Water quality analysis involves testing water to ensure it is safe for human use, aquatic life, and the environment. Various techniques are used to measure physical, chemical, and biological parameters.
1. Physical Analysis
- Turbidity Measurement:
- Indicates cloudiness caused by suspended particles.
- Instruments: Nephelometers or turbidity meters.
- Color and Odor Tests:
- Visual observation or spectrophotometers for color.
- Smell indicates contamination by organic matter or chemicals.
- Temperature Measurement:
- Affects dissolved oxygen and aquatic life.
2. Chemical Analysis
- pH Measurement:
- Indicates acidity or alkalinity of water.
- Instruments: pH meter or pH indicator paper.
- Dissolved Oxygen (DO):
- Measured using DO meters or Winkler titration.
- Shows the water’s ability to support life.
- Biochemical Oxygen Demand (BOD):
- Indicates organic pollution by measuring oxygen consumed by microbes.
- Chemical Oxygen Demand (COD):
- Measures total oxygen required to oxidize all chemicals in water.
- Heavy Metal Detection:
- Techniques: Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma (ICP-MS).
- Detects Pb, Hg, Cd, As, etc.
- Nutrient Analysis:
- Nitrates, phosphates, and ammonia measured using spectrophotometry or ion-selective electrodes.
- Organic Pollutants:
- Pesticides, herbicides, and hydrocarbons measured using Gas Chromatography (GC) or HPLC.
3. Biological Analysis
- Microbial Analysis:
- Detects bacteria, viruses, and protozoa.
- Techniques: Plate counts, Most Probable Number (MPN), or PCR for pathogens.
- Bioindicators:
- Presence of certain organisms (like algae or macroinvertebrates) indicates water quality.
4. Emerging Techniques
- Sensors and Probes:
- Real-time monitoring of pH, DO, conductivity, and turbidity.
- Remote Sensing:
- Satellites or drones detect large-scale water pollution, algal blooms, or sediment levels.
In short:
Water quality analysis uses physical tests (turbidity, color, temperature), chemical tests (pH, DO, BOD, heavy metals, nutrients), and biological tests (microbial counts, bioindicators), often combined with instrumental techniques for precise monitoring.