SYSTEM NOTICE

Auto translation by AI. Be sure, accuracy, nuances and authorial intent may not be fully reflected.
見出し画像

Discoveries made during an adult field trip 🔍

エシカルな日々を綴る

Hello, at the beginning of last month, I went to the Chigasaki Water Reclamation Center for an adult field trip organized by meguru, a bulk shop in Chigasaki City, Kanagawa Prefecture.

There are many sewage treatment facilities in Kanagawa Prefecture.

This facility treats sewage from cities and towns in the Sagami River basin, such as Sagamihara, Hiratsuka, and Fujisawa.
I participated in a session where we could learn through a lecture and tour the actual treatment areas.

Sewage pipes gradually get wider and apparently end up being this size.
Eriko-san 🤭


The collected sewage first has its waste settled out.
The sewage is this color and smells a little.
The facility is vast.
Next, microorganisms 🦠 are used to eat the impurities.
Various types of microorganisms are at work.
Because mud is mixed in with the microorganisms, it smells quite strong.
The microorganisms then settle, and clean water is produced.
The water in this cross-shaped trench is the clean water.
It is disinfected here and then discharged into the sea.

Things I learned

  • Sewage from upstream in Sagamihara takes about 24 hours to reach the sewage treatment facility.

  • There are several stages to sewage treatment.

  • Large waste is removed (apparently including things like plastic bags), and small floating items (including oil) are removed by a mechanism that adsorbs the upper layer.

Here, a problem arises.

  • I think microplastics are removed to some extent if they are floating, but if they are in the middle layer, they just leak right through.

  • It seems the settled waste is burned in an incinerator at the facility. Then, the ash is taken to a separate processing facility. This means that disposing of the ash is just as difficult as the waste treatment process itself.

  • There are combined and separate sewer systems for sewage treatment. In combined sewer systems, where rainwater and wastewater (domestic sewage) are drained through a single pipe, an increase in rainfall can cause some of it to be discharged into the ocean untreated, which leads to water pollution and microplastic contamination.

As I looked into combined sewer systems, it seems there is a trend toward implementing countermeasures, but it still feels insufficient.

https://www.nilim.go.jp/lab/ebg/pdf/usui11.pdf

Perfection seems difficult.

Things we can do

  • For domestic wastewater, do not pour oil or trash down the drain (this includes food scraps too).

  • Do not throw trash into street storm drains. Cigarettes 🚬 are common... cigarettes are plastic too!

  • Try not to do laundry as often.

  • If you do, use a net that stops microplastics from flowing out.

  • I've heard that washing clothes several times reduces the release of microplastics, so wear them for a long time.

Something like that...
Food scraps often accidentally get washed down, so I have to be careful!

By the way, the rooftop of the water reclamation center has become a very beautiful park, which also contributes to the local community.

I could see Mt. Fuji beautifully from the park!


Thank you for reading today as well! See you later 👋

いいなと思ったら応援しよう！