Aluminum Based Chemical Additive Compounds

Aluminum based chemicals have been used for many years in wastewater treatment applications for suspended solids removal. These include dry and liquid alum, with sodium aluminate used in activated sludge plants for phosphorus removal. 

The commercial dry alum most often used in wastewater treatment is known as filter alum, and has the approximate chemical formula A 12(804)3 T4H2O and a molecular weight of about 600. Alum is white to cream in color and a 1 percent solution has a pH of about 3.5. The conunercially available grades of alum and their corresponding bulk densities and angles of repose are given in Table 1. 

Each of these grades has a minimum aluminum content of 27 percent, expressed as AljOj, and maximum FejOj and soluble contents of 0.75 percent and 0.5 percent, respectively. 

Since dry alum is only partially hydrated, it has hygroscopic tendencies. However, it is relatively stable when stored under normal temperature and humidity conditions encountered. 

Grade Angle of repose Bulk density (lbs. /cubic feet) 

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The most commonly used inorganic polymers are the polyacrylamides. Chemical flocculant concentrations employed normally range from 100 to 500 mg/Liter. The wastewater pH may require adjustment between 4.5 and 5.5 for the ferric compounds or between 5.5 and 6.5 for the aluminum compounds using an acid such as H2SO4 or a base such as NaOH. In many applications, the DAF effluent requires additional pH adjustment, normally with NaOH to assure that the effluent pH is within the limits specified by the POTW.. The pH range of the effluent from a DAF is typically between 6 and 9. 

In alkyl aluminum chlorides of the type RxAlyClz two different chemical moieties which cause alkylation as well as chlorination are present in one molecule. Therefore, RAAL,Clz-type activators do not require the separate addition of other halide donors in order to achieve high cis-1,4-contents. In Nd-based catalyst-systems the dual role of RXA1 C1Z compounds is demonstrated by Watanabe and Masuda [364], These findings only hold true for Nd-based catalyst systems. For lanthanum-based catalyst systems Lee et al. found that the use of alkyl aluminum chlorides results in trans- 1,4-polymerization (93-94%) [371]. However, usually, in Nd catalysts the alkylating power of RxAlyClz is not sufficient at the applied amounts of RXA1 C1Z. Thus, an additional standard cocatalyst has to be added for the activation of the Nd precursor. 

A solution of 110 mg. (0.83 mmoles) of 5ab in ether was added slowly to a solution of methyllithium (10% excess, Foote Chemical) in ether. The highly exothermic reaction was cooled in a room temperature water bath. Methane (39 ml.), ether vapor, and possibly carbon dioxide were collected [theoretical for proton abstraction reduction 19 ml. of methane]. After addition of ozonide was complete, the reaction was worked up in the same manner as the lithium aluminum hydride reduction. GPC analysis of the crude mixture revealed isopropyl alcohol (9) (>—60% by GPC standard) and 3-methyl-2-butanol (10) —60%). Methanol is normally produced in approximately the same yield (—60% ) as 9 and 10. We were unable to collect a sufiicient quantity from the labeling experiment for mass spectral analysis. Product identification was based on GPC retention times and by comparison of infrared spectra with those of authentic compounds. Mass spectral results were as follows isopropyl alcohol- assay 11.88% oxygen-18 3-methyl-2-butanol (10) assay 2.45%. 

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