ERW-Darjeeling-PHREEQC

Enhanced Rock Weathering Geochemical Modeling for Tea Plantation Carbon Removal

🌱 Project Overview

Geochemical simulation of Enhanced Rock Weathering (ERW) in Darjeeling tea plantation soils using PHREEQC reactive transport modeling. This study quantifies carbon removal potential while demonstrating agricultural co-benefits through soil pH buffering and nutrient release.

🎯 Key Results

• pH Improvement: +3.73 units (4.8 → 8.53) over 365 days
• Carbon Sequestration: Linear alkalinity increase with exponential HCO₃⁻ formation
• Nutrient Release: 133% Mg²⁺ increase, stable Ca²⁺ supply
• Dual Benefits: Climate action + agricultural soil enhancement

🚀 How to Run

1. PHREEQC Simulation

2. Python Visualization

Prerequisites

• PHREEQC 3.8.6+ - Download from USGS
• Python 3.7+ with pandas, matplotlib, numpy
• wateq4f.dat database (included with PHREEQC installation)

🔬 Technical Features

• Kinetic modeling: Temperature and pH-dependent mineral dissolution rates
• Multi-mineral system: Anorthite, Diopside, Olivine weathering kinetics
• Real conditions: Darjeeling climate (18°C) and acidic soil chemistry (pH 4.8)
• Advanced rate laws: Arrhenius temperature dependence and pH effects
• Professional visualization: Python-based data analysis and plotting

📊 Key Findings

Soil Chemistry Transformation

• Initial conditions: Acidic tea plantation soil (pH 4.8, low nutrients)
• Final conditions: Alkaline soil (pH 8.53, enhanced nutrients)
• Mechanism: Basalt weathering consumes H⁺ and releases Ca²⁺, Mg²⁺

Carbon Removal Quantification

• Process: Atmospheric CO₂ → dissolved bicarbonates (HCO₃⁻)
• Storage timeframe: >10,000 years in stable carbonate minerals
• Verification: Progressive alkalinity increase over 365-day simulation

Agricultural Co-benefits

• Nutrient enhancement: Essential Ca²⁺ and Mg²⁺ for plant growth
• pH buffering: Optimal conditions for nutrient availability
• Soil health: Transformation from acidic, leached soil to fertile growing medium

🌍 Applications

• Carbon removal verification: MRV protocols for climate tech companies
• Agricultural assessment: Soil improvement quantification for farming applications
• Climate tech optimization: Basalt application rate determination
• Enhanced rock weathering research: Academic and commercial feasibility studies

🛠️ Technologies

• PHREEQC 3.8.6 - Industry-standard geochemical modeling software
• Python - Data analysis, visualization, and scientific computing
• wateq4f.dat - Comprehensive thermodynamic database for aqueous systems
• Matplotlib/Pandas - Professional scientific plotting and data manipulation

📈 Model Validation

• Kinetic rate constants: Literature-based values for basalt mineral dissolution
• Temperature effects: Arrhenius kinetics calibrated for 18°C Darjeeling conditions
• pH dependencies: Validated against experimental weathering studies
• Mass balance: Conservative element tracking ensures model accuracy

🎓 Educational Value

This project demonstrates:

• Advanced geochemical modeling skills using industry-standard software
• Climate tech applications of Enhanced Rock Weathering technology
• Data science capabilities in environmental modeling and analysis
• Professional presentation of scientific results for technical audiences

📝 Citation

If you use this model or approach in your research, please cite:

🤝 Contributing

Contributions welcome! Please feel free to:

• Report issues or bugs
• Suggest improvements to the model
• Add additional analysis features
• Enhance documentation

📄 License

This project is open source and available under the MIT License.

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Developed for Enhanced Rock Weathering research, carbon removal verification, and climate tech applications.

Contact: sutradharmanadip01@gmail.com| Research Focus: Geochemical Modeling & Climate Solutions