Optimization of phosphorus removal in secondary effluent using immersed ultrafiltration membranes with in-line coagulant pretreatment — implications for advanced water treatment and reuse applicationsA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (7) ◽  
pp. 1272-1283 ◽  
Author(s):  
Joel Citulski ◽  
Khosrow Farahbakhsh ◽  
Fraser Kent

In-line addition of alum and ferric chloride was conducted at a hollow-fibre immersed ultrafiltration (UF) membrane pilot plant, using secondary effluent from a municipal wastewater treatment plant (WWTP) as the feed. The objective of such pretreatment was to remove phosphorus from the feed from an initial concentration of approximately 5 mg/L to below 0.3 mg/L. The simplified in-line coagulant addition process involved hydraulic mixing of the coagulant into the feed and subsequent flocculation, and a greatly reduced (12–14 min) flocculation time relative to conventional coagulation-flocculation-settling treatment. Both alum and ferric chloride effectively removed phosphorus to below the 0.3 mg/L threshold when applied as a pretreatment at optimized doses, both of which were below the WWTP’s current coagulant dose (as ferrous chloride). This simplified pre-treatment scheme provided consistent enhanced removal of phosphorus and organic compounds. These results suggest that simplified in-line coagulant addition in advance of immersed UF membranes enhances the ability to produce treated effluent suitable for water-reuse applications.

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2100
Author(s):  
Peter Sanciolo ◽  
Paul Monis ◽  
Justin Lewis ◽  
Greg Ryan ◽  
Andrew Salveson ◽  
...  

Pasteurisation was investigated as a process to achieve high microbial quality standards in the recycling of water from unfiltered secondary effluents from a wastewater treatment plants in Melbourne, Australia. The relative heat sensitivity of key bacterial, viral, protozoan and helminth wastewater organisms (Escherichia coli, Enterococcus, FRNA bacteriophage, adenovirus, coxsackievirus, Cryptosporidium, and Ascaris) were determined by laboratory scale tests. The FRNA phage were found to be the most heat resistant, followed by enterococci and E. coli. Pilot scale challenge testing of a 2 ML/day pasteurisation pilot plant using unfiltered municipal wastewater and male specific coliphage (MS2) phage showed that temperatures between 69 °C and 75 °C achieved log reductions values between 0.9 ± 0.1 and 5.0 ± 0.5 respectively in the contact chamber. Fouling of the heat exchangers during operation using unfiltered secondary treated effluent was found to increase the energy consumption of the plant from 2.2 kWh/kL to 5.1 kWh/kL. The economic feasibility of pasteurisation for the current municipal application with high heat exchanger fouling potential can be expected to depend largely on the available waste heat from co-generation and on the efforts required to control fouling of the heat exchangers.


1994 ◽  
Vol 30 (4) ◽  
pp. 125-132 ◽  
Author(s):  
D. Carnimeo ◽  
E. Contini ◽  
R. Di Marino ◽  
F. Donadio ◽  
L. Liberti ◽  
...  

The pilot investigation on the use of UV as an alternative disinfectant to NaOCI was started in 1992 at Trani (South Italy) municipal wastewater treatment plant (335 m3/h). The results collected after six months continuous operation enabled us to compare UV and NaOCl disinfection effectiveness on the basis of secondary effluent characteristics, quantify photoreactivation effects, evidence possible DBP formation and assess costs.


1997 ◽  
Vol 35 (6) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Yoshihiko Iwasaki

This paper describes a pilot plant study on the performance of a hybrid small municipal wastewater treatment system consisting of a jet mixed separator(JMS) and upgraded RBC. The JMS was used as a pre-treatment of the RBC instead of the primary clarifier. The treatment capacity of the system was fixed at 100 m3/d, corresponding to the hydraulic loading to the RBC of 117 L/m2/d. The effluent from the grid chamber at a municipal wastewater treatment plant was fed into the hybrid system. The RBC was operated using the electric power produced by a solar electric generation panel with a surface area of 8 m2 under enough sunlight. In order to reduce the organic loading to the RBC, polyaluminium chloride(PAC) was added to the JMS influent to remove the colloidal and suspended organic particles. At the operational condition where the A1 dosage and hydraulic retention time of the JMS were fixed at 5 g/m3 and 45 min., respectively, the average effluent water quality of hybrid system was as follows: TOC=8 g/m3, Total BOD=8 g/m3, SS=8 g/m3, Turbidity=6 TU, NH4-N=7 g/m3, T-P=0.5 g/m3. In this operating condition, electric power consumption of the RBC for treating unit volume of wastewater is only 0.07 KWH/m3.


2013 ◽  
Vol 838-841 ◽  
pp. 2712-2716
Author(s):  
Yong Tu ◽  
Yong Gang Bai ◽  
Yong Chen ◽  
Wei Jing Liu ◽  
Jun Xu ◽  
...  

The research on ultrafiltration membrane assisted by powdered zeolite for the treatment of secondary effluent from a municipal wastewater treatment plant was studied. The results show that membrane fouling rate is reduced by pre-coating the ultrafiltration membrane with powdered zeolite, and the treatment performance of secondary effluent is enhanced. UV-vis, three-dimensional excitation emission matrix (3D-EEM) fluorescence spectra and scanning electron microscopy (SEM) images for ultrafiltration were also discussed.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 361-368 ◽  
Author(s):  
L. Bonomo ◽  
G. Pastorelli ◽  
E. Quinto ◽  
G. Rinaldi

Two bench-scale reactors, fed with the secondary effluent of a municipal wastewater treatment plant (WWTP), were used in order to study tertiary nitrification in pure oxygen moving bed biofilm reactors (PO-MBBRs) with patented KMT® media as biofilm carriers. The process allowed to measure very high nitrification rates, both in ammonia limiting conditions (up to 7 gN m−2 d−1; oxygen-to-ammonia nitrogen ratio higher than 3–4 mgO2 (mgN)−1) and in oxygen limiting conditions (up to 8 gN m−2 d−1; oxygen-to-ammonia nitrogen ratio lower than 1–2 mgO2 (mgN)−1). Since the process proved flexible and reliable, it is suitable for full-scale application to municipal WWTPs. Typical application could regard, but is not limited to, tertiary nitrification of secondary effluent from existing high-purity oxygen activated sludge systems designed to achieve only organic carbon removal.


2016 ◽  
Vol 74 (4) ◽  
pp. 816-823 ◽  
Author(s):  
R. Nogueira ◽  
K.-U. Utecht ◽  
M. Exner ◽  
W. Verstraete ◽  
K.-H. Rosenwinkel

A community-wide outbreak of Legionnaire's disease occurred in Warstein, Germany, in August 2013. The epidemic strain, Legionella pneumophila Serogruppe 1, was isolated from an industrial wastewater stream entering the municipal wastewater treatment plant (WWTP) in Wartein, the WWTP itself, the river Wäster and air/water samples from an industrial cooling system 3 km downstream of the WWTP. The present study investigated the effect of physical–chemical disinfection methods on the reduction of the concentration of Legionella in the biological treatment and in the treated effluent entering the river Wäster. Additionally, to gain insight into the factors that promote the growth of Legionella in biological systems, growth experiments were made with different substrates and temperatures. The dosage rates of silver micro-particles, hydrogen peroxide, chlorine dioxide and ozone and pH stress to the activated sludge were not able to decrease the number of culturable Legionella spp. in the effluent. Nevertheless, the UV treatment of secondary treated effluent reduced Legionella spp. on average by 1.6–3.4 log units. Laboratory-scale experiments and full-scale measurements suggested that the aerobic treatment of warm wastewater (30–35 °C) rich in organic nitrogen (protein) is a possible source of Legionella infection.


2018 ◽  
Vol 77 (11) ◽  
pp. 2723-2732 ◽  
Author(s):  
Xiaowei Zheng ◽  
Shenyao Zhang ◽  
Jibiao Zhang ◽  
Deying Huang ◽  
Zheng Zheng

Abstract With the improvement of wastewater discharge standards, wastewater treatment plants (WWTPs) are continually undergoing technological improvements to meet the evolving standards. In this study, a quartz sand deep bed denitrification filter (DBDF) was used to purify WWTP secondary effluent, utilizing high nitrate nitrogen concentrations and a low C/N ratio. Results show that more than 90% of nitrate nitrogen (NO3-N) and 75% of chemical oxygen demand (COD) could be removed by the 20th day of filtration. When the filter layer depth was set to 1,600 mm and the additional carbon source CH3OH was maintained at 30 mg L−1 COD (20 mg L−1 methanol), the total nitrogen (TN) and COD concentrations of DBDF effluent were stabilized below 5 and 30 mg L−1, respectively. Analysis of fluorescence revealed that DBDF had a stronger effect on the removal of dissolved organic matter (DOM), especially of aromatic protein-like substances. High throughput sequencing and qPCR results indicate a distinctly stratified microbial distribution for the main functional species in DBDF, with quartz sand providing a good environment for microbes. The phyla Proteobacteria, Bacteroidetes, and Chloroflexi were found to be the dominant species in DBDF.


2013 ◽  
Vol 9 (2) ◽  
pp. 166-173

The present study investigated tertiary physico-chemical treatment of the secondary effluent from the Chania municipal Wastewater Treatment Plant (WTP). Laboratory experiments were carried out with the aim of studying coagulation efficiency regarding reduction of turbidity, soluble COD and phosphorus both in a conventional Coagulation-Settling treatment scheme, as well as by means of Contact Filtration. The results showed that high doses of coagulants (0,5 mmol Me+3 l-1 or higher) are required to achieve significant removals of turbidity after settling. At these high doses, soluble COD can be removed by about 50%, while soluble Phosphorus by 80-95%. Ferric Chloride demonstrated slightly better removal ability as compared to Alum. The Chania WTP effluent was also treated by Contact Filtration, using a very low dose of coagulants, 0,1 mmol Me+3 l-1. Turbidity was removed by around 50%, while at this low coagulant dose removals of COD and Phosphorus were insignificant. Filtration was effective in the first 35cm of the filter bed. No significant differences were observed between the coagulants Alum and FeCl3 in the elimination of turbidity. Nevertheless, with the use of Alum a smaller filter headloss was observed, during the first two hours of continuous filtration, in comparison with the use of FeCl3 (nearly double). No difference was observed between the headloss developed at a filter depth of 5cm as compared to that developed at a depth of 70cm. This indicates that the headloss increase was due to the accumulation of suspended and colloidal solids within the first layers of the sand filter.


2019 ◽  
Vol 3 (2) ◽  
pp. 53 ◽  
Author(s):  
N. Evelin Paucar ◽  
IIho Kim ◽  
Hiroaki Tanaka ◽  
Chikashi Sato

A municipal wastewater treatment plant (WWTP) is a melting pot of numerous pharmaceuticals and personal care products (PPCPs) together with many other substances. The removal of PPCPs using advanced oxidation processes within a WWTP is one way to reduce the amount of PPCPs that potentially enter an aquatic environment. The aim of this study was to examine the effectiveness of the ozone (O3)/UV treatment process, especially, the effects of O3 dose and reaction time, on the removal of PPCPs in the secondary effluent of a WWTP. Experiments were conducted using a pilot-scale treatment process that consisted of two flow-through reactors connected in series. Each reactor was equipped with three 65 W lamps (UV65W). The experimental variables were ozone dosage (1, 2, 3, 4, and 6 mg L−1) and hydraulic retention time (HRT; 5 and 10 min). On the basis of the PPCP concentrations after O3/UV65W treatment and their limit of detection (LOD), 38 PPCPs detected in the secondary effluent were classified into 5 groups ranging from the category of “sensitive” to O3/UV65W or “unstable” in the O3/UV65W process to the category of “insensitive” to O3/UV65W or “very stable” in the O3/UV65W process.


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