Apart from the classical process via nitrates, Ahidra, agua y energía, S.L. has two innovative processes at industrial facilities for the removal of nitrogen:

• MBR-NO2® Process: aerobic biological process for nitrogen removal via nitrite, with UF membranes for separation of biomass. This process involves a 40% reduction of the organic matter necessary to carry out denitrification, a 25% saving of the required oxygen and a 30-40% reduction in the volume of reactors.
• Process MBR – NAS ®, an aerobic biological process with UF membranes, which allows nitrogen removal (denitrification) without carbon source. This process saves 40 % of the required oxygen and a 30-40% reduction in reactor´s volume.

Ahidra, agua y energía, S.L. is able to choose the appropriate process based on the carbon/nitrogen affluent relation and design and build reactors that can operate with high efficiencies of ammonia concentrations greater than 3.000,0 ppm.

Applications of these technologies:

• Treatment of leachate from MSW / ISW.
• Effluents from biomethanisation plants using the organic fraction of municipal waste.
• Liquid fraction of the anaerobic digestion of urban sewage sludge.
• Liquid fraction of the anaerobic co-digestion of organic waste.
• Effluent from scrubbers condensate and purges at thermal sludge drying plants.

The technical solution proposed in the above applications is: N-DN aerobic biological process, MBR type , removal of dissolved salts in the UF membranes permeate, by an open channel reverse osmosis and evaporation by thermocompression of the OI retentate.

Anaerobic digestion of organic waste has following purposes:

• Solve the environmental problem of waste biomass.
• Put primary biomass in value.
• Increase incomes adding other waste biomass to cattle waste (manure, etc.).
• Reuse of anaerobic digestion liquid fraction for irrigation or nutrient removal according to disposal requirements.
• Nutrients recovery (N and P) for mineral/organic fertilizers production, together with the solid fraction of digestate.

Process advantages:

Temperature range:
Thermophilic range (55,0 ºC). Half digestor size related to the mesophilic range.

Global solution:
Anaerobic co-digestion, solid-liquid separation of digestate, biogas desulphurization (Bidox^® system) and different Nitrogen removal/recovery technologies (MBR- NAS^® process) from anaerobic digestion liquid fraction effluent.

Recent application:
Anaerobic thermophilic digestion of urban wastewater dewatered sludge. More biogas production and less sludge disposal cost related to the mesophilic range.

In wastewater treatment and reuse, Ahidra, agua y energía, SL is able to design and build any type of process, either anaerobic (UASB) or aerobic (MBR, SBR, etc.).

Ahidra´s proposal for high organic load effluent treatment is composed by a anaerobic treatment (UASB) up-flow anaerobic sludge blanket, and an aerobic treatment to reduce organic matter to comply with discharge limits.

The positioning of the company in recent years has been the treatment of effluents with high nitrogen content, with high phosphorus content, high organic load and high salts concentration.

Ahidra, agua y energía, SL is able to reduce nitrogen and phosphorus in urban waste water, by using biological processes and comply with disposal requirements.

We have developed a specific process for high phosphorus content effluents: ANPHOS^® Process.

The ANPHOS^® process consist on a chemical precipitation, in a batch reactor, to produce ammonium magnesium phosphate (MAP) called struvite.

Recent application: Recovery of nitrogen and phosphorus from the liquid fractions on an anaerobic co-digestion of organic waste.

Leachate treatment and anaerobic digestion liquid effluents of organic wastes and others contain a high salt concentration that has to be removed before its disposal. We implement an open channel reverse osmosis treatment designed for this specific effluents.

Treatment of high loads of hydrogen sulfide for industrial biogas production facilities.

Ahidra, agua y energía, S.L. offers its potential customers a new technology successfully tested on an industrial scale: The aerobic biological process for reducing hydrogen sulphide in gas streams (BIDOX^® Process).

BIDOX^® System  for the treatment of 600 Nm³/h of biogas with highloads of hydrogen sulfide

Advantages:

• Low operation cost, because it requires no specific chemical reagents
• The reactor does not produce any toxic waste that needs to be managed as hazardous waste.
• Compact and relatively simple reactor in terms of control and monitoring systems.

Treatment of other contaminants:

• Aerobic biological oxidation of ammonia.
• volatile organic compounds (VOCs).
• Mercaptans.
• Treatment of odors and/or complex mixtures of pollutants in urban or industrial facilities.

The generation of gas streams containing complex mixtures of gases is a common problem in all types of industrial facilities. A valid alternative to conventional expensive and complex treatment systems, is the use of next-generation bioreactors, whose investment and maintenance costs are significantly lower than for physical-chemical systems.

Ahidra, agua y energía, S.L. can ensure a degree of knowledge of the process, which will involve the design of more efficient and economical reactors.