A review on the alternatives to antibiotics and the treatment of antibiotic pollution: Current development and future prospects.

Antibiotics, widely used in the fields of medicine, animal husbandry, aquaculture, and agriculture, pose a serious threat to the ecological environment and human health. To prevent antibiotic pollution, efforts have been made in recent years to explore alternative options for antibiotics in animal feed, but the effectiveness of these alternatives in replacing antibiotics is not thoroughly understood due to the variation from case to case. Furthermore, a systematic summary of the specific applications and limitations of antibiotic removal techniques in the environment is crucial for developing effective strategies to address antibiotic contamination. This comprehensive review summarized the current development and potential issues on different types of antibiotic substitutes, such as enzyme preparations, probiotics, and plant extracts. Meanwhile, the existing technologies for antibiotic residue removal were discussed under the scope of application and limitation. The present work aims to highlight the strategy of controlling antibiotics from the source and provide valuable insights for green and efficient antibiotic treatment.

Characteristics of polycyclic aromatic hydrocarbons in food oils in Beijing catering services.

The concentrations and characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in 48 oil samples randomly collected from 30 catering services that employ six cooking methods were quantified via high-performance liquid chromatography (HPLC). These 16 PAHs were detected in almost all of the samples. The levels of Σ16PAHs, Σ4PAHs, benzo[a]pyrene (BaP), and total BaP equivalents (ΣBaPeq) for the six cooking methods exceeded the legal limit. The concentrations of Σ4PAHs were approximately 9.5 to 16.4 times the legal limit proposed by the European Commission (Off J Eur Union 215:4-8, 2011), and the level of BaP exceeded the national standard in China by 4.7- to 10.6-fold, particularly in oil from fried foods. Low molecular weight PAHs (LMW PAHs) were predominant in fried food oil from different catering services and accounted for 94.8 % of these oils, and the ΣBaPeq of the high molecular weight PAHs (HMW PAHs) was 11.5-fold higher than that of the LMW PAHs. The concentrations of Σ16PAHs (3751.9-7585.8 µg/kg), Σ4PAHs (144.6-195.7 µg/kg), BaP (79.7-135.8 µg/kg), and ΣBaPeq (231.0-265.4 µg/kg) were highest in the samples from fast food restaurants/buffets (FB), followed by those from fried food stalls (FS) and then cooking restaurants/cafeterias (RC). The results of this study suggest that the government should strengthen control and supervision of PAH contamination in food and edible oils.

Characteristics of PAHs from deep-frying and frying cooking fumes.

Cooking fumes are an important indoor source of polycyclic aromatic hydrocarbons (PAHs). Because indoor pollution has a more substantial impact on human health than outdoor pollution, PAHs from cooking fumes have drawn considerable attention. In this study, 16 PAHs emitted through deep-frying and frying methods using rapeseed, soybean, peanut, and olive oil were examined under a laboratory fume hood. Controlled experiments were conducted to collect gas- and particulate-phase PAHs emitted from the cooking oil fumes, and PAH concentrations were quantified via high-performance liquid chromatography (HPLC). The results show that deep-frying methods generate more PAHs and benzo[a]pyrene (B[a]P) (1.3 and 10.9 times, respectively) because they consume greater volumes of edible oil and involve higher oil temperatures relative to those of frying methods. In addition, the total B[a]Peq concentration of deep-frying is 2.2-fold larger than that of frying. Regarding the four types of edible oils studied, rapeseed oil produced more PAH emission than the other three oil varieties. For all of the cooking tests, three- and four-ringed PAHs were the main PAH components regardless of the food and oil used. Concerning the PAH partition between gas and particulate phase, the gaseous compounds accounted for 59-96 % of the total. Meanwhile, the particulate fraction was richer of high molecular weight PAHs (five-six rings). Deep-frying and frying were confirmed as important sources of PAH pollution in internal environments. The results of this study provide additional insights into the polluting features of PAHs produced via cooking activities in indoor environments.

Treatment of polluted landscape lake water and community analysis of ammonia-oxidizing bacteria in constructed wetland.

Three lab-scale horizontal subsurface flow constructed wetlands (HSSF CWs) were installed to demonstrate the use of constructed wetlands as a viable low-cost treatment option to purify the polluted scenery water. The goals of this study were to determine the effectiveness of the wetland treatment technology in reducing contaminants in polluted natural water body and to characterize bacterial composition present in 3 constructed wetlands. Water samples were collected periodically for 12 months from three wetlands to determine the efficiency of the treatment system in removal of chemical pollutants. The reduction by the treatment was greatest for chemical oxygen demand (COD), total nitrogen and total phosphorus, but the removal of nutrients obviously varied with seasons. Plant uptake was highly responsible for nitrogen and phosphorus removal. Denaturing gradient gel electrophoresis (DGGE) was used to study the diversity of microbial community in the constructed wetland. Changes in the total bacterial community and ammonia-oxidizing bacterial composition were examined by DGGE and sequencing of polymerase chain reaction (PCR)-amplified fragments of the gene carrying the ammonia monooxygenase subunit A gene (amoA) recovered from matrix samples and DGGE bands. DGGE analysis of wetlands samples revealed that seasonal change had an effect on the diversity and composition of microbial communities in constructed wetlands. The sequence analysis showed ammonia-oxidizing bacteria (AOB) in constructed wetlands were uncultivable and the population of AOB had a higher percentage of Nitrosomonas-like sequences from wetlands, while no Nitrosospira-like sequences were found.