A. High loaded anaerobic treatment
Depending on the degree of pollution and on the parameters that characterize the wastewater, there are two types of treatment:
I. AEROBIC TREATMENT
The main pollution parameters in all waste waters are:
a. the organic contents - measured in chemical oxygen demand and the biological oxygen demand;
b. the solid fraction;
c. the presence of fat, oils and greases;
d. the presence of nutrients (nitrogen in all forms and phosphorus)..
When the presence of the solid factors in the waste water increases, the mechanical or the chemical pretreatment is necessary..
The presence of nitrogen in any form requires the application of aerobic biological nitrification-denitrification in order to remove it in the desired level.
II. ANAEROBIC TREATMENT
When the waste water to be treated is characterized by high organic loading and low concentration of suspended solids, fats, oils, greases and nutrients, the optimum process to apply is the anaerobic treatment, based on the granular sludge technology.
The anaerobic treatment is a microbiological process that consists of the organic matter degradation to biogas production. The biogas produced consists of methane (CH4) 60 – 90% and carbon dioxide ( CO2) 10 – 40%.
||Low plus production of energy under biogas form
||High consumption of energy necessary for aeration
||Low production of excess sludge
||High production of excess sludge
||Low (at least 15 times)
|Necessary plant area occupied
||Large (at least 10 times)
The main industries where the anaerobic technology can be successfully applied are:
- Breweries and Alcohol Factories
- Chemical and Pharmaceutical Industry
- Pulp and Paper Industry
- Industria celulozei si hartiei
- Sugar Industry
- Milk Industry.
B. Nutrients removal - to be completed at a later stage