A measure of the amount of dissolved oxygen (measured in mg/L) required for the decomposition of organic matter by micro-organisms. BOD is most frequently used as a test method to gauge the effectiveness of water treatment processes. This is usually specified as a BOD5 which is the oxygen required to oxidise the biodegradable organics in 5 days.
Coagulation is a chemical process which neutralises the charge on particles. This is often achieved through the addition of ferric or aluminium salts. Coagulation is often used together with flocculation.
Physical process for bonding together small, lightweight particles into larger, heavier groups which can then be clarified or filtered, helping the removal of suspended solids. Often used in association with coagulation.
Wastewater generated by commercial activities such as: manufacturing, agriculture or mining. Industrial wastewater typically contains more contaminants than domestic wastewater and requires further treatment.
Substances are added to neutralise water, so that the water it is neither acid, nor basic. Neutralisation does not exactly result in a pH of 7.0, it just means the balance point of an acid-base reaction.
pH is one of the measures of water quality and is calculated from the amount of hydrogen ions that are present. This is used to specify the acidity or alkalinity of a solution, it is measured on a scale from 0 to 14. A pH of less than 7 is considered acidic, a pH of 7 is neutral and pHs greater than 7 are alkaline.
The Reversed Osmosis (RO) process uses a semi-permeable membrane to remove dissolved solids and molecules from water. The process requires pressure to overcome osmotic pressure and produce water safe for use. It also produces a concentrate stream containing all the dissolved.
Sand filtration is a method to remove suspended solids from water. The filtration method consists of multiple layers of sand with a variety in size. Sand filters can be supplied in different sizes and can be both hand operated and fully automated.