Effect of the Different Types of Substrates on the Biodegradability of Sm Plastic Bags
1701 Words7 Pages
I. Background of the Study:
Official figures show that plastics make up around 25% of the garbage that metro manila churns out, while an independent survey conducted by Eco waste Coalition and Greenpeace on the composition of discards on manila bay in 2006 found that 51% were plastic bags,19% sachets and junk food wrappers, 5% Styrofoam, 1% hard plastics,10% rubber, 13% biodegradable wastes (Cayetano, 2008;www.senatorpiacayetano.com/psc/pressreleasedetails.php?recordID=175) Biodegradable plastics are degradable plastics on which the degradation results from the action of naturally occurring micro-organisms such as bacteria, fungi , and algae (firstname.lastname@example.org). These plastics are broken down into water, carbon dioxide, methane and…show more content… Another three aluminum trays ( 7’ x 9” ) were labeled L1, L2, L3. Five hundred grams of loam soil were placed in each 3 tray.
One hundred mL of tap water were mixed with the soils. Plastics strips labeled C1, C2, and C3 were placed in trays labeled C1, C2 and C3 containing ( compost soils). Plastics strips L1, L2 and L3were placed in trays L1, L2 and L3 containing ( loam soil ).
Five hundred mL of ( sea water ) were placed each in three glass jars. The jars were labeled S1, S2 and S3. In another three jars, 500mL of tap water were placed. The jars were labeled T1, T2 and T3. Plastic strips labeled S1, S2 and S3 were placed in jars containing sea water while plastics strips T1, T2 and T3 were placed in jars containing tap water. The plastic were immersed in different substrates last September 9, 2008.
The set-ups were placed in the Biology laboratory room and were observed from time to time. Physical observations of the plastic strips were made on the following dates: September 24, 2008,October 6, 2008, and November 15, 2008.
Last November 15, 2008, the plastic strips were harvested from the different substrates. They were washed with tap water and air dried for 48 hours. Physical changes in each strip were noted and recorded. Pictures of the plastic strips were also taken to observe changes before they were immersed in the different substrates and after immersion for about two months. The dry weights in grams of each plastic strips were