Jiayi XU (18)

City/Region: Shanghai
E-mail: essentialeric@hotmail.com
Hobbies: Reading, Sports, Internet, Chess, Calligraphy, Travelling
Career: Engineer or Enterpriser
School: Shanghai Yan'an Senior School

 
Intelligent surface garbage hunting and collecting device

There is often a considerable amount of garbage floating on the surface of rivers and lakes. This waste is generally removed manually. However, in scenic areas, the manual collection of garbage may spoil the region’s natural beauty. The focus of my project is an un-piloted intelligent surface garbage hunting and collecting device controlled by a Single Chip Microcomputer (SCM). Manual monitoring and control are performed through a wireless photograph transmission system. The device’s automatic search system resembles radar scanning, i.e. active infrared detecting devices are used to scan for surface waste. A model of the device is also available for verification. This project offers the prospect of a simple, efficient and cost-effective method for the removal of unsightly waterborne waste.
 

Shaoxuan LI (18)

City/Region: Beijing
E-mail: singlelovem@sohu.com
Hobbies: Singing, Playing basketball, Playing the guitar, Reading, Drawing
Career: Activity Manager
School: Beijing No.166 High School

The associated toxicity between Cu and Cd in green algue

The main pollutants existing in the open water include organic materials and metal salts. Nowadays, research related to the toxicity of heavy metals is one of the focuses of public attention.
Green algae, which are the main producers in rivers, play a very important role in the aquatic ecosystem in polluted water. Therefore, algae that are easy to be observed and counted are chosen as our research objects.
I tried to explore the associated effect of two heavy metals Cu and Cd, with the following two aims. One is to evaluate the quality of water and the other is to supply some theoretic basis for measuring metals’ toxicity exactly and bringing the application of environmental monitoring closer to the factuality.
Photo density and cell number scale were chosen as the two parameters according to OECD’s standard method of experiments in the hindering of the growth of algae. Chlorella Pyrenoidosa Chick and Scenesesmus Obliguus were selected as the objects in my research. The results show: (1) The EC50 values of Cu and Cd with Chlorella Pyrenoidosa Chick are 0.05 mg/L and 0.024 mg/L respectively; (2) The EC50 values of Cu and Cd with Scenedesmus Obliguus are 36 mg/L and 3.68 mg/L respectively; (3) When the proportion of Cu to Cd is 1 to 1 and 3 to 1, the associated toxicity is both Antagonistic action. I think that Cu reduces Cd’s toxicity and the cause may be the reaction of heavy metals with metallothionein-like (LMT), the capability of Cu2+ conjugate to LMT is more than that of Cd. When the proportion is 1 to 3, it is Cooperative action. Whether Chlorella Pyrenoidosa Chick or Scenedesmus Obliguus, the results are the same.