Natural Organic matter (NOM)

In a water supply system total Trihalomethanes (THMs) content in drinking water may vary considerably depending on water quality and treatment conditions. Most urban water treatment plants generally use chlorine as disinfectant. The effect of various parameters on the formation of THMs has been widely studied around the world over the past few decades. Almost universally, it has been found that increasing any of these parameters tends to promote the formation of THMsexcept for ammonia, which has a negative effect on the process. Surprisingly, this exception has not received the attention it deserves in THM research globally. Given the high concentration of ammonia in Dhaka's drinking water sources-particularly during the dry months-this study aimed to evaluate how ammonia affects the formation of THMs in water samples from the largest water treatment plant in Dhaka, Bangladesh. The water samples were tested for a wide range of parameters including pH, ammonia, UV 254 , TOC, DOC and bromide following the standard methods of testing. THMs was measured by THM plus Method (Method:10132) using UV-VIS Spectrophotometer DR 6000(HACH, USA). A detailed quantitative study was conducted to examine how ammonia affects the formation of trihalomethanes (THMs) when water is chlorinated under varying conditions. Experiments were carried out using treated water from the supply system, which had a dissolved organic carbon (DOC) content of 6.0 mg/L. Chlorination was performed with a free chlorine residual of 0.89 mg/L and a total chlorine residual of 1.29 mg/L. Different doses of ammonia-0.0, 0.5, 1.0, 5.0, and 10.0 mg/L-were applied. The results showed that the presence of ammonia at various concentrations significantly reduced THM formation at the given chlorine levels, however it did not completely eliminate it. THMs formation decreased continuously with increasing ammonia concentration, and the decline is sharp during relatively low concentration of ammonia up to 3 mg N/L then remained near to flat slope after ammonia exceeded 3 mg N/ L. It is noticed that the formation of THMs significantly reduced with increasing ammonia concentration from 0 to 10 mg N/L in chlorinated drinking water. The suppression of THMs was prominent with increasing ammonia concentration from almost zero to 5 mg N/L. However, the formation of THMs remain low and constant after ammonia addition over 5 mg N /L. A general correlation for predicting THM formation based on ammonia concentration is presented, and its predictions align well with the observed results, although it is specific to this study. Further research using a more diverse dataset is recommended. In water supply systems like Dhaka, where significant amounts of ammonia and other organic pollutants are present in river water-along with the perceived risk of THM formationcomprehensive studies should be undertaken to determine how to manage or utilize ammonia effectively during water treatment. One potential approach could be the controlled use of ammonia to form chloramine, which can act as a disinfectant in the treatment process.

Dissolved organic matter (DOM) in marine sediments is a complex mixture of thousands of individual constituents that participate in biogeochemical reactions and serve as substrates for benthic microbes. Knowledge of the molecular composition of DOM is a prerequisite for a comprehensive understanding of the biogeochemical processes in sediments. In this study, interstitial water DOM was extracted with Rhizon samplers from a sediment core from the Black Sea and compared to the corresponding water-extractable organic matter fraction (<0.4 lm) obtained by Soxhlet extraction, which mobilizes labile particulate organic matter and DOM. After solid phase extraction (SPE) of DOM, samples were analyzed for the molecular composition by Fourier Transform Ion-Cyclotron Resonance Mass Spectrometry (FT-ICR MS) with electrospray ionization in negative ion mode. The average SPE extraction yield of the dissolved organic carbon (DOC) in interstitial water was 63%, whereas less than 30% of the DOC in Soxhlet-extracted organic matter was recovered. Nevertheless, Soxhlet extraction yielded up to 4.35% of the total sedimentary organic carbon, which is more than 30-times the organic carbon content of the interstitial water. While interstitial water DOM consisted primarily of carbon-, hydrogen-and oxygen-bearing compounds, Soxhlet extracts yielded more complex FT-ICR mass spectra with more peaks and higher abundances of nitrogenand sulfur-bearing compounds. The molecular composition of both sample types was affected by the geochemical conditions in the sediment; elevated concentrations of HS -promoted the early diagenetic sulfurization of organic matter. The Soxhlet extracts from shallow sediment contained specific three-and four-nitrogen-bearing molecular formulas that were also detected in bacterial cell extracts and presumably represent proteinaceous molecules. These compounds decreased with increasing sediment depth while one-and two-nitrogen-bearing molecules increased, resulting in a higher similarity of both sample types in the deep sediment. In summary, Soxhlet extraction of sediments accessed a larger and more complex pool of organic matter than present in interstitial water DOM.

Dissolved organic matter (DOM) in marine sediments is a complex mixture of thousands of individual constituents that participate in biogeochemical reactions and serve as substrates for benthic microbes. Knowledge of the molecular composition of DOM is a prerequisite for a comprehensive understanding of the biogeochemical processes in sediments. In this study, interstitial water DOM was extracted with Rhizon samplers from a sediment core from the Black Sea and compared to the corresponding water-extractable organic matter fraction (<0.4 lm) obtained by Soxhlet extraction, which mobilizes labile particulate organic matter and DOM. After solid phase extraction (SPE) of DOM, samples were analyzed for the molecular composition by Fourier Transform Ion-Cyclotron Resonance Mass Spectrometry (FT-ICR MS) with electrospray ionization in negative ion mode. The average SPE extraction yield of the dissolved organic carbon (DOC) in interstitial water was 63%, whereas less than 30% of the DOC in Soxhlet-extracted organic matter was recovered. Nevertheless, Soxhlet extraction yielded up to 4.35% of the total sedimentary organic carbon, which is more than 30-times the organic carbon content of the interstitial water. While interstitial water DOM consisted primarily of carbon-, hydrogen-and oxygen-bearing compounds, Soxhlet extracts yielded more complex FT-ICR mass spectra with more peaks and higher abundances of nitrogenand sulfur-bearing compounds. The molecular composition of both sample types was affected by the geochemical conditions in the sediment; elevated concentrations of HS -promoted the early diagenetic sulfurization of organic matter. The Soxhlet extracts from shallow sediment contained specific three-and four-nitrogen-bearing molecular formulas that were also detected in bacterial cell extracts and presumably represent proteinaceous molecules. These compounds decreased with increasing sediment depth while one-and two-nitrogen-bearing molecules increased, resulting in a higher similarity of both sample types in the deep sediment. In summary, Soxhlet extraction of sediments accessed a larger and more complex pool of organic matter than present in interstitial water DOM.

The natural organic matter in the water continuously affects the treatment units due to their transformations. The NOM characteristics are complex, and it is challenging to clarify and remove the NOM in water. Due to the modifications of NOM during the disinfections, which results in the formation of by-products, their removal is problematic and causes adverse effects on human health. Several techniques are adopted to remove NOM from the water; one standard method involves coagulation and similar processes. The current review provides insights about the methods available for removing the natural organic matter and highlights the coagulation techniques that are gaining prominence in the current scenarios to remove the NOM from the various sources. Key Words: Coagulants, Coagulation, Natural organic matter, coagulating aids.

Natural organic matter (NOM) constitutes a significant contaminant in water sources, adversely affecting drinking water quality and complicating purification processes. To mitigate these contaminants, the current state of the application uses membrane filtration along with structural and surface modification of membranes. This study presents the development of polysulfone (PSU) flat-sheet ultrafiltration (UF) membranes, modified with three different concentrations of chitosan (0.05, 0.06, and 0.08 g), a natural polymer, to enhance NOM removal. The membranes were rigorously characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and water contact angle (WCA), porosity, and pore size analysis. Furthermore, the study delves into the interaction mechanisms between chitosan and the PSU polymer matrix, as well as the transport phenomena involved. The findings indicate that increasing the chitosan content from 0.05 to 0.08 g markedly enhanced the membrane's surface properties, reducing the contact angle from 72.8 • to 53.5 • and nearly doubling the permeation rate despite the decrease in porosity and pore size. The PSU UF membrane with 0.08 g chitosan demonstrated a superior humic acid (HA) rejection rate of 90 %, underscoring chitosan's potential for improving polymeric membranes in NOM removal applications.

Flow field flow fractionation (FlFFF), inductively coupled plasma-mass spectroscopy (ICP-MS), and transmission electron microscopy (TEM) coupled to X-ray energy dispersive spectrometry (X-EDS) are used in series for the first time to characterize colloids. Results demonstrate the utility of FlFFF-ICP-MS-TEM/X-EDS to relate physical properties (size) of colloids to their chemical properties (chemical composition, surface chemical composition, and colloids-trace elements association). Results suggest that the major part of natural organic matter (NOM) is concentrated in the fraction <0.01 µm (C2). Aluminum, iron, and manganese are the main colloidal components in the fraction 0.01-0.45 µm (C1). Aluminum occurs as aluminum oxides or aluminosilicates in the whole size range, while iron and manganese occur as individual oxyhydroxides in the size range <0.20 µm. Within the C2 fraction, Al, Mn, Cu, and Ni elements are complexed to NOM (e.g., humic substances). Iron is complexed to NOM in some samples and probably free in other samples. Lead is totally free in all samples. Within the C1 fraction, Cu and Pb are mostly associated to Fe and Mn oxyhydroxides. Consequently, NOM with Fe and Mn oxyhydroxides are the main colloidal carriers of trace elements in the Loire watershed system.

The present study was conducted to identify and examine locally available natural coagulant (Sorghum bicolor [NC]) and its blended form with chemical coagulant (alum) to treat turbid water. Blended form of NC was prepared by mixing different proportions of NC and alum. NC, alum and blended coagulant (NC B) were compared with each other to check maximum turbidity removal efficiencies. At optimum doses and pH, turbidity removal efficiencies by alum, NC and NC B were 97.9%, 93.2% and 98.96%, respectively. Also statistical analysis was performed for validation of results. Further, NC was characterized by Fourier transformed infrared test that confirmed the presence of protein-specific functional groups (medium, small and broad 1° and 2° amines, medium aliphatic amines and small saturated aliphatic groups) responsible for coagulation activity. Floc sizes were also observed through micro-photographic analyses of NC, alum and NC B were found out to be 19, 39 and 45 µm, respectively. In water treatment, NC B proved to be the best coagulant for turbidity removal and the coagulation mechanism observed was charge neutralization in it.

Today, many urban streams are under continuous pressure from human activities which take place in the adjacent built environment. These pressures are related to the change in the quality of the water, the alterations in the geometrical characteristics of the riverbed and the drainage capacity of the stream, while the biodiversity of these open pipelines is also affected. Streams in cities, besides their hydraulic role, may also serve other purposes to benefit the citizens living in nearby neighborhoods. In recent decades, an effort has been made to redefine the role of streams and to reintegrate them into the life of modern cities. The stream of Dendropotamos in the city of Thessaloniki, Greece, is a typical example of a degraded rainwater drainage system, partly converted to closed conduit. However, today the only function it performs is that of the drainage of rainwater, both from its mountainous hydraulic basin and from adjacent urban areas. The part of the stream that passes through a densely built area of Thessaloniki is the most degraded.
In this paper, we present the factors, which have affected and significantly degraded the stream of Dendropotamos. Moreover, we present indicative field measurements regarding the water quality, the geometric characteristics of the stream bed at selected points, as well as of the flow rate close to the stream outlet to the gulf of Thermaikos. In addition, emphasis is placed on the accessibility of the stream and its interaction with the surrounding area, which has also been significantly affected by the continuous degradation of the stream area.

Department of Civil Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah-711 103, West Bengal, India JIS Institute of Advanced Studies and Research (JISIASR), Kolkata-700 091, India E-mail: ray.soumya5@gmail.com Manuscript received online 08 January 2020, accepted 25 June 2020 Dissolved organic carbon (DOC) is produced from different anthropogenic activities and microbial activities on organic matter. TOC influences the production of carcinogenic disinfection by-product (DBP) at the time of disinfection during water treatment. This TOC is extremely hydrophilic in nature and difficult to separate from water by the conventional treatment procedures. Therefore, an integrated system is introduced to control TOC where a pre-treatment by electrocoagulation (EC) followed by adsorption with a nano-adsorbent made of reduced graphene oxide (fRGO) coated sand impregnated by iron was used. The pre-treatment reduced 38.19% of TOC whereas 99.3% of TOC was removed b...

Abstract: This study presents removal of residual natural organic matter (NOM) from drinking water by ultrafiltration (UF). Three different UF membranes were prepared by phase inversion technique and membranes were subjected to compaction followed by filtration, ...

High boron levels in drinking water can be toxic to humans. According to the WHO regulations (2011), the boron concentration should be reduced to less than 2.4 mg L-1 for drinking water. The aim of this study is to investigate the feasibility of coagulation-flocculation and electrocoagulation as a pre-treatment process to remove boron from natural water. Standard jar tests using coagulation and flocculation simulator were carried out to determine the effectiveness of chemical pretreatment for removal of boron. (MgCl2, 6H2O) was used as coagulation adjuvant in combination with optimum coagulant dose to observe their differential effects. To optimize the experimental conditions of boron removal, commercial flocculant was used. Afterward the performance of electrocoagulation process to remove boron was investigated by optimizing the experimental conditions, such as pHi, electrolysis time, initial conductivity of the solution ( i), and current density. Experiments were carried out with ...

Organic matter (OM), such as natural organic matter (NOM) in surface waters, and effluent organic matter (EfOM) in wastewaters causes many problems. For example, color, taste and odor derogate potable water quality, while the presence of endocrine disrupting substances and the formation of disinfectant byproducts (DBPs) are public health concerns. Over the years various analytical methods have been developed to characterize organic matter in natural and wastewaters. However, it remains difficult to determine the properties and characteristics of various OM constituents. Since all OM components in water have their own specific sizes, size distribution is a useful analytical tool to characterize complex OM. The results also enable the better interpretation of experimental results, the determination of future research directions, and the evaluation of the progress of investigations. This review presents the common analytical size distribution methods used to characterize OM present in waters and wastewaters.

Natural organic matter (NOM) is an important parameter in drinking water due to its roles as one of main precursors of trihalomethanes (THMs). The characteristic of NOM might be influenced by land use of catchment area. The present study aims to analyse the correlation between various NOM parameters and THMs, and physical characteristics of raw water. The effect of land use around the catchment is also presented. The samples were taken from Cikapundung river pond, which is used by the water company of Bandung City as raw water sources for drinking water. Geographic Information System (GIS) was applied to distinguish anthropogenic and natural land use around the water catchment. The samples were categorised as unfiltered samples and filtered samples to measure dissolved material. Turbidity and conductivity were measured to obtain the physical characteristics of water. NOM parameters were as of TOC, DOC, COD, UV254 and UV355. The turbidity and conductivity of water were 5-34.7 NTU and 132-306 µmhos/cm, respectively. COD was from 32 to 76.8 mg/L. TOC was between 4.22 and 6.92 mg/L. UV254 and UV355 ranged 0.15-0.38 cm-1 and 0.09-0.16 cm-1 , respectively. COD and conductivity correlated well in unfiltered (r = 0.923) and filtered sample (r = 0.995). In both unfiltered and filtered samples, UV254 were correlated with UV355 with r of 0.986 and 0.995 respectively. The results revealed that catchments area of the pond was possibly dominated by anthropogenic activities.

SummaryThe basic principles of the electrophoretic behaviour of humic substances (HS) still need to be systematically investigated. HS extracted from a Cryorthod (HS–1) and from an Haplumbrept (HS–2) were first fractionated by ultrafiltration to obtain two series of fractions of reduced polydispersity with a nominal mean relative molecular mass (M) of 7500, 20000, 40000, 75000 and 200 000 Da. Fractions extracted from the same soil behaved like an homologous series when tested by size exclusion chromatography, showing a linear relation of M with molecular size. When plotted against their mean M, the elution volumes of HS fractions extracted from the two different soils originated lines of different slope. Absolute electrophoretic mobilities of the fractions were determined in polyacrylamide gel slabs of increasing polyacrylamide concentration using a single buffer system; in all gels there was a close linear relation between the electrophoretic mobility and the logarithm of the mean ...

Chlorination is the most common disinfection method used in the drinking water production. Reactivity of chlorine with organic molecules could generate disinfection by-product (DBPs), which are harmful to the human health. Natural organic matter (NOM) is a complex mixture of chemicals existing in source water. Because of its complexity, it is conjectured that formation of many different DBPs can arise from the reaction of organic matter and a chemical disinfectant. This study used model compounds as NOM surrogates in order to reveal the specific organic fraction and DBPs formation potential removed by different coagulants. Model compounds, as an artificial sample, were made from a mixture of Suwannee River Humic Acid (SRHA), Suwannee River Fulvic Acid (SRFA), Bovine Serum Albumin (BSA), Alginic Acid (AA). Alum and FeCl 3 were used as coagulants. The samples were analyzed for organic parameters, such as total organic carbon (TOC), ultraviolet at 254 nm wavelength (UV 254), specific UV absorbance (SUVA), and organic fractionated by high performance size exclusion chromatograph with organic carbon detector (HPSEC-OCD). The concentration of trihalomethanes (THMs) and haloacetic acids (HAAs) was measured to present the DBPs formation. The results show alum and FeCl 3 removed biopolymer (Peak A), humic substances-like (Peak B, Peak C) at the same percentage, while low molecular weight acid and neutral (Peak D) showed a higher removal with alum than FeCl 3. HAAs removal led to a greater reduction than THMs removal, and FeCl 3 showed a higher removal than the alum coagulant. It indicated that alum and FeCl 3 coagulant have different ability in removing specific organic fractions, which are precursors of THMs and HAAs formation.

This review paper deals with the formation of disinfection by-products (DBPs). Water basin remains a wonderful chemical reactor that allows the occurrence of intricate secondary disinfection chemical reactions, forming several hundreds of DBPs at the same time with microorganisms killing. The kinetics of DBPs formation is tightly dependent on water physicochemical characteristics such as temperature, hydrophobic/hydrophilic fractions in natural organic matter (NOM), pH, and pretreatment. Reducing DBPs levels in drinking water is not a relevant measure as the newly-developed analytical techniques and the health-related research reveal that the tolerable DBPs' levels must be further decreased and would be detected at ng L-1 instead of μg L-1 scale. Furthermore, because of the fact that man is being exposed to DBPs concentrations in drinking water in his lifetime, there will be a cumulative effect of these toxic chemical products even at their more reduced concentrations. Hence, the removal of these chemical products is sought for and is considered a real challenge and the main objective of water treatment technology for mankind survival.

The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 265122. This publication reflects only the author's views and the European Union is not liable for any use that may be made of the information contained therein.

Both dissolved organic carbon (DOC) and iron play an important role in biogeochemical processes in lacustrine benthic environments. Moreover, recent evidence has shown that both substances can act as active reductants in the redox transformation of organic pollutants. This paper examines the nature and abundance of DOC and dissolved ferrous iron (Fe II) in porewaters from a sediment core collected in Green Bay, WI, USA. The concentration of dissolved Fe II and the abundance, absorbance at 280 nm (A 280 nm), molar absorptivities (e 280 nm), molecular weights, and polydispersities of DOC were measured as a function of depth in porewaters. Dissolved Fe II concentrations increased from 3.6 lM near the sediment-water interface to 163 lM at a depth of 11 cm, then gradually declined. The DOC distribution varied with sediment depth, with the greatest variation in porewater DOC content and properties occurring in the transitional zone between oxic and suboxic conditions. The down-core porewater DOC profile was characterized by an increase in DOC concentration with depth from 0.64 mM OC at 1 cm to 1.23 mM OC at 13 cm, below which it remained relatively constant. A strong correlation was observed between Fe II and DOC concentrations, suggesting that these constituents co-accumulate in these porewaters. The correlation between the DOC concentration of the porewaters and A 280 nm was significant, making this parameter a good predictor for DOC concentrations in these waters. The molecular weight distributions of the porewater DOC were primarily monomodal, with relatively low polydispersivities. Weight-average molecular weights ranged from 1505 to 1949 Da. This data set is unique in that it is the first detailed study of a relatively highly resolved DOC profile of benthic porewater in surficial sediment from the Laurentian Great Lakes.

This paper reports on a study of calcium carbonate (CaCO 3) precipitation potentials of cooling water (CW) at Eskom power stations. It is important to understand the complexation reaction between calcium and dissolved organic carbon (Ca-DOC) because the natural organic matter (NOM) affects the precipitation potentials of CaCO 3. Secondly, it is necessary to understand the nature of the organic matter in the cooling and raw water. This study was carried out in raw and cooling water samples collected from Lethabo and Kriel power stations. These power stations obtain their cooling water from the Vaal River and Usuthu schemes, respectively. The DOC concentration in both water systems was higher in winter (little/no rainfall) as compared to spring (more rainfall). Specific ultraviolet absorption (SUVA) was calculated for the raw and cooling water for both stations. The SUVA results obtained for the raw water (RW) indicated that the NOM had a high degree of aromaticity (humic substances), whereas for the recycled CW the NOM present was found to be less aromatic. The Visual MINTEQ data for the winter sampling indicated that both Lethabo and Kriel were supplied by raw water that was under-saturated with respect to CaCO 3 , with saturation indices (SI) of −0.29 and −0.43, respectively. In addition, the % Ca-DOC in the raw water at Lethabo was 2.01 compared to 3.08 in the raw water at the Kriel plant. Therefore this study gives an indication that % Ca-DOC is one of the factors that affect the CaCO 3 precipitation potentials. The difference in SUVA-254 values for both stations has been identified and requires further investigation. The SUVA values help in identifying the type of fractions that make up the NOM. The interaction between calcium/magnesium and NOM determines the potential for CaCO 3 to form scale in condenser tubes carrying cooling water in the power generation plants at Eskom.

Water containing natural organic matter (NOM) has adverse effect on the aesthetic water qualities, and may cause some problems in water treatment processes. The aim of this research is to assess the changing of fluorescence dissolved organic carbon by using Fluorescence Excitation Emission Matrices (FEEMs) analysis through Parallel Factor (PARAFAC) modelling. In addition, this study purposed to examine the correlation between organic fluorescence with bulk parameters concentration, such as dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm (UV254), and specific UV absorbance (SUVA) during water treatment processes. The results show humic-like compound, such as tryptophan-like and fulvic acids-like are the two major organic components contained in the water. Organic matter fluorescence identified that fulvic acid-like shows a higher removal than aromatic protein-like. The correlations of organic fluorescence are higher with DOC than with UV254 and SUVA value. Combinatio...

Elevated concentrations of heavy metals in groundwater are one of the
common water quality issues due to the anoxic and reductive conditions in groundwater. In addition, high NOM content in groundwater decreases the water aesthetic value and develops disinfection by-products when reacted with disinfectants. Such abstracted groundwater prior to any treatments is not suitable for consumption due to the elevated concentrations of contaminants that affect its acceptability and chemical
aspects. This paper aims to assess the groundwater quality abstracted from a tubewell located in Universiti Sains Malaysia, Pulau Pinang. This study also evaluates the potential of metakaolin as an absorbent for nickel and NOM’s adsorption. In average, the selected groundwater samples contain high concentration of contaminants, namely iron (615.4 µg/L), manganese (444.0 µg/L), nickel (174.6 µg/L) and NOM (as measured in UV254: 1.23 cm−1). The anoxic and circumneural characteristics of the groundwater are known to be the governing factors for these contaminants’ concentrations. The removals of nickel and NOM were achieved at approximately 35% and 22%, respectively, with an optimum value of dosage of 14 g. The high ionic strength and competitive adsorption in a multi-solute system have been recognised as the limiting factors. The optimum contact time for these removals was 120 min.

Dissolved organic matter (DOM) in 6 water samples collected from 4 surface waters were fractionated using some or all of 5 physicochemical separation processes (activated carbon and XAD-8 batch adsorption, alum coagulation, ultrafiltration (UF), and XAD-8 column fractionation). Activated carbon, XAD-8 batch adsorption and alum coagulation processes fractionated DOM by preferentially removing high-SUVA components from solution. The XAD-8 column method fractionated DOM into hydrophobic and hydrophilic ...

Adsorption of gallic acid from water onto Natural Quartz Sand, (NQS) (Left) and onto Goethite-Coated Natural Quartz Sand, GCQS (Right). Adding small amount of goethite to NQS leads to a several fold increase of the gallic adsorbed amount (Right). : Negative charge

This work aims to study the physicochemical and biological parameters of Boukerdene Dam's water and treated water at different steps of the treatment processes in Sidi-Amar's Station (Tipaza, Algeria) with a particular interest to the phytoplankton. This work is also related to the demonstration of the enhanced coagulation (EC) process as an efficient method in algae and organic matter (OM) removal from surface water by its application in jar tests. The diversity of the phytoplankton shows the presence of 21 genera comprising 30 algae species out of 8 samples taken from the Boukerdene Dam. Among the identified genera, seven of them are responsible for the unpleasant tastes and odours of water; six others are responsible for filter fouling. Generally, the conventional drinking water treatment processes employed at this water treatment plant shows a limited efficiency of OM and algae removal. The novelty of this work is that the jar tests of EC (pH 6 and alum dose 15 mg L-1) as only one stage of water treatment, without chlorination and filtration, improve the removal of OM and algae at 97 to 99%, respectively.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

This paper describes a laboratory study comparing three coagulants (alum, ferric chloride, and ferric sulfate) to determine which coagulant would not only remove NOM but DBP precursors as well. Experiments were conducted to compare the effectiveness of three coagulants in removing DBPs precursors from raw water samples. The results show that the removal of total organic carbon (TOC) which is mean NOM here, was dependent on the coagulant type and was enhanced with increasing coagulant dose, but ferric chloride, and ferric sulfate have no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum and ferric sulfate at similar doses and the mean values of treatment efficiencies were 30%, 37%, and 45% by ferric sulfate, alum, and ferric chloride respectively. The range of TOC removal rates obtained using ferric sulfate (18-48%), (14-50%) for alum, and (21-59%) for ferric chloride. F...

Recent studies have shown that NF membranes can effectively remove natural organic matter (NOM). However, NOM also serves as an organic foulant to membranes, resulting in flux decline. In this study, the flux decline of NF membranes was analyzed through the transport characterization of NOM in NF membrane pores. The transport of NOM through NF membrane pores was influenced by either convection or diffusion, depending on the applied hydrodynamic operating conditions, as represented by the ratio Jo/k (Jo represents the initial pure water flux, and k is the mass transfer coefficient) [ 1]. Different behaviors of flux decline, and flux recovery of tested membranes could be obtained: depending on which transport mechanism (either convection or diffusion) dominates during NOM filtrations. The removal (or rejection) behavior of NOMs, by NF membranes, was evaluated with respect to the ratio Jo/k under a dominant transport condition, along with the performance of the flux decline effects.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

This paper reviews the various methods available for removing planktonic microalgae (microstraining, direct ®ltration, sedimentation,¯otation, polishing using ozonation and granular activated carbon [O 3 +GAC], membrane ®ltration), and discusses their comparative eectiveness, optimisation and limitations. Also described are the treatments considered most eective in the removal of odorous and/or toxic metabolites. In each case French technology and its worldwide applications are compared to those documented in the literature. The article concludes with recommendations on the most appropriate processes for treating eutrophic waters.

This paper discuss about the role of Graphene oxide [GO] in wastewater treatment. The increasing level of water consumption and water contamination by industrial sector is the big problem that needs to be solved. From different methods of wastewater treatment adsorption proved to be simple and economical. The properties and structure of GO are suitable for adsorption of contaminants. Different methods for synthesis of GO are available. Textile industry is primary target due to volume of discharge and contaminants present. Then performance of GO to treat effluent at different concentrations, different pH range and kinetic study. Next section focus on the applications of GO and the major challenges. Finally conclusion of research.

Abstract: This study presents removal of residual natural organic matter (NOM) from drinking water by ultrafiltration (UF). Three different UF membranes were prepared by phase inversion technique and membranes were subjected to compaction followed by filtration, ...

Meta-material is a word made of two parts; ‘meta’ meaning beyond and ‘materials’. They are materials engineered to exhibit properties which are not found in nature. They are made from assemblies of multiple elements fashioned from composite materials such as metals and plastics. The structural elements of these materials are arranged in repeating as well as non-repeating patterns. Meta-materials derive their properties from the base metal i.e., chemical composition as well as from their newly designed structures. Their precise shape, geometry, size, arrangement and orientation give them their smart properties capable of manipulating, absorbing, enhancing as well as bending waves ranging from acoustics to electromagnetic waves to achieve benefits that go beyond what is possible with conventional materials. Metamaterial research is an interdisciplinary field and involves various engineering domains such as electrical engineering, mechanical engineering, material science, solid state p...

Natural organic matter (NOM) seriously challenges the drinking water supply. It typically exists as complex organic substances generated in the natural water ecosystem as part of hydrologic, biological, and geological cycles. The significant variation, composition, and abundance of NOM in natural water or wastewater necessitate the implementation of robust and adaptive technologies, particularly in addressing even more stringent standards of drinking water supply or treated water discharge. Coagulation is one of the most common processes for water and wastewater treatments. It is highly desirable to treat feed containing NOM because it prevents the disinfection of by-products formation. Therefore, current dynamics of NOM in terms of varying compositions and concentrations demand improvement in handling the coagulation process through optimization of operational parameters (dosing and the control of pH), application of novel and more effective coagulants, and as a combination with ot...

Monocrotophos (MCP) and chlorpyrifos (CPS) are most popular and broadly used organophosphorous pesticides owing to its low cost and high efficiency in controlling pests in agriculture. Presence of pesticides in aquatic environments causes serious problems to human beings and other organisms. Photocatalytic degradation has been proved to be a promising method for the treatment of water. In view of this, TiO 2 photocatalyst was prepared by sol-gel method and characterized by SEM with EDAX, XRD, BET and FTIR. The photocatalytic degradation of MCP and CPS was carried out using prepared TiO 2 photocatalyst irradiated with 16 W UV light source. The effect of various parameters, i.e., photocatalyst concentration, pesticide concentration and pH of the solution on the percentage of degradation of selected pesticides had been examined. The kinetic analysis of photodegradation of MCP and CPS under different initial concentration followed the Langmuir-Hinshelwood model. TiO 2 found to be an excellent photocatalyst for the degradation of MCP and CPS under UV light irradiation.

The dinoflagellate, Ceratium hirundinella (C. hirundinella) cells are known to cause many problems when source water due for purification contains relatively high concentrations. The objective of this study was to investigate strategies for the effective and simultaneous removal of turbidity and C. hirundinella cells using turbidity and total photosynthetic pigments (TPP) as indicators of appropriate coagulant dosages during conventional drinking water purification. Source water samples with low turbidity, and high number of C. hirundinella cells were collected. A laboratoryscale conventional water purification plant was used to simulate coagulation, flocculation, sedimentation and sand filtration. Various coagulant options were dosed as part of conventional coagulation. The coagulant option Ca(OH) 2-organic polymer achieved the best removal of both turbidity (50%) and C. hirundinella cells (75-82%) after sedimentation using TPP as an indicator. Ca(OH) 2-SiO 2 and organic polymer alone achieved better removal of C. hirundinella (57-75%) and turbidity (33-50%) respectively when TPP was used as an indicator rather than turbidity. Sand filtration removed the remaining turbidity and C. hirundinella cells from the supernatant completely. Implementing new purification strategies may increase treatment costs, but the focus of drinking water purification utilities should always be primarily the production of safe and aesthetically acceptable drinking water.

Increasingly stringent regulations for drinking water quality have stimulated the application of ultrafiltration to water treatment. In addition to removing particulate materials from water (including microorganisms, bacteria and viruses), the use of membrane treatment also meets purification requirements. However, irreversible fouling curtails the economic viability of such a process. Experiments in stirred-cells were conducted to evaluate the effects of surface water composition on rejection and fouling of two ultrafiltration membranes with different molecular weight cutoffs (10kDa and 100kDa). Experimental solutions consisted of natural organic matter or humic substances in a background electrolyte. The effect of calcium concentration decreased rejection of humic acid under certain circumstances. This is believed due to reduced molecular size with an initial increase in calcium concentration. However, at about 2.5mM CaCl 2 , IHSS humic acid aggregates. This aggregation increased rejection, and also caused irreversible fouling of the 100kDa membrane, presumably as a result of pore size reduction due to internal deposition of aggregates. This was confirmed by blocking law analysis. The variation of transmembrane pressure indicated the importance of a 'critical flux' effect. The organics and their various fractions showed differences both in rejection and flux decline. The larger and more UV-absorbing fraction of humic acid was shown to be responsible for irreversible pore adsorption and plugging. The fulvic acid and the hydrophilic fraction showed a smaller and mostly reversible flux decline.

Surface waters contain colloids and natural organic matter, largely composed of humic substances. In this work the effect of natural organic matter (NOM) and humic substances (IHSS stream humic and fulvic acid reference material) on the deposition and rejection of inorganic colloids (hematite) by GVWP and GVHP microfiltration (MF) membranes was studied. Parameters of interest were solution pH, ionic strength, calcium concentration, primary colloid size (75, 250 and 500 nm), organic type and concentration, as well as membrane type and hydrophobicity, aggregate structure and colloid stability. The method of preparation of the equilibrated suspensions, and thus their aggregation state, had a large influence on the rejection of the colloids and their aggregates, as well as the association of the particles with the membrane material and flux decline. The systems studied were grouped into (a) organics in the absence of inorganic colloids, (b) stable primary particles, (c) primary particles at pH extremes with organics, (d) particles pre-aggregated in electrolyte solution prior to adsorption of organics (SPO), and (e) particles stabilised with organics (OPS). Extreme pH conditions and pre-adsorption of organics onto the particle surface created very stable systems (colloids retained their primary particle size) and the deposition of the colloids at the membrane surface was reduced significantly. This lead to a penetration of the particles into the pores and adsorption on the pore walls leading to full rejection in the absence of organics. Flux decline was in this case dependent on colloid size, with the size closest to the membrane pore size causing the greatest flux decline. In the presence of organics, membrane-colloid charge interaction and adsorption were reduced and rejection decreased to near zero for these stable colloid systems. For aggregates the presence of organics lead to a greater flux decline. Rejection of colloids was complete, now determined by the large size of the aggregates formed, which also indicates great mechanical stability of these aggregates. Calcium played a key role in flux decline of all systems. In the absence of hematite, calcium contributed to organic aggregation and increased flux decline. Calcium lead to an increased flux for hematite aggregates (SPO) presumably due to the formation of looser aggregates and a decreased flux for stable colloid-organic systems (OPS) due to destabilisation of these systems.

Soil degradation processes due to intensified agriculture may be counteracted by an extended knowledge on soil humus dynamics at molecular level. Here we show that the molecular composition of the soil Humeome changes substantially after 1 and 3 years of conventional tillage under maize cropping. Application of Humeomics sequential chemical fractionation not only separated from soil more than twice the organic carbon extracted by traditional methods, but also enabled to identify ten times more molecular structures using GC-MS and high-resolution ESI-Orbitrap-MS. The fine molecular description of the soil Humeome revealed a decrease of soil organic matter (SOM) hydrophobic protection with prolonged tillage and a potential loss of small nitrogen-rich compounds. We showed for the first time an abundance of heterocyclic nitrogen compounds which are persistent in SOM due to a This article is protected by copyright. All rights reserved. covalent binding to soil iron. The formation of organo-Fe complexes appeared not only as a major mechanism of molecular stabilization of SOC but also as an adsorption substrate for other nitrogen-rich soil components. The detailed molecular insight of SOM composition reached by Humeomics, may become the key to develop new technologies for the control of soil carbon.

The global paucity of water resources and the degradation of water quality have necessitated a need for the restoration of water bodies for the last two decades. Due to increasingly stringent requirements in quality, reliability, economics and sustainability, treatment of polluted water employing traditional technologies has become a formidable challenge many a time in meeting the desired goals. Green technologies are identified as a sustainable method that can boost social and economic growth, conserve natural resources and reduce detrimental impacts on the environment and social wellbeing. However, less effort has been made to render a comprehensive overview from the perspective of the real-world application of these technologies and their underlying mechanisms. This review attempts to provide a critical insight into the frugal and eco-friendly technologies under three groups viz. microbial technologies, bio preparations and integrated eco-technologies by considering various factors such as optimum operating conditions, underlying mechanisms, efficiency, techno-economic viability, and potential challenges. Among these, integrated ecotechnologies have shown the best performance for the removal of a wide range of pollutants in the real-world scenario. These are superior in ensuring the consistency and durability of the efficacy of the systems. The present review is expected to aid in the selection of appropriate technologies for surface water rejuvenation under varying conditions and would lead to an addition in the existing knowledge base on surface water remediation methods enabling further research in this domain.

Potential problems arising from the presence of cyanobacteria in water intended for human consumption have been reported by several researchers. Regarding water treatment plants, intact cells of cyanobacteria should be removed to avoid the release of cyanotoxins due to cell lysis. Water treatment techniques with different degrees of complexity can be employed but, whenever possible, the method of easiest installation, operation and maintenance should be selected, especially for non-industrialized countries and rural communities. In this context, research was carried out to evaluate the efficiency of slow sand filtration to treat water from Gavião reservoir in the city of Pacatuba, Ceara, Brazil, which has exhibited phytoplankton density of approximately 105 cells/mL with a prevalence of cyanobacteria representing over 90% of total cells. The results have demonstrated that slow sand filtration can be used to achieve water purification that meets federal standards. However, it was est...

Background: This study aims was to assess the water quality and efficiency of the Ouled Mellouk dam treatment plant (North Western Algeria). This plant consists of conventional water treatment units, like other treatment plants in Algeria, these were coagulationfloculation, sedimentation, filtration and disinfection. Methods: The study was based on analyzes and monitoring of the main physico-chemical and bacteriological parameters of raw and treated water monthly from January to December 2018. Result: Raw water has relatively high hardness (49F). Turbidity was high (23.93 NTU), manganese has a max of 0.407 mg/l.These values exceeded the Algerian standards limits. Nutrients and organic matter were in increase and coliforms were present with high levels. All analysed parameters were in decrease in treated water, with the exception of sulphate which was in increase and they were within the Algerian standards. The plant has a moderate removal efficiency of 48%, with a high removal effeciency of coliforms (100%), of turbidity (94.62%) and manganese (88.69%).

Green Chemistry is the design, development, and implementation of chemical products and processes to reduce or eliminate the use and generation of substances hazardous to human health and the environment. It is an innovative, non-regulatory, economically driven approach toward sustainability. The unequivocal value of Green Chemistry to the business and to the environment is illustrated through industrial examples. Green Chemistry must be recognized for its ability to address sustainability at the molecular level. By designing for sustainability at this fundamental level, Green Chemistry challenges innovators to design and utilize matter and energy in a way that increases performance and value while protecting human health and the environment. The principles of Green Chemistry today need to become the core for tomorrow's chemistry, integrating sustainability into science and its innovations.

The objective of this project is to create clean fuel for transportation using hydrogen powered by solar energy. Hydrogen has been generated by solar photovoltaic (PV) array and then collected for data analysis to demonstrate efficiency of the hydrogen production in all the steps of the experiment. The hydrogen produced from the electrolysis process was either stored in a metal hydride canister or directly fed into Proton Exchange Membrane (PEM) Fuel Cell to generate electricity. A hydrogen fuel cell remote control car has successfully designed, and demonstrates at least one hour operation per hydrogen charging at room temperature.

The Cipageran Water Treatment Plant (WTP) is one of water treatment plants managed by PDAM Tirta Raharja, Bandung Regency, which supply drinking water for Cimahi District and Central Cimahi Subdistricts with an average production capacity of 169 L/sec. This research aims to evaluate the performance of the operating unit and process in Cipageran WTP and provide optimization recommendations based on evaluation results. The steps in this research include evaluated the existing conditions of Cipageran WTP, providing recommendations on the results of evaluations and analyzing the quality of the production of Cipageran WTP. From the results of Cipageran WTP evaluation, there were several parameters that did not fulfil the design criteria which were Gtd on coagulation, NFr values on sedimentation and backwash rate on filtration. The evaluation result of maximum discharge in intake was 400 L/second, coagulation of 210 L/second, flocculation of 210 L/second, sedimentation of 270 L/second and...

To prevent the concentration of water pollution, efficient safety measures have be employed that prevent point-source and nonpoint-source pollution. Green chemistry solutions should be employed, where it is possible. An effective way to deal with the water pollution problem is to use the least harmful ways to prohibit contaminants. Chromatography methods and separation chemistry principles offer a variety of encouraging methods to attain these attainable goals. Proper remediation has been provided to aid correct contamination of groundwater, which affects nearly hundred million people worldwide. A variability of novel methods has been included for prevention and remediation of water pollution that occasion radical reaction and the utilization of advanced nano-based techniques. This current paper is mainly focusing on current aspect of water pollution control strategies with green chemistry.

Background: This study aims was to assess the water quality and efficiency of the Ouled Mellouk dam treatment plant (North Western Algeria). This plant consists of conventional water treatment units, like other treatment plants in Algeria, these were coagulationfloculation, sedimentation, filtration and disinfection. Methods: The study was based on analyzes and monitoring of the main physico-chemical and bacteriological parameters of raw and treated water monthly from January to December 2018. Result: Raw water has relatively high hardness (49F). Turbidity was high (23.93 NTU), manganese has a max of 0.407 mg/l. These values exceeded the Algerian standards limits. Nutrients and organic matter were in increase and coliforms were present with high levels. All analysed parameters were in decrease in treated water, with the exception of sulphate which was in increase and they were within the Algerian standards. The plant has a moderate removal efficiency of 48%, with a high removal effeciency of coliforms (100%), of turbidity (94.62%) and manganese (88.69%).

h i g h l i g h t s Recent R&D studies in the field of NOM removal by coagulation are overviewed. Various metallic and polymeric coagulants are included. Biocoagulants are promising alternatives to conventional metal-based coagulants. Novel composites are enabling efficient NOM removal from drinking water supplies. Coagulation-based integrated processes for improved efficiency and resilience.

Carbon nanomaterials are effective adsorbents for water treatment. This study examines natural organic matter (NOM) removal from drinking water with combined coagulation processes using single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs). Conventional coagulation using aluminum sulfate (alum) and ferric chloride (FeCl 3) was also conducted using Ulutan Lake water (ULW) samples collected in four seasons. The removal was characterized by ultraviolet absorbance at 254 nm (UV 254) and dissolved organic carbon (DOC). The proposed process was more effective than using alum and FeCl 3. The highest removal occurred for FeCl 3 with SWCNTs in winter (94.13% DOC and 96.14% UV 254). In spring and fall, DOC (90% and 84.63%) and UV 254 (95.87% and 88.8%) removal was highest when using FeCl 3 with MWCNTs. The DOC removal was lowest in summer (67-71% for alum and 72-79% for FeCl 3). Summer UV 254 removal was similar to DOC removal for combined coagulation. Hydrophobic NOM in winter ULW samples is more easily removed by SWCNTs than by MWCNTs, while MWCNTs were more effective in other seasons. The results reveal that the proposed process is more effective than the conventional coagulants alone in different seasons.

To prevent the concentration of water pollution, efficient safety measures have be employed that prevent point-source and nonpoint-source pollution. Green chemistry solutions should be employed, where it is possible. An effective way to deal with the water pollution problem is to use the least harmful ways to prohibit contaminants. Chromatography methods and separation chemistry principles offer a variety of encouraging methods to attain these attainable goals. Proper remediation has been provided to aid correct contamination of groundwater, which affects nearly hundred million people worldwide. A variability of novel methods has been included for prevention and remediation of water pollution that occasion radical reaction and the utilization of advanced nano-based techniques. This current paper is mainly focusing on current aspect of water pollution control strategies with green chemistry.