Color And Image Analysis Approach in Determination of Soluble Copper in Water Using Tannic Reaction Analysis Jan Fern Historillo PUP Graduate School Polytechnic University of the Philippines shanxcreatives@gmail.com Marife Rosales PUP Graduate School Polytechnic University of the Philippines marosales@pup.edu.ph Menandro M. Merlin Department of Industrial Technology Marinduque State College cjrmerlin@gmail.com Evangeline B. Mandia Department of Environmental Science Marinduque State College ebmandia@up.edu.ph The 1993 and 1996 Marcopper Mining Disaster caused excessive amounts of copper to water sources in Marinduque. Determining this soluble metal in water has been a challenge to Marinduqueños as there is no water testing laboratory in the province. This research aims to develop a system that determines soluble Copper (Cu) in water through color reaction analysis of tannins. Specifically, it aims to develop a system for determining different levels of soluble copper in water and evaluate the developed system through comparative analysis of the results from laboratory. An image processing box was prepared to capture the color reaction of Jatropha Curcas sap to water solutions containing 0.5 to 5 ppm soluble copper. The color reaction was recorded using a Logitech C922 Camera through image acquisition and labeler of MatLab Software. The recorded color reactions were analyzed for their red, green, and blue (RGB) channels using a color detection system of the same software. The RGB color values were then related to the copper concentrations. To assess the reliability of the data generated, it was compared to water samples of unknown soluble contents from various locations in the province. Based on these procedures, it was found that copper produces green and blue colors, especially for the water solutions with 2.0 to 3.5 ppm mg/L of copper. It was concluded that the system can determine the soluble copper in water samples (from 0.5 mg/L to 5mg/L), but calibration must be done using genetic algorithm optimization features and other ways such as machine vision. Relevant to analytic chemistry, it is recommended that titrimetric conditioning and the use of the Sigmoid function be performed to improve color resolution. Keywords: Color Reaction Analysis; Copper; Image Processing; Tannic Reaction; I. INTRODUCTION Marinduque Island is a small island province in the Philippines' Luzon southernmost region. In 2017, the Mines and Geosciences Bureau (MGB) reported that the country's total projected production for metallic minerals was PhP 109.45 billion. Marinduque was thought to have one of the Philippines' largest copper reserves. Mining techniques for copper extraction began in Marinduque between 1969 and 1996. [1] In 1991, an earth dam was built in the Mogpog River's hilly source area. The Mogpog River's silt from a waste dump for the new San Antonio Mine Pit was intended to be captured by the dam. In 1993, the dam burst, devastating the communities below. Mogpog's town suffered severe devastation, leading to large losses in terms of structural assets, agricultural, and public health. The toxic waste from the dam had a significant negative impact on the 23-kilometer Mogpog River. [1] Three years later, in 1996, one of the worst mining accidents in history occurred when the Tapian Pit burst, leaving tailings in the nearby location polluting the 27- kilometer Boac River on the island of Marinduque. 20,000 people had to be evacuated, and five villages had to be abandoned. [2] The pollution's impact on the river and coastal ecosystems were so severe that the United Nations classified the occurrence as an environmental disaster. [3] Another affected area is the Boac River which is a prominent river system in the Philippines' province of Marinduque. Before 1996, the river provided a significant source of subsistence food and family income for the residents. The Marcopper catastrophe, on the other hand, occurred on March 24, 1996, releasing millions of tons of poisonous mining wastes into the Boac River. [4] Heavy metals, which are metallic elements with a relatively high density and are dangerous even in low quantities, may be found in mine waste. Although heavy metals such as copper, cobalt, iron, magnesium, nickel, zinc, and others are needed for many biochemical and physiological processes, they can be potentially detrimental in excessive amounts. Heavy metals discharged with mine tailings can be absorbed by plants and accumulate along the food chain, putting animal and human health at risk. [4] In the various assessment conducted through the years, it was found that the mining-affected areas are heavily concentrated with Copper and other heavy metals making the affected bodies' water unsafe for drinking and domestic uses. [1] [4] [5] [6] [7] The findings from these studies have been evident in the plants growing on the riverbanks. [8] [7] Even though it has been years since the tragic mining accident happened, huge toxic waste is still prevalent in the mining-affected areas. [5] Given these findings, water potability along the mining- affected areas has been one of the challenges. [1] [8] [5] In addition, the effects on health due to the increased presence of heavy metals were manifested in the municipalities of Boac, Sta. Cruz and Mogpog. It has been recommended by