Wastewater and Effluent Parameters

Oil and Grease

Oil and grease is defined as any material recovered as a substance soluble in extracting solvent. It can be composed of fatty matter from animal and vegetable sources and from hydrocarbons of petroleum origin. Oil and grease in water can cause surface films and shoreline deposits leading to environmental degradation, and can induce human health risks when discharged in surface or ground waters. Presence of excessive amounts may interfere with aerobic and anaerobic biological processes and lead to decreased wastewater treatment efficiency. Liquid-liquid partition by solvent extraction is the most widely used method for the determination of oil and grease.

Total Suspended Solids (TSS)

Total suspended solids (TSS) are particles that are larger than 2 microns found in the water column. Most suspended solids are made up of inorganic materials, although bacteria and algae can also contribute to the total solids concentration. TSS is also a significant factor in observing the aesthetics of the water, as the more suspended solids that are present the less clear the water will become. Excessive suspended solids can because for concern for aquatic and human life as well as impede navigation and increase flooding risks. TSS can be measured through gravimetric determination.


Temperature is a key parameter in checking water quality. It affects the dissolved oxygen levels in water, the rate of photosynthesis, as well as metabolic rates of organisms. Each species of organism thrives in a specific temperature range. Some organisms use temperature as an indicator for reproduction and migration. Abnormality in water temperature can disrupt the balance of aquatic ecosystems with devastating effect.


Comes from the word surface active agent. They are amphiphilic molecules and are thus absorbed in the air-water interface. At the interface, they align themselves so that the hydrophobic part is in the air and hydrophilic part is in water. This will cause the decrease in surface or interfacial tensions.


Phosphorus occurs in natural water and wastewater almost solely as phosphates. It is a common constituent of agricultural fertilizers, manure, and organic wastes in sewage and industrial effluent. It is an essential element for the growth of plants and animals and in lake ecosystems. But excessive amount of phosphorus in water can lead to eutrophication resulting in reduced stability of the ecosystem. Phosphorus concentrations can be measured by colorimetric determination by stannous chloride method or ascorbic acid reduction method.


pH is a measure of how acidic or basic water is. Its technical and scientific definition is that it is a measure of the activity of the hydrogen ion (H + ). The pH of water is a very important measurement parameter concerning water quality. It affects aquatic life wherein some creatures can only live at a usual pH range. It can also affect the solubility and toxicity of chemicals and heavy metals in the water. pH can be measured using a potentiometric instrument such as pH meter.