Influence of various surface-active agents on the activity of several enzymes in the brush border of enterocytes

Research on modified blast furnace dust in demulsification: The synergistic effect of ferric oxide, hydrophobic carbon, and polysilicate

Current treatment processes for the cold rolling emulsion wastewater were in the dilemma that the cost was so high while the efficiency was not satisfied in China. In this work, a novel material with high-performance demulsification was obtained and used to treat the emulsion wastewater efficiently by modifying blast furnace dust (BFD), a steel industry waste. Firstly, the BFD was characterized by various analytical techniques and the results suggested that hydrophobic functional groups, positively charged iron oxide, and polysilicon in the BFD were contributed to removing stable oil droplets. Therefore, the BFD modification was conducted accordingly by optimizing the proportion and reaction conditions of these three components. The study demonstrated that the removal rate of oil and COD_cr reached 75.21% and 81.23% under the conditions of the carbon type of GWF-HAC-R90, the carbon content of 14.86%, and the n_(Fe)/n_(Si) of 1.55, respectively. Based on this, the effects of pH, demulsifier dosage, and average agitation rate were investigated. The emulsion components before and after demulsification were analyzed by GC-MS, and the demulsification mechanism was expounded combined with kinetics. Results showed that the Fe₂O₃ with positive charge played a dominant role in emulsions with mainly anionic surfactants, while hydrophobic carbon structures and polysilicate acted as the auxiliaries. Besides, comprehensive analysis and characterization results suggested that the demulsification effect was a combination of the synergic processes: 1) electrostatic interaction developed by the anionic surfactant oil droplets and the positively charged the BFD particles; 2) hydrophobic association among the oil droplet with nonionic surfactant and amphiphilic carbon-iron complexes; 3) adsorption bridging between the surfactant oil droplets and polysilicate. The results of comparative tests in treating the actual cold-rolling emulsion wastewater showed the MBFD could bring about significant technical, economic benefits and achieve utilization of metallurgical solid wastes.Implications: Blast furnace dust (BFD) is an industrial solid waste obtained by dry de-dusting from blast furnace gas during the blast furnace ironmaking process. The main components of BFD are iron oxide and carbon, and also contain small amounts of different recoverable non-ferrous metals zinc, secret, indium and lead, which have recovery value. In this study, we enhanced the three parts of BFD and used to demulsification. In this study, the BFD was modified in three aspects (hydrophobic functional groups, positively charged iron oxide, and polysilicon) to achieve the secondary utilization of waste in emulsion wastewater treatment. And investigated the effect of reaction conditions on the demulsification effect with modified blast furnace dust (MBFD). Furthermore, the GC-MS analyzes combined with kinetics interpret the demulsification mechanism with the MBFD as a secondary resource. Finally, the comparative tests in treating the actual cold-rolling emulsion wastewater showed the MBFD could bring about significant technical and economic benefits and achieve utilization of metallurgical solid wastes.

1 Final Report on the Safety Assessment of Polysorbates 20, 21, 40, 60, 61, 65, 80, 81, and 85

The Polysorbates are a series of polyoxyethylenated sorbitan esters that are used as hydrophilic, nonionic surfactants in a variety of cosmetic products. Polysorbates are hydrolyzed by pancreatic and blood lipases; the fatty acid moiety is released to be absorbed and metabolized, whereas the polyoxyethylene sorbitan moiety is very poorly absorbed and is excreted unchanged. Acute and long-term oral toxicity in animals indicates a low order of toxicity with oral ingestion of the Polysorbates.

Polysorbate 80 was shown to be nonmutagenic in the Ames and micronucleus tests. The Polysorbates were noncarcinogenic in laboratory animals. Multiple studies have shown that the Polysorbates enhance the activity of known chemical carcinogens while not actually being carcinogenic themselves.

Extensive clinical skin testing showed Polysorbates to have little potential for human skin irritation or evidence of skin sensitization or phototoxicity. The available data indicate that these ingredients are used in numerous preparations without clinical reports of significant adverse effects. It is concluded that they are safe for use in cosmetics at present concentrations of use.

Gastric carcinoma promoted by alkaline reflux gastritis -- with special reference to bile and other surfactants as promoters of postoperative gastric cancer

For reasons that are not known, the incidence of stomach cancer is declining in most countries. In contrast, cancer of the gastric remnant after partial gastrectomy for peptic ulcer disease seems to be increasing. "Stump cancer" has been claimed to be a separate disease entity and has recently been mentioned as an iatrogenic cancer. Alkaline bile reflux, dietary surfactants and maybe the abuse of tobacco are postulated as promoting or initiating agents, in causing malignant transformation of the operated as well as non-operated stomach. Variations in gastric pH, microflora and emptying rate may be of importance in the carcinogenic process. The decline in cancer incidence in the non-operated stomach has mainly been restricted to the intestinal type of cancer. Thus, it is important to note that stump cancer often is of the diffuse type. Different target cells and/or modes of carcinogen exposure may be of etiological importance in these histologically and clinically separate neoplastic diseases.