Water efficient ways of washing the plastic

Hello everyone!
I live at the Caribbean coast of Colombia and it is easy to find plastic waste, the problem is cleaning it in a water efficient way. Due to ongoing drought this area often experiences water shortages. Therefore I am looking for a water efficient way of cleaning plastic.
Another question: does the plastic have to be completely clean before it goes into the shredder… or could you clean it roughly, then shred it and after do a proper cleaning? If so, then a manual washing drum would do the trick?
What about drying the plastic afterwards?


This is a very important question!

I hope to see a few different options to cleaning

Also how to dispose of waste water.

I guess you could clean in multiple stages, re-using dirty water to do rough cleaning? But that still uses quiet a lot of water.

It also depends om the type of plastic i guess. If you have jerry cans that held chemicals, then you need to be more carefull then when using water bottles. BUT then you need to make sure that none of those bottles was ever used for chemicals.

So it also can be important to collect the plastic before it is trashed.

In a dry period you could then focus on using clean plastic, storing dirty plastic for wet periods. (if that is an option?)

And eventually focus on making products that are not critical for food.

For making plastic handles a bit of dirt does not seem a big issue to me.
For fruitbowls etc. better not use dirty plastic at all.

When drying the plastic maybe use sunlight and condense the watervapor against glass? (not sure ow viable that is, just thinking out loud)

@layla oye lo lamento pero creo escribi mal mi correo es este : jorgemerchandmc@gmail.com , si puedes reenviame el correo

Hello/ Hola!

thanks for the input. great ideas! we dont really have electric limitation as such, it is more that we deal with frequent electricity cuts and high costs!

As we will be starting this as a small project and dont have a lot of space for now non of the alternative electricity option would be suitable (hopefully, this will change in the future).

. Que buena idea! Te mande un correo.

te mande un correo…

hola @sebasencinas podrías enviarme la info del filtro? creo tener el mismo problema que @layla. soy del sur de chile, puerto Montt.


Hola @layla que tal si usas el agua de la lavadora normalmente esta utiliza tres ciclos o así es la mía y las segunda y tercer agua que expulsa contiene una baja cantidad de detergente o lo que tu le agregues. También la idea de evaporizar el agua es bastante buena ya que si puedes mantener la temperatura a la que se evapora el agua esta quedara casi por completo limpia en donde la condenses.

Vi que estas en la costa Colombiana, yo quiero empezar un proyecto en Santa Marta con mi colegio si te parece bien me puedes escribir a jorgemechandmc@gmail.com

Si vas a limpiar botellas PET que contenían líquidos no tóxicos, refrescos, agua, jugos, puedes utilizar un Filtro de Arena ya que este plástico tiene una carga baja de contaminantes, esta se va limpiar casi en su totalidad y como lo que estas recolectando esta en la playa se removerán todos los sólidos y vas a utilizar el agua eficientemente, casi sin perdidas. Es muy fácil hacer un filtro de arena y colocando carbón activado podrás remover también muchísimos mas contaminantes, grasas, aceites, cloro. Es un buen sistema para limpiar el agua y poder reutilizarla. Puedes buscar en google o enviarme un correo a sebasiciam@gmail.com puedo explicarte paso a paso como hacer un Filtro y desarrollarlo optimamente. Soy estudiante de Ingeniería en Ciencias Ambientales. Es mi primer Post. Saludos desde México.

If want to clean PET bottles that contained non-toxic liquids, soda, water, juice , you can use a sand filter because this plastic has a low pollutant loading , this will clean almost entirely.You are collecting this on the beach all solids will be removed and you will use water efficiently, with minimum losses. It is very easy to make a sand filter and using activated carbon can also remove many more contaminants, oils, chlorine. It is a good system to clean the water. You can search google or send me an email to sebasiciam@gmail.com I can explain step by step how to make a filter. I am a student of Engineering in Environmental Sciences. It’s my first reply. Greetings from Mexico.


Hi Layla!

Its a real issue. The way understood it, and correct me if i’m wrong, was that the dirt in the recycled plastic interferes with the production process and in some cases can damage the equipment. That’s why so much of it is new raw material. I dont think its a hygiene thing.


Just to get an idea, what are the electric limitations?
Is there a maximum power you can use? If yes, how many Amps or Watts?
Is the electricity comming form the power grid or from generators? Diesel, Wind, Solar?

What powersources are else available? Wind could power a windmill driven schredder? Or a water mill if you are near a river?
What about hacking a bicycle into a shredder driver?
A threadmill or hand cranked shredder should work.

I’m not a big fan of combustion engines, but maybe a small motor from a leafblower, lawnmower or moped could be used?

For the extrusion however, you probably need electricity to provide a constant reliable melting temperature and also for a constant extrusion speed.
That eventually could be solar powered, and might be most efficient when suing all DC then you don’t have losses in AC converters etc.

Is there anything that sounds as a usable option?

@elcompi realmente se trata de todo tipo de suciedad que encuentras en las playas! Todavía estamos en proceso de buscar las partes necesarias para poder empezar de construir las maquinas. Pero antes queremos pensar en todo el resto que tiene que ver con este proyecto!

we don’t really have the space to build greenhouses! unfortunately, but sounds interesting…

unfortunately we have to also keep in mind that electricity is scarce here too, so any ideas that exclude using electricity would be better for us! However we have decided to go for the electricity run shredder…

a little greenhouse can evaporate lots of water. Maybe you van recycle PET into window panes and build greenhouses? recycle buckets into extruded t slot pipes

Slide the PET panes between a frame of T slots and you have a recycled greenhouse.

Or use real glass… or poly carbonate. glass and plastic from flatbed scanners.

uhmmm. well im sure there are more options then this…

Another idea:

Once the water used to wash your plastic get’s dirty, you can clean it first with a thin mesh to remove any solids, and then evaporate and condensate the water to make it clean again. Building an evaporator should not be complicated or costly. You just need to add a resistor on one of your recipients (the one with dirty water) to heat the water and start the evaporation process, and then a tube that transports and cools down that vapor to be deposited into another container.


After washing the veggies collect the vinegar water to wash the plastic.
First filter it roughly. Then that water and vinegar is 50% less wasted.

Saludos Layla que tipo de suciedad quieres remover de los envaces plasticos @layla y como vas con la construccion de la trituradora de plastico… mi correo aecg30@gmail.com para estar en contacto

thanks for the replies! I don’t really want to add any additives…if possible!

we use a water-vinager solution to wash our vegetables, but would it work with really dirty plastic ( plastic rubbish collected on the beach)?

!! Vinegar thats a great tip!!

Tips like this should be in a ‘main manual for recycling plastic’

Maybe also make a vinegar machine?

Hi layla

You can have a designated tub-barrel-tank and reuse its water. Use vinegar to clean up the water and reuse. You will need a way to collect the residue from the bottom of the tank. Vinegar is great for disinfectant,cheap and non toxic.

Hi @layla, UV does have a deteriorating effect on plastic, apparently there is a UV additive you can add to your products to help with longevity.

Side note: I heard the water you buy in supermarkets in plastic bottles 600mm or 1Lt, it takes 3x the the amount of water just to make that 🙁

Thank you and good point about plastic containers that used to contain chemicals. I guess for now we will be focussing on drink and food containers, and indeed focus on making products that will not be used for holding food.
About using sunlight… doesnt uv-radiation have a deteriorating effect on plastic?