Producing wine entails the consumption of large quantities of fresh water, and consequently the production of large quantities of wastewater the treatability of which becomes increasingly difficult as purification standards get stringent, year after year. The problem is in the presence of aldehydes, phenolic compounds and detergents which are not easily broken down by the microorganisms of ordinary biological treatment. Wastewaters from wineries command high levels of Chemical Oxygen Demand (COD). In recent years research has focused on using Advanced Oxidation Processes (AOPs) as a means to abate the concentration of organic compounds and polluting contaminants, to render the wastewater suitable for ensuing biological treatment. The object of this study was to investigate how effective a particular type of AOP, the Fenton’s reaction, could be as a pre-treatment step aimed at destroying the toxic and biologically stable organic contaminants to reduce the organic load on the ensuing biological treatment of the wastewater. In particular, our experiments showed that if oxidation with Fenton’s reagents was followed by neutralization with lime and precipitation with bentonite, the COD reduction could be as high as 54%. Experimental tests were designed according to a 23 full factorial plan. Elaboration of results led to a model of COD reduction as a function of two significant factors. Finally, the flowsheet and the mass balance of the proposed process were defined.
The article deals with issues related to the study of the connection forms of moisture removed during the drying process of thermolabile heterogeneous products. The difficulties, emerging while developing drying process controlling methods, optimizing energy, material costs, and temperature regimes, necessitate further research. It is shown that the existing methods of studying the forms of moisture connection with the material have significant drawbacks and generally give a qualitative assessment of the state of moisture in the material or are very time-consuming and require long-term laboratory studies. An approach to determining the forms of moisture bond in the material based on graph-analytical analysis of the drying kinetics is proposed, which allows qualitative and quantitative assessment of the state of moisture in the product. With the help of a graphical editor, typical drying kinetics curves were processed and the dependences of the value that characterizes the speed of change in the drying rate on the moisture content of the product were obtained. It is proposed to introduce a new value in the drying theory - drying acceleration. The analysis of the obtained curves testifies to the presence of extremes and inflection points corresponding to the critical moisture content, as well as the presence of areas with slowing or accelerating changes in the drying rate, allowing setting intervals for removing moisture with different binding energy. The approach considered in the article to determining the forms of moisture communication in the material will not only give a qualitative and quantitative assessment of the state of moisture in products, but also reduce the time for analysis and improve the accuracy of the results.
The circular economy and maximization of environmental sustainability are increasingly becoming the vision and mission of companies competing in present-day global markets. In particular, in the energy sector, the transition from fossil fuels to renewable sources of energy has become the widespread mantra. One typical example is the deployment of devices which produce clean energy, such as solar photovoltaic panels and solar thermal panels, wind generators, tidal stream generators, wave power generators, etc. These are undoubtedly generating clean energy, but their manufacture creates hazardous by-products, the disposal of which results in increased environmental pollution. Chemical Vapor Deposition (CVD) is widely used in manufacturing of solar photovoltaic cells. In these processes, typically, crystalline silicon is precipitated from chlorosilanes, iodides, bromides and fluorides. Polluting by-products include deposition of a silicon film, formation of SiO2 powder and formation of toxic vapors of HF, SiH4 and PH3. Usually, these gaseous products are eliminated in a central scrubber, whose unwanted by-product consists in large quantities of hazardous fluorine-containing sludge. This article concerns an effective and inexpensive detoxification of fluorinated sludge, developed by the authors during research into the sludge collected from the scrubber of a PV cell manufacturing plant located in southern Italy.
Based on the results of the analysis of the scientific literature, it is concluded that insufficient attention is paid to the assessment of the expert economist's conclusion. In this regard, the problem area of the study is considered taking into account the practice of conducting forensic economic examinations by experts of the ECC of the Ministry of Internal Affairs of Russia in St. Petersburg and the Leningrad region, non-state experts of St. Petersburg, as well as the practice of reviewing the conclusions of forensic experts from other regions of Russia. The purpose of the work is to study and develop methodological and practical recommendations for improving the assessment of expert opinions that reflect the results of the performed forensic economic examinations, for the presence of insufficient clarity or completeness, as well as in cases of doubts about the validity of the expert's conclusion or the presence of contradictions in the expert's conclusions. The main objectives of the study: review of the review of the expert opinion of the forensic expert; questions to the expert who performed the expert study for the court session. The solution of the research tasks that determine the achievement of the goal of this scientific work meets the requirements of consistency and contains an in-depth presentation of recommendations for evaluating the conclusions of expert economists, taking into account existing practice and positive experience in this area. The methodological basis of the research is based on general scientific methods of synthesis, analysis, induction, deduction, and the dialectical method of cognition of socio-economic phenomena. In the process of writing the work, private scientific methods were used: methods of comparative and formal-logical analysis. The result of the study-specific criteria for evaluating the expert-economist's conclusion within the framework of its review are formulated, directly related to the forensic economic expertise, and a list of typical violations identified within the framework of reviewing the expert-economist's conclusions is disclosed.
Synthetic polymer materials are in high demand due to their exceptional properties. Their main consumers are the tire and rubber industries. When producing synthetic rubbers, there is a loss of polymer in the form of fine crumb rubber, which is formed at the final stage of their production. Today, the removal of this crumb from the wastewater of latex rubber extraction plants is an urgent issue. The results of a study on the extraction of fine rubber crumbs are presented. The task is solved by using an apparatus for separating water phases in the technology, which allows more complete and rational use of expensive products of chemical and petrochemical production, increase productivity and environmental friendliness of production, which leads to an increase in technosphere safety in general. The optimal flow rates of aqueous phases passed through the spiral belt of the filter element, which is 15–25 m/s, have been determined. The separated water stream containing concentrated fine rubber crumb is returned to the styrene-butadiene latex coagulation stage. The purified water phase after the filter element is collected in a separate collector and used to prepare solutions of coagulating and acidifying agents. The additional introduction of finely dispersed rubber crumbs into the composition of the resulting coagulum do not lead to a deterioration in the basic physical and mechanical properties of the resulting rubbers and vulcanizates. The proposed method for industrial wastewater treatment improves safety in the technosphere.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.