Removal of total solids from surface water of Malihao River, Victorias, Negros Occidental using chitosan derived from green mussel (<i>Perna viridis</i>) shell

Abstract

Total solids are water pollutants that can either be suspended or dissolved in water. Suspended solids are those that can be filtered while those that can passed through are considered as dissolved solids. Five sampling stations were tested along Malihao River in Victorias City, Negros Occidental to determine parameters such as pH, temperature, total settleable solids (TSeS), total suspended solids (TSS), total dissolved solids (TDS), volatile suspended solids (VSS), conductivity, and salinity. Among these parameters, the focus of the study is on TSS and TDS and assess the removal efficiency of chitosan with these pollutants. The chitosan used was obtained from the shells of green mussel (Perna viridis) through deacetylation of chitin. The chitosan obtained has 73% degree of deacetylation and has characteristic peaks in the IR spectra at 3470.82 cm-1 and 1636.36 cm-1 representing the vibrating aliphatic O-H and bending N-H group, respectively. The optimum chitosan dosage was determined at 15 mg, which has removal efficiency of 83.46% and 25.48% for TSS and TDS, respectively. It also decreases the turbidity of the water based on the clarity in color. High TSS values were observed at Station 2 (Malihao Bridge) and Station 5 (Daan Banwa Wharf) with values of 125.5 and 232.0 mg/L, respectively. These values exceed the DENR Administrative Order 2016-08 for Class C waters, which is 80 mg/L. The optimum dosage was used to remove TSS and TDS at each sampling stations. TSS of all sampling stations were reduced to more that 50% of the initial value while TDS values rose to 80% and higher of the initial value. Thus, chitosan derived from green mussel shells were effective in removal of TSS but not with TDS.