Development of an integrated membrane process for water reclamation

2005 ◽  
Vol 51 (6-7) ◽  
pp. 455-463 ◽  
Author(s):  
C.H. Lew ◽  
J.Y. Hu ◽  
L.F. Song ◽  
L.Y. Lee ◽  
S.L. Ong ◽  
...  
Keyword(s):  
Retention Time ◽  
Unique Feature ◽  
Inhibitory Effect ◽  
Water Reclamation ◽  
The Novel ◽  
Membrane Process ◽  
Treatment Efficiency ◽  
Effluent Quality ◽  
Toc Removal ◽  
Ro Concentrate

An integrated membrane process (IMP) comprising a membrane bioreactor (MBR) and a reverse osmosis (RO) process was developed for water reclamation. Wastewater was treated by an MBR operated at a sludge retention time (SRT) of 20 days and a hydraulic retention time (HRT) of 5.5 h. The IMP had an overall recovery efficiency of 80%. A unique feature of the IMP was the recycling of a fraction of RO concentrate back to the MBR. Experimental results revealed that a portion of the slow- and hard-to-degrade organic constituents in the recycle stream could be degraded by an acclimated biomass leading to an improved MBR treatment efficiency. Although recycling concentrated constituents could impose an inhibitory effect on the biomass and suppress their respiratory activities, results obtained suggested that operating MBR (in the novel IMP) at an F/M ratio below 0.03 g TOC/g VSS.day could yield an effluent quality comparable to that achievable without concentrate recycling. It is noted in this study that the novel IMP could achieve an average overall TOC removal efficiency of 88.94% and it consistently produced product water usable for high value reuse applications.

Evaluation of Small Wastewater Treatment Plants in the County of Århus – Denmark

1993 ◽  
Vol 28 (10) ◽  
pp. 33-41
Author(s):  
Jes la Cour Jansen ◽  
Bodil Mose Pedersen ◽  
Erik Moldt
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Chemical Precipitation ◽  
Common Type ◽  
Treatment Efficiency ◽  
Effluent Quality ◽  
Different Types

Influent and effluent data from about 120 small wastewater treatment plants (100 - 2000 PE) have been collected and processed. Seven different types of plants are represented. The effluent quality and the treatment efficiency have been evaluated. The most common type of plant is mechanical/biological treatment plants. Some of them are nitrifying and some are also extended for chemical precipitation of phosphorus. Constructed wetlands and biological sandfilters are also represented among the small wastewater treatment plants.

scholarly journals UVA-LED Technology’s Treatment Efficiency and Cost in a Competitive Trial Applied to the Photo-Fenton Treatment of Landfill Leachate

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1026
Author(s):  
Javier Tejera ◽  
Antonio Gascó ◽  
Daphne Hermosilla ◽  
Víctor Alonso-Gomez ◽  
Carlos Negro ◽  
...  
Keyword(s):  
Landfill Leachate ◽  
Mercury Vapor ◽  
Cod Removal ◽  
Treatment Efficiency ◽  
Alternative Source ◽  
Effluent Quality ◽  
Radiation Sources ◽  
Initial Ph ◽  
Pre Treatment ◽  
Set Up

The objective of this trial was to assess the application of UVA-LED technology as an alternative source of irradiation for photo-Fenton processes, aiming to reduce treatment costs and provide a feasible treatment for landfill leachate. An optimized combination of coagulation with ferric chloride followed by photo-Fenton treatment of landfill leachate was optimized. Three different radiation sources were tested, namely, two conventional high-pressure mercury-vapor immersion lamps (100 W and 450 W) and a custom-designed 8 W 365 nm UVA-LED lamp. The proposed treatment combination resulted in very efficient degradation of landfill leachate (COD removal = 90%). The coagulation pre-treatment removed about 70% of the COD and provided the necessary amount of iron for the subsequent photo-Fenton treatment, and it further favored this process by acidifying the solution to an optimum initial pH of 2.8. The 90% removal of color improved the penetration of radiation into the medium and by extension improved treatment efficiency. The faster the Fenton reactions were, as determined by the stoichiometric optimum set-up reaction condition of [H2O2]0/COD0 = 2.125, the better were the treatment results in terms of COD removal and biodegradability enhancement because the chances to scavenge oxidant agents were limited. The 100 W lamp was the least efficient one in terms of final effluent quality and operational cost figures. UVA-LED technology, assessed as the application of an 8 W 365 nm lamp, provided competitive results in terms of COD removal, biodegradability enhancement, and operational costs (35–55%) when compared to the performance of the 450 W conventional lamp.

COD removal of phenolic wastewater by biological activated carbon-sequencing batch reactor in the presence of 2,4-DCP

2000 ◽  
Vol 42 (5-6) ◽  
pp. 171-178 ◽  
Author(s):  
S.-R. Ha ◽  
L. Qishan ◽  
S. Vinitnantharat
Keyword(s):  
Activated Carbon ◽  
Retention Time ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Cod Removal ◽  
High Loading ◽  
Treatment Efficiency ◽  
Biological Activated Carbon ◽  
Treatment Performance ◽  
Phenolic Wastewater

Treatment performance of COD in the presence of 2,4-dichlorophenol (2,4-DCP) was explored by using a biological activated carbon-sequencing batch reactor (BAC-SBR) system. Two COD levels of basic substrate were synthesized with a mixture of phenol and 2,4-dichlorophenol. Although effluent concentration was increased with reduction of sludge retention time (SRT) from 8-days to 3-days, treatment efficiency was indicated more than 90% of COD in all SRTs applied. Reactors operated with acclimated sludge could be expected to cope with quite high loading of inhibitory substances.

scholarly journals Renovation and Reuse of Reactive Dyeing Effluent by a Novel Heterogeneous Fenton System Based on Metal Modified PTFE Fibrous Catalyst/H2O2

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Bing Li ◽  
Yongchun Dong ◽  
Zhizhong Ding ◽  
Yiming Xu ◽  
Chi Zou
Keyword(s):  
Reactive Dyes ◽  
Cotton Fabrics ◽  
Molar Ratio ◽  
The Novel ◽  
Heterogeneous Fenton ◽  
Reactive Dyeing ◽  
Toc Removal ◽  
Dyeing Effluent ◽  
Fenton System

Cu-Fe bimetallic grafted polytetrafluoroethylene (PTFE) fiber complexes were prepared and optimized as the novel heterogeneous Fenton catalysts for the degradation of reactive dyes under UV irradiation. Cotton fabrics were dyed with three reactive dyes, namely, Reactive Red 195, Reactive Yellow 145, and Reactive Blue 222, in tap fresh water using exhaustion process. The spent dyeing effluents were then collected and degraded with the optimized Cu-Fe bimetallic grafted PTFE fiber complex/H2O2system. The treated dyeing effluents were characterized and reused for the dyeing of cotton fabrics through the same process. The effect of reuse process number on quality of the dyed cotton fabrics was examined. The results indicated that the Cu-Fe bimetallic modified PTFE fiber complex with a Cu/Fe molar ratio of 2.87 was found to be the most effective fibrous catalyst, which enhanced complete decolorization of the treated dyeing effluents with H2O2in 4 h. However, the TOC removal for the treated dyeing effluents was below 80%. The dyeing quality was not affected for three successive cycles. The increase in residual TOC value influences fourth dyeing cycle. Further TOC reduction of the treated effluents is needed for its repeated reuse in more than three dyeing cycles.

The Effect of Baffle Installation on the Performance of a Single-Cell Stabilization Pond

1993 ◽  
Vol 27 (7-8) ◽  
pp. 45-52 ◽  
Author(s):  
R. Pedahzur ◽  
A. M. Nasser ◽  
I. Dor ◽  
B. Fattal ◽  
H. I. Shuval
Keyword(s):  
Retention Time ◽  
Thermal Stratification ◽  
Optical Observations ◽  
Tracer Study ◽  
Treatment Efficiency ◽  
Long Tail ◽  
Stabilization Pond ◽  
Indicator Microorganism ◽  
Influent Flow

The effect of baffles on the performance of an ineffective, single-celled stabilization pond with theoretical retention time of 5-10 days, was investigated. The efficiency of the pond was evaluated by comparing the microbiological and chemical quality of pond's influent and effluent, as well as by hydraulic tests. Removal of indicator microorganism (1 log) and BOD5 (55%) remained unchanged, regardless of the number of baffles. Tracer study findings were characterized by the appearance of a peak of tracer within 15-20 hours after injection of the tracer, followed by a long “tail” of lower concentration. These findings, along with optical observations, indicated that the baffles succeeded in channeling influent flow to the planned routes (resulting in increased traveling distance of the wastewater). However, the actual retention time of the influent, particularly a small but important fraction of it, remained short regardless of baffle installation. The lack of mixing caused by thermal stratification of the water column resulted in rapid bottom flow in the cool hypolimnion. These findings may explain, in part, the lack of success in improving treatment efficiency.

scholarly journals Evaluating occurrence of contaminants of emerging concerns in MF/RO treatment of primary effluent for water reuse – Pilot study

2019 ◽  
Vol 9 (4) ◽  
pp. 350-371
Author(s):  
Mojtaba Farrokh Shad ◽  
Graham J. G. Juby ◽  
Saied Delagah ◽  
Mohamadali Sharbatmaleki
Keyword(s):  
Water Reuse ◽  
Polyvinylidene Fluoride ◽  
Phase 1 ◽  
Settling Tank ◽  
Second Phase ◽  
The Novel ◽  
Inland Empire ◽  
Novel Approach ◽  
Treatment Train ◽  
Ro Concentrate

Abstract This study experimented with the novel approach of using a microfiltration (MF) and reverse osmosis (RO) treatment train to treat the effluent of a primary settling tank at the Inland Empire Utility Agency in Chino, CA. The pilot used polyvinylidene fluoride hollow-fiber MF modules as pretreatment for an RO skid, which used Hydranautics ESPA2 membranes in a two-stage configuration with a feed capacity of 6 gallon per minute (gpm). In this pilot configuration, researchers monitored the removal of 38 most prevalent contaminants of emerging concerns (CECs) through the MF/RO process. To investigate how operating the RO process at two fixed recovery rates of 55% and 80% would affect the performance of the MF/RO membranes, researchers applied different fluxes (8, 10, 12 and 14 gal/d/ft2 (gfd)) and evaluated the removal of CECs in 1-stage and 2-stage RO configurations. The occurrence of CECs in the MF influent, MF effluent, RO permeate, and RO concentrate were analyzed and studied. In the first phase (1-stage the RO process), flux of 14 gfd showed a better rejection value of inorganics (95.2%) when compared with those of other fluxes. Meanwhile, in the second phase (2-stage RO process), flux of 12 gfd showed a better rejection of inorganics (93.7%) when compared with those of other fluxes. Although concentrations of CECs slightly decreased in the RO permeate as the flux has increased, statistical analysis showed no significant differences between different fluxes in terms of CEC rejection.

scholarly journals Cloning and characterization of novel human SLC4A8 gene products encoding Na+-driven Cl−/HCO3− exchanger variants NDCBE-A, -C, and -D

2008 ◽  
Vol 34 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Mark D. Parker ◽  
Patrice Bouyer ◽  
Christopher M. Daly ◽  
Walter F. Boron
Keyword(s):  
In Silico Analysis ◽  
Functional Expression ◽  
Inhibitory Effect ◽  
Functional Difference ◽  
The Novel ◽  
Equivalent Position ◽  
Rapid Amplification ◽  
Novel Exon ◽  
Silico Analysis

The reported sequences of the human and mouse Na+-driven Cl−/HCO3− exchangers (NDCBEs) differ greatly in their extreme cytosolic COOH termini (Ct). In human NDCBE (NDCBE-B), a 17-amino acid (aa) sequence replaces 66 aa at the equivalent position in mouse NDCBE (NDCBE-A). We performed 5′- and 3′-rapid amplification of cDNA ends (RACE) on human brain cDNA, followed by PCR of full-length cDNAs to determine whether the human SLC4A8 gene was capable of producing the mouselike Ct sequence. Our study confirmed the presence in human cDNA of mouse NDCBE-like transcripts (human NDCBE-A) and also disclosed the existence of three further novel NDCBE transcripts that we have called NDCBE-C, NDCBE-D, and NDCBE-D′. The novel NDCBE-C/D/D′ transcripts initiate at a novel “exon 0” positioned ∼35 kb upstream of the first exon of NDCBE-A/B. NDCBE-C/D/D′ protein products are predicted to be truncated by 54 aa in the cytosolic NH2 terminus (Nt) compared with NDCBE-A/B. Our data, combined with a new in silico analysis of partial transcripts reported by others in the region of the human SLC4A8 gene, increase the known extent of the SLC4A8 gene by 49 kb, to 124 kb. A functional comparison of NDCBE-A/B/C/D expressed in Xenopus oocytes demonstrates that the Nt variation does not affect the basal functional expression of NDCBE, but those with the shorter Ct have a 25–50% reduced functional expression compared with those with the longer Ct. By comparison with an artificially truncated NDCBE that contains neither 17-aa nor 66-aa Ct cassette, we determined that the functional difference is unrelated to the 66-aa cassette of NDCBE-A/C, but is instead due to an inhibitory effect of the 17-aa cassette of NDCBE-B/D.

scholarly journals Targeting Indoleamine 2,3-Dioxygenase in Cancer Models Using the Novel Small Molecule Inhibitor NTRC 3883-0

2021 ◽  
Vol 11 ◽  
Author(s):  
Yvonne Grobben ◽  
Jos de Man ◽  
Antoon M. van Doornmalen ◽  
Michelle Muller ◽  
Nicole Willemsen-Seegers ◽  
...  
Keyword(s):  
Small Molecule ◽  
Malignant Ascites ◽  
Inhibitory Effect ◽  
The Novel ◽  
Indoleamine 2,3 Dioxygenase ◽  
Cancer Models ◽  
Molecule Inhibitor ◽  
Syngeneic Mouse Model ◽  
Ido1 Expression

Indoleamine 2,3-dioxygenase (IDO1) is a key regulator of immune suppression by catalyzing the oxidation of L-tryptophan. IDO1 expression has been related to poor prognosis in several cancers and to resistance to checkpoint immunotherapies. We describe the characterization of a novel small molecule IDO1 inhibitor, NTRC 3883-0, in a panel of biochemical and cell-based assays, and various cancer models. NTRC 3883-0 released the inhibitory effect of IDO1 on CD8-positive T cell proliferation in co-cultures of IDO1-overexpressing cells with healthy donor lymphocytes, demonstrating its immune modulatory activity. In a syngeneic mouse model using IDO1-overexpressing B16F10 melanoma cells, NTRC 3883-0 effectively counteracted the IDO1-induced modulation of L-tryptophan and L-kynurenine levels, demonstrating its in vivo target modulation. Finally, we studied the expression and activity of IDO1 in primary cell cultures established from the malignant ascites of ovarian cancer patients. In these cultures, IDO1 expression was induced upon stimulation with IFNγ, and its activity could be inhibited by NTRC 3883-0. Based on these results, we propose the use of ascites cell-based functional assays for future patient stratification. Our results are discussed in light of the recent discontinuation of clinical trials of more advanced IDO1 inhibitors and the reconsideration of IDO1 as a valid drug target.

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