Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Alum Compounds”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2001

Potential and limitations of alum or zeolite addition to improve the performance of a submerged membrane bioreactor.

In this study, alum and natural zeolite were added to a submerged membrane bioreactor (MBR) not only to reduce membrane fouling but also to increase the removal of nitrogen and phosphorus. Alum addition reduced significantly the rising rate of suction pressure and also resulted in stable and better COD removal. Although phosphorus removal was more than 90% by chemical precipitation, nitrification inhibition was observed. With the addition of natural zeolite, membrane permeability was greatly enhanced by the formation of rigid floc that had lower specific resistance than that of the control activated sludge floc. In particular, the nitrification efficiency was over 95% even at N-shock loading due to the ion-exchange capacity of zeolite. The mechanisms for improved membrane permeability through alum or zeolite addition were discussed in detail.

Alum Compounds↗
PubMed1975

Allpyral: An appraisal.

In Allpyral the alum which has been added to the highly alkaline-pyrididium extract of non-defatted pollen absorbs only 25% of the extracted nitrogenous material, the larger quantity having been discarded with the supernanant. Allpyral contains a relatively small amount of antigenic material compared with conventional aqueous or glycerol preparations. Chemical studies show Allpyral to be a product resulting from an unrealized concept and a faulty method of preparation involving injudicious use of alum.

Allergens↗
PubMed2001

Distribution of aluminum species and the characteristics of structure of poly-aluminum-chloride-sulfate(PACS).

A series of poly-aluminum-chloride-sulfate (PACS), which has different basicities (gamma) and Al3+/SO4(2-) molar ratio, has been prepared and dried at 105 degrees C and 65 degrees C, respectively. The distribution of aluminum species of PACS was examined, and the effect of gamma value, Al3+/SO4(2-) molar ratio, dilution on the distribution of aluminum species of PACS was also investigated by using Alferron timed complex colorimetric method. The IR spectroscopy and X-ray diffraction were used to study the effect of gamma value, Al3+/SO4(2-) molar ratio and the drying temperature on the structure of PACS. The experimental results show that Al3+/SO4(2-) molar ratio has a great effect on the distribution of aluminum species, but the dilution has a little effect on the distribution of aluminum species. The lower the Al3+/SO4(2-) molar ratio, the higher the proportions of the polymer and colloidal species in PACS. The polymeric degree of PACS was related to gamma value and Al3+/SO4(2-) molar ratio. Drying temperature has an influence on the structure and the solubility of solid PACS products.

Alum Compounds↗
PubMed1999

[Effect of alum on intestinal microecological balance in mice].

OBJECTIVE: To observe the degree of microecological imbalance induced by alum in normal intestine of mice, and the bacterial adherence activity in the intestine of the mice administered orally with alum. METHODS: The mice were medicated orally with alum of small and large doses (0.25 g/kg and 1 g/kg) for 8 weeks, then 5 weeks after stopping administration of alum, microflora analysis and bacterial adherence to intestinal mucosal epithelial cells were carried out respectively. RESULTS: Eight weeks after administration with alum, the counts of Bifidobacteria and Lactobacilli decreased significantly, but the numbers of pathogenetic E. Coli increased significantly. The adherence rate of Bifidobacteria to the enterocytes of mice reduced markedly, but E. Coli was on the contrary of Bifidobacteria. Five weeks after the ceasing of medication, the intestinal flora were balanced, the adherence rate of both strains as mentioned above recovered to normal level. CONCLUSION: The imbalance of intestinal flora of mice administered with alum for a long time were only the transient change of bacterial counts. The imbalance of intestinal flora and the adherence rate of bacteria regained normal status five weeks after cancelling action factor.

Alum Compounds↗
PubMed2001

Properties of flocs produced by water treatment coagulants.

Hydrolyzing coagulants are extensively used in water and wastewater treatment, often under conditions where hydroxide precipitation is important, giving "sweep flocculation". Pre-hydrolyzed coagulants, such as polyaluminium chloride (PACl) are also widely used and have several advantages over traditional additives, such as aluminium sulfate. Their action is usually discussed in terms of cationic species and charge neutralization. However, precipitation may also be important and this aspect has not been considered in detail. The present work has compared the action of alum and three commercial PACl products on model clay suspensions. The conventional jar test procedure has been used, along with measurements of settled floc volume and dynamic monitoring of floc formation and break-up by an optical technique. The latter method gives very useful information on the nature of the flocs produced and their response to different shear conditions. It is clear from the results that the PACl products form larger and stronger flocs than alum. With all coagulants floc breakage appears to be essentially irreversible. Sediment volumes are slightly lower for flocs produced by PACl than by alum, but the value is proportional to the dosage in all cases.

Alum Compounds↗
PubMed2001

Parallel studies on dewatering and conditioning of an alum sludge and an aluminium hydroxide suspension.

The paper shows a comparison between properties of an alum sludge gained from the coagulation of a coloured water with those of a suspension of aluminium hydroxide at a concentration equivalent to the coagulant fraction within the sludge. Background information is provided on composition and aspects of the source floc. The comparisons embraced floc size, polymer adsorption, and dewatering parameters including specific resistance to filtration, capillary suction time and the equilibrium moisture content under pressure. In all cases, there were strong similarities in the behaviour of the two suspensions. It is suggested that such features emanate from a common fractal structure within the source floc, whose fractal index (approximately/= 1) has been found to be insensitive to the composition of the floc.

Adjuvants, Immunologic↗
PubMed2001

Effect of charge neutralization on the dewatering performance of alum sludge by polymer conditioning.

Cationic and anionic polymers with the same molecular weight were used as sludge conditioning reagent to study the polymer charge effect on alum sludge dewatering characteristics. On the basis of capillary suction time, bound water content, and zeta-potential measurement in this study, the function of charge neutralization appears to be an important consideration in the sludge dewaterability and moisture content. Using the dilatometric technique to measure the bound water content, we found that alum sludge conditioned by cationic polymer presented more significant variation in the bound water content than sludge subject to anionic conditioning. We hypothesise that the mechanism of charge neutralization caused much water depletion by replacement and exclusion in sludge and results in the decrease of bound water within the cationic polymer conditioning. An insignificant bound water variation found during the anionic conditioning resulted from the lack of charge neutralization. A lighter and looser floc structure is also be found in the anionic conditioned sludge after the analysis of wet floc density and fractal dimension. Such open floc structure can be attributed to the lack of charge neutralization as the flocs aggregate with anionic polymer.

Adjuvants, Immunologic↗
PubMed1999

[Assay of aluminum content in alum and alum-processed medicinal herbs and its distribution in blood and brain in mice].

OBJECTIVE: To assay the aluminum content in alum and some Chinese medicinal herbs processed with alum, and compare the aluminum distribution of these herbs in blood and brain in mice. METHOD: Aluminum content of the herbs was assayed with spectrophotometry, snd aluminum distribution in blood and brain was assayed with atomic absorption spectrophotometry. RESULTS: Aluminum content in alum was found higher than that in the alum-processed herbs. Aluminum distribution in blood and brain after oral administration at equimolecular doses, equivalent to 5.7 mg/kg of metal Al, was studied in mice, and no significant differences were observed. CONCLUSION: Aluminum distribution in blood and brain in mice is related to the dosages of aluminum administered and has little to do with the kind of herbs used. All these medicinal herbs do not improve the absorption of aluminum in mice.

Alum Compounds↗
PubMed1998

[Influence of alum on intestinal flora in mice].

OBJECTIVE: To observe the influence of alum on the intestinal microecological balance in normal microorganisms. METHOD: The mice were administered orally with alum of a small dosage(0.25/kg) and a large dosage(1 g/kg) for half a month, two months and three months, and a micro flora analysis of the mice was carried out at intervals of the above mentioned administrations. RESULT: The intestinal flora in the animals administered with alum was imbalanced. The counts of bifidobacteria and lactobacilli closely related to human physiological activities were decreased. The counts of pathogenic E. Coli significantly increased; and the longer the animals were treated with alum, the stronger the microecological balance was influenced. CONCLUSION: Alum could induce imbalance of the normal intestinal flora in mice.

Alum Compounds↗