A very easy screening test to calculate surfactants biodegradation

Kurzfassung

An Italian research centre has developed a screening test certifying the degradation speed of chemicals into a biological wastewater treatment plant. The test is extremely fast and assesses the possibility to treat with biodegradation different substrates on the basis of the demolition kinetics of a key parameter; an activated sludge taken from a wastewater treatment plant is used as microbiological source. The centre is looking for companies willing to employ this method.

Details

Textile sector companies, together with some other sectors that utilise surfactant products generating wastewater, are looking for methods to decrease the costs of de-pollution treatments and asking suppliers for products that can be ecologically purified. Consequently, surfactants producers are focusing on new environment-friendly products and production cycles.
In particular, the obligation to prevent pollution and improve de-pollution processes implies analysis of quantitative (pollution capacity per mass unit in the environment) and qualitative (high biodegradability, low persistence in environment) environmental impact.
Industries producing surface-active agents have deeply studied the way to improve the biodegradability of wastewaters that generally have high COD and surfactants content.
"Ecological" products have been gradually put on the market; these products have a lower content of surfactant, MBAS (Methylene-Blue Active Substances), etc., and their formulations are based on easily degradable molecules, maintaining their performance quality in the working cycle. An Italian research centre has developed an evaluation system to measure the demolition rapidity of the molecules using active mud.
The method assesses the possibility to treat with biodegradation different substrates on the basis of the demolition kinetics of a key parameter (COD or/and reference substances); an activated sludge taken from a wastewater treatment plant is used as microbiological source.
The test has the following objectives:
1) To provide, in a short time, sufficient data in order to foresee the possibility to purify wastewater containing a particular substance through an activated sludge treatment and the time needed to reduce its concentration within the limits fixed by the law.
2) To indicate the maximum acceptable concentration that the substance can reach in the waters to be biologically treated, without exceeding the limits imposed by the law.
3) To underline possible inhibiting or stimulating effects of the bacterial metabolism from the used substances.
4) To mathematically extrapolate the degradation kinetics of each substance, in order to provide only one interpretation to compare different groups of compounds, which can be alternatively used in industries.

A control with no test-substance is included in the programme. It is treated in the same way as the other samples, so that it can be considered as "zero" in the final calculations.
Other parameters, beyond COD (Chemical Oxygen Demand), are taken into account depending on which substance is tested.
Respiration coefficient measurements are carried out, in order to spot possible variations of the metabolism during the experiment.
This screening test certifies the degradation speed of chemicals into a biological wastewater treatment plant, and it is applicable by chemicals producers and surfactants manufacturers.
The research centre is looking for companies, industries and SMEs producing detergents and surface-active agents and compounds, willing to employ this method to test their products.

Innovative Aspects:
This new method is extremely fast: testing time is of 7 days against 28 days required by present technologies.
It is applicable to a higher number of substances with comparison to the other available test methods.