Background, aim, and scope In papermaking, there is a continuous interest both to minimize fresh water consumption and to reduce discharges into the environment. These general trends mean an increase in the amounts of detrimental substances, such as resin and fatty acids, in papermaking process waters. Resin acids, in particular, are responsible for much of the toxicity typically present in paper mill effluents and, for this reason, the routine and rapid monitoring of these compounds in various process streams is necessary. This also means that there is a continuous need to develop straightforward offline and online techniques to clarify problems occurring, for example, as a result of the introduction of more intensively closed systems of water circulation. In the present study, we describe the use of a novel, online, sample enrichment technique followed by atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) suitable for monitoring the concentration levels of common resin and fatty acids in papermaking process waters. Materials and methods The representative process water samples were taken from the grinding zone of a thermomechanical pulping mill. The samples were first preconcentrated in a precolumn C18, and the analytes were transferred online to MS. The high intensive [M-H]⁻ ion was used for the identification of each analyte since, according to the present ionization method, no other fragmentation was observed. Laboratory-scale, online measurements with an online sample feed were carried out by connecting a centrifugal pump and a ceramic filter to the APCI-MS. Results Quality parameters, such as repeatability, linearity, and limit of detection (LOD), were determined by using dehydroabietic acid (DHAA) in order to evaluate the suitability of the method for the rapid screening of concentration levels. This method provided satisfactory linearity and a good correlation between analyte concentration and peak area. The suitability of the system for the continuous analysis of the same acids was evaluated in laboratory-scale, online experiments. In all cases, the response to changes in the analyte concentration was linear, and the repeatability of the system was also satisfactory. Discussion Only a few studies have been published on the analysis of resin and fatty acids with MS techniques. The present method was applied to the monitoring of dehydroabietic, oleic, and stearic acids. The quality parameters were highly comparable with those reported earlier, and the LOD values of the DHAA were below the levels usually encountered in process waters. The quality parameters were only slightly higher than those obtained by the traditional methods of analysis, probably due to the absence of an effective sample clean-up before analysis. Conclusions The results of the laboratory-scale, online experiments indicated that the online enrichment APCI-MS system is a suitable alternative for monitoring the concentration levels of selected resin and fatty acids in papermaking process waters. The method can be used, for example, to provide useful information about the concentration levels of these acids in different stages of the process, thus signaling possibly impending problems. In general, faster and simpler measurements are needed to meet the requirements for a reduction in fresh water usage in papermaking. Recommendations and perspectives Compared to the conventional methods used for this purpose, the main benefits of the method are rapidity of measurement, simplicity of use, and absence of the need for multistage sample treatments (short analysis time). For this reason, this online method is more suitable for the control of papermaking by analyzing the concentration levels of interfering substances (i.e., selected resin and fatty acids) than an offline analysis detailing all the individual extractives-based compounds in process streams. It is also obvious that the technique can easily be modified for other environmental pollutants as well.

Background, aim, and scope Unsaturated esters are emitted to the atmosphere from biogenic and anthropogenic sources, including those from the polymer industry. Little information exists concerning the atmospheric degradation of unsaturated esters, which are mainly initiated by OH radicals. Limited information is available on the degradation of alkenes by Cl atoms and almost no data exists for the reactions of unsaturated esters with Cl atoms. This data is necessary to assess the impact of such reactions in maritime environments where, under circumstances, OH radical- and Cl atom-initiated oxidation of the compounds can be important. Rate coefficients for the reactions of chlorine atoms with vinyl acetate, allyl acetate, and n-butyl acrylate have been determined at 298 ± 3 K and atmospheric pressure. The kinetic data have been used in combination with that for structurally similar compounds to infer the kinetic contributions from the possible reaction channels to the overall reaction rate. Materials and methods The decay of the organics was followed using in situ Fourier transform infrared spectroscopy and the rate coefficients were determined using a relative kinetic method and different hydrocarbon reference compounds. Results The following room temperature rate coefficients (in cm³ molecule⁻¹ s⁻¹) were obtained: k ₁ (Cl + CH₃C(O)OCH=CH₂) = (2.68 ± 0.91) x 10⁻¹⁰, k ₂ (Cl + CH₃C(O)OCH₂CH=CH₂) = (1.30 ± 0.45) x 10⁻¹⁰, and k ₃ (Cl + CH₂=CHC(O)O(CH₂)₃CH₃) = (2.50 ± 0.78) x 10⁻¹⁰, where the uncertainties are a combination of the 2σ statistical errors from linear regression analyses and a contribution to cover uncertainties in the rate coefficients of the reference hydrocarbons. Discussion This is the first kinetic study of the title reactions under atmospheric conditions. The kinetic data were analyzed in terms of reactivity trends and used to estimate the atmospheric lifetimes of the esters and assess their potential importance in the marine atmosphere. Conclusions Although reaction with OH radicals is the major atmospheric sink for the unsaturated esters studied, reaction with Cl atoms can compete in the early morning hours in coastal areas where the Cl concentration can reach peak values as high as 1 x 10⁵ atoms cm⁻³. The calculated residence times show that the chemistry of unsaturated esters will impact air quality locally near their emission sources. Recommendations and perspectives The reactions need to be studied over the range of temperatures and pressures generally encountered in the marine atmosphere. In addition, product studies should also be performed as a function of temperature since this will allow degradation mechanisms to be derived, which are representative for the wide range of conditions occurring in marine environments. Inclusion of the kinetic and product data in tropospheric numerical models will allow an assessment of potential environmental impacts of the esters for different marine pollution scenarios.

Background, aim, and scope Ten years of public health interventions on industrial emissions to clean air were monitored for the Mediterranean city of Cartagena. During the 1960s, a number of large chemical and non-ferrous metallurgical factories were established that significantly deteriorated the city's air quality. By the 1970s, the average annual air concentration of sulfur dioxide (SO₂) ranged from 200 to 300 μg/m³ (standard conditions units). In 1979, the Spanish government implemented an industrial intervention plan to improve the performance of factories and industrial air pollution surveillance. Unplanned urban development led to residential housing being located adjacent to three major factories. Factory A produced lead, factory B processed zinc from ore concentrates, and factory C produced sulfuric acid and phosphates. This, in combination with the particular abrupt topography and frequent atmospheric thermal inversions, resulted in the worsening of air quality and heightening concern for public health. In 1990, the City Council authorized the immediate intervention at these factories to reduce or shut down production if ambient levels of SO₂ or total suspended particles (TSP) exceeded a time-emission threshold in pre-established meteorological contexts. The aim of this research was to assess the appropriateness and effectiveness of the intervention plan implemented from 1992 to 2001 to abate industrial air pollution. Materials and methods The maximum daily 1-h ambient air level of SO₂, NO₂, and TSP pollutants was selected from one of the three urban automatic stations, designed to monitor ambient air quality around industrial emissions sources. The day on which an intervention took place to reduce and/or interrupt industrial production by factory and pollutant was defined as a control day, and the day after an intervention as a post-control day. To assess the short-term intervention effect on air quality, an ecological time series design was applied, using regression analysis in generalized additive models, focusing on day-to-day variations of ambient air pollutants levels. Two indicators were estimated: (a) appropriateness, the ratio between mean levels of the pollutant for control days versus the other days, and (b) effectiveness, the ratio between mean levels of the pollutant for post-control days versus the other days. Ratios in regression analyses were adjusted for trend, seasonality, temperature, humidity and atmospheric pressure, calendar day, and special events as well as the other pollutants. Results A total of 702 control days were made on the factories' industrial production during the 10-year period. Fifteen reductions and five shutdown control days took place at factory A for ambient air SO₂. At factory B, more controls were carried out for the SO₂ pollutant in the years 1992-1993 and 1997. At factory C, the control days for SO₂ decreased from 59 reductions and 14 shutdowns to a minimum from 1995 onwards, whereas the controls on TSP were more frequent, reaching a maximum of 99 reductions and 47 shutdowns in the last year. SO₂ ambient air mean levels ranged from 456 to 699 μg/m³ among factories on reduction control days and between 624 and 1,010 μg/m³ on shutdown days. The TSP ambient air mean levels were 428 and 506 μg/m³ on reduction and shutdown days, respectively. For all types of control days and factories, a mean ratio of 104% (95% confidence interval [CI] 88 to 121) in SO₂ levels was obtained and a mean ratio of 67% (95% CI 59 to 75) in TSP levels. Post-control days at all factories showed a mean ratio of -16% (95% CI -7 to -24) in SO₂ levels and a mean ratio of -13% (95% CI -7 to -19) in TSP levels. Discussion Interventions on industrial production based on the urban SO₂ and TSP ambient air levels were justified by the high concentrations detected. The best assessment of the interventions' effectiveness would have been to utilize the ambient air pollutant concentration readings from the entire time of the production shutdowns or reductions; however, the daily hourly maximum turned out to be a useful indicator because of meteorological factors influencing the diurnal concentration profile. A substantial number of interventions were carried out from 1 to 3 am, when vehicular traffic was minimum. On the other hand, atmospheric stability undergoes diurnal cycling in the autumn-winter period due to thermal inversion, which reaches maximum levels around daybreak. Therefore, this increases the ambient air levels and justified the interventions carried out at daybreak in spite of the traffic influence. Conclusions All the interventions for SO₂ and TSP were carried out when the measured ambient air levels of pollutants were exceeded, which shows the appropriateness of the intervention program. This excess was greater when intervening on SO₂ than on the TSP levels. For both ambient air levels of SO₂ and TSP, significant drops in air pollution were achieved from all three factories following activity reductions. The production shutdown controls were very effective, because they returned excess levels, higher than in the reduction controls, to everyday mean values. Recommendations and perspectives The Cartagena City observational system of intermittent control has proven to effectively reduce industrial emissions' impact on ambient air quality. This experienced model approach could serve well in highly polluted industrial settings. From a public health perspective, studies are needed to assess that the industrial interventions to control air pollution were related to healthier human populations. Legislation was needed to allow the public administration to take direct actions upon the polluting industries.