scholarly journals Current Levels and Composition Profiles of Emerging Halogenated Flame Retardants and Dehalogenated Products in Sewage Sludge from Municipal Wastewater Treatment Plants in China

2014 ◽  
Vol 48 (21) ◽  
pp. 12586-12594 ◽  
Author(s):  
Lixi Zeng ◽  
Ruiqiang Yang ◽  
Qinghua Zhang ◽  
Haidong Zhang ◽  
Ke Xiao ◽  
...  
2006 ◽  
Vol 53 (8) ◽  
pp. 81-90 ◽  
Author(s):  
V. Parravicini ◽  
E. Smidt ◽  
K. Svardal ◽  
H. Kroiss

Further reduction of volatile suspended solids (VSS) during a post-stabilisation step was applied to evaluate the stabilisation degree of digested sewage sludge. For this purpose digested sludge was collected at four municipal wastewater treatment plants (WWTPs) and further stabilised in lab-scale chemostat reactors either under anaerobic or aerobic conditions. Experimental results showed that even in adequately digested sludge a consistent amount of VSS was degraded during aerobic post-stabilisation. It seems that aerobic conditions play a significant role during degradation of residual VSS. Additionally, specific VSS production (gVSS/peCOD110.d) as well as specific oxygen uptake rate were shown to be suitable parameters to assess the degree of sludge stabilisation at WWTPs. Fourier transform infrared spectroscopy was used to reveal changes in the sludge composition. Spectra of treated and untreated sludge samples indicated that the major component of residual VSS in stabilised sludge for instance consisted of biomass, while cellulose was absent.


2014 ◽  
Vol 49 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Antonette Arvai ◽  
Gary Klecka ◽  
Saad Jasim ◽  
Henryk Melcer ◽  
Michael T. Laitta

The Great Lakes and their connecting channels form the largest fresh surface water system on earth. Over the past 10 years, focus on environmental monitoring has shifted to an array of recently discovered compounds known as ‘chemicals of emerging concern’ (CEC). These chemicals are found in products used daily in households, businesses, agriculture and industry, such as flame retardants, pharmaceuticals, personal care products, and pesticides. Wastewater treatment plants are among the important pathways by which CEC enter the Great Lakes, with concentrations highest in the vicinity of wastewater discharges. Treated sewage is often discharged into the nearshore waters, which also provide a source of drinking water to the public. In 2009–2011, the International Joint Commission addressed the need to assess the effectiveness of existing wastewater treatment technologies in the basin to remove CEC, as well as to gain insight on potential advanced technologies to improve their removal. This assessment encompassed three major activities, development of an inventory of municipal wastewater treatment plants that discharge in the basin; a survey of detailed operational data for selected wastewater facilities; and a comprehensive literature review and analysis of the effectiveness of various wastewater treatment technologies to remove chemicals of emerging concern.


2016 ◽  
Vol 74 (7) ◽  
pp. 1602-1609 ◽  
Author(s):  
Long Pang ◽  
Peijie Yang ◽  
Jihong Zhao ◽  
Hongzhong Zhang

Organophosphate esters (OPs), widely used as flame retardants and plasticizers, are regarded as a class of emerging pollutants. The effluent of municipal wastewater treatment plants is generally considered to be the main contributor of OP pollution to the surface water. In this study, anoxic–oxic (AO) and University of Capetown (UCT) processes were selected to investigate the removal efficiency of OPs. The results indicated that the UCT process showed better removal efficiency than that of the AO process. For the chlorinated OPs, approximately 12.3% of tri(2-chloroethyl)phosphate and 11.8% of tri(chloropropyl)phosphate can be removed in the UCT process, which was 12% and 7.8% higher than that of the AO process. In contrast, non-chlorinated OPs, including tris(2-butoxyethyal)phosphate, triphenyl phosphate, and tributyl phosphate, were able to be removed in both processes, with the removal rate of 85.1%, 74.9%, and 29.1% in the AO process, and 88.4%, 63.6%, and 25.2% in the UCT process. Furthermore, linear correlation between the removal rate and logKow of OPs (r2 = 0.539) was observed in the AO process, indicating that OPs with high Kow value (e.g. tri(dichloropropyl)phosphate and triphenyl phosphate) are prone to be removed by adsorption on the residual activated sludge.


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