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Some wastes from the paper pulp production process are still sent to a controlled waste landfill. These materials can constitute alternative resources for constructing road pavements. The study aimed to characterize and explore the sustainable application of two inorganic wastes resulting from the paper pulp process, the dregs (green liquor wastes) and the grits (slaker wastes), in the production of bituminous mixtures by the analysis of samples prepared with 5 and 10% of dregs and 5 and 10% of grits on the baseline reference bituminous mixture AC 14 surf 35/50. Some relevant mechanical properties of the blends were assessed based on Marshall compression, sensitivity to water and wheel-tracking tests. Additionally, water poured on the loose asphalt and compacted slabs' surface was analysed to determine the portion of harmful chemical compounds leached from the asphalt material. The results show that using dregs presented some technical limitations related to mechanical performance and that the incorporation of grits has an acceptable mechanical behaviour. Moreover, the study shows that the measured leachate resulting from water flow in a reference asphalt mixture and the blends with grits are insignificant. It can be concluded that using grits in asphalt mixtures is a promising technique regarding mechanical behaviour and environmental impacts that need further studies. [ABSTRACT FROM AUTHOR]

The objective of research was to study the intensity of respirable dust exposure, irregular's respiratory system and behavior of personal protective equipment for respiratory protection in pulp and paper manufacturing factory employees in Khon Kaen. For a case study, we collected information from employees using 6 work scopes, in two departments1 Preparation of Materials2 Produce lime and chemicals for return [in total 18 examples]. We found that the Intensity of respirable dust in both departments had a mean equal to 0.22±0.13 mg/m3 and 0.12±0.06 mg/m3 respectively [95%CI=0.02-0.41] and there for passed the standards announced by the Ministry of Interior and Occupational Safety and Health Administration [OSHA]. Lung efficiency information derived from Annual Health checkups between 2013-2015 indicated that employees tend to irregular lung efficiency with values of FVC, FEV1 and FEV1/FVC in 2 types as [FVC < 80% FEV1 and FEV1/FVC > 70% and FVC >80% FEV1 and FEV1/FVC < 70%] are increasing and employees [50 people, 60.98%] mostly choose a cloth mask for respiratory protection. 33 people [40.24%] did not wear a respirator because they found it uncomfortable. Hand cleaning after work' behavior occurred in 64 persons [78.05%] and the incidence of training in hazards from total dust within 1-3 mouths amounted to 57 persons [69.51%]. Even if intensity of respirable dust is not over standard levels, a hazard to health may accumulate in the long term. The factory should be more concerned with employees' health. [ABSTRACT FROM AUTHOR]

Abstract: On-site measurement of methanethiol (CH3SH) was performed for three years on ships and cars near a pulp and paper plant standing on the shore of Lake Baikal in Siberia, Russia, to investigate the behavior and impact of atmospheric CH3SH emitted from a point source. Despite its strong odor, there are few reports on atmospheric CH3SH, while many investigations have been carried out on dimethyl sulfide (DMS). In this work, CH3SH and DMS were measured every 15 min by a recently developed automated instrument based on single column trapping/separation and chemiluminescence measurement. Hydrogen sulfide, sulfur dioxide and ozone were also measured simultaneously by individual instruments. Of these sulfur compounds, CH3SH was dominant and its concentration sometimes reached several tens of ppbv. The concentration of CH3SH was high at night, because of the lack of photodecomposition and local winds from the mountain to the lake. Such time variation was marked in the summer. The CH3SH level decreased significantly downwind, while decreases in concentrations of other compounds such as DMS and SO2 were relatively small. From these temporal and spatial variations, the behavior of CH3SH is described in this paper. The impact of CH3SH near the Siberian big sources is discussed with the presented data. [Copyright &y& Elsevier]

Production of sludge as waste in pulp and paper plants can be considered as one of the serious environmental problems that have to be solved. While landfilling is not a suitable solution from the environmental point of view, thermal treatment proved to be the most appropriate one.This paper describes an efficient way of processing sludge including waste-to-energy aspects. A thermal treatment unit with a capacity of more than 100 tons of wet sludge per day had been built in a large pulp and paper plant some years ago. This pulp and paper plant is located in a mining area. When built, this unit was quite modern. However, because of more and more sweeping environmental laws affecting the process industry, the unit needed a complete retrofit. The retrofit has been realised in three stages.A brief description of the unit for the thermal treatment of sludge is as follows: the waste sludge (after transport from a sludge storage system) is burnt in a multiple hearth incinerator with a fluidised-bed chamber. Then, the flue gas enters a secondary combustion chamber (afterburner chamber). During the first stage of retrofit, only a part of heat from flue gas was utilised for heat recovery (pre-heating air for combustion and fluidisation) and a contact cooler was involved in the unit. The second stage of retrofit can be characterised as a “waste-to-energy” one. The contact cooler was replaced by a system for preheating water for steam generation. Off-gas cleaning system consists of a filter for particulate removal and a three-stage scrubber system. (Several alternatives of retrofit were considered and simulated and the most promising one was selected.) [Copyright &y& Elsevier]