Mathematical Modeling of Effluent Quality of Cha-Am Municipality Wastewater Treatment Pond System Using PCSWMM

Abstract

Water quality around Cha-Am, Thailand is of prime concern because of its extensive oceanfront beach area. Cha-Am uses an aerated lagoon system consisting of three ponds and a natural wetland to treat the municipal wastewater. A personal computer version of the storm water management model, PCSWMM, was used to simulate the effluent quality of the treatment system. Water quality samplings for total suspended solids (TSS), total Kjeldahl nitrogen (TKN), Escherichia coli (E. coli), chemical oxygen demand (COD), as well as evaporation measurements, were conducted on a bi-weekly basis for three months to calibrate the model. The four ponds were considered as four storage zones in the model. Based on the observed water quality data distribution, Monte Carlo simulation was used (1 000 iterations, 20 times) to get the most probable input concentration for each pond to determine the appropriate treatment fractions for the model. Data on daily inflow rates, pump operation and bathymetric survey also were obtained from the system operator as model input. The dynamic wave method was used with observed inflow rates to generate a continuous water quality simulation from 2015-07-19 to 2015-09-12. Observed mean treatment efficiency was 51.9%, 77.3%, 99.6% and 9.4% for TSS, TKN, E. coli and COD respectively. Observed concentrations at the outlet ranged between, 10 mg/L to 25.5 mg/L, 0.98 mg/L to 3.92 mg/L, 0.1 CFU/100 mL to 260 CFU/100 ml and 48 mg/L to 119 mg/L for TSS, TKN, E. coli and COD respectively. The treatment fraction approach in PCSWWM was able to accurately represent the outlet concentrations of TSS, TKN, E. coli and COD.

Mathematical Modelling of Wastewater Collection System in Cha-Am Municipality using PCSWMM

“…The model can also help to evaluate future expansion of the sewer network by analyzing available capacity and identifying locations for new drainage construction to offset new development. The next step in this research will be to link the collection system with the ALTS system that has been modelled separately in PCSWMM [10] and explore the impact of future development scenarios on treatment efficiency.…”

Integrated Environmental Modelling Framework for Cumulative Effects Assessment

“…SWMM is included in the BASINS and is publicly available. Two widely used proprietary software packages derived from SWMM are PCSWMM (Bhowmick et al, 2017) and XP-SWMM (Ricks, 2015), which have additional graphic user interface functions and capabilities.…”

Spatial Patterns of Heavy Metals in the Sediments of a Municipal Wastewater Treatment Pond System and Receiving Waterbody, Cha am, Thailand

“…The aerated lagoon treatment system consists of four ponds: an aeration pond, a settling pond, an extended aeration pond, and an evaporation pond, which is part of the original wetland system in the area. Bhowmick et al (2017) provide more detail on pond configuration and operation, but briefly the surface area and depths of each pond were: aeration pond (Pond 1): surface area 40 082 m 2 , depth 2.5 m-2.8 m; settling pond (Pond 2): surface area 16 452 m 2 , depth 2.3 m-2.5 m; extended aeration pond (Pond 3): surface area 48 522 m 2 , depth 1.7-1.8 m; and evaporation pond (Pond 4): surface area 323 612 m 2 , depth 2.0 m-2.3 m.…”

“…Past studies (e.g. But et al 2016;Bhowmick et al 2017;Koko et al 2017) have examined the water quality and the efficiency of the pond system in managing conventional wastewater parameters such as chemical oxygen demand (COD), total suspended solids (TSS), total Kjeldahl nitrogen (TKN), E. coli and dissolved oxygen, but to date no evaluations have assessed levels of metals in the ponds. The objectives of this study were therefore: to examine the spatial variation of metals levels, longitudinally, from the ponds on through the receiving river channel system, to the ocean; to compare metal levels in the ponds to those in the upper reach of the receiving river to assess the pond system as a source area; and to compare metal levels in the ponds and river with sediment quality guidelines to provide a first indication of environmental risk.…”