Waste disposal + recycling Zurich
| ERZ Disposal + Recycling Zurich | |
|---|---|
| legal form | Municipal Service Department |
| founding | 1867 |
| Seat | Zurich , Switzerland |
| Number of employees | 888 (2017) |
| sales | 340 million CHF (2017) |
| Branch | Waste disposal, recycling, sewage treatment, district heating, city cleaning |
| Website | www.erz.ch |
ERZ Disposal + Recycling Zurich is a service department of the City of Zurich . ERZ collects, recycles and disposes of solid and liquid waste . At the same time, ERZ wants to avoid the generation of waste as much as possible, as is also provided by the “Federal Law on Environmental Protection”. For this reason, as well as in accordance with the “Ordinance for waste management in the city of Zurich (VAZ)”, ERZ informs the city population and businesses about the options for avoiding waste.
The ERZ infrastructure includes two waste-to- energy plants and a sewage treatment plant , into which the wastewater is fed via a public network of around 1000 kilometers to which a further 3500 kilometers of private sewer pipes are connected. The service department belongs to the municipal civil engineering and waste disposal department (TED) and is therefore integrated into the city administration. Around 900 people are employed; In 2017, around 340 million Swiss francs were turned over in the areas of waste, sewage, district heating and city cleaning.
Field of activity
There are the business areas of drainage , sewage treatment , city cleaning , disposal logistics , waste- to- energy plants and district heating .
Sewage and drainage
The drainage division creates, operates and maintains the urban sewer network and is responsible for the streams and Lake Zurich in the urban area. ERZ protects groundwater, streams and the lake from pollution through its work. The drainage network comprises around 1,000 kilometers of urban and around 3,500 kilometers of private pipes. Since 1988, ERZ has uncovered around 18 km of streams, creating space for people, animals and plants in the city.
Werdhölzli sewage treatment plant
The sewage treatment works annually purifies around 80 million cubic meters of wastewater from the entire city of Zurich and the affiliated municipalities - half of the water volume of the Greifensee. After a multi-stage cleaning (mechanical, biological, chemical as well as ozonation and filtration), ERZ feeds the clean water to the Limmat. Sewage gas is produced from the remaining, rotting sludge. This is processed and fed into the city's natural gas network.
City cleaning
City cleaning is responsible for cleaning and the appropriate winter service in the public space of the city of Zurich. The employees keep regularly around 8.2 million square meters of roads, sidewalks and squares, as well as 1.6 million m 2 clean parks and manage all public litter bin.
Disposal logistics
The waste disposal logistics division is responsible for collecting waste from households and businesses. Around 100,000 tons of waste are collected in the city every year - these are then recycled in the Hagenholz waste-to-energy plant . Paper and cardboard are also regularly collected and recycled . Disposal logistics manages over 160 recycling collection points for glass and small metal in the city of Zurich. The cargo tram and the e-tram take bulky goods resp. Electrical appliances against.
Waste-to-energy plants
The two waste-to- energy plants operated by ERZ, Hagenholz and Josefstrasse, burn waste and other combustible waste around the clock. In addition to the waste collected by ERZ in the city of Zurich, waste from other municipalities, companies and private individuals is also disposed of at the Hagenholz plant. With thermal recycling, the volume of waste is reduced by 90 percent. The waste heat that arises from waste recycling is used to generate electricity and heat.
District heating
Several production plants supply the energy for the Zurich heat product:
- 2 waste-to-energy plants
- 1 wood-fired power station
- 12 fossil heating boilers
District heating from ERZ, Zürich Wärme, is a mix of several energy sources. The most important source of energy is the waste heat from the waste-to-energy plants. Like the wood from the canton of Zurich and the ambient heat , it is CO 2 -neutral and thus contributes to the creation of fewer greenhouse gases that are harmful to the climate. In the winter half of the year, fossil fuels provide additional energy to cover peak loads. On average, the waste heat from waste covers around two thirds of the total needs of the connected buildings and businesses. 20 percent supply gas and heating oil, the rest comes from wood. Zürich heat relieves the climate by contributing to 70,000 t less heating oil being burned and 200,000 t less CO 2 being produced every year .
ERZ is the largest electricity producer in the city of Zurich. The two waste-to-energy plants and the wood-fired power plant each have a steam turbine and are operated using the cogeneration process. This means that electricity and usable heat can be produced for heating or production processes at the same time. The waste-to-energy plants convert around 70 percent of the energy in the waste into heat and electricity.
history
The city of Zurich's collection system was founded in the middle of the 19th century, when city engineer Arnold Bürkli had the first sewers built and developed the so-called drainage bucket system. The buckets held back the faeces while the wastewater flowed into the Limmat. The introduction of this system was decided in 1867 by the municipal assembly of Zurich. The city of Zurich set up a collection system to remove the buckets.
After the Josefstrasse waste incineration plant went into operation in 1904, the waste was collected separately. The heat from the combustion process has been used to heat houses and settlements since 1928.
In 1927, the Zurich collection system introduced the legendary Ochsner bucket made of metal , which was replaced by plastic bags in 1979.
In 1926, Zurich put the first municipal wastewater treatment plant Werdhölzli into operation. In 1949, the Glatt sewage treatment plant in Opfikon went into operation for wastewater treatment in northern districts 11 and 12. This was closed in 2001 - since then the wastewater has been directed through a 5.3 kilometer long tunnel to the Werdhölzli sewage treatment plant.
The permanent increase in the amount of waste over decades threatened to suffocate Zurich in the mid-1980s. This situation was alleviated in 1993 by the expansion of the separate collections for recyclable waste and the introduction of the rubbish bag fee . This in turn meant that within a few years the amount of recycled materials in the city of Zurich rose to more than 50,000 tons per year. Since certain materials require special treatment for recycling, the special waste collection point was opened in 1996 together with the Canton of Zurich, where these materials are collected and disposed of properly.
Since 2013, ERZ has also been collecting kitchen and garden waste as well as leftover food from households and businesses. ERZ brings this biowaste to the fermentation plant of Biogas Zürich AG, where the biogas produced is captured and fed into the natural gas network of the city of Zurich. The biogas is available as an environmentally friendly fuel, for electricity production as well as for cooking and heating.
In recent years, ERZ has put further, future-oriented systems into operation. The dewatered sewage sludge from the city and canton of Zurich has been incinerated in the central sewage sludge recycling plant since 2015. The resulting heat covers the entire heat requirement of the sewage treatment plant. The incinerated ash is retained and stored for later recovery of the raw material phosphorus.
In the metal recovery logistics hall, the slag from the Hagenholz waste incineration plant has been filled into specially developed containers since 2016 and transported to ZAV Recycling AG in Hinwil. There, almost 100% of the metals contained in the slag are filtered out and can be recycled.
In order to remove residues from medicines, personal care products or cleaning agents contained in the wastewater, ERZ built an ozonation system on the site of the Werdhölzli sewage treatment plant between 2015 and 2018. Treatment with ozone converts these micropollutants into harmless substances.
Web links
Individual evidence
- ↑ ERZ: ERZ Annual Report 2017 (PDF) ERZ, February 28, 2018, accessed on February 28, 2018 .