Contamination of wastewater by organic pollutants is a major worldwide issue. For instance plastic additives such as phthalates
are found in wastewater. Efficient techniques are thus needed to clean wastewaters. The Fenton reaction involving H2O2 and Fe(II) salts can be used to treat polluted water. During the Fenton reaction pollutants are decomposed directly by hydroxyl
radicals. In some cases toxic by-products are produced. Here dimethyl phthalate, diethyl phthalate, and dipropyl phthalate
by-products formed during the Fenton reaction were studied. Fenton degradation of selected phthalates yielded numerous transformation
products such as hydroxylated phthalates. The hydroxylation reaction occurred at the aromatic ring of phthalates and yielded
mono- and dihydroxylated phthalates. For monohydroxylated phthalate, 3-hydroxy- and 4-hydroxydialkylphthalates are the main
transformation products. In addition to hydroxylated derivatives, aliphatic chain degraded mono- and dihydroxylated phthalates
were also detected. 相似文献
Polyethylene laminated disposable paper cups are commonly used as a container for hot drinks, yet there is limited knowledge on the transfer of contaminants from the cup to the drink. Here we poured 95?C hot water in 14 cups, to simulate the preparation of hot beverage for daily use. We studied the water composition after 15 min by inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography. Results show the presence of metals such as vanadium, chromium, copper, cobalt and arsenic at concentration ranging from 0.04 to 1.80 µg/L. Nitrate, nitrite, chloride, bromate, fluoride and sulfate ions were also detected at concentration from 0.003 to 49.21 mg/L. All concentrations are below the WHO maximum permissible limits in drinking water. However, the levels of vanadium at 1.24 µg/L and fluoride ions at 1.03 mg/L are likely to induce a health risk by bioaccumulation after long-term water ingestion. Therefore paper cups composition should be modified to avoid the release of contaminants in hot drinks.
Environmental Science and Pollution Research - In light of the COVID-19 pandemic, it is becoming extremely necessary to assess respiratory disease transmission in passenger cars. This study... 相似文献
Natural radionuclides, such as 210Po and 210Pb were measured in the water samples collected from six stations at Kuala Selangor, Malaysia. Results for 210Po and 210Pb in dissolved and particulate phases have showed the difference in distribution and chemical behavior. The fluctuation activities of 210Po and 210Pb depend on wave action, geology and degree of fresh water input occurring at study areas and probably due to different sampling dates. The distribution coefficient, Kd, values of 210Po and 210Pb ranged from 2.0 × 103 l g−1 to 265.15 × 105 l g−1, and from 3.0 × 103 l g−1 to 558.16 × 105 l g−1, respectively. High Kd values of 210Po and 210Pb indicated that a strong adsorption of 210Po and 210Pb onto suspended particles, and the sinking of both nuclides on the seabed at study locations were controlled by the characteristics of suspended particles. 相似文献
Journal of Material Cycles and Waste Management - The accumulation of floatable litter load captured in gross pollutant trap (GPT) due to the hydrological runoff has become challenging due to rapid... 相似文献
Environmental Geochemistry and Health - Soil stabilization is a remedial technique that reduces the exposure of the soil environment to soil contaminants. Its efficacy can be assessed by... 相似文献
Soil contamination with heavy metals occurs as a result of both anthropogenic and natural activities. Heavy metals could have
long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. Soil enzymatic
activities are recognized as sensors towards any natural and anthropogenic disturbance occurring in the soil ecosystem. Similarly,
microbial biomass carbon (MBC) is also considered as one of the important soil biological activities frequently influenced
by heavy metal contamination. The polymerase chain reaction–denaturing gradient gel electrophoresis (DGGE) has recently been
used to investigate changes in soil microbial community composition in response to environmental stresses. Soil microbial
community structure and activities are difficult to elucidate using single monitoring approach; therefore, for a better insight
and complete depiction of the soil microbial situation, different approaches need to be used. This study was conducted in
a greenhouse for a period of 12 weeks to evaluate the changes in indigenous microbial community structure and activities in
the soil amended with different application rates of Cd, Pb, and Cd/Pb mix. In a field environment, soil is contaminated with
single or mixed heavy metals; so that, in this research, we used the selected metals in both single and mixed forms at different
application rates and investigated their toxic effects on microbial community structure and activities, using soil enzyme
assays, plate counting, and advanced molecular DGGE technique. Soil microbial activities, including acid phosphatase (ACP),
urease (URE), and MBC, and microbial community structure were studied. 相似文献
The lakes’ fisheries play an important role in Egyptian economy. In 1980s, they provided more than 50 % of harvested fish in Egypt but now their contribution to the Egypt fish production decreased to only 12.5 % in 2012. Lake Timsah, one of the Suez Canal lakes, faced many challenges that lead to serious changes in its water and fish quality, fish production, as well as the catch composition. The present work investigated the impact of pollution, food availability, and excessive fishing mortality on the haffara production in lake Timsah. The distribution of four heavy metals (Pb, Zn, Ni, and Fe) was detected seasonally in water and in muscles, gills, and livers of Rhabdosargus haffara, during 2012 through 2013. Fe and Zn were presented by high values in liver, while Pb and Ni in gills. Generally, the lowest concentrations of all metals were found in muscles. The recorded crustacean organisms (the main food of haffara) decreased from 12 species and 32,079 organisms?m2 in 2012 to only 7 species and 7290 organisms?m2 in 2013 while the amphipods completely disappeared. This serious change was due to the severe pollution in the lake. A logistic surplus production model was fitted to the catch per unit effort indices, to estimate the maximum sustainable yield and the optimum level of fishing effort. The results revealed that haffara stock at lake Timsah is overfished, and the estimated precautionary target reference points advised the reduction of fishing effort by about 30–50 %. 相似文献
In spite of the importance and popularity of swimming pools in summer, they have been identified as posing some public health risks to users due to either chemical or microbiological contamination. This study was carried out aiming at assessing the quality of water for some Alexandria's swimming pools in order to determine its compliance with the Egyptian standards no. 418/1995. Five swimming pools were selected randomly from different districts. Physical and chemical parameters, as well as biological examination of a total of 30 samples, were carried out using standard analytical methods. Water samples were collected from the studied swimming pools monthly over 6?months and pool water monitoring was carried out during afternoon of the weekends when the pools were most heavily used. The results indicated overall poor compliance with the standards. Compliance of the pool water to the microbial parameters, residual chlorine, pH, and turbidity were 56.7% (17 samples), 20% (6 samples), 46.7% (14 samples), and 46.7% (14 samples), respectively. Statistical analysis showed significant association between water contamination with microbial indicators and physical–chemical aspects such as residual chlorine, temperature, turbidity, and load of swimmers. Furthermore, Cryptosporidium oocysts and Giardia lamblia cysts has been found in 10% of samples. It was concluded that there is a need to improve disinfection and cleaning procedures, with consideration given to safety, and size of the pool in relation to bathing load. There is also a need to monitor swimming pool water quality continuously, and to increase bather hygienic practices and awareness of the risks as well as training of governmental inspectors. 相似文献
This study investigates the applicability of multivariate statistical techniques including cluster analysis (CA), discriminant analysis (DA), and factor analysis (FA) for the assessment of seasonal variations in the surface water quality of tropical pastures. The study was carried out in the TPU catchment, Kuala Lumpur, Malaysia. The dataset consisted of 1-year monitoring of 14 parameters at six sampling sites. The CA yielded two groups of similarity between the sampling sites, i.e., less polluted (LP) and moderately polluted (MP) at temporal scale. Fecal coliform (FC), NO3, DO, and pH were significantly related to the stream grouping in the dry season, whereas NH3, BOD, Escherichia coli, and FC were significantly related to the stream grouping in the rainy season. The best predictors for distinguishing clusters in temporal scale were FC, NH3, and E. coli, respectively. FC, E. coli, and BOD with strong positive loadings were introduced as the first varifactors in the dry season which indicates the biological source of variability. EC with a strong positive loading and DO with a strong negative loading were introduced as the first varifactors in the rainy season, which represents the physiochemical source of variability. Multivariate statistical techniques were effective analytical techniques for classification and processing of large datasets of water quality and the identification of major sources of water pollution in tropical pastures. 相似文献