scholarly journals Phosphorus removal in domestic wastewater treatment plant by calcined eggshell

Author(s):  
Rafael Renato Fritzen ◽  
Antônio Domingues Benetti

Abstract Recovery of phosphorus (P) from wastewater is a topic of great interest. Besides being a non-renewable resource, P discharge in receiving waters can trigger algae blooms. The present study aimed to quantify the removal of P from two sites at a wastewater treatment plant using calcined eggshell (CES) as adsorbent. CES was prepared from raw shells calcined at 600 °C (CES600) and 800 °C (CES800). Calcined eggshells at 800 °C proved to be an efficient material for P removal. Efficiencies greater than 70% were achieved using CES800 concentrations of 0.1 g L−1 for synthetic sample, 0.3 g L−1 for preliminary treated wastewater and 20 g L−1 for supernatant from sludge anaerobic digester. The adsorption process was fast, occurring mostly in the first 30 minutes. Both Langmuir and Freundlich isotherms fitted the experimental data on adsorption. In kinetic experiments, a pseudo-second order model fitted P adsorption from synthetic, preliminary effluent and digester supernatant. Thermogravimetric analysis showed a 54% eggshell mass loss at 800 °C. Calcination increased calcium and reduced carbon fractions in the eggshells, while increasing the surface area.

2001 ◽  
Vol 43 (2) ◽  
pp. 91-99 ◽  
Author(s):  
T. Iwane ◽  
T. Urase ◽  
K. Yamamoto

Escherichia coli and coliform group bacteria resistant to seven antibiotics were investigated in the Tama River, a typical urbanized river in Tokyo, Japan, and at a wastewater treatment plant located on the river. The percentages of antibiotic resistance in the wastewater effluent were, in most cases, higher than the percentages in the river water, which were observed increasing downstream. Since the possible increase in the percentages in the river was associated with treated wastewater discharges, it was concluded that the river, which is contaminated by treated wastewater with many kinds of pollutants, is also contaminated with antibiotic resistant coliform group bacteria and E.coli. The percentages of resistant bacteria in the wastewater treatment plant were mostly observed decreasing during the treatment process. It was also demonstrated that the percentages of resistance in raw sewage are significantly higher than those in the river water and that the wastewater treatment process investigated in this study works against most of resistant bacteria in sewage.


2017 ◽  
Vol 77 (2) ◽  
pp. 337-345 ◽  
Author(s):  
I. Brückner ◽  
K. Kirchner ◽  
Y. Müller ◽  
S. Schiwy ◽  
K. Klaer ◽  
...  

Abstract The project DemO3AC (demonstration of large-scale wastewater ozonation at the Aachen-Soers wastewater treatment plant, Germany) of the Eifel-Rur Waterboard contains the construction of a large-scale ozonation plant for advanced treatment of the entire 25 million m³/yr of wastewater passing through its largest wastewater treatment plant (WWTP). In dry periods, up to 70% of the receiving water consists of treated wastewater. Thus, it is expected that effects of ozonation on downstream water biocoenosis will become observable. Extensive monitoring of receiving water and the WWTP shows a severe pollution with micropollutants (already prior to WWTP inlet). (Eco-)Toxicological investigations showed increased toxicity at the inlet of the WWTP for all assays. However, endocrine-disrupting potential was also present at other sampling points at the WWTP and in the river and could not be eliminated sufficiently by the WWTP. Total cell counts at the WWTP are slightly below average. Investigations of antibiotic resistances show no increase after the WWTP outlet in the river. However, cells carrying antibiotic-resistant genes seem to be more stress resistant in general. Comparing investigations after implementation of ozonation should lead to an approximation of the correlation between micropollutants and water quality/biocoenosis and the effects that ozonation has on this matter.


2013 ◽  
Vol 68 (2) ◽  
pp. 433-440 ◽  
Author(s):  
Wanhui Zhang ◽  
Chaohai Wei ◽  
Chunhua Feng ◽  
Yuan Ren ◽  
Yun Hu ◽  
...  

The occurrence of 14 phenolic compounds (PCs) was assessed in the raw, treated wastewater, dewatered sludge and gas samples from a coking wastewater treatment plant (WWTP) in China. It was found that 3-cresol was the dominant compound in the raw coking wastewater with a concentration of 183 mg L−1, and that chlorophenols and nitrophenols were in the level of μg L−1. Phenol was the dominant compound in the gas samples, while 2,4,6-trichlorophenol predominated in the dewatered sludge sample. The anaerobic and aerobic tanks played key roles in the elimination of chlorophenols and phenols, respectively. Analysis of daily mass flows of PCs in WWTP showed that 89–98% of phenols and 83–89% of nitrophenols were biodegraded, and that 44–69% of chlorophenols were adsorbed to sludge, indicating that the fate of PCs was highly influenced by their biodegradability and physical–chemical property.


2002 ◽  
Vol 46 (10) ◽  
pp. 195-198 ◽  
Author(s):  
C.X. Ramos ◽  
S.L. Estévez ◽  
E. Giraldo

VOCs emitted by two composting static piles of biosolids coming from the “El Salitre” wastewater treatment plant (Bogotá, Colombia) were analysed during the composting process. Each pile in its sampling time was maintained with a different aeration system. The sampling was made using Solid Phase Microextraction (SPME); separation and identifications were made using Gas Chromatography (GC) coupled to Mass Spectrometry (MS). Aliphatic and aromatic hydrocarbons, chlorinated compounds, ketones, mercaptans, alcohols and amines were identified in concentrations greater than the norms stipulated by the EPA for inhalation in humans beings. The emission behavior varied according to the aeration system used.


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