Loss Of Chlorine Research Articles

Unveiling the Role of Additive Molecular Characteristics in Regulating Chlorine Loss and Phase Distribution for Blue Perovskite Light‐Emitting Diodes

Unveiling the Role of Additive Molecular Characteristics in Regulating Chlorine Loss and Phase Distribution for Blue Perovskite Light‐Emitting Diodes

Compatibility of Dual Rinse 1-Hydroxyethane-1,1-Diphosphonic Acid with Sodium Hypochlorite Solutions Containing Proprietary Additives

IntroductionA salt of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) was commercialized some years ago. This so-called Dual Rinse (DR) HEDP has been tested for its combined actions and interactions with pure sodium hypochlorite (NaOCl) solutions. The aim of this study was to assess DR interactions with NaOCl solutions containing proprietary additives. MethodsDesignated endodontic NaOCl solutions that come at 2 different strengths (2% and 5.25%), and without or with additives (Chloraxid and Chloraxid Extra, respectively) were tested. Some of their key chemical and physical properties were determined in the presence or absence of HEDP (9%) in the solution. In addition, soft tissue dissolution efficacy of test and control solutions was assessed in extracted teeth (n = 10 per group, 90 teeth in total). ResultsThe NaOCl content in the 2% Chloraxid solutions was slightly above, that in the 5.25% solutions below the labeled concentration. The additives in the Chloraxid Extra solutions neither altered their surface tension nor their viscosity. The addition of HEDP to any of the tested NaOCl solutions reduced their pH, and increased their surface tension and viscosity. HEDP-induced available chlorine loss over the first hour was similar between all NaOCl solutions. Soft tissue dissolution in the root canals was affected by NaOCl concentration, but neither by any proprietary NaOCl additive in the Chloraxid solutions, nor the addition of DR HEDP. ConclusionsProprietary additives had no influence on any of the tested parameters, including surface tension of the "Extra" solutions. The increased viscosity of combined NaOCl/HEDP solutions deserves further attention.

Modeling Nicotine-Induced Chlorine Loss in Drinking Water Using Updated EPANET-MSX.

Multispecies water quality modeling is critical for simulating complex chemical reactions in drinking water distribution systems. An updated EPANET 2.2-compatible version of EPANET multi-species eXtension (EPANET-MSX) was used, which included dispersion and improved mass balance reporting, to simulate an experimental study. The use of EPANET-MSX was supplemented by an automated Python script to process experimental data, handle model execution, and analyze results. Nicotine-associated chlorine loss in drinking water-initially investigated from a drinking water security perspective-modeled with EPANET-MSX was compared with bottle test and test injection data. Two reaction models were tested (with and without a reactive intermediate), and the model that included a reactive intermediate nicotine species using dispersion was found to produce the best model agreement with experimental data. These results provide a demonstration of the new features within EPANETMSX in the context of the nicotine-chlorine reaction.

Shipboard Observations of Aerosol Chemical Properties Over the Western Pacific Ocean in Winter 2018

AbstractBased on a shipboard observation conducted in winter 2018, we reported the aerosol chemical properties and their differences in offshore and remote oceans over the Western Pacific Ocean (WPO). It's found that the chemical compositions over the WPO have significant spatial heterogeneity due to the influences of regional transport of anthropogenic aerosols and long‐path transport of dust aerosols. The average concentration of water soluble ions during the whole sampling period followed Cl− > OC > Na+ > > > Ca2+ > Mg2+ > EC > K+ > . Crustal elements of Ca (980.41 ng/m3), Na (971.55 ng/m3), and Al (781.16 ng/m3) were uniformly distributed in offshore area, but high proportion of Na elements dominated in remote regions. The total concentration of heavy metals including Zn, Cu, Cr, Pb and others originating from anthropogenic sources were 208 ng/m3 along the coastal region, about 10 times higher than that of 20.2 ng/m3 in the offshore and remote seas. For the reconstructed components, we found an increase of sea‐salt aerosol ranged from 3% to 72%, and a decrease of black carbon, organic matter and secondary inorganic salts, indicating a transformation from anthropogenic influence to marine environment. The rapidly increased secondary organic matter during dust event revealed that the transport of dust serves as catalysts to promote multi‐phase reactions. Cl− photochemical reaction rate in offshore area was mainly affected by sulfate from anthropogenic emissions, with an average chlorine loss rate of 18%, whereas it was inverse Cl− excess in the remote oceans.

Possibility of condensation of nitric acid for cloud condensation nucleus in the summer at Mt. Fuji

We carried out measurements of size-segregated ionic and elemental components of aerosols at the Mt. Fuji, Japan, in the summers of 2013 and 2015. We studied aerosol chemistry in the free troposphere (FT). We investigated ratios of elements and the transformation of nitrate in long-range transported air pollution (LRTAP) mixed with domestic air pollution (DAP). We distinguished aerosols from LRTAP during daytime (D) and nighttime (N) and DAP (D) at a relative humidity of 80% based on CALIPSO satellite, back-trajectory analysis, volatile organic carbon (VOC) tracers, and elements. We identified the sources of LRTAP and DAP. DAP containing Zn and high concentrations of biogenic VOCs (BVOCs) was transported by valley winds from and forests near the foothill of the mountain. The contribution of BVOCs and secondary organic aerosols (SOAs) from the forest was high in FT. LRTAP containing high concentrations of VOCs and Pb was transported from China. The contribution of SOAs in LRTAP (N) was higher at Mt. Fuji than at a remote site in Okinawa. A comparison of chlorine loss in this study with the remote site revealed that HNO3 was absorbed in coarse particles in LRTAP (D) from urban sites when LRTAP (D) was mixed with DAP. When (NH4) 2 NO3 was degraded to NH3 and HNO3 during transport to Mt. Fuji, the high excess-HNO3 was absorbed in the aqueous phase without neutralization. This result indicates that nitrate can be enriched during cloud processes when LRTAP (D) is mixed with DAP.

Predicting chlorine demand by peracetic acid in drinking water treatment.

Peracetic acid (PAA) may be used in drinking water treatment for pre-oxidation and mussel control at the intake. PAA may exert a downstream chlorine demand, but full details of this reaction have not been reported. There are three possible mechanisms of this demand: (1) PAA may react directly with chlorine; (2) PAA exists in equilibrium with hydrogen peroxide, which is known to react with chlorine; and (3) as H2O2 reacts with chlorine, PAA will hydrolyze to form more H2O2 to re-establish PAA/H2O2 equilibrium, thereby serving as an indirect reservoir of chlorine demand. While the H2O2 reaction with chlorine is well known, the other mechanisms of possible PAA-induced chlorine demand have not previously been investigated. The observed molar stoichiometric ratio of PAA to free chlorine (n) for the presumed direct PAA+free chlorine reaction was determined to be approximately 2, and the corresponding observed reaction rate coefficients at pH 6, 7, 8, and 9 were 2.76, 3.14, 1.61, 10.1 M-n·s-1, respectively (at 25°C). With these estimated values, a kinetic model was built to predict the chlorine demand by PAA. The results suggest that chlorine demand from PAA is likely to be negligible over the course of several days (e.g., < 20% chlorine loss) for most conditions except for high pH (e.g., >8) and high PAA:Cl2 molar ratios (e.g., >2:1).

Novel insight of the thermal degradation kinetics, environmental impact and transformation behavior of heavy metals and chlorine of municipal solid waste incineration fly ash in nitrogen

Thermal treatment is an effective method to dispose of municipal solid waste incineration (MSWI) fly ash (FA), however, present research mainly focuses on the thermal behavior of FA in air, neglecting the investigation of FA pyrolysis characteristic in inert gases. The weight loss, phase transition, environmental impact, and conversion behavior of heavy metals and chlorine during the FA pyrolysis in N2 were measured using TG-FTIR-XRD-ICP-IC to increase understanding of the transformation process and decomposition features of FA in inert gas. The results demonstrated that CO2, NO, C-O(H), HCl, SO2, and H2O are emitted during FA pyrolysis due to the decomposition of inorganic salts and organic compounds. After being roasted at 1200 °C, the volatilization rates of As, Cr, Cd, Cu, Pb, and Zn were 56.71%, 34.75%, 99.56%, 83.41%, 96.22%, and 97.19%, respectively. However, the removal rate of Cl was only 51.43%, owing mostly to the formation of Ca2SiO4CaCl2 at high temperatures, which hampered chlorine volatilization. The kinetic of FA pyrolysis was investigated using FWO, KAS, and CR methods at heating rates of 10, 20, 30, and 40 °C/min, which suited the experimental data of each stage well. Chemical reaction (No. 2), assumed random nucleation and its subsequent growth (No. 11), and three-dimensional diffusion and spherical symmetry (No. 21) were the reaction control procedures of stages I, III and IV, with activation energies of 54.04, 213.03 and 280.85 kJ/mol, respectively. The degradation kinetics, environmental emissions, and reaction mechanisms of FA pyrolysis in the N2 atmosphere can provide a novel insight for pollution reduction and process optimization.

A new absorbent system for reducing chlorine gas escape and enhancing pollutants removal during ship exhaust wet scrubbing

Using chlorine-containing oxidants to remove pollutants in the exhaust gas of ships is normally accompanied by Cl2 escape, which poses a significant threat to the environment and the health of the crew. This paper proposes a method to solve the problem of Cl2 escape in a single NaClO solution system using BAD (a new amide absorbent, C12H25NO). The electrostatic potential (ESP) theoretical calculations, FT-IR and UV–vis spectra tests showed that the strong field effect interaction between BAD and Cl2, which can form a stable symmetrical structure similar to a “sandwich”, results in a strong binding ability of BAD to Cl2. The effects of the initial pH, the concentration of NaClO solution, aeration time, and some operating parameters on the loss of active chlorine (AC) components were studied. Under the same conditions, a two-phase composite absorbent system with the addition of BAD can reduce the loss of AC components by 32.67% on average and up to 56.12%. It also can effectively capture the Cl2 escaping with the gas flow and keep it in the system, which enhances the oxidation of NO by Cl2 at the gas–liquid interface. It also has a strong ability to remove pollutants for a long period, as the removal efficiencies of SO2, NO, and NOx within 20 mins were 97.84%, 77.98%, and 76.01%, respectively. The results show that the BAD-NaClO two-phase composite absorbent system can effectively reduce Cl2 escape, and it is a sustainable wet treatment scheme for ship exhaust gas with great application prospects.

Effects of storage conditions on superoxidised water

Superoxidised water (SOW) in the food industry has several advantages over traditional chemical disinfectants. SOW is non-toxic and environmentally friendly and does not leave any harmful by-products. In addition, SOW is easy to use and can be applied to various food surfaces. SOW has been used to avoid the food industry's biological pollution caused by food-borne bacteria pathogens with recognized as a short producing time and evident in the sterilization process, SOW is highly recommended for its eco-friendly ability. Chlorine-containing solutions such as SOW are used for broad disinfection purposes, including in the food industry. Still, their effectiveness and stabilities often need to be investigated as residues such as chlorine in SOW are not stable. The efficacy of SOW can be easily affected by several factors, including pH, temperature, and organic matter content. In this study, the two different storage conditions influenced by the light exploration were used to investigate the light condition that directly impacts the chlorine level in SOW. Light intensity plays an important role in determining chlorine loss from SOW. Chlorine dissipation rates in the light condition are higher than in the dark condition. With the initial 40+0.00 mg/L of chlorine, the chlorine level was decreased as plastic bottle/light &gt; glass bottle/light &gt; plastic bottle/without light&gt; glass bottle/without light. They show that the change in chlorine level is significantly influenced by the type of bottle and the environmental condition, such as light intensity, in this study. The results obtained in this study validate the practice of SOW’s storage condition to slow down chlorine's bulk decay when applied in various industries, such as the food industry.

A data-driven model for the prediction of chlorine losses in water distribution trunk mains

A data-driven model that uses 4 different machine learning (ML) algorithms (Feed forward artificial neural networks (ANN), Nonlinear autoregressive exogeneous (NARX) ANN, support vector machine and Random Forest) was designed for the prediction of chlorine loss events in water distribution trunk mains. The model, firstly, identifies past chlorine loss events and their associate flow or temperature events. Then, the detected past flow events and their associate past chlorine loss events are used to train the ML algorithms. The model was tested in 3 trunk mains of the same drinking water distribution system with similar diameter but with different characteristics, using each time a different combination of parameters (flow (input) - past chlorine losses (output) or flow, temperature, and chlorine (input) - past chlorine losses (output)) and machine learning algorithms. Results indicate that the model could predict a future chlorine loss event with a period between 2 to 10 hours depending on the parameter and ML algorithm used and the trunk mains’ hydraulic characteristics.

Tunable functionalization of poly(ethylene terephthalate) with short-chained quaternary ammonium salt and N-chloramine to enhance conversion of N-H to N-Cl and the antibacterial activity of the resulting N-Cl

Cross-contamination mediated by fomites such as textiles has been identified as one of the major pathways of infectious disease transmission. It is therefore critical to endow those substrates with rechargeable potent antimicrobial activity. N -chloramines, compounds with N-Cl bonds, are a typical group of broad-spectrum effective antimicrobials. Once immobilized onto a substrate, N -chloramines can attain repeated cycles of killing pathogens (loss of active chlorine) and regeneration (recovery of the original N -chloramine structure). However, relatively high levels of free chlorine are needed to recharge the biocidal function on N -chloramine containing textile substrates especially on such hydrophobic ones such as poly(ethylene terephthalate) (PET). We found the introduction of a short-chained quaternary ammonium group to N -chloramines could lead to higher conversion rate of surface bound N-H to N-Cl. Here, we separately clicked an azido N -chloramine precursor (AzH) and a short chain QAS (AzQAS) onto a previously established clickable PET platform to explore the effect of such surface bound QAS on the conversion of surface N-H to N-Cl and the antibacterial activity of the resulting N-Cl. Despite not being covalently bonded to hydantoin, the source of a cyclic N-H, the positive charge center dramatically facilitates the conversion of the hydantoin N-H to N -chloramine in dilute chlorine bleach (<250 ppm Cl 0 ). At a 5 0 :50 ratio to the cyclic N -chloramine precursor (hydantoin), the surface bound QAS enables the PET substrate, after being activated with dilute chlorine bleach (100 ppm Cl 0 ), to achieve 5.81 log reduction of MDR- E. coli within 10 minutes of contact. • A new way to achieve tunable functionalization of poly(ethylene terephthalate) (PET) with short-chained quaternary ammonium salt (QAS) and N-chloramine at varying ratios • Despite being separately bonded to PET surface with an N-chloramine precursor hydantoin, a quaternary ammonium molecule can dramatically facilitate the conversion of the hydantoin N-H to N-chloramine in dilute chlorine bleach (<250 ppm Cl0). • At a 50:50 ratio to the cyclic N-chloramine precursor (hydantoin), the surface bound QAS enables the PET substrate, after being activated with dilute chlorine bleach (100 ppm Cl0), to achieve 5.81 log reduction of MDR-E. coli within 10 minutes of contact. • Positive charge contributes to faster killing of MDR-E. coli by N-chloramine immobilized on PET.

Chlorellestadite (Synth): Formation, Structure, and Carbonate Substitution during Synthesis of Belite Clinker from Wastes in the Presence of CaCl2 and CO2

The synthesis of low-temperature belite (C2S) clinker from wastes of autoclaved aerated concrete and limestone was studied in the presence of CaCl2 as a mineralizing agent. Synthetic chlorellestadite (SCE; Ca10(SiO4)3(SO4)3Cl2) forms in experiments at temperatures between 700 and 1200 °C. Samples were investigated by X-ray diffraction and Raman spectroscopy. In general, the amount of SCE depends mainly on the sulfate content and to a lesser extent on the synthesis temperature. At lower temperatures of formation, a non-stoichiometric SCE seems to crystallize in a monoclinic symmetry similar to hydroxylellestadite. Rietveld refinements revealed the presence of chlorine and calcium vacancies. Raman spectroscopy proved the partial substitution of sulfate by CO32− groups in ellestadites formed at 800 °C and 900 °C in air. Incorporation of CO3 results in a shorter unit cell parameters and smaller cell volume similar to CO3−apatite. At low temperatures, SCE coexists with spurrite intermixed on a very fine nm scale. At temperatures above 900 °C in air, ellestadite is carbonate-free and above 1000 °C chlorine loss starts in all samples.

CaCl2 as a Mineralizing Agent in Low-Temperature Recycling of Autoclaved Aerated Concrete: Cl-Immobilization by Formation of Chlorellestadite

The suitability of CaCl2 as a mineralizing agent in the synthesis of a low-temperature C2S-cement clinker from wastes of autoclaved aerated concrete was investigated. As chlorellestadite is a potential host mineral for the immobilization of chlorine, the formation conditions for the highest joint content of chlorellestadite and C2S were studied in samples with different sulfate contents. Oven experiments were conducted at temperatures between 700 and 1200 °C. The samples were analyzed by X-ray diffraction in combination with chemical and thermal analysis and Raman spectroscopy. Calculation of the yield of C2S and ellestadite for all samples proves the optimum temperature range for the C2S-ellestadite clinker from 950 to 1000 °C. At lower temperatures, the formation of a carbonate-rich halogenide melt promotes the crystallization of a significant amount of spurrite at the expense of C2S. Ellestadite formation mainly depends on the sulfate content and to a lesser extent on the synthesis temperature. However, at higher temperatures, with ternesite another sulfate coexists in sulfate-rich samples at the expense of ellestadite. In addition, distinct evidence for non-stoichiometry and carbonate substitution in the structure of low-temperature ellestadite was found. Low sulfate content leads to the crystallization of Ca10[Si2O7]3Cl2 at higher temperatures. In all samples treated at temperatures above 1000 °C chlorine loss starts. Its extent decreases with increasing sulfate content.

Chlorine decay and disinfection by-products transformation under booster chlorination conditions: A pilot-scale study

Booster chlorination was usually employed in water distribution systems with a long hydraulic retention time. The free chlorine decay and disinfection by-products (DBPs) transformation under booster chlorination conditions were investigated within a pilot-scale water distribution system (WDS). Compared with the initial chlorination in water plants, the loss of chlorine was relatively slow and could be described with first-order kinetic model. The rate of chlorine decay and the generation of DBPs in WDS were much greater than those in beaker. High flow rate and the hydraulic transients both promoted chlorine decay and DBPs formation, especially for dichloroacetonitrile (DCAN). The formation of trihalomethanes (THMs) and haloacetic acids (HAAs) was higher in the ductile iron pipe than in the steel pipe. After booster chlorination, THMs, HAAs, and DCAN all climbed up and then declined continuously, but the peak times were different during the reaction process. The results showed the generation period of DBPs followed the order: THMs (27 h) > HAAs (22 h) > DCAN (5 h). DCAN was not stable in WDS and could be decomposed for a long hydraulic retention time (HRT). The decrease of dichloroacetic acid (DCAA) and increase of trichloroacetic acid (TCAA) indicated that DCAA may turn into TCAA. Linear relationships between the free chlorine demand (FCD) and the generation of THMs that considered both buck water and the pipe wall, as well as the different hydraulic conditions, were established to predict the formation of DBPs in WDS after booster chlorination.

Dehydro-aromatization of renewable bio-naphtha over Pd/[formula omitted]-Al2O3 catalyst

An effort has been made to eliminate the problem of chlorine loss and equipment corrosion caused by the conventional chlorinated alumina-based reforming noble metal catalyst. The manuscript has reported the gas phase aromatization of renewable bio-naphtha in the molecular hydrogen and monometallic Pd/γ-Al2O3 catalyst. In addition, First-principle density functional theory calculations were considered to calculate the free energy and heat of reaction for the conversion of renewable bio-naphtha into toluene on the surface of Pd/γ-Al2O3. The catalyst was characterized by XRD, SEM, TEM, BET, NH3-TPD, TGA/DTA, XPS, and FTIR. All the experiments were carried out in a stirred batch reactor at various reaction conditions for the dehydroaromatization of bio-naphtha. The maximum selectivity towards aromatics of 72.3% was achieved at the optimal reaction conditions of temperature = 375 °C, PH2 = 5 bar, catalyst mass = 0.6, and the reaction time = 14 h. The reaction and coking kinetics were applied to calculate the activation energy of 78.02 kJ/mol and 16.17 kJ/mol, respectively. The catalyst activity was reported in terms of turnover frequency (TOF), i.e., 90.2 h−1. A plausible mechanism for bio-naphtha aromatization via catalytic dehydrogenation route with the active species Pd (0)/Pd (II) is also elucidated.

N-halamine surface coating for mitigation of biofilm and microbial contamination in water systems for space travel

A copolymer termed HASL produced from monomeric units of 2-acrylamido-2-methyl-1-(5-methylhydantoinyl)propane (HA) and of 3-(trimethoxysilyl)propyl methacrylate (SL) has been coated onto stainless steel and Inconel™ substrates, which upon halogenation with either aqueous oxidative chlorine or bromine, became antimicrobial. It has been demonstrated that the halogenated stainless steel and Inconel™ substrates were effective in producing 6 to 7 log inactivations of Staphylococcus aureus and Escherichia coli O157:H7 within about 10 min, and in prevention of Pseudomonas aeruginosa biofilm formation over a period of at least 72 h on the stainless steel substrates. Upon loss of halogen, the HASL coating could be re-charged with aqueous halogen. The HASL coating was easily applied to the substrates via a simple dip-coating method and was reasonably stable to contact with water. Both chlorinated substrates could be loaded with at least 6 × 1016 oxidative Cl atoms per cm2 and maintained a loading of greater than 1 × 1016 chlorine atoms per cm2 for a period of 3–7 days while agitated in aqueous solution. After loss of chlorine to a level below 1 × 1016 atoms per cm2, the substrates could be recharged to the 6 × 1016 Cl atoms per cm2 level for at least 5 times over a 28 day period. The new antimicrobial coating technology has potential for use in a variety of important applications, particularly for water treatment and storage on spacecraft.

Sputter-deposited CdMgTe for rear contact to CdSeTe/CdTe solar cells

CdTe-based photovoltaic device performance improvement is predominantly limited by open-circuit voltage. This work approaches the voltage deficit challenge through the incorporation of a cadmium magnesium telluride (CdMgTe) electron reflector layer at the back of 1.5- μm CdSeTe/CdTe absorbers to reduce back-surface recombination through a conduction band offset. A sputtered CdMgTe electron reflector layer permitted low fabrication temperatures and circumvented the intolerance of CdMgTe to thermal processing present in traditional close-space sublimation (CSS)-deposited CdMgTe devices. We demonstrate that sputtered CdMgTe simultaneously promotes the retention of chlorine passivation and magnesium which is not feasible with CSS fabrication. We also show the importance of the Cu and Te back contact order in CdMgTe devices. Through the optimization of the sputtered CdMgTe substrate temperature, doping, and back structure configuration, 1.5 μm CdSeTe/CdTe devices with a sputtered CdMgTe layer achieved an efficiency of 16.0%, significantly higher than with CSS CdMgTe, and demonstrated partial enactment of electron-reflector behavior. • Sputtered CdMgTe electron reflector solar cells achieve higher efficiencies than close-space sublimation-deposited. • Low temperatures of sputtered CdMgTe reduce magnesium diffusion and chlorine loss. • CdTe devices with CdMgTe electron reflectors require back contact optimization. • CdTe voltage improvement with CdMgTe limited by a partial negative back valence band offset.

A Novel Step-by-Step Assessment Methodology for the Correction of Sampling Artifact and Chlorine Loss Reaction on HNO3 in Ambient Air

A Novel Step-by-Step Assessment Methodology for the Correction of Sampling Artifact and Chlorine Loss Reaction on HNO3 in Ambient Air

Overcoming Degradation Pathways to Achieve Stable Blue Perovskite Light-Emitting Diodes

Mixed halide (Br/Cl) perovskite nanocrystals (NCs) that represent an advanced blue emitter commonly suffer from spectral instability and poor lifespan; notably, the lack of understanding of the failure mechanisms of these devices has restricted the future progress. Here, we determine that the degradation of CsPbBrxCl3–x NCs containing blue light-emitting diodes (LEDs) is due to the combination of two effects. Cl– drift among adjoining NCs under an electric field is found to induce a Cl-deficient material region in multiple NC layers, which dominates the unstable electroluminescence and causes fast degradation in the corresponding devices. In comparison, the monolayer NC devices that feature restricted anion drift pathways exhibit better operational stability; however, excess hole injection is demonstrated to induce irreversible chlorine loss in NCs. Such a process that largely arises from electrochemical oxidation of Cl– initiates a mild device failure in operation of tens of minutes. Through revealing these mechanisms, we modulate the devices’ construction and operational conditions to achieve a longer lifespan.

Impact of pipe material on the wall reaction coefficients and its application in the rehabilitation of water supply system of San Pedro Nexapa, State of Mexico

Abstract One of the major challenges faced by water companies around the world is the high level of chlorine losses in distribution networks. This paper presents an experimental study to examine chlorine loss in different types of pipe materials and select the ones with low chlorine demand for the rehabilitation of the water distribution network of San Pedro Nexapa, State of Mexico. The materials investigated include: polyvinyl chloride (PVC), galvanized steel (GS), polypropylene (PP) and high-density polyethylene (HDPE). A 24-h chlorine consumption study was performed in a simulated water distribution network to assess the impact of wall reaction coefficient on chlorine decay. Four sets of independent pipe loops of 50 mm in diameter and 12 m in length were used. Two different scenarios were considered based on different initial chlorine concentration (1.21 mg/L and 1.60 mg/L). Samples were collected at each loop at two-hour intervals and physicochemical analyses were conducted. Results from the experimental distribution network showed that the wall coefficient values for GS, HDPE, PP and PVC were 0.165 h−1, 0.059 h−1, 0.043 h−1 and 0.026 h−1, respectively. Experimental results showed that wall reaction coefficient values depend on initial chlorine concentration and the characteristics of pipe material. The rate of free chlorine decay was found to be faster in steel pipe and slower in the plastic pipes. Based on its having the lowest chlorine demand compared with the other pipes, PVC pipe would be selected to rehabilitate Nexapa water distribution network, State of Mexico. The wall coefficients from the experimental study were incorporated into EPANET through four simulation runs to predict chorine decay of San Pedro Nexapa water distribution network, State of Mexico. In the PVC and PP pipes higher residual chlorine concentrations were observed that ranged from 0.30 to 0.90 mg/L and 0.50 to 0.95 mg/L, respectively. This study is important for utilities to operate their system effectively and protect public health.