// THESIS GUIDANCE PORTAL · Engineering

Solar-Powered Water Purification Unit for Terai Communities

Level: Bachelor, MasterDifficulty: Intermediate

1. Introduction & Problem Statement

Overview: Low-cost solar purification design targeting groundwater arsenic and biological contamination in Terai districts.

Background Context (Nepal): Groundwater in several Terai districts contains unsafe levels of natural arsenic, iron, and coliform bacteria. Off-grid solar-powered electrocoagulation and filtration units provide clean drinking water.

2. Research Objectives

›Design solar PV-powered electrocoagulation (EC) reactor for dissolved arsenic and iron removal
›Integrate multi-stage sand, activated carbon, and UV disinfection filtration pipeline
›Determine optimal current density and solar panel wattage for 500 liters/day clean water output
›Test water quality parameters (pH, arsenic ppm, turbidity, bacterial count) pre- and post-treatment
›Conduct unit cost analysis to ensure affordability for rural Terai user committees

3. Proposed Methodology

Water sampling from tubewells in Nawalparasi / Rautahat districts following WHO testing protocols
Bench-scale reactor fabrication with iron/aluminum sacrificial electrodes powered by PV array
Atomic Absorption Spectroscopy (AAS) laboratory analysis of heavy metals pre- and post-reaction
Solar irradiance profiling using PVsyst software for Terai climate conditions
Economic cost computation per liter produced against National Drinking Water Quality Standards

$ Worked Example / Sample Scenario

Sample Scenario: Water from a tubewell in Nawalparasi with 0.12 mg/L arsenic (above WHO 0.01 limit) is passed through a 12V PV-powered electrocoagulation cell. After 15 minutes of operation, arsenic concentration drops below 0.008 mg/L.

4. Thesis Chapter-by-Chapter Outline

Chapter 1: IntroductionTU/KU standard

Background, problem statement, research questions, objectives, scope, limitations, and significance of the study

Chapter 2: Literature ReviewTU/KU standard

Theoretical framework, conceptual models, previous empirical studies in Nepal and developing nations, groundwater chemistry, electrocoagulation kinetics, and PV sizing formulas, and gap analysis

Chapter 3: Research MethodologyTU/KU standard

Research design, population/sampling framework, data collection instruments, analytical tools, and ethical considerations

Chapter 4: Data Analysis & ResultsTU/KU standard

Empirical findings, statistical testing, model estimations, arsenic removal efficiency curves, UV dosage charts, and unit cost tables, and detailed discussion

Chapter 5: Conclusion & RecommendationsTU/KU standard

Summary of key findings, theoretical contributions, policy recommendations, and future research directions

5. Recommended Tools & Technologies

To implement the practical, technical, or analytical portions of this thesis topic, the following software tools, libraries, or APIs are recommended:

PVsystMATLABAutoCADSPSSMS Excel

6. Core References & Academic Sources

[1]Department of Water Supply and Sewerage Management (DWSSM Nepal) — Drinking Water Guidelines
[2]WHO Groundwater Contamination Reports — Arsenic in Terai Region
[3]Journal of Hazardous Materials / Elsevier — Solar electrocoagulation water treatment

7. Frequently Asked Questions (FAQs)

Q: What is the official WHO limit for arsenic in drinking water?

The WHO guideline value for arsenic in drinking water is 0.01 mg/L (10 ppb), though Nepal's interim standard is 0.05 mg/L.

Q: How does electrocoagulation work?

A low DC voltage applied to iron or aluminum electrodes releases metal cations that adsorb and precipitate dissolved arsenic and colloidal impurities.

Q: What solar capacity is needed for a community purification unit?

A 100W–200W solar panel array paired with a 12V deep-cycle battery easily powers a small electrocoagulation reactor and UV lamp.

Q: Where can I perform water sample testing in Nepal?

University environmental labs, DWSSM testing facilities, or certified private water testing laboratories in Kathmandu/Terai cities.