Chloramine Treatment Research Articles

Formation of nitrogen-containing disinfection by-products during the chloramination treatment of an emerging pollutant

Chloramination was commonly used as disinfectant for killing pathogens in water. However, in this process, nitrogen-containing disinfection by-products (N-DBPs) would accidently form and subsequently rise toxicity. Here, we investigated acute toxicity variation and by-products formation during chloramination treatment on UV filter 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone (BP-4). Under alkaline conditions, the acute toxicity of this system had significant increase. A total of 17 transformation products were tentatively identified, and for them, plausible transformation pathways were proposed. Noticeably, numerous aniline and nitrosobenzene analogs were detected, and the dramatic increase of acute toxicity in this system might be primarily attributed to the formation of benzoquinone and aniline analogs. Besides, bromophenol, iodophenol and iodobenzoquinone analogs exhibiting high toxicity were generated in the presence of bromine and iodide ions. This study indicates that chloramination treatment may significantly increase potential health risk, further management on disinfection system is reasonable.

Feel the Burn: Disinfection Byproduct Formation and Cytotoxicity during Chlorine Burn Events

Nitrification and biofilm growth within distribution systems remain major issues for drinking water treatment plants utilizing chloramine disinfection. Many chloraminated plants periodically switch to chlorine disinfection for several weeks to mitigate these issues, known as "chlorine burns". The evaluation of disinfection byproduct (DBP) formation during chlorine burns beyond regulated DBPs is scarce. Here, we quantified an extensive suite of 80 regulated and emerging, unregulated DBPs from 10 DBP classes in drinking water from two U.S. drinking water plants during chlorine burn and chloramination treatments. Total organic halogen (TOX), including total organic chlorine, total organic bromine, and total organic iodine, was also quantified, and mammalian cell cytotoxicity of whole water mixtures was assessed in chlorine burn waters for the first time. TOX and most DBPs increased in concentration during chlorine burns, and one emerging DBP, trichloroacetaldehyde, reached 99 μg/L. THMs and HAAs reached concentrations of 249 and 271 μg/L, respectively. Two highly cytotoxic nitrogenous DBP classes, haloacetamides and haloacetonitriles, increased during chlorine burns, reaching up to 14.2 and 19.3 μg/L, respectively. Cytotoxicity did not always increase from chloramine treatment to chlorine burn, but a 100% increase in cytotoxicity was observed for one plant. These data highlight that consumer DBP exposure during chlorine burns can be substantial.

Integrated Omics in salmon skin mucus for determining consequences of chloramine treatment against parasite infestation

Integrated Omics in salmon skin mucus for determining consequences of chloramine treatment against parasite infestation

Synthesis and antiproliferative assessments of new derivatives of isothiazolo[3,4-d]pyrimidine

ABSTRACT Various derivatives of 5-aryl-4-imino-3-(phenylamino)-4,5-dihydroisothiazolo[3,4-d]pyrimidines (3a-f) were synthesized. The synthesis has been done through treatment of 3-amino-4-cyano-5-(phenylamino)isothiazole with various aryl isothiocyanates. The isothiazole skeleton was obtained by the reaction of malononitrile and phenyl isothiocyanate followed by chloramine treatment. Some of the synthesized dihydroisothiazolo[3,4-d]pyrimidines were tested against different cancer cell lines, including ACHN, HeLa, HL-60, MCF-7, and PC3. Malignant cells were cultured in RPMI medium and incubated with different concentrations of the mentioned compounds. Cell viability was assessed using the MTS assay. The cytotoxicities of the synthesized compounds are not significant and are probably safe for other biological use.

Degradation behaviors of Isopropylphenazone and Aminopyrine and their genetic toxicity variations during UV/chloramine treatment

Combination of ultraviolet and chloramine (i.e., UV/chloramine) treatment has been attracting increasingly attention in recent years due to its high efficiency in removing trace organic contaminants. This study investigated the degradation behaviors of two pyrazolone pharmaceuticals (i.e., Isopropyl phenazone (PRP) and Aminopyrine (AMP)) and their genetic toxicity variations during UV/chloramine treatment. The results showed that chloramine could hardly degrade PRP and AMP, while UV/chloramine greatly increased the observed first-order rate constant (kobs) of PRP and AMP degradation. The quenching and probe experiments illustrated that the reactive chlorine species (RCS) contributed dominantly to PRP removal, and hydroxyl radical (HO•) was the major contributor to the degradation of AMP, while the reactive amine radicals (RNS) could hardly degrade them. The overall degradation rates of PRP and AMP decreased as pH increased from 6.5 to 10. The kobs of PRP and AMP increased along with NH2Cl dosage increasing and reached a plateau at higher concentrations (0.2–0.5 mM). The present background carbonate (HCO3−, 1–10 mM), chloride (Cl−, 1–10 mM) and natural organic matter (NOM, 5-10 mg-C L−1) exhibited inhibition impacts on PRP and AMP degradation. In addition, the intermediates/products of PRP and AMP were identified and their general degradation pathways were proposed to be hydroxylation, deacetylation, and dephenylization. Specifically, Cl-substitution was inferred during PRP degradation, while demethylation in tertiary amine group was only observed in AMP degradation. These mechanisms including the main reactive sites of PRP and AMP were further confirmed by the frontier orbitals calculation. Moreover, the results of the genetic toxicity according to the micronucleus test of Viciafaba root tip indicated that UV/chloramine treatment could partially reduce the genetic toxicity of PRP and AMP.

Application of stabilized hypobromite for controlling membrane fouling and N-nitrosodimethylamine formation

Chloramination is a conventional and successful pre-disinfection approach to control biological fouling for reverse osmosis (RO) treatment in water reuse. This study aimed to evaluate the possibility of using a new disinfectant—stabilized hypobromite—in controlling membrane fouling and the formation of a particular carcinogenic disinfection byproduct (DBP)—N-nitrosodimethylamine (NDMA). Our accelerated chemical exposure tests showed that the new disinfectant reduced the permeability of a polyamide RO membrane permeability from 6.7 to 4.1 L/m2hbar; however, its treatment impact was equivalent to that of chloramine. The disinfection efficacy of stabilized hypobromite was greater than that of chloramine when evaluated with intact bacterial counts, which suggests its potential for mitigating membrane biofouling. Additional pilot-scale tests using synthetic wastewater demonstrated that pre-disinfection with the use of stabilized hypobromite inhibits membrane fouling. Among 13 halogenated DBPs evaluated, the formation of bromoform by stabilized hypobromite was higher than that by chloramine at a high dose of 10 mg/L, thus suggesting the need for optimizing chemical doses for achieving sufficient biofouling mitigation. NDMA formation upon stabilized hypobromite treatment in two different types of actual treated wastewaters was found to be negligible and considerably lower than that by chloramine treatment. In addition, NDMA formation potential by stabilized hypobromite was 2–5 orders of magnitude lower than that by chloramine. Our findings suggest the potential of using stabilized hypobromite for controlling NDMA formation and biofouling, which are the keys to successful potable water reuse.

Using UV/H2O2 pre-oxidation combined with an optimised disinfection scenario to control CX3R-type disinfection by-product formation

The effects of UV/H2O2 pre-oxidation or disinfection methods on the formation of partial disinfection by-products (DBPs) have been studied previously. This study assessed the effect of UV/H2O2 pre-oxidation combined with optimisation of the disinfection method on the formation of six classes of CX3R-type DBPs, including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetaldehydes (HALs), haloacetonitriles (HANs), halonitromethanes (HNMs), and haloacetamides (HAMs). Experimental results showed that a simulated distribution system (SDS) in-situ chloramination or pre-chlorination followed by chloramination effectively decreased total CX3R-type DBP formation by 51.1–63.5% compared to SDS chlorination, but little reduction in DBP-associated toxicity was observed. The dominant contributors to the calculated toxicity were HANs and HALs. UV/H2O2 pre-oxidation was able to destroy the aromatic and dissolved organic nitrogen components of natural organic matter. As a consequence, THM, HAA, and HAL formations increased by 49.5–55.0%, 47.8–61.9%, and 42.0–67.1%, respectively, whereas HAN, HNM, and HAM formations significantly decreased by 52.1–83.6%, 42.9–87.3%, and 74.1–100.0%. UV/H2O2 pre-oxidation increased total CX3R-type DBP formation, during SDS chlorination, whereas SDS in-situ chloramination or pre-chlorination followed by chloramination of UV/H2O2-treated water produced lower total CX3R-type DBPs than water without UV/H2O2 pre-oxidation. Nevertheless, the DBP-associated toxicity of water with UV/H2O2 pre-oxidation was substantially lower than the toxicity for water without UV/H2O2 pre-oxidation, decreased by 24.1–82.7%. HALs followed by HANs contribute to major toxic potencies in UV/H2O2 treated water. The best DBP concentration and DBP-associated toxicity abatement results were achieved for water treated by UV/H2O2 coupled with in-situ chloramination treatment.

Enhanced formation of chlorinated disinfection byproducts in the UV/chlorine process in the presence of benzophenone-4

Benzophenone-4 (BP4) is UV-filter that is widely in sunscreens and cosmetics to prevent skin damage from sunlight exposure. Washing off of BP4 from the human body in swimming pools represents a direct source of BP4 in the environment. In this study, we investigated the transformation of BP4 by free chlorine, chloramine, and UV/chlorine, which can be found in swimming pool water. It was found that BP4 can be rapidly removed by both chlorine and chloramine treatment, but only chlorination led to appreciable formation of chlorinated disinfection by-products (DBPs), such as dichloroacetic acid and trichloroacetic acid. However, chloramination of BP4 resulted in higher levels of chlorinated intermediates, which were relatively recalcitrant to further chlorination. The UV/chlorine process was significantly more efficient than the chlorine treatment alone for BP4 removal and resulted in trace chlorinated intermediates and formation of DBPs. Radical scavenger tests revealed that the removal of BP4 in the UV/chlorine process was mostly ascribed to reactions with the Cl and OH generated from HClO photolysis. The presence of methanol as a radical scavenger resulted in incomplete removal of BP4 in the UV/chlorine process and enhanced the formation of DBPs. The increase in DBP formation was because the residual BP4 can be exited to a triplet state (3BP4∗) upon UV irradiation. 3BP4∗ subsequently reacted with O2 to form 1O2, a reactive oxygen species that generated DBPs by reacting with chlorinated intermediates in water. All benzophenone-type UV-filters may have similar photochemical activity and thus influence the transformation of other organics in sunlit surface water environments.

Evaluation of glycine-bearing celecoxib derivatives as a colon-specific mutual prodrug acting on nuclear factor-κB, an anti-inflammatory target.

In an inflammatory state where HOCl is generated, glycine readily reacts with HOCl to produce glycine chloramine, an anti-inflammatory oxidant. Colonic delivery of celecoxib elicits anticolitic effects in a trinitrobenzene sulfonic acid-induced rat colitis model. Glycine-bearing celecoxib derivatives were prepared and evaluated as a colon-specific mutual prodrug acting on nuclear factor-κB (NFκB), an anticolitic target. Glycylcelecoxib (GC), N-glycylaspart-1-ylcelecoxib (N-GA1C), and C-glycylaspart-1-ylcelecoxib (C-GA1C) were synthesized and their structures identified using infrared and proton nuclear magnetic resonance spectrometer. The celecoxib derivatives were chemically stable in pH 6.8 and 1.2 buffers. GC and C-GA1C were resistant to degradation in the small intestinal contents, while N-GA1C was substantially cleaved to release celecoxib. In contrast, all the celecoxib derivatives were degraded to liberate celecoxib in the cecal content. These results suggest that GC and C-GA1C could be delivered to and liberate celecoxib and glycine in the large intestine. In human colon carcinoma HCT116 and murine macrophage RAW264.7 cells, combined celecoxib–glycine chloramine treatment additively suppressed the production of proinflammatory NFκB target gene products. Collectively, our data suggest that C-GA1C is a potential colon-specific mutual prodrug acting against NFκB.

Which Drinking Water Disinfection Process Generates the Least Toxic DBP Mixture: Chlorination, Chloramination, Ozonation, or Chlorine Dioxide Treatment?

NOM in natural waters mainly originates from the decomposition of plants. It consists of a wide variety of complex organic compounds with molecular weights ranging from hundreds to hundreds of thousands of Da [1]. The complexity of NOM determines a higher magnitude of complexity of the reaction products from disinfectants and NOM with/without bromide and iodide. Since Rook [2] first found trihalomethanes as DBPs in finished drinking water in 1974, numerous DBPs have been identified in real or simulated drinking waters. Commonly known DBPs include trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, cyanogen halides, chloropicrin, chloral hydrate, N-nitrosodimethylamine, bromate, and chlorite. Richardson [3] compiled a review on drinking water DBPs formed from using four major disinfectants, in which she listed about 600 DBPs that were identified by gas chromatography/mass spectrometry (GC/MS). Of the 600 DBPs, some are commonly known DBPs and occur at low-μg/L levels, some occur at sub-μg/L or ng/L levels, and some may still not be quantifiable [4]. The non-quantifiable DBPs are because of no corresponding standard compounds for calibration or their concentrations below detection limits. In addition, there are a countless number of unidentified/unknown DBPs.

Shock chloramination: potential treatment for Chironomidae (Diptera) larvae nuisance abatement in water supply systems.

In the early 1990s, infestations of midge larvae (Chironomidae, Chironomus sp.) were discovered in the potable water system of Tel Aviv, Israel. Control measures, such as draining and cleaning tanks, spraying water into the tank's air space, and electrocution traps of midge adults, were either inadequate or ineffective. In this system, monochloramine concentrations of up to 0.75 mg/liter are used routinely as a secondary disinfectant. This chemical was tested in the laboratory as a toxicant of midge larvae. The mortality of 4th instar midge larvae after short exposure to high chloramine concentrations (LC50 values of 32 mg/liter for 75 min) suggested the efficacy of instituting a Shock Chloramination treatment program. Tanks were partially drained until they contained only 20 cm of water and were then temporarily disconnected. Chloramine was added to this water to produce a concentration of approximately 70 mg/liter for 1-2 h. Subsequently, all dead chironomids were flushed out, and the tank was refilled to attain the operational volume of water. A 2nd identical treatment of water in the tank was suggested 7 d later to kill midges from reproductive adults and egg-masses that survived the 1st treatment. This treatment program was tested in commercial covered tanks and gave complete control of these pests for 6-10 wk. These results suggest that this treatment program may effectively prevent midge outbreaks in Israel's drinking water supply system during the height of the summer.

Certification Corner

This portion of “Certification Corner” includes questions on limesoda ash softening, calcium hypochlorite ph, chloramine treatment, methods of corrosion control for municipal water treatment, treatment of metal surfaces before painting, backwash rates, and backwash indicators in rapid sand filters.

Chloramine Treatment of Sea Water

Chloramine Treatment of Sea Water Lewis V. Carpenter, Lloyd R. Setter, and Morris Weinberg CopyRight*Read before the Public Health Engineering Section of the American Public Health Association at the Sixty-sixth Annual Meeting in New York, N. Y., October 5, 1937. https://doi.org/10.2105/AJPH.28.8.929 Published Online: August 29, 2011

Chloramine Treatment in Duluth

The credit for introducing the chloramine treatment in Duluth is due to E. W. Kelly, former head of the Water and Light Department. An emergency arose on August 22, 1930, that required action. For several weeks before this date we had a spell of calm, sunny weather, which produced a marked growth of algae in Lake Superior. Then a strong northeast wind whipped up the algae into our intake. Immediately a strong cod-liverish oil taste developed in the water. To combat this taste, several tanks of ammonia were obtained from a local distributor. The ammonia was then fed into the water at the Lakewood Station in conjunction with our chlorine treatment. A hand valve and scales was the only method of control at first. Within a few hours a marked diminution in taste was obtained. Having overcome this taste problem, it was decided to continue this method of treatment as the tastes in our water had been more or less intermittent before this. An ammoniator was ordered and efforts were then made to keep a close control of this treatment. Our hourly residual chlorine tests and bacterial checks were continued. When the ammonia was first tried heavy amounts were used. After the initial emergency, we found it possible to cut down the ammonia to small amounts and still obtain taste reduction. In order to keep our factor of safety high, we kept our residual chlorine at our previous level, but the ammonia was cut down to a ratio of 1 to 3 with chlorine. This was continued for a month or two until we ran into further tastes. To reach an understanding of this treatment as a taste preventative, it seems best to consider it as a combination of competing chemical reactions. Undoubtedly the two commonest tastes in our water were free chlorine and the combination algae and chlorine. The addition of ammonia to chlorine in preventing taste interferes with these other reactions. Anything that favors or speeds up the ammonia chlorine reaction will help in taste prevention. Several things according to the laws of chemical reaction favor the speed of reaction

Notes on the Chloramine Treatment of Water.

Notes on the Chloramine Treatment of Water.

B. Coli in Cold Blooded Animals

coli, and that the organism may persist in the intestines for considerable time. One of these animals threw off 36,000 B. coli per day. This work records 80 individual animals: 21 reptiles (12 species) and 59 amphibia (9 species). It may add to a not too full literature on the subject, and to the persistence of the organism in forms other than salamanders. In early July, 1932, it was noticed that a small (800,000 gallon) concrete storage reservoir at Easton, Pa., was victimized by newly metamorphized frogs, Rana pipiens. A conservative estimate of the number was 2000. This reservoir was situated on the top of a small mountain, and not subject to the catchment of drainage. The frogs spent their life from the egg to the adult in this water, and due to the reservoir water level did not get off the concrete slope of the reservoir. Moreover, this water received the chloramine treatment, with analyses showing it to be a safe water for public consumption. Eleven of these frogs were dissected (see below for procedure), and contents of intestines put in lactose broth, and then on E.M.B. Analysis of the reservoir water was made at the same time. All individuals yielded organisms showing acid ада gas in lactose, and characteristic coli с olonies on E . M . В . The reservoir water was negative . A few days later three more frogs from the same source were dissected. From one of these specimens were taken several parts of the

Chlamydomonas in Storage Reservoirs

During the summer of 1932 the storage reservoirs of the Lehigh Water Company, which supplies Easton, Pennsylvania, were continuously troubled with growths of Chlamydomonas. Although of no sanitary significance, the growths were, at times, so heavy that the water became decidedly objectionable to users. Numerous complaints were received from consumers, beginning about the first week in April and continuing off and on until the early part of November. Many of these complaints were due to an unpleasant taste and odor present in the raw water. This everpresent taste and odor, which we have called with no originality the Delaware River taste, will be discussed elsewhere. However, complaints regarding a green color and turbidity of the tap water, a green ring or sediment in a glass of water which had, for example, stood overnight by a bedside, a greenish scum on boiled water used in cooking, a sediment in pots and pans, and occasionally of a grassy odor were definitely traceable to the reservoirs. One of the most embarrassing complaints came from a beauty parlor where a ring of green scum was formed in white enamel bowls used for heating water. The Lehigh Water Company supplies the city with unaltered1 Delaware River water, purified by chloramine treatment. The pumping station is off the Pennsylvania bank on the northern outskirts of the city, approximately a mile above the junction of the Lehigh River with the Delaware River. The distribution system centers in four reservoirs. The water is lifted from the river into two reservoirs situated about a mile northeast of the river on the side of Paxinosa Mountain. These main reservoirs are in tandem, with a combined capacity of 13

Chloramine Treatment at the Chatham Filtration Plant

The new method was adopted with a view to overcoming an unpleasant, weedy taste in our water supply which would always be noticeable during the midsummer months. It was believed to be largely due to abundant growth of vegetation of the algae type. Such growth was stimulated by the river conditions usual at that time of the year, low river level, slow current, and water temperature above 70 degrees, Fahr. Freedom from the weedy taste during the past summer proved the efficiency of chloramine as a hot weather treatment. A substantial reduction in the amount of chlorine required in the filter effluent to complete sterilization induced us to adopt the chloramine treatment as an all-the-year-round method of sterilization. The extra cost is negligible, less than 30 cents per million gallons.

Removal of Taste and Odor from Municipal Water Supplies

Since the spring of 1931 the Ontario Department of Health has conducted an extensive experimental investigation into the problem of tastes and odors in municipal water supplies. The results accomplished are summarized in tables 1 and 2. Laboratory and plant-scale experiments were performed. The success of each treatment is shown by the sign affixed. Plus indicates that the treatment was successful; minus, that no good was accomplished; and plus-and-minus, that only partial improvement was obtained. At Chatham chloramine was effective in preventing algae growth, and thereby also was effective in reducing the taste to a considerable extent. At Wallaceburg chloramine prevented the formation of the taste-producing chlorphenol by reducing the activity of the chlorine. The details of these two experiments will be given by others. They illustrate the two uses of chloramine treatment; first, in preventing taste by preventing algae growth, and second, in preventing the formation of taste producing substances by reducing the activity of chlorine. Chloramines cannot be expected to remove tastes already present in the water. The use of granular activated carbon received considerable attention at Chatham, Haileybury, Kirkland Lake, Lindsay, and Timmins. The carbon was used in the form of small filter beds through which water was passed. The amount of water obtained before a noticeable taste was secured was not large. At Chatham the experiment was discontinued before the carbon was saturated. At Haileybury the filter was used only during short periods of extremely offensive taste. At Kirkland Lake and Timmins, unfiltered water was used. This probably reduced the life of the carbon. At Timmins, color was removed as well as taste and odor. At Lindsay, clear and colorless tap water was used. The yield of tasteless water was 18,000 gallon per cubic foot. This is evidently too low to make

Chloramine Treatment of Water in the Field

Chloramine Treatment of Water in the Field