Comparative chemical investigations of alum treated archaeological wood from various museum collections

From the mid-1800s to the late 1960s, conservation by alum salts (KAl(SO4)2·12H2O—potassium aluminium sulphate), using various recipes, was a common method to prevent shrinkage and to strengthen waterlogged archaeological wooden objects. This method was mainly used in Scandinavia. The alum method appears to have also been applied to highly degraded archaeological waterlogged wood in other countries, for example in the U.S and Germany. Today, many of the archaeological wooden objects treated with alum show extreme deterioration and very low pH, which are attributed to the effects of the alum-treatment. This study investigated the extent of the current levels of chemical degradation in wooden objects conserved with alum salts at different points in time (1880s, 1930s and 1905–13) in order to understand their current condition and whether extent of degradation was in any way related to time of treatment, in an attempt to understand the rate of degradation. It was also an opportunity to compare the chemical state of preservation of alum-treated wood from different collections, as only the Oseberg collection has been intensively studied in this way up until now. Samples from historical wooden objects from the following collections were investigated and compared: the Dejbjerg collection (National Museum of Denmark in Copenhagen); the Oseberg collection (Museum of Cultural History, Oslo, Norway); the Glimmingehus collection (Swedish History Museum, Sweden). Analyses of lignocellulosic polymers and of inorganic compounds were undertaken to evaluate the chemical preservation of the wooden objects. The investigations were performed using a multi-analytical approach which consisted of: pH measurements, analytical pyrolysis (Py-GC/MS), X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS). It was possible to link the extent of degradation with time, on a general level but we found a great variability in the state of preservation of the wood also within the same collection. It is clear, however that alum-treated wood is more degraded than archaeological wood not treated with alum.

Impact of rock alum pretreatment on biosand filter performance in Cambodia

Alum is often recommended by WASH agencies as a pretreatment flocculent to improve filtration in biosand filters (BSFs) for communities using a turbid drinking water source. Floating villages on the Tonle Sap Lake in Cambodia using BSFs encounter severe declines in filtration rates while using alum, resulting in reduced use of the BSF. We tested the effect of rock alum treatment on flow rate and turbidity. The flow rate of all BSFs declined over time, but degradation of flow was more rapid for alum-treated water than untreated water. Rock alum treatments significantly reduced the turbidity of borrow pit source water. Filters switched to untreated river water decreased in turbidity to levels ≤ rock alum-treated river water. Rock alum treatments increased aluminum in source water 4–15 times, but filtration by BSFs decreased levels of aluminum to near 0.05 mg/L. Though rock alum effectively reduces turbidity in source water, we believe it continues its coagulation inside the BSF during pause periods, negatively impacting flow rates.

Effect of Alum (Aluminum Sulfate) Addition to Poultry Litter on Layer Performance, Litter pH and Litter Composition

The current experiment was conducted to assess the effect of using different litter types with or without alum on performance and litter quality of the hen layers. A total number of 120 Inshas layer hens of 24 weeks of age were randomly distributed into 4 groups (3 replicates each 10 hens) of floor litter: T1 birds were raised on wood shaving litter, T2 birds were raised on wheat straw litter, T3 birds were raised wood shaving with 100 g of alum / kg of bedding, and T4 birds were raised on wheat straw litter with 100 g of alum / kg of bedding. Topping of fresh litter with acidifier amendment improved body weight, egg weight, egg number, egg mass, feed intake and feed conversion ratio of layers compared to chickens in the untreated litter group. In comparison with the control group, alum treatment reduced the pH level of the litter. Regarding the NH4+-N content, alum-treated litter showed a higher value than the untreated litter. On average, alum-treated litter had lower P content than the untreated litter. Alum treated group showed a significant increase in dry matter and total nitrogen content when compared with the untreated group. The study results showed significant variability (p < .05) in the moisture content and pH of the control and treated litter. This clearly shows the effectiveness of litter treatment products enhancing litter quality and therefore the bird’s environmental climate. Thus it can be decided that litter modification with alum treatment had a significant impact on litter quality and in turn enhanced the productive performance of layer chickens without any adverse effect.

Ammonium alum in alum-treated wooden artefacts: discovery, origins and consequences

Alum-treatment was extensively applied to archaeological wood from the Oseberg collection in the early 1900s, and was a common conservation method at the time involving impregnating objects with hot concentrated solutions of potassium alum (KAl(SO4)2⋅12H2O). This now obsolete consolidation method has led to dramatic long-term consequences, heavily affecting the state of preservation of the historical wooden artefacts, and dedicated chemical characterisation campaigns have been undertaken to better understand the degradation processes and aid development of re-treatment strategies. Analyses with Fourier transform infrared spectroscopy (FTIR), elemental microanalysis, and ion chromatography (IC) was performed, suggesting the presence of ammonium alum (NH4Al(SO4)2·12H2O) in many alum-treated wood samples, though no record exists of use of ammonium compounds during treatment of the artefacts. C/N rations of 1.70–68.8 in wood samples, and ammonium alum contents between 8 and 84% of the alum component and 23–168 mmol/100 g of total sample suggested that objects were actually treated with various mixes of potassium and ammonium alum. The two alums have similar properties, and in model studies of their behaviour under the conditions of alum-treatment appeared to form similarly acidic solutions, thus the different alum mixtures probably did not significantly influence object treatment. Nor have we observed other indications of unusual degradation pathways related specifically to the presence of ammonium alum. Nonetheless, investigations into potential re-treatment of the archaeological objects must be adjusted accordingly.

Ammonia, Hydrogen Sulfide, and Greenhouse Gas Emissions from Lab-Scaled Manure Bedpacks with and without Aluminum Sulfate Additions

The poultry industry has successfully used aluminum sulfate (alum) as a litter amendment to reduce NH3 emissions from poultry barns, but alum has not been evaluated for similar uses in cattle facilities. A study was conducted to measure ammonia (NH3), greenhouse gases (GHG), and hydrogen sulfide (H2S) emissions from lab-scaled bedded manure packs over a 42-day period. Two frequencies of application (once or weekly) and four concentrations of alum (0, 2.5, 5, and 10% by mass) were evaluated. Frequency of alum application was either the entire treatment of alum applied on Day 0 (once) or 16.6% of the total alum mass applied each week for six weeks. Ammonia emissions were reduced when 10% alum was used, but H2S emissions increased as the concentration of alum increased in the bedded packs. Nitrous oxide emissions were not affected by alum treatment. Methane emissions increased as the concentration of alum increased in the bedded packs. Carbon dioxide emissions were highest when 5% alum was applied and lowest when 0% alum was used. Results of this study indicate that 10% alum is needed to effectively reduce NH3 emissions, but H2S and methane emissions may increase when this concentration of alum is used.

Advances in coagulation technique for treatment of fluoride-contaminated water: a critical review

Fluoride contamination of groundwater has become a major concern worldwide, resulting in serious medical conditions such as dental and skeletal fluorosis. Consequently, the WHO recommends that drinking water should not contain more than 1.5 mg/l of fluoride. Various defluoridation techniques such as coagulation, reverse osmosis, activated alumina adsorption, and biosorbent adsorption have been developed. Adsorption through the activated alumina and biosorbent process is not cost effective and has regeneration problems, and the reverse osmosis process has the high initial cost which makes it unacceptable for developing countries. Coagulation is a commonly employed field technology for defluoridation, which involves the addition of aluminum salts, lime, and bleaching powder followed by rapid mixing, flocculation, sedimentation, and filtration but suffers from a limitation of high residual aluminum in treated water. This paper critically reviews the recent developments in the coagulation technique for defluoridation along with its comparison to other defluoridation techniques. The review describes the pertinent gaps in the process and throws open suggestions for extending research by citing the recent studies which may lead to the revival of the process. The description about the suspension of alumino-fluoro complexes that constitute a substantial part of the residual aluminum after alum treatment has been narrated in the paper that helps in a deeper understanding of the defluoridation mechanism. To make the process highly suitable for communities, appropriate technological interventions, such as converting it to a continuous mode of operation, replacing alum with poly-aluminum chloride (PAC), and attaching a micro-filtration unit in series of the existing process, can be done. Also, using PAC as a coagulant with sand filtration has to be considered for making the process more efficient.

Relative Coagulation Potentials of Aluminum Sulphate and Mangifera indica Seeds in Purifying Domestic Waste Water

The high cost of most chemical coagulants and their non-availability coupled with their negative health impacts necessitates the use of natural or bio-coagulants. This study compares the effectiveness of using powdered extract from matured dried Mangifera indica (M. indica) seeds (bio-coagulant) with Aluminum sulphate (alum, chemical coagulant) for the coagulation of domestic waste water. The treatments include: control culture (no coagulant is added), 150 mg/L of alum, 100 mg/L, 150 mg/L and 200 mg/L of M. indica seeds. All the treatments were cultured in 15-litres buckets. The experiment was design based on Completely Randomized Design (CRD) replicated 3times. Physical, chemical and bacteriological properties of the domestic sewage were determined before and after the application of the coagulants on weekly basis. Results show that for turbidity, at the point of collection, the value was 013NTU was reduced to a minimum value of 001NTU for both 100 mg/L and 150 mg/L of M. indica seeds treatments. The Total Hardness at the point of collection was 2.73 mg/L; the highest value during the period of study was 5.30 mg/L at the fifth week for the alum treatment, followed by 4.37 at the fourth week for 100 mg/L of M. indica seeds treatment. The study showed that M. indica seeds powder perform very well as a bio-coagulant and be used as a replacement for alum or any other chemical coagulant in the purification of domestic waste water.Kathmandu University Journal of Science, Engineering and TechnologyVol. 13, No. 2, 2017, page:26-38

Breaching peripheral tolerance promotes the production of HIV-1–neutralizing antibodies

A subset of characterized HIV-1 broadly neutralizing antibodies (bnAbs) are polyreactive with additional specificities for self-antigens and it has been proposed immunological tolerance may present a barrier to their participation in protective humoral immunity. We address this hypothesis by immunizing autoimmune-prone mice with HIV-1 Envelope (Env) and characterizing the primary antibody response for HIV-1 neutralization. We find autoimmune mice generate neutralizing antibody responses to tier 2 HIV-1 strains with alum treatment alone in the absence of Env. Importantly, experimentally breaching immunological tolerance in wild-type mice also leads to the production of tier 2 HIV-1–neutralizing antibodies, which increase in breadth and potency following Env immunization. In both genetically prone and experimentally induced mouse models of autoimmunity, increased serum levels of IgM anti-histone H2A autoantibodies significantly correlated with tier 2 HIV-1 neutralization, and anti-H2A antibody clones were found to neutralize HIV-1. These data demonstrate that breaching peripheral tolerance permits a cross-reactive HIV-1 autoantibody response able to neutralize HIV-1.