Physico-chemical monitoring of biodegradation of furfural from oil industry effluents from the Arzew refinery (Oran) Algeria

Furfural is one of the petroleum products posing a potential danger to the environment and human health. However, the decontamination of these pollutants released into the environment is primarily governed by biodegra-dation processes. This study is based on biodegradation kinetics at increasing concentrations of furfural by natural mixed culture in order to assess the potential of this process in the elimination of furfural from petrochemical effluents from the ARZEW refinery. This biodegradation was measured through physicochemical parameters such as pH, electrical conductivity, con-centration of hydrocarbons, the chemical oxygen demand (COD), biochemi-cal oxygen demand (BOD5) and the concentration of furfural. The results obtained show at a concentration of 250ppm of injected furfural: a decrease in pH 4.9 and an increase in other parameters (conductivity 3450 μS.cm-1, HC 102 mg / l; furfural 210 ppm, COD 327mg / l, BOD5 98mgO2 / l. The study findings indicated that the injection of these effluents with concentrations greater than 180 ppm leads to values of pH, EC, HC, Furfural, COD, BOD5 which do not comply with direct discharge standards and disrupt biological treatment. The high levels of furfural not only cause a pollution problem but can also disrupt the functioning of bacteria at the biological treatment level. Therefore, dilution with the filtration wash water before switching to biologi-cal treatment is recommended in order to reduce the concentrations below 180 ppm.

Achieving a High Selectivity for Nitrate Electrochemical Reduction to Ammonia over MOF-Supported RuxOy Clusters

Nitrate (NO3-) electroreduction to ammonia(NH4+) is a sustainable alternative strategy for the NH4+ synthesis, and it can be used to solve the water pollution problem by simultaneously turning waste into...

An introduction to heavy metal pollution and different technologies available for remediation

This paper revises the fundamental facts about potentially toxic elements belonging to the group of heavy metals. The study highlights the ongoing soil pollution status affected by these non-biodegradable elements, the basic characteristics of these metals that make them toxic, their mode of accumulation in different trophic levels, their toxic effect on human beings and the probable remediation technologies being used to remediate soils contaminated with heavy metal when the pollution problem has evolved. The technologies focused on solidification, soil washing, soil flushing, electro-kinetic remediation and phytoremediation are presented. The choice of the technology to be used for remediation depends on the condition of the soil and the extent of contamination. Conventional electro-kinetics is the most effective and rapid technology, but on the scale of ecosystem restoration, phytoremediation is an eco-friendly, green and cost-effective solution.

Dining Lampblack Treatment Processes in China

The PM2.5 and other small particles produced by cooking oil fumes have contributed up to 25% to the urban atmospheric PM2.5, which has a bad impact on air quality and seriously threatens human health. Aiming at the pollution problem caused by catering oil fume, this article analyzes the threats of air pollution to human health based on the compositions and characteristics of catering oil fume, illustrates the development trend of China′s food and beverage lampblack control policy, and summarizes and points out the current situation and development trend of catering oil fume treatment. In order to provide ideas for the design of more efficient and energy-saving treatment processes in the future, the advantages and disadvantages were reviewed, and the improvement direction of the treatment technology was discussed.

Comparative Transcriptomic Analysis of Root Cadmium Responses in Two Chinese Rice Cultivars Yuzhenxiang and Xiangwanxian 12

Cadmium (Cd) pollution in paddy soil is an increasingly serious issue in rice production. It has been reported that there is a higher or lower grain Cd accumulation in the rice cultivars Yuzhenxiang (YZX) or Xiangwanxian 12 (XWX), respectively. To better manage the Cd pollution problem, the genes that might play vital roles in governing the difference in root Cd responses between these two rice cultivars were examined. In this study, the results of RNA sequencing (RNA-seq) showed that there were 341 and 161 differentially expressed genes in the roots of YZX and XWX after Cd exposure, respectively. Among these genes, 7 genes, such as Os06g0196300 (OsJ_019618), Os07g0570700 (OsJ_24808), ADI1, GDCSH, HSFB2C, PEX11-4, and CLPB1, possessed higher degree nodes with each other, through interaction analysis by the STRING (search tool for the retrieval of interacting genes/proteins) software, suggesting that they might play vital roles in Cd response. Based on GO enrichment analysis, 41 differently expressed genes after Cd treatment in YZX or XWX were identified to be related to Cd response. Through comparative transcriptomic analysis, 257 genes might be associated with the root Cd response difference between YZX and XWX. Furthermore, we supposed that ADI1, CFBP1, PEX11-4, OsJ_019618, OsJ_24808, GDCSH, CLPB1, LAC6, and WNK3 might be implicated in Cd response based on the combined analysis of RT-qPCR, interaction, and GO annotation analysis. In conclusion, the numerous genes that might be related to Cd stress response and root Cd response difference between YZX and XWX at the booting stage may be of benefit for the development of rice varieties with low Cd consumption.

Responses of Net Anthropogenic N Inputs and Export Fluxes in the Megacity of Chengdu, China

Anthropogenic N inputs have become progressively more problematic and have profoundly affected the water quality in megacities throughout China. Thus, to design and implement appropriate megalopolis watershed management, it is important to understand the relationship between N inputs and exports and to identify the N pollution sources. To that end, in this work, the net anthropogenic N inputs (NANI) in Chengdu City were estimated based on statistical data collected between 1970 and 2019. N input fluxes and pollution sources were estimated through sample collection and field measurements that were performed between 2017 and 2019, while nitrate (NO3−) was identified using stable isotope and Bayesian model (SIAR) analysis. The NANI was found to be affected primarily by livestock and poultry consumption of N rich feed. Moreover, the N export fluxes and runoff showed a high degree of correlation. Notably, NO3− fluxes exhibited a significant increase over the course of the study period, such that, by 2019, the total N fluxes (18,883.85 N kg/km2) exceeded the NANI (17,093.87 N kg/km2). The results indicate that although livestock and poultry farming were the original primary sources of NANI, their contributions declined on an annual basis. Moreover, with the emphasis placed on point source management in Chengdu City, domestic sewage discharge has been significantly reduced. Therefore, N retention in groundwater is thought to be the factor driving the N flux increase. These findings are pivotal to solving the N pollution problem in megacities like Chengdu (China).

Microplastics pollution in salt pans from the Maheshkhali Channel, Bangladesh

Microplastics (MP) were recognized as an emergent pollution problem due to their ubiquitous nature and bioaccumulative potential. Those present in salt for consumption could represent a human exposure route through dietary uptake. The current study, conducted in Bangladesh, reports microplastics contamination in coarse salt prepared for human consumption. Sea salt samples were collected from eight representative salt pans located in the country's largest salt farming area, in the Maheshkhali Channel, along the Bay of Bengal. Microplastics were detected in all samples, with mean concentrations ranging from 78 ± 9.33 to 137 ± 21.70 particles kg−1, mostly white and ranging in size from 500–1000 µm. The prevalent types were: fragments (48%) > films (22%) > fibers (15%) > granules and lines (both 9%). Fourier transform mid-IR and near-IR spectra (FT-MIR-NIR) analysis registered terephthalate (48%), polypropylene (20%), polyethylene (17%), and polystyrene (15%) in all samples. These results contribute to the MP's pollution knowledge in sea salts to understand and reduce this significant human exposure route and environmental pollution source in the future.

Optimal Control of a Partially Known Coupled System of BOD and DO

The work presented in this paper is concerned with the organic pollution problem and water quality valuation. Biochemical oxygen demand has been used to evaluate the quality of water. If organic matter is present the dissolved oxygen is consumed. This article considers an optimal control problem of coupled system with missing initial conditions, which presents the relation between the biochemical oxygen demand and the dissolved oxygen. The main objective is to control the concentration of dissolved oxygen using the information given in the biochemical oxygen demand equation. The main tool used to characterize the optimal control of the investigate system under the Pareto control formulation.

Analysis of Factors Influencing the Trophic State of Drinking Water Reservoirs in Taiwan

Eutrophication is an environmental pollution problem that occurs in natural water bodies. Regression analyses with interaction terms are carried out to identify the factors influencing the Shimen, Mingde, and Fongshan Reservoirs in Taiwan. The results indicate that the main factor influencing these reservoirs is total phosphorus. In the Shimen and Mingde Reservoirs, the influence of total phosphorus, when interacting with other factors, on water quality trophic state is more serious than that of total phosphorus per se. This implies that the actual influence of total phosphorus on the eutrophic condition could be underestimated. Furthermore, there was no deterministic causality between climate and water quality variables. In addition, time lagged effects, or the influence of their interaction with other variables, were considered separately in this study to further determine the actual relationships between water trophic state and influencing factors. The influencing patterns for three reservoirs are different, because the type, size, and background environment of each reservoir are different. This is as expected, since it is difficult to predict eutrophication in reservoirs with a universal index or equation. However, the multiple linear regression model used in this study could be a suitable quick-to-use, case-by-case model option for this problem.