Water quality. Determination of the chemical oxygen demand index (ST-COD). Small-scale sealed-tube method

2015 ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 196-209 ◽  
Author(s):  
H. S. Lim ◽  
L. Y. Lee ◽  
S. E. Bramono

This paper examines the impact of community-based water treatment systems on water quality in a peri-urban village in Yogyakarta, Indonesia. Water samples were taken from the wastewater treatment plants (WWTPs), irrigation canals, paddy fields and wells during the dry and wet seasons. The samples were tested for biological and chemical oxygen demand, nutrients (ammonia, nitrate, total nitrogen and total phosphorus) and Escherichia coli. Water quality in this village is affected by the presence of active septic tanks, WWTP effluent discharge, small-scale tempe industries and external sources. We found that the WWTPs remove oxygen-demanding wastes effectively but discharged nutrients, such as nitrate and ammonia, into irrigation canals. Irrigation canals had high levels of E. coli as well as oxygen-demanding wastes. Well samples had high E. coli, nitrate and total nitrogen levels. Rainfall tended to increase concentrations of biological and chemical oxygen demand and some nutrients. All our samples fell within the drinking water standards for nitrate but failed the international and Indonesian standards for E. coli. Water quality in this village can be improved by improving the WWTP treatment of nutrients, encouraging more villagers to be connected to WWTPs and controlling hotspot contamination areas in the village.


2021 ◽  
Vol 9 (1) ◽  
pp. 47
Author(s):  
Maria elisa Leite Costa ◽  
Sérgio Koide ◽  
Daniela Junqueira Carvalho ◽  
Jeremie Garnier

<p>Entre fevereiro de 2018 e janeiro de 2020, foi realizado o monitoramento hidrológico e de qualidade da água do Córrego Vicente Pires, localizado em uma zona urbana do Distrito Federal, a fim de avaliar as alterações na qualidade da água a partir da determinação de parâmetros físico-químicos, em eventos nos períodos seco e chuvoso. Foram elaborados polutogramas para os parâmetros de condutividade (elétrica), turbidez, pH, sólidos, demanda química de oxigênio e nutrientes (nitrogênio e fósforo), associados aos hidrogramas dos mesmos eventos, com vazões variando de 0,5 m³/s a 72,2 m³/s. O monitoramento dos eventos de cheia obteve concentrações de sólidos totais de até 7.583 mg/L, fosfato até 0,9 mg/L de PO<sub>4</sub><sup>3 </sup>e demanda química de oxigênio de até 958 mg/L. No período de estiagem, devido à menor disponibilidade de água no córrego, não há diluição de poluentes e  ressalta-se a concentração de nitrato (NO<sub>3</sub>até 9 mg/L)  em função dos lançamentos de esgotos domésticos no córrego. No período chuvoso, evidenciam-se os sólidos totais associados à lavagem da superfície e erosão do solo por grandes volumes gerados no escoamento superficial. Esses resultados expõem a necessidade de investimentos em infraestrutura de coleta de esgoto e drenagem urbana, inclusive, na adoção de medidas de contenção de sedimentos durante a realização de obras.</p><p><strong>Palavras-chaves:  </strong>Monitoramento hidrológico; Polutograma; Cheias.</p><p> </p><h2 align="center">URBAN WATERQUALITY IN THE VICENTE PIRES STREAM – FEDERAL DISTRICT</h2><p><strong>Abstract</strong></p><p>Between February 2018 and January 2020, hydrological and water quality monitoring of Vicente Pires Stream, located in the urban area of the Federal District, was carried out in order to assess the changes in water quality from the determination of physical-chemical parameters during events in the dry and rainy periods. Polutographs were prepared for parameters such as (electric) conductivity, turbidity, pH, solids, chemical oxygen demand and nutrients (nitrogen and phosphorus), associated with hydrographs of the same events, with flows that ranged from 0.5 m³/s to 72.2 m³/s. The monitoring of flood events showed concentrations of total solids up to 7,583 mg/L, phosphate up 0,9 mg/L PO43 and chemical oxygen demand up to 958 mg/L. During the dry season, due to the lower availability of water in the stream, there is no dilution of pollutants and the nitrate concentration stands out (NO3 up to 9 mg/L), due to discharges of domestic sewage into the stream. In the rainy season, the total solids associated with the washing of the surface and soil erosion by large volumes of runoff stand out. These results expose a need for investment in sewage collection and urban drainage infrastructures, including the adoption of sediment containment measures during the execution of construction.</p><p><strong>Keywords:</strong> Hydrological monitoring; Polutograph; Floods.</p>


2018 ◽  
Vol 69 (10) ◽  
pp. 2940-2952 ◽  
Author(s):  
Martina Zelenakova ◽  
Pavol Purcz ◽  
Radu Daniel Pintilii ◽  
Peter Blistan ◽  
Petr Hlustik ◽  
...  

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.


Author(s):  
H. Garba ◽  
C. A. Elanu

An assessment of the chemical characteristics of industrial and domestic wastewater discharges on seven parameters into Kaduna River on a bimonthly basis was carried out. PH, dissolved oxygen (DO), chloride, nitrite, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and iron were analyzed to determine their concentration levels. From the analysis, the highest mean concentration of the parameters were 8.24 of pH, 7.7 mg/l of DO, 233.4 mg/l of chloride, 55.68 mg/l of COD, 27.95 mg/l of nitrite, 122.22 mg/l of BOD, and 17.05 mg/l of iron. After comparing with prescribed standards, it can be concluded that there is evidence of organic and inorganic accumulation of contaminants into River Kaduna.


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