This research studied the factors that affect the efficiency of phosphate reduction in the wastewater of the washing process with CaCO3 and CaO produced from eggshell and mussel shell. The study found that the optimum condition for adsorption when using CaCO3 from eggshell is to adjust the pH to be equal to 10 take 15 minutes to absorb and add 1 gram of sorbent which can reduce the phosphate content by 25 percent and when changing the adsorbent to CaO the optimum condition for phosphate removal is to adjust the pH to 7 take 15 minutes to absorb and add 1 gram of adsorbent which can reduce the phosphate content by 24 percent. The optimum conditions for adsorption when using CaCO3 from mussel shell were to adjust the pH to 10 take 45 minutes to absorb and add 1 gram of sorbent which can reduce the phosphate content by 25 percent and when changing adsorbents to CaO the optimum condition for phosphate removal is to adjust the pH to 10 take 15 minutes to absorb and add 3 grams of adsorbents which can reduce the phosphate content by 24 percent. In addition when studying the adsorption of impurities in the wastewater such as conductivity turbidity COD and BOD it is found that the optimum reduction conditions can reduce the impurities of the parameters that mentioned above were 19.32 2.60 54.77 and 16.67 percent respectively. CaCO3 and CaO produced from eggshell and mussel shell can be used to absorb impurities in wastewater before releasing into natural water sources.

The purpose of this study is to produce the soil improvement materials from food waste and water hyacinth by using a dehydration process. The experiments were divided into two parts : 1) the study of the optimum temperature and time for converting food waste and water hyacinths to soil improvement materials by determining the temperatures of 100 °C 150 °C and 200°C in the periods of 1 hour 2 hours and 3 hours respectively 2) the study of nutrient content in the materials before and after mixing into the soil for 5 days. The soil used in the experiment was sampled from Sai Ma Subdistrict Nonthaburi Province. The parameters used to evaluate the ability to improve the soil quality were soil moisture pH electro conductivity total nitrogen total phosphorus total potassium and organic matter. The results showed that the optimum temperature for drying the food waste was 150°C for 2 hours and the optimum temperature for drying the water hyacinth was 200°C for 3 hours. When the materials were mixed into soil it found that the soil drainage was improved. Mixing the materials into soil could increase the pH value from 5.2 to 5.4 and increase the electrical conductivity from 0.72 mS/cm to 14.78 mS/cm. Besides the plant nutrients including Nitrogen phosphorus and potassium also increased after adding soil improvement materials.