About 70% of the Earth’s surface is covered by water, a crucial natural resource for all living organisms. The physical and chemical properties of river water, like temperature, pH, alkalinity, salinity, turbidity, and dissolved oxygen, significantly impact aquatic life. Each of these factors plays a specific role in determining water quality, making regular monitoring essential to maintain a healthy aquatic environment (Ahmed, F. et al., 2015).
Water from surface sources such as rivers, lakes, estuaries, ponds, streams, and marshes is not consumed directly due to varying quality influenced by different physicochemical parameters. Even if water appears clear, it might not be suitable for domestic or agricultural use, necessitating quality checks (Beat Stauffer et al., 2009).
Rivers are natural habitats for aquatic life and sources of drinking water (Nongmaithem and Basudha, 2017). In Pangasinan, Dagupan City, the Pantal and Calmay Rivers rise during high tides, causing issues for residents (Leonardo Micua, 2017).
The Pantal River, one of seven surrounding Dagupan City, is vital for its rich mangrove reserves. Although not suitable for direct drinking due to aquaculture activities, it serves as a key navigation route. A recently launched river cruise has become a new attraction, supporting local fishermen (New Lifestyle, 2015).
According to the Provincial Environment and Natural Research Officer (PENRO) in the Philippines, the Pantal River is classified as Class C, meaning it can be used for drinking after proper disinfection. It is also safe for fish propagation, recreation, agriculture, irrigation, and manufacturing (DENR).
Every water body has unique physical and chemical characteristics affecting its quality. Physicochemical analysis is the method used to investigate these characteristics. The chemical quality of aquatic environments varies based on local geology, climate, proximity to the ocean, and soil cover. Physical characteristics include temperature, pH, color, odor, and taste (Shweta Tyagi et al., 2018; Venkatesharaju et al., 2010).
The physicochemical properties of a river influence its biological characteristics. For instance, chlorine reduces coliform organisms and viruses, regulating aquatic life. Biological qualities are crucial for rivers, as unsuitable physicochemical conditions can disrupt ecosystems (Indian Standard ICMR).
Physicochemical parameters affect water quality, influencing aquatic life like fish, insects, and microorganisms. While water may naturally contain nutrients and dissolved oxygen, elements like arsenic, fertilizers, pesticides, and insecticides can degrade quality. Particulate matter, both organic and inorganic, also impacts water quality. The variability in dissolved and particulate matter results from environmental interactions, mineral solubility, and organism activity.
Environmental characteristics support aquatic flora and fauna, which in turn affect river water quality. Qualitative analysis provides a clear picture of water quality (Shweta Tyagi et al., 2018; Venkatesharaju et al., 2010). Water quality is measured using the Water Quality Index (WQI), with standards set by organizations like WHO, ICMR, and BFAR (A. Rajendiren, 2015).
Water quality and water pollution are often confused but are distinct concepts. Water quality refers to the concentrations and physical states of substances, including aquatic life. Pollution is an adverse change in water quality, affecting human and animal health, agriculture, industries, and the economy (Nabakishor Nongmaithem, 2017).
