Experimentation of Evaporation Reduction by a Use of Plastic Bottles Covering

Evaporation significantly affects the loss of water in reservoir. The effective use of water-surface covering materials for evaporation reduction purpose is commercially performed including plastic spherical and circular shapes. This study initiates to reuse very common Polyethylene Terephthalate (PET) drinking-water bottles to cover water surface instead. The bottle shape could have a covering percentage ratio as much as 91% equal to a commercial ball or circular disk. The experiment was designed and conducted to prove the reduction of water evaporation rate using eight simulated ponds. The testing aspects are the opacity of the floating bottles, the coverage area, and the floating pattern. Based on environmental impact concern, the deterioration of PET bottles due to hydrolysis reaction and ultraviolet rays in natural conditions is also investigated. The water samples from the testing ponds are collected and analyzed to be compared with the water quality standard. Initial result from the experiment showed that PET bottles containing laminated-aluminum-foiled (LAF) plastic bags have the greatest reduction in evaporation among different opaque materials. Cover flotation percentages of 75% and 100% were able to reduce evaporation the most and with little difference. The raft-floating pattern has a slightly lower evaporation rate compared to the free-floating. All this has the potential to reduce evaporation which are a very cost-effective alternative to the existing commercial materials and help support the reuse of plastic waste.