Environmental Engineering
O. Phewnil; T. Pattamapitoon; N. Semvimol; W. Wararam; K. Duangmal; A. Intaraksa; K. Chunkao; P. Maskulrath; S. Hanthayung; P. Wichittrakarn
Abstract
BACKGROUND AND OBJECTIVES: Landslide disasters in Thailand between 1970 and 2011 revealed a notable pattern: they primarily originated on mountain slopes, distinguished by a deeper soil profile. This soil profile comprised clay loam and sandy loam textures and was situated over aged geological formations ...
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BACKGROUND AND OBJECTIVES: Landslide disasters in Thailand between 1970 and 2011 revealed a notable pattern: they primarily originated on mountain slopes, distinguished by a deeper soil profile. This soil profile comprised clay loam and sandy loam textures and was situated over aged geological formations of granite and shale rocks. The affected areas included the southern and northern provinces of Thailand.This study investigated the consequences of landslide hazards on stream water and sediment quality in two watersheds: the Mae Phul–Mae Prong watershed in Uttaradit province, the northern part of Thailand, and the Klong Kram watershed in Surat Thani province, the southern part of Thailand. These watersheds had experienced recurrent landslides, primarily on mountain slopes characterized by deep clayey and sandy loam soils over old granite and shale rock types as well as old granite limestone.METHODS: During wet and dry periods in April and November 2015, 108 samples were collected from 18 stations (9 stations in the Klong Kram watershed and 9 stations in the Mae Phul–Mae Prong watershed). These samples included upland soil, stream water, and sediments. For upland soils, 1 kilogram samples were collected through auger and V-shaped pit techniques using a stainless-steel spade, with composite sampling conducted at 0–30 centimeters across all 18 stations. Stream water was collected in one part using a 1-L polyethylene bottle at 30 centimeter from the stream layer, while other samples were compositely collected in sterilized glass bottles to determine coliforms. Soil and sediment samples were compositely collected from the bottom using a stainless-steel spade. All samples were stored at 4 degrees Celsius and transported to a laboratory for analysis. The insight gained from these collection efforts elucidated the dynamics of landslide impacts at the spatial scale for the two watersheds.FINDINGS: Most water samples met Thai surface water quality standard for various parameters; however, microbial contamination of the water samples attributed to community activities along stream banks was detected. Notably, arsenic was consistently detected in upland soil, stream water, and sediment samples. For Uttaradit, the average arsenic concentrations were 0.22 ± 0.09 milligram per kilogram, 0.01 ± 0.14 milligram per liter, and 9.74 ± 4.42 milligram per kilogram in upland soil, water, and sediment samples, respectively. For Surat Thani, arsenic concentrations were 87.63 ± 208.83 milligram per kilogram, 0.01 ± 0.01 milligram per liter, and 19.44 ± 36.38 milligram per kilogram in upland soil, water, and sediment samples, respectively, particularly near landslide scars where the arsenic concentrations were significantly higher in sediments and upland soils compared with stream water, highlighting the role of landslides near streams. These data suggest that sediment transport from upland soil in the landslide scar into stream water affects water quality, particularly in terms of arsenic concentration near the landslide scar, often surpassing natural standards.CONCLUSION: The study concluded that stream water was directly affected by landslides as these watersheds were unsuitable for consumption due to arsenic and microbial contaminations. This conclusion emphasizes the critical need to incorporate landslide hazard considerations into watershed management practices to safeguard downstream communities and preserve water resources.
Environmental Science
M. Srichomphu; O. Phewnil; T. Pattamapitoon; Ratcha Chaichana; K. Chunkao; W. Wararam; N. Dampin; P. Maskulrath
Abstract
BACKGROUND AND OBJECTIVES: As a producer within the ecological food chain, phytoplankton provides the base energy and oxygen to the environment through photosynthesis and higher tropic levels. These benefits can be applied in five consecutive nature-by-nature oxidation ponds for the treatment of community ...
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BACKGROUND AND OBJECTIVES: As a producer within the ecological food chain, phytoplankton provides the base energy and oxygen to the environment through photosynthesis and higher tropic levels. These benefits can be applied in five consecutive nature-by-nature oxidation ponds for the treatment of community wastewater coming through a high density polyethylene pipeline from the Phetchaburi Municipality located at the King’s Royally Initiated Laem Phak Bia Environmental Research and Development Project, Ban Laem District, Phetchaburi Province (Universal Transverse Mercator 47P 1442725 North 617774 East). This study focuses on the vertical distribution of the phytoplankton Cylindrospermopsis sp. and its relationship with nitrogen compounds in oxidation ponds.METHODS: Samples were collected from a community wastewater treatment system at various depths (30, 60, 90, 120, and 150 centimeters) below the water surface in April 2019 between 11:00 and 13:00 hours and analyzed for their chemical and physical properties. The analysis revealed a vertical relationship between Cylindrospermopsis sp. and wastewater. In the density of phytoplankton which were collected by measuring 20 liters of water and filtered using a 36-micron plankton net, calculated and counted under a high magnification microscope, as the species are classified according the taxonomy.FINDINGS: The results of the wastewater quality were as follows: the content of suspended solids was 65–81 milligram per liter, water temperature was 31.8–33.2°C, potential of hydrogen was 8.7–9.2, total nitrogen content was 4.0–5.3 milligram per liter, ammonium content was 0.03–0.06 milligram per liter, nitrate content was 0.09–0.12 milligram per liter, total phosphorus content was 0.9–1.3 milligram per liter, and phosphate content was 0.4–0.5 milligram per liter. In the density of phytoplankton, a significant correlation was observed between the population of Cylindrospermopsis sp. and water depth (R2 = 0.9324). The number of populations at the depths of 30, 60, 90, 120, and 150 centimeters were 3.2 × 107, 1.6 × 107, 1.1 × 107, 5.5 × 107, and 1.1 × 108 cells per cubic meter, respectively.CONCLUSION: The different densities of Cylindrospermopsis sp. found at different depths throughout the treatment pond are related to the nitrogen dynamics of the water body. The results of this study revealed that organic nitrogen, including ammonium, was assimilated and converted to inorganic nutrients, which promoted the growth of other phytoplankton species. The correlation between Cylindrospermopsis sp. and total nitrogen and ammonium showed significance at R2 = 0.7268 and 0.797, respectively, with a confidence level of 0.05. Therefore, to ensure treatment effectiveness, the depth of wastewater treatment ponds should be considered during their construction because phytoplankton regulation plays an important role to maintain the overall treatment efficiency.
Environmental Science
K. Seethong; K. Chunkao; N. Dampin; W. Wararam
Abstract
BACKGROUND AND OBJECTIVES: The increasing population and urban growth have led to a higher demand for water in various sectors, resulting in a significant amount of wastewater. Constructed wetlands mimic natural wetlands, using the interaction between plants, soil, and microorganisms to treat wastewater ...
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BACKGROUND AND OBJECTIVES: The increasing population and urban growth have led to a higher demand for water in various sectors, resulting in a significant amount of wastewater. Constructed wetlands mimic natural wetlands, using the interaction between plants, soil, and microorganisms to treat wastewater efficiently. This study assesses the diversity, species composition, and distribution of benthic organisms in a community wastewater-filter grass system and explores the relationship between water quality and benthos.METHODS: Water samples were collected from plant plots between December 2021 and March 2022. On-site measurements included temperature, dissolved oxygen, salinity, and pH, whereas laboratory analysis encompassed the biochemical oxygen demand, ammonia, nitrate, total phosphorus, orthophosphate, and suspended solids. Soil samples were taken before and during planting at 2-week intervals, evaluating organic matter, pH, electrical conductivity, salinity, phosphorus, potassium, calcium, magnesium, and plant growth indicators. Benthos sampling involved polyvinyl chloride pipe cores at a depth of 5 cm from the soil surface. Statistical tests were performed to analyze the water quality data.FINDINGS: The study observed a decrease in Chironomid abundance in both constructed wetland systems, indicating their effectiveness in treating wastewater. A comparison of system types revealed that the 5-day detention–2-day dry release system exhibited higher Chironomid abundance than the continuous flow system, and the biological oxygen demand maximum decreasing rate was 95%. The ammonia and nitrate maximum decreasing rates were 97% and 94%, respectively, indicating greater wastewater-treatment efficiency. The study also identified diverse benthic organisms, particularly chironomids, as bioindicators for assessing wastewater conditions.CONCLUSION: The continuous flow system and the 5-day detention–2-day dry release system of constructed wetlands can reduce the organic compounds and increase the oxygen levels in the plant plots. The interaction among plants, soil, and microorganisms is critical in wastewater treatment. In addition, the study highlighted the diversity and abundance of benthic organisms, particularly chironomids, which were more prominent in the continuous flow system. Consequently, the 5-day detention–2-day dry release system was more efficient in treating wastewater than the continuous flow system.
Environmental Science
S. Saneha; T. Pattamapitoon; S. Bualert; O. Phewnil; W. Wararam; N. Semvimol; K. Chunkao; C. Tudsanaton; M. Srichomphu; U. Nachaiboon; O. Wongsrikaew; P. Wichittrakarn; C. Chanthasoon
Abstract
BACKGROUND AND OBJECTIVES: The bacterial community plays a crucial role in the nitrogen cycle. Oxidation ponds act as a natural treatment system for wastewater and are designed to promote the growth and activity of certain bacterial species that remove contaminants from the water. The nitrogen cycle ...
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BACKGROUND AND OBJECTIVES: The bacterial community plays a crucial role in the nitrogen cycle. Oxidation ponds act as a natural treatment system for wastewater and are designed to promote the growth and activity of certain bacterial species that remove contaminants from the water. The nitrogen cycle in these ponds involves the conversion of nitrogen compounds through biological processes by bacteria. The presence or absence of certain bacterial species can greatly influence the efficiency of the nitrogen cycle in these ponds. This research investigates the relationship between bacteria and nitrogen dynamics, the key components of wastewater treatment, in oxidation ponds. This work aims to identify the bacterial community composition in oxidation ponds, investigate the role of bacteria in the transformation and removal of nitrogen compounds from wastewater in oxidation ponds, and evaluate the impact of environmental factors on the microbial communities and nitrogen dynamics in oxidation ponds. This study was carried out in the oxidation wastewater treatment at the King’s Royally Initiated Laem Phak Bia Environmental Research and Development or LERD Project, in Phetchaburi, Thailand.METHODS: Wastewater samples were collected from the 1st–5th oxidation ponds at a depth of 30 centimeter from the water surface and analyzed for various quality parameters including temperature, dissolved oxygen, potential of hydrogen, biochemical oxygen demand, nitrates, ammonia, and total kjeldahl nitrogen. Next-generation sequencing by Illumina Miseq was used to examine the 16S ribosomal ribonucleic acid of bacteria in the collected samples. Correlation test was used for statistical analysis.FINDINGS: The temperature, potential of hydrogen (1st to 5th ponds), and dissolved oxygen (2nd to 5th ponds) in the oxidation ponds were within the standard value. Fifteen bacterial phyla were identified in the five oxidation ponds, with phylum Proteobacteria accounting for the highest population comprising 47.56% of the total bacterial population.CONCLUSION: Genera Novosphingobium (phylum Proteobacteria), Ammonia-11 (phylum Verrucomicrobiota), and Vicinamibacteraceae (phylum Acidobacteriota) have the strongest relationships with ammonia, nitrate, and total kjeldahl nitrogen (R2 = 0.9710, 0.986, 0.8124). The bacterial population is a crucial factor in nitrogen nutrient and water quality. Novosphingobium is involved in the removal of ammoniafrom wastewater, Verrucomicrobiota act as denitrifiers, and Vicinamibacteraceae increases the total kjeldahl nitrogen levels.
