An Alternative Way in Determining Mixed-Liquor Suspended Solids and Mixed-Liquor Volatile Suspended Solids Parameters Simultaneously Based on Wastewater Turbidity in Activated Sludge System Casdi1, Jasmansyah1, Anceu Murniati1, Hernandi Sujono1, Arie Hardian1,*
1Department of Chemistry, Faculty of Sciences and Informatics, Universitas Jenderal Achmad Yani, Cimahi, West Java, Indonesia
*E-mail: arie.hardian[at]lecture.unjani.ac.id
Abstract
In wastewater treatment with activated sludge systems, the Mixed-Liquor Suspended Solids (MLSS) parameter which states the concentration of sludge in the aeration tank, and the Mixed-Liquor Volatile Suspended Solids (MLVSS) which state the biomass concentration of activated sludge is a parameter that must be controlled to maintain the population of microorganisms in the sludge. Both parameters correlated with turbidity since most turbidity is caused by particles suspended in water. Usually, MLSS and MLVSS are completed by gravimetric methods that are time-consuming, costly, and high-temperature risk, therefore a mathematical model can use in order to reduce the disadvantages of the gravimetric method. This study aimed to obtain a mathematical model that linked MLSS and MLVSS with turbidity, hence from the turbidity value can estimate the value of MLSS and MLVSS parameters. MLSS and MLVSS parameters were measured by gravimetric methods following the APHA 2540D and APHA 2540E methods, and the turbidity was measured by a spectrophotometer that following the ISO 7027 method. Two linear models showed a strong positive correlation between MLVSS-MLSS and MLSS-turbidity with the regression equation of MLVSS = 0.8773(MLSS) - 38.415 (N = 42 with R2 = 0.9581) and MLSS = 0.9104(Turbidity) + 4.0953 (N = 42 with R2 = 0.9391). MLVSS was calculated as an indirect correlation with turbidity, the equation was MLVSS = 0.7987 (Turbidity) - 34.8222. This study can be applied to reduce working time, analysis cost, and risk of work accidents.
