Production of chalk from crab (Scylla serrata) shells /
by Glen P. Ambata and Remerson L. Poblete.
- Indang, Cavite : Cavite State University- Main Campus, 2004.
- xi, 33 pages : illustrations ; 28 cm.
Research Study (General Science curriculum) Cavite State University.
Includes bibliographical references.
Science High School, College of Education (CED) Science High School, College of Education (CED)
Ambata, Glen Pascual and Poblete, Remerson Layno, Applied Research III (General Science Curriculum), Laboratory School College of Education, Cavite State University, Indang, Cavite, April 2004, “Production of Chalk from Crab (Scylla serrata) Shells”. Adviser: Ms. Miriam C. Du. Mrs. Dulce Ramos
The research study entitled “Production of Chalk from Crab (Scylla serrata) Shells” was conducted at 525 P. Burgos St. Indang, Cavite from June 2003 to November 2003. This was conducted to determine if the crab shells could be used in making chalk as a substitute to calcium carbonate and other chemicals. Generally, this study aimed to use crab shells in the manufacture of chalk.
Four treatments replicated three times were used in the study: T, (30 grams of powdered crab shells + 100 ml of cassava sap); T2 (90 grams of powdered crab shells + 100 ml of cassava sap); T; (150 grams of powdered crab shells + 100 ml of cassava sap); and T, (210 grams of powdered crab shells + 100 ml of cassava sap). Complete Randomized Design (CRD) was used in the study. One — way analysis of Variance (ANOVA) was used to analyze the data for physical evaluation and Duncan’s Multiple Range Test (DMRT) for the comparison of treatments. It was found out that T, got the highest score in terms of texture (mean= 4.0000), brittleness (mean=4.2111), adherence, (mean=2.7222) and in general acceptability with the mean of 2.8889. On the other hand, T, got the mean score of 3.1222 in terms of compactness.
Based on the results of the study, it can be concluded that crab shells can be used in the manufacture of chalk. Ninety grams of powdered crab shells: 100 ml cassava sap is the optimum ratio needed to produce a good quality chalk. The cost of the produced chalk is almost the same as the cost of the commercial chalk.
Chalk from crab shells does not contain harmful chemicals that may cause breathing problems and skin allergies. Production of chalk from crab shells is inexpensive, simple and easy.