Purification

WASTE-WATER TREATMENT 

Each time we use the bathroom we “condemn” an average of between 10 and 20 litres of water, in most cases drinking water, to be converted into waste water or sewage that could become a serious environmental problem, not only due to the pollution of rivers and subsoil but also due to the low level of reuse of this waste water for other uses, something that translates into energetic and financial losses. The waste water is made up, therefore, of water that has been used in the homes, in industry, in farming and public services, and could also include rain water that has fallen on the streets, open spaces, patios, gardens and the roofs of the buildings.

During the last decades there is an awareness of this problem and domestic waste water is now piped to sewage plants (in Spanish, Estaciones Depuradoras de Aguas Residuales or EDAR) to be adequately treated. For this it is necessary a network of drains and sewers and other installations that allow the water, once treated, to be returned to the environment in a condition that is compatible with the same. 

When untreated sewage drains into a river or filters down into an aquifer it produces various effects:

• The vegetation of the banks which is covered by the solid waste transported in the waste water such as plastics, utensils, organic waste, etc.

• The pollution of underground water and aquifers, resulting in a deterioration that is difficult to repair.

• The accumulation of suspended solids, such as sand and organic waste, that creates sediments on the river bed and shores. Reduction in the oxygenation of the river water due to the breaking down of the organic waste and ammonia based compounds of the sewage.

• Formation of bad smells due to the depletion of the oxygen dissolved in the river water.

• Pollution of the river with large quantities of micro-organisms amongst which there could be a high number of pathogens.

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  • Pollution with toxic chemical components or substances that harm other living organisms.
  • Possible increase in the eutrophication (presence of living organisms) due to the presence of phosphorus and nitrogen.

• The treatment of sewage has a series of objectives:

  • Reduce pollution to a minimum.
  • Protect the environment.
  • Maintain the quality of life of the individual.
  • Energy savings.
  • Reuse of the resulting waste matter.
  • Reuse of the treated water.

Benissa-Senija Sewage Plant in the Santa Ana area, (Benissa)

BENISSA-SENIJA SEWAGE PLANT

The town of Benissa and the "La Pedrera" industrial estate together with the village of Senija pipe their waste waters to the to the joint Benissa-Senija sewage plant, facility that belongs to the Valencia Community’s Water Treatment Entity “EPSAR”.                                                             

The Town Councils of Benissa and Senija have joined forces to obtain the necessarypermissions and the Jucar Water Confederation authorized the treatment of waste waters in a resolution number 1999VS0028 notified on the 9th March 2007.

The facility, the running of which is contracted out periodically by EPSAR, has a estimated capacity for treating 2.500 m3 of sewage per day, with 249 Kw of energy and the following UTM coordinates:

X:765711

Y:4288670

Z:125

The sewage plant entered into service in 2006 treating 1.114 m3 of sewage per day serving a population of 6.875 and with the following yields:

SS: 98%

BOD5: 98%

QOD: 97%

As far as the treatment methods used, the first step is a primary treatment to separate solids consisting of a filter, sieve, a sand extractor and a grease extractor followed by a secondary treatment consisting of a prolonged exposition to air and a biological reactor to reduce the BOD5 and the decantation of the water that is finally disinfected using chlorine.

In the treatment of the resulting sludge a gravity thickening system is used followed by the dehydration and filtering. 

Plant of the sewers that transport waste water to the sewage plant.

The Water Cycle

The constant circulation of water on the Earth is called the Water Cycle.

The evaporation of the seawater provides humidity to the atmosphere where with the help of the air and the sun, clouds are formed. The evaporation from the ground and the transpiration of plants increase the humidity of the air and this water vapor, on cooling down, turns into mist, dew, frost and clouds and falls back down to earth in the form of rain, snow or hail stones.

This water falls to the earth and runs over or soaks into the ground. It washes down to the meadows and fields and waters the crops and the orchards. The water forms streams, rivers, lakes and reservoirs on the earth’s surface. It filters through cracks in the rocks to form the underground rivers and aquifers that supply our wells with water, and sometimes reappear on the surface in the form of springs.

Both surface and ground waters finally ends up back in the sea, process that, in the case of surface water, can take only a few days or, in the case of groundwater, as long a various centuries, and the water cycle starts again.

Man has an impact on the water cycle since the fresh water we use is returned polluted to the environment something that is putting life on this planet in grave danger.

Water in the world

The water that we drink today has been used during millions of years. Both the quantity and the characteristics of this water have been conserved almost without changes since the planet Earth was formed. The water is present in three states: liquid, gas (vapour) and solid (ice) and is constantly recycled, that is to say, it purifies and renovates itself working together with the sun, the earth and the air to maintain Natures balance.

A transformation has taken place and what started in vapour form has gradually, throughout the centuries, turned into water, at first with a low level of salinity and later a higher level due to the minerals dissolved by the rain that started to fall when the Earth cooled down.

Of the total of 1.400 million cubic kilometres of water that exist on Earth only 33 million cubic kilometres are fresh water. Of this volume 68,7% is in ice form in the polar ice caps and glaciers and 30,5% corresponds to unobtainable subterranean water which means that only 0,9%, some 140.000 cubic kilometres, of the existing fresh water can be used.

This last quantity, which corresponds to surface and rain water, has a dynamic character since it is constantly in movement fulfilling a continuous cycle, known as the water cycle, which makes life possible on this planet.

The conclusion is that, taking into account that saltwater and ice-caps cannot be used as drinking water, only a very small percentage of the Earth’s water is suitable for human consumption. The possibility of water shortage on this planet is very high.

Water is very important for living beings since most biochemical reactions can only take place with the help of water. That is to say, water transports dissolved substances between different parts of our body as, for example, in the blood stream. The blood serum has a water base and 65 % of the weight of a human being corresponds to water with a salinity of 0.9 %.

Apart from being necessary for the internal function of the human body, water is also essential for people in other many ways. Water is used for personal and domestic cleanliness, for cooking and drinking, in central heating systems and to eliminate our waste.

The consumption of water has increased manifold over the last h

undred years. The United Nations recommends 75 litres per person every 24 hours as a minimum limit for an acceptable water supply although many industrial countries consume an average of between 300 and 500 litres per person, per day. Most of this consumption is not for domestic use but for industry and sumptuary purposes.

Attachments:

Informe de las Naciones Unidas sobre el Desarrollo de los Recursos Hídricos

Collaborating Plumbers

The Municipal Drinking Water Services carries out the maintenance of the drinking water distribution network.   

For the installation of new networks, new residential connections, changes of stopcocks, change of pressure regulation valves, etc.,  the user must make arrangements with a professional plumber to carry out these jobs under the supervision of the Municipal  Service.