolivia.pdf . Bolivia Environmental Policy Brief: Environmental Sustainability, Poverty and the National Development Plan. June 2007

lid b / b/E bi t l df I f d l t d bi t l• www.lidema.org.bo/mamb/Eambiental.pdf . Informe del estado ambiental de Bolivia 2007-2008. Liga de defensa del medio ambiente.

• aguasdemina.pieb.org/proyecto.htm . Tratamiento de aguas de mina con g p g p y gpiedra caliza y compost.

• Paul L. Younger, Steven A. Banwart and Robert S. Hedin. Mine Water Hydrology Pollution Remediation Kluwer Academic Publishers 2002Hydrology, Pollution, Remediation Kluwer Academic Publishers. 2002.

• www.gardguide.com/index.php/Chapter_7 . Drainage treatment.

• www.pieb.com.bo/p

• www.opex-energy.com/termosolares/planta_tratamiento_aguas_termosolar.html.

Tiwanaku Chiquitania Samaipata

Muchas gracias t ipor su atencion.

Valle de la Luna

Salar de Uyuni Lago Titicaca Laguna Colorada