scholarly journals Microstructural characterization of white charcoal for rapid reduction of chemical oxygen demand and automatically adjust pH to neutral in wastewater treatment

Author(s):  
Nuchanaporn Pijarn ◽  
Janpen Intaraprasert ◽  
Sukanya Ophap ◽  
Thanida Uma ◽  
Siripan Deekarnkol ◽  
...  
2014 ◽  
Vol 69 (7) ◽  
pp. 1482-1488 ◽  
Author(s):  
Shutao Wang ◽  
Xingwen Zhang ◽  
Zhi-Wu Wang ◽  
Xiangkun Li ◽  
Jun Ma

This study provided insight into the characterization of secondary effluent from a wastewater treatment plant located in northeastern China. The secondary effluent was separated into three fractions, the dissolved, the near-colloidal and the suspended, to study their individual characteristics. It revealed that most of the organics in the secondary effluent existed in the dissolved form, accounting for 78.1–86.5% of the total chemical oxygen demand and 82.6–86.6% of the total organic carbon. Results from the molecular weight distribution study further indicated that organics with MW < 1k Da constituted 56.3–62.7% of total organics. Moreover, the particle size distribution study suggested that particles between 2.0 and 6.8 μm in diameter made up 80.0% of the total suspended solids. Both biological oxygen demand/chemical oxygen demand and biological dissolved organic carbon/dissolved organic carbon were measured ranging from 0.2 to 0.3, suggesting the most secondary effluent organics were biologically refractory. This conclusion was further strengthened by the functional groups information obtained from the GC/MS (gas chromatography/mass spectrometry) analysis. The characteristics information revealed from this study will help the design and selection of water quality-specific tertiary treatment technologies for secondary effluent water purification and reuse.


2021 ◽  
Vol 221 ◽  
pp. 31-40
Author(s):  
A.S. Mubarak ◽  
Parvaneh Esmaili ◽  
Z.S. Ameen ◽  
R.A. Abdulkadir ◽  
M.S. Gaya ◽  
...  

2020 ◽  
Vol 9 (6) ◽  
pp. e183963748
Author(s):  
Rafael Souza Leopoldino Nascimento ◽  
Ludymyla Marcelle Lima Silva ◽  
Lucas Periard ◽  
Anibal da Fonseca Santiago

The technology of microalgae photobioreactors and illuminated by LEDs has been widely studied for the treatment of wastewater. However, sunlight is a free resource and should be taken advantage of. But the question remains whether photobioreactors illuminated by natural (sunlight) light in combination with artificial light can have greater operational stability or greater performance when compared to systems illuminated only by artificial light. In this context, continuous flow photobioreactors illuminated by Light Emitting Diodes (LEDs) combined, or not, with sunlight were operated and had their performance evaluated. The variables analyzed were pH, OD, chemical oxygen demand (COD), chlorophyll - a and total suspended solids. The photobioreactors were effective for removing organic matter, with 75 ± 15% in the photobioreactor illuminated by LED and 65 ± 10% in the photobioreactor illuminated by sunlight and LED. The results showed that the use of combined lighting favors the production of dissolved oxygen and ensures greater operational stability in the removal of carbonaceous organic matter.


Author(s):  
Fagbenro Oluwakemi Kehinde ◽  
Salem S. Abu Amr ◽  
Hamidi Abdul Aziz

As textile and dyeing industries increase, pollution due to effluent discharges from the same industries also increase and become of great concern to a healthy environment. In an attempt to understand the generation and treatment of textile wastewater, this chapter discusses the processes from which textiles are made, items of importance that are used in the production process which may account for the characteristics of the wastewater and persulfate, applied in the treatment of textile wastewater. Although these wastewaters are generally characterized by color, fluctuating pH, heat, salts, suspended solids (SS), the presence of metal ions, biological oxidation demand (BOD), and chemical oxygen demand (COD), color is the most obvious. The presence of color in the effluents from textile dyeing and finishing is due to the inefficient dyeing processes, resulting in unfixed forms of the dyestuff. To achieve the primary objective of obtaining a clean environment, there is a need for continuous monitoring of textile wastewater discharges, of which major concern is color.


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.


2006 ◽  
Vol 53 (1) ◽  
pp. 149-157 ◽  
Author(s):  
F. Grognard ◽  
O. Bernard

This paper presents a saturated proportional controller that achieves depollution of wastewater in a continuous anaerobic digester. This goal is reached by defining a region of the state-space where the depollution is achieved and forcing attractivity and invariance of this region. The control variable is the dilution rate and the controlled variable is a linear combination (Sλ) of the substrates concentrations, that could be the chemical oxygen demand or the biological oxygen demand, depending on the value of λ. No measurement of the substrates concentrations in the input flow is required: the only necessary measurement is Sλ.


2015 ◽  
Vol 72 (6) ◽  
pp. 850-857 ◽  
Author(s):  
Naoyuki Kishimoto ◽  
Takuya Kitamura ◽  
Yu Nakamura

The applicability of an electrochemical Fenton-type process (EF-HOCl-ReFe) to the treatment of three actual wastewaters, namely wastewater from an automobile factory (automobile wastewater), metal scrap-cleansing wastewater, and municipal wastewater, is discussed in this research. The EF-HOCl-ReFe successfully removed the chemical oxygen demand (COD) from automobile wastewater pre-treated by a coagulation process without any inhibition. The apparent current efficiency reached 86%, 46% of which was ascribed to the electrochemical Fenton-type mechanism. The metal scrap-cleansing wastewater had a yellow colour and high concentrations of COD (6550 mg/L) and Cl− (1560 mM). The EF-HOCl-ReFe could achieve almost complete COD removal and decolourization after 48 h of treatment, although a temporary intensification of colour was observed before the decolourization. The EF-HOCl-ReFe was also effective in the removal of 1,4-dioxane from municipal wastewater pre-treated by activated sludge and coagulation processes, which were unable to remove 1,4-dioxane. The 1,4-dioxane removal efficiency after 30 min of treatment reached 68.5%. Thus, the EF-HOCl-ReFe was applicable to the treatment of these actual wastewaters.


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