Chemical Plant Research Articles

Biogeochemical In Situ Barriers in the Aquifers near Uranium Sludge Storages

The long-term operation of uranium sludge storages causes serious problems: it contaminates the neighboring aquifers with dangerous substances (uranium, nitrate, ammonium, and sulfate). To purify the aquifers can be costly and time-consuming; therefore, it is important to use the potential of in situ conditions, e.g., the aboriginal microflora and its ability to biologically remediate water reservoirs. In this work, we study the geological, geochemical, and microbiological characteristics of groundwater contaminated by uranium sludge storages resulting from the production cycles of four Russian chemical plants. All of the sites under consideration were extremely contaminated with nitrate (up to 15 g/L); in each case, we used denitrifying bacteria as a dominant group of microorganisms for purification. Our laboratory studies showed that microbial stimulation of water samples by milk whey promotes O2 and nitrate removal; this, in turn, started the cycle of anaerobic processes of authigenic precipitation caused by the reduction of iron and sulfate in the system. Thus, a mineral geochemical barrier preventing uranium immobilization formed. As a result, the uranium of the liquid phase decreased about 92–98% after 3–6 months (decomposition time depends on the nitrate concentration in the groundwater probe). The resulting amorphous biogenic phases contain sulfur, iron, phosphorus, and uranium.

Chemical plant security law expires

Chemical plant security law expires

Innovative DMHS Algorithm Application in Wireless Sensor Networks for Efficient Routing in High-Risk Environments.

Efficient routing is essential for the proper functioning of wireless sensor networks (WSNs). Recent research has focused on optimizing energy and delay for these networks. Nevertheless, there is a dearth of studies that have examined the effects of volatile settings, such as chemical plants, coal mines, nuclear power plants, and battlefields, where connectivity is inconsistent. In such contexts, sensor networks may face security incidents, and environmental factors such as node movement and death can result in dynamic changes to the network topology. A novel design algorithm grounded on Dynamic Minimum Hop Selection (DMHS) was introduced in this paper. The key principle behind DMHS is to use a probabilistic forwarding decision-making process through a distributed route discovery strategy that utilizes dynamically adjusted minimum hop counts of nodes. Simulation results indicate that the life cycle of the DMHS algorithm increases by more than 12% over 700 nodes when compared to the traditional energy-saving algorithm. Furthermore, our algorithm performs better in the average delivery rate of node, and has a 10% to 21% improvement compared to the other algorithms. Overall, the DMHS algorithm represents an important contribution to the development of WSNs that can function robustly in high-risk and unstable environments.

US chemical plant security law expires in Senate dispute

US chemical plant security law expires in Senate dispute

Techno-economic assessment of butanol and pentanol productions from sorption enhanced chemical looping gasification of a lignocellulosic biomass

The major aim of this study is to propose an economic chemical plant for conversion of biomasses into biofuels within CO2 capture which can make a big contribution to the energy demand and environmental protection. Therefore, a novel process for conversion of rice straw using sorption enhanced biomass chemical looping gasification (SE-BCLG) to butanol and pentanol is simulated in Aspen Plus V 8.8. In this regard, the wet rice straw is turned into the syngas after drying and SE-BCLG stages. Then, the butanol and pentanol are produced after acid gas removal, alcohol production and purification sections. In addition, an optimization and a techno-economic assessment are carried out to evaluate the process. The technological analysis shows that the process can produce 222.6 t.day−1 butanol and pentanol from 960 t.day−1 rice straw. The economic analysis illustrates that the total investment to start the project and the total annual operating cost of the process are MUS$ 642.707 and 43.965 MUS$.year−1, respectively. Finally, it is proved that the butanol production cost for the proposed plant is 1286.532 US$.t−1. Therefore, these results indicate that the proposed process if this study is more economic than some other studies.

ASSESSMENT OF GEOCHEMICAL CHARACTERISTICS FOR AGRICULTURAL LAND USE IN PERUNDURAI TALUK, ERODE DISTRICT, TAMILNADU, INDIA

In Perundurai Taluk, which is part of Tamil Nadu's Erode District, the adequacy of underground water for agricultural use was evaluated. Numerous tanneries, chemical plants, textile factories, and dyeing facilities are located close to Perundurai. These industries directly discharge their effluents into the groundwater, which then becomes contaminated. To determine the suitability of subsurface water for agricultural use, groundwater samples from 15 villages were analyzed over the course of two seasons. The appropriateness of the groundwater's chemical type was determined by interpreting Piper trilinear diagrams. It demonstrates that underground water is more alkaline. Most groundwater samples fall into class 4 and Seenpuram falls into class 2, as shown by the USSL Staff diagram. The test results indicate that contamination in the Seenapuram is more due to SIPCOT which poses a potential risk to both agricultural soils and the local population in that area.

Mechanical Characterization and Microstructural Analysis of Stir-Cast Aluminum Matrix Composites (LM5/ZrO2)

Aluminum matrix composites (AMCs) are largely used in defense, maritime, and space applications for their excellent properties. LM5 is used where very high resistance to corrosion from seawater or marine atmospheres is required, for equipment used for the manufacture of foodstuffs, cooking utensils, and chemical plants. Zirconia is preferred over other reinforcements as it shows comparatively great refractory properties, high scratch resistance, and thermal shock resistance. Utilizing the stir casting technique, an attempt was made to produce AMCs of LM5 aluminum alloy strengthened with ZrO2. The weight percentage of ZrO2 was changed to 0%, 3%, 6%, and 9%. The specimens were prepared and tested as per ASTM standards to find the density, micro and macro hardness, impact, tensile, and compressive strength. The micrographs and SEM images confirm the uniform distribution of ZrO2 particles in the aluminum matrix. LM5/9%ZrO2 AMC has the highest density value of 2.83 g/cm3 and LM5/3%ZrO2 has the least porosity of 2.55%. LM5/9% ZrO2 has the highest hardness values of 78 VHN and 72 HRE. LM5/6% ZrO2 AMC has the highest tensile strength of 220 MPa, compressive strength of 296 MPa, and toughness of 12 J. LM5/6% ZrO2 AMCs may be used for many structural applications.

Attributional and consequential life cycle perspectives of second-generation polylactic acid: The benefits of integrating a recycling strategy

The climate crisis calls for a shift from petrochemicals to bio-based products to reduce environmental consequences. Polylactic acid (PLA) is one of the most widely used biopolymers, due to its mechanical properties and renewable origin, to produce bio-based compostable plastic for food packaging. The objective of this study is to determine the environmental feasibility of a second-generation PLA production based on wheat straw; and the role of a chemical recycling plant on the environmental performance of a bioproduct at an early design stage. A holistic assessment was performed through the Life Cycle Assessment (LCA) methodology considering both attributional and consequential perspectives, through a cradle-to-grave approach. The attributional LCA results show that lactic acid production was the main contributor due to the wheat straw pre-treatment and downstream separation and purification (DSP) processes. The integration of a recycling plant leads to a significant reduction of burdens, ranging from 1.38 to 0.44 kg CO2eq in the Global Warming category. Furthermore, consequential LCA results shows that the increased demand for substitute products for activities such as feeding, fertilisation and energy generation and the indirect emissions from land use change related to the conversion of land for the cultivation of raw materials are relevant factors in the environmental effects associated with the possible implementation of straw-based bioPLA production system.

Minimum production scale for economic feasibility of a titanium dioxide plant

AbstractTitanium dioxide (TiO2) is an important industrial chemical that is completely import dependent in Nigeria. Local entrepreneurs seeking to establish a production scale TiO2 plant in Nigeria face both financing challenges and challenges to right‐sizing plants to best fit the local markets. In this study, we ask: What is the minimum scale for the economic feasibility of establishing a TiO2 plant in Nigeria, considering the country's currently small market size for the chemical and the limitations imposed by the economy of scale? We determine that the required minimum production scale varies from 21 867.44 to 11 202.16 tonnes per annum (tpa) for an investment lifetime of 10–20 years – compared to a typical developed world plant size of 150 000 tpa. A sensitivity study shows that minimum production scale decreases rapidly as product price increases, enhancing the economic prospect of a small‐scale plant in Nigeria where the retail price of TiO2 is as high as 328% of the average global price. Further studies emphasize the importance of future growth in demand and government incentives in enhancing the plant's economic prospect. The modeling framework developed and used for this analysis is adaptable to other applications in determining minimum scales for economic feasibility of constructing and operating flexible chemical plants in young and uncertain markets with potential to scale in the future. This study offers unique contributions to address investment challenges around chemical manufacturing, a critical component of industrialization and economic development for developing countries.

Presence of Perfluoroalkyl Substances in Landfill Adjacent Surface Waters in North Carolina.

Landfills pose an important public health risk, especially in historically disenfranchised communities that are disproportionately sited for landfills and in rural areas where private wells may be impacted. Landfills are major sources of perfluoroalkyl substances (PFAS) that migrate into the surrounding environment. This study characterized PFAS in surface waters adjacent to two landfills, one in Sampson County (SC) and one in Orange County (OC) in North Carolina. In addition to municipal solid waste and construction and demolition waste, the landfill in SC accepts industrial sludge from a chemical plant that produces proprietary PFAS. Over four months, 35 surface water samples were collected at upstream, landfill-adjacent, and downstream/downgradient sites. Thirty-four PFAS were analyzed using liquid chromatography with tandem mass spectroscopy. Of those, six novel and six legacy PFAS were detected. Legacy PFAS were detected in surface water near both landfills, with the highest concentrations adjacent to the landfill. Novel PFAS were only detected in surface water near the SC landfill and showed the highest concentrations adjacent to the landfill, indicating offsite migration of PFAS. These findings support the need for more comprehensive and frequent monitoring of groundwater and surface water wells near landfills and stricter regulation regarding the landfilling of industrial materials.

Revealing Smart Selective Jamming Attacks in WirelessHART Networks

As a leading industrial wireless standard, WirelessHART has been widely implemented to build wireless sensor-actuator networks (WSANs) in industrial facilities, such as oil refineries, chemical plants, and factories. For instance, 54,835 WSANs that implement the WirelessHART standard have been deployed globally by Emerson process management, a WirelessHART network supplier, to support process automation. While the existing research to improve industrial WSANs focuses mainly on enhancing network performance, the security aspects have not been given enough attention. We have identified a new threat to WirelessHART networks, namely smart selective jamming attacks, where the attacker first cracks the channel usage, routes, and parameter configuration of the victim network and then jams the transmissions of interest on their specific communication channels in their specific time slots, which makes the attacks energy efficient and hardly detectable. In this paper, we present this severe, stealthy threat by demonstrating the step-by-step attack process on a 50-node network that runs a publicly accessible WirelessHART implementation. Experimental results show that the smart selective jamming attacks significantly reduce the network reliability without triggering network updates.

Demonstration Test of Triaxial Superconducting Cable System Installed in Commercial Chemical Plant Grid

A triaxial high-temperature superconducting (HTS) cable for practical cable systems was installed in the chemical plant of a private company (BASF Japan), and a large-scale demonstration test was performed. An HTS (REBa2Cu3O7-d) triaxial cable with a length of 200 m was used, and it was laid at a height of approximately 6 m above the ground and cooled using circulating liquid nitrogen. The test was performed from November 2020 to September 2021. In this paper, we report the results of the demonstration test and the energy-saving effects of the cable system.

Zinc foliar spray enhances growth, yield and economic return of cassava variety Kasetsart 50 production

Cassava is extensively cultivated in low fertility sandy soils in the Northeast Thailand. Low yield and economic return of cassava grown in this area is partly due to deficiency of micronutrients especially zinc (Zn). The objective of this study was to investigate the effects of foliar spray of Zn on growth, yield, quality and economic return of the cassava variety Kasetsart 50. Five treatments consisted of unfertilized control (T1), recommended fertilizer (formula (formula 15-15-15 at the rate of 313 kg ha-1) (T2), recommended fertilizer plus foliar spray of Zn at the rate of 6.25 kg ha-1 (2% Zn) (T3), recommended fertilizer plus foliar spray of Zn at the rate of 12.50 kg ha-1 (4% Zn) (T4) and recommended fertilizer plus foliar spray of Zn at the rate of 18.75 kg ha-1 (6% Zn) (T5). The treatments were assigned in a randomized complete block design with three replications. The crop was planted in a Korat soil series (loamy sand soil) under rainfed conditions. Data were recorded for soil chemical properties and plant growth parameters at 11 months after planting. The recommended fertilizer plus foliar spray of 2% Zn (T3) resulted in the highest fresh root yield (26.0 t ha-1), starch content (27.83%), and economic return over the fertilizer cost (960.0 USD ha-1), and the increases in fresh root yield, starch content and economic return over the fertilizer cost compared to T1 were 100, 54 and 69%, respectively. The results suggested that foliar spray of 2% Zn together with chemical fertilizer was effective in overcoming Zn deficiency in the loamy sand soils for cassava variety Kasetsart 50 production

Assessment of the water quality and toxicity effects on zebrafish (Danio rerio) of a stream near a phosphorus chemical plant in Guizhou Province, southwestern China.

To reveal the influence of the phosphorus chemical industry (PCI) on regional water environmental quality and safety, the water quality and ecotoxicological effects of a stream near a phosphorus chemical plant (PCP) in Guizhou Province, southwestern China, were investigated based on water samples collected from the stream. The results showed that the average concentrations of NH3-N, TN, P, F-, Hg, Mn, and Ni were 3.14mg/L, 30.09mg/L, 3.34mg/L, 1.18mg/L, 1.06μg/L, 45.82μg/L, and 11.30μg/L, respectively. The overall water quality of the stream was in the heavily polluted category, and NH3-N, TN, P, F-, and Hg were the main pollution factors. The degree of pollution was in the order of rainy period > transitional period > dry period, and the most polluted sample site was 1100m from the PCP. After 28 days of exposure to stream water, there was no significant change in the growth parameters of zebrafish. The gills of zebrafish showed a small amount of epithelial cell detachment and a small amount of inflammatory cell infiltration, and the liver tissue displayed a large amount of hepatocyte degeneration with loose and lightly stained cytoplasm. Compared with the control group, the%DNA intail, tail length, tail moment, and olive tail moment were significantly increased (p < 0.05), indicating that the water sample caused DNA damage in the peripheral blood erythrocytes of zebrafish. The stream water in the PCI area was found to be polluted and exhibited significant toxicity to zebrafish, which could pose a threat to regional ecological security.

Water and chemical consumption in the textile processing industry of Bangladesh

The textile wet processing industry is considered a notorious polluter due to its widespread use of natural resources without proper replenishment. Bangladesh is one of the largest producers of textile products in the World, and therefore, it is vulnerable to environmental degradation. Bangladesh is predominantly a cotton processing country; therefore, reactive dyes are commonly used, and the dye combination is very water and chemical-intensive. There is a scarcity of information on the consumption of water, textile dyes and the generation of wastewater in the textile sector. Thus, this study aimed to estimate the amount of water use, wastewater generation, and chemical use in textile wet processing units. Therefore, a face-to-face in-depth questionnaire-based survey was conducted in 18 textile wet processing factories, including knit composite, knit dyeing, yarn dyeing, denim dyeing, and knit and yarn dyeing. The average specific groundwater consumption to process 1 Kg of textile materials was 164 L/Kg (SD ~ 81.8); dyehouse water was136 L/Kg (SD ~ 70.6), while corresponding wastewater was 119 L/Kg (SD ~ 73.0). This high consumption of groundwater is directly linked to the depletion of groundwater in the region, where textile industries are situated and also, causes water pollution through wastewater generation. The water used in the dyehouse water was usually soft water and found to be in a range of 68% to 100% that of groundwater extracted. For chemical use, a factory used 449 g of chemicals to process 1 Kg of textile materials, in which the most widely used chemicals were inorganic and basic chemical in nature. However, the chemical use varied from 152 g/Kg to 705 g/Kg of textile production. The total chemical consumption ranged from 954 tons to 4,525 tons a year. More than 50% of the wastewater treatment plants were biological, a quarter of combination and physico-chemical and biological, and the rest were chemical treatment plants in this study. Even though this study may not represent the whole textile wet processing industry of Bangladesh, however, This study provides baseline information on water and chemical consumption and wastewater generation. Our findings would be helpful for policy makers and researchers to identify transformative challenges required at the national level.

Real-time emission characteristics, health risks, and olfactory effects of VOCs released from soil disturbance during the remediation of an abandoned chemical pesticide industrial site.

Volatile organic compounds (VOCs) released along with soil disturbance during the remediation of abandoned industrial sites have attracted great attention due to their possible toxicity and odour. However, the real-time emission characteristics of these VOCs and their subsequent effects on health and olfaction are less understood. In this study, the gaseous VOCs released from soil disturbance by excavators and drilling rigs at an abandoned chemical pesticide plant were monitored online with a laboratory-built single photoionization time-of-flight mass spectrometer (SPI-TOFMS). Twelve main VOCs with total mean concentrations ranging from 2350 to 3410 μg m-3 were observed, with dichloromethane (DCM) having a significant contribution. The total concentrations of the remaining 11 VOCs increased substantially during soil disturbance, with the total mean concentrations increasing from 18.65-39.05 to 37.95-297.94 μg m-3 and those of peak concentrations increasing from 28.46-58.97 to 88.38-839.13 μg m-3. This increase in VOC concentrations during soil disturbance leads to an enhanced heath risk for on-site workers. The distinctive difference between the mean and peak concentrations of VOCs indicates the importance of using mean and peak concentrations, respectively, for risk and olfactory evaluation due to the rapid response of the human nose to odours. As a result, the cumulative noncarcinogenic risk at the relatively high pollutant plot was higher than the occupational safety limit, while the total carcinogenic risks at all monitored scenarios exceeded the acceptable limit. Among the VOCs investigated, DCM and trichloroethylene (TCE) were determined to be crucial pollutants for both noncarcinogenic and carcinogenic risks of VOCs. With regard to olfactory effects, organic sulphides, including dimethyl disulphide (DMDS), dimethyl sulphide (DMS), and dimethyl trisulphide (DMTS) were identified as dominant odour contributors (78.28-92.11%) during soil disturbance.

A licensing plan for coupling nuclear–renewable hybrid energy systems

South Africa committed to reducing greenhouse gas emissions by 34% below "Business As Usual" levels by 2020 and 42% by 2025 at the Copenhagen climate change conference. However, global energy demand was projected to rise due to population and industrial growth, with energy usage expected to increase by 13% through 2040. In South Africa, a steady increase in electricity demand prompted the government to implement a new growth path (NGP), which prioritized job creation in all economic policies, including energy. To address the growing energy demand, an alternative energy source for combined heat and power was necessary, particularly for synthetic fuel production. The coupling of a high temperature reactor (HTR) with a chemical process plant could improve carbon and thermal efficiency, as seen in international organizations like the ARCHER (Advanced High-Temperature Reactors for Cogeneration of Heat and Electricity R&amp;D) project. HTRs are still in their conceptual stages andaresuitable candidate forcouplingto an energy-intensiveindustrythat require process heat with sufficiently hightemperatures,with potential uses for NRHES (Nuclear-Renewable Hybrid Energy Systems). The South African team aimed to model the SASOL process, assess its financial viability, and develop a licensing plan.

Fungicidal and Stimulating Effects of Heteroleptic Copper Complex on the Germination and Phytosafety of Plants

At present, when the whole world is intensively switching to organic farming, the refusal or minimization of the usage of chemical plant protection products and synthesized fertilizers is a very urgent issue for the agro-industrial complex (AIC). Accordingly, the solution to the problems of increasing yields and ensuring the fight against pathogenic components should be carried out in accordance with the principles of “green” chemistry. In this regard, the usage of heteroleptic complexes based on carboxylic and amino acids with biogenic metals is dictated not only by their availability, low cost, and ability to increase crop yields but also by fungicidal activity, lower toxicity, and easy biodegradability, which lists them among the “green” and cost-effective plant biostimulants. In the present work, for the first time, a heteroleptic complex based on succinic acid and glycine, with the formula [Cu(succ)(gly)], was developed for usage as a fungicidal biostimulant, which has the ability to significantly reduce the number of pathogens. We found that this compound has a layered structure and was able to increase soybean germination up to 100%.

Integrating information, financial, and material flows in a chemical supply chain

We address the flows involved in a real supply chain and discuss how they can be integrated for supply chain management. A scheduling model is proposed based on a State-Task Network representation to schedule order transactions and manufacturing operations in a make-to-order chemical plant. The proposed model is compared to scheduling models that focus on either the order transactions or the manufacturing operations. The advantage of the integrated approach is found in the accuracy of the solutions attained, whereas the siloed models produce suboptimal or infeasible solutions. Each model is compared in a stochastic discrete event simulation environment. An integrated scheduling model is also presented, which includes information, financial, and material flows along a three-echelon supply chain. This integrated model serves as a starting point for developing decision-support systems that take a more comprehensive view of the complex relationships amongst the different flows involved in real supply chains.

Positive effects of two decades of passive ecological restoration in a historically polluted marine site

The Mediterranean Sea is one of the most exploited regions of the world’s oceans. Here industrial activities have determined either acute or long-term impacts on coastal marine ecosystems. In this study, we investigated macrofauna distribution and diversity, and food-web functioning in a coastal area of the Mediterranean Sea facing an industrial chemical plant abandoned in the ‘90s to assess benthic ecosystem health. This area has been identified as a Site of National Interest (SNI) since 2002 and has been closed to any human activity awaiting to be remediated according to national laws. Our results indicate that, two decades after the SNI declaration (a decade after the plant decommissioning), there is no longer any sign of the impact of historical contaminations on macrofauna and benthic food web functioning. Overall, all the thirty-six sites showed high/good ecological quality according to the score assigned by AMBI and M-AMBI indexes, reflecting the absence of chronic impacts. Our findings reveal, for the first time, the positive effects of passive restoration (i.e., unassisted, or spontaneous recovery following cessation of anthropogenic impacts) on historically impacted coastal ecosystems since their health conditions, in terms of both abiotic (environmental variables and contaminant concentration) and biotic (macrofauna diversity and community composition, and benthic food-web structure) factors, were indistinguishable from surrounding non-impacted areas. These findings also suggest that other effective area-based conservation measures (OECMs) could be useful not only for biodiversity conservation of vulnerable and priority habitats in larger ocean sectors but also to promote the passive recovery of historically contaminated ecosystems.