Alum Treatment Research Articles

돈분뇨 퇴비화 과정에서 Alum 처리가 암모니아 휘산과 인산 안정화에 미치는 영향

Composting is a good strategy for management of livestock manure. However, it leads to large ammonia emissions and has a potential phosphorus runoff due to high content of soluble phosphorus. The objective of this study was to evaluate the efficiency of alum on reducing ammonia emissions and stabilizing phosphorus during composting of pig manure. For this study, alum was applied at rates of 0 (No-Alum), 1.0 (Alum-L), and 3.0 (Alum-H) g Al pig manure and sawdust mixture (fresh matter basis). The thermophilic stage was quickly achieved in Alum-L and No-alum treatment, but it was delayed to 5 days in Alum-H treatment. The thermophilic stage was maintained for 2 weeks in all treatment. The pH of compost treated with alum remained below 8.0 for the 35 d but it was above 8.0 in No-Alum treatment. For the first 15 days of composting process, 93, 87, and 58% of total ammonia emissions were occurred in No-Alum-L and Alum-H, respectively. The Alum-H and Alum-L treatments reduced volatilization by 31 and 78% compared with No-Alum treatment. Alum treatments shifted manure P form and extractable P into NaOH extractable P which is very stable under acid and alkaline condition. Therefore, alum is a good chemical amendment for reducing ammonia emission during composting and potential losses of P following compost applications.

Sedimentary and historical context of eutrophication and remediation in urban Lake McCarrons (Roseville, Minnesota)

Geochemical analysis of the varved (annually laminated) sediments of a small, deep urban lake in east-central Minnesota shows that some water-quality and watershed indicators are approaching prehistoric (pre-1850s) values after an excursion to anomalous levels during the 1920s through 1950s. This high-resolution paleolimnological information (annually resolved for most of the 20th century), including varve thickness measurements on a digital image, carbon stable isotopic composition of organic matter, and sedimentary component quantification, provides historical perspective to lake managers planning remedial measures with reference to the “natural” state of the lake, especially in regard to the perception that water quality has declined only in recent decades (i.e., in the late 20th century). The lake is at present eutrophic and oligomictic, with oxygen-depleted bottom waters enriched in dissolved solids relative to surface waters; an alum treatment has contributed to the problem of persistent stratification at the same time as it has reduced phosphorus and increased transparency in lake surface waters. The sedimentary record shows the lake's strong response to agricultural, recreational, and urban development in the watershed, gradual improvement beginning at the time of sanitary sewer installation in the 1960s, and only a minor additional response to a concerted remediation effort in the mid-1980s to 1990s. Indices of terrestrial inputs and algal productivity show evidence of a lake that was at its most heavily impacted during the mid-20th century, and which has improved in some respects since the 1960s.

Effect of Alum Treatment on the Concentration of Total and Ureolytic Microorganisms in Poultry Litter

Microbial mineralization of urea and uric acid in poultry litter results in the production of ammonia, which can lead to decreased poultry performance, malodorous emissions, and loss of poultry litter value as a fertilizer. Despite the fact that this is a microbial process, little is known about how the microbial populations, especially ammonia-producing (ureolytic) organisms in poultry litter, respond to litter amendments such as aluminum sulfate (Al(2)(SO(4))(3).14H(2)O; alum). The goal of this study was to measure the temporal changes in total bacterial and fungal populations and urease-producing microorganisms in nontreated litter or litter treated with 10% alum. Quantitative real-time polymerase chain reaction was used to target the bacterial 16S rRNA gene, the fungal 18S rRNA gene, or the urease gene of bacterial and fungal ammonia producers in a poultry litter incubation study. Nontreated poultry litter had relatively high total (2.8 +/- 0.8 x 10(10) cells g(-1) litter) and ureolytic (2.8 +/- 1.3 x 10(8) cells g(-1) litter) bacterial populations. Alum treatment reduced the total bacterial population by 50% and bacterial urease producers by 90% within 4 wk. In contrast, at 16 wk after alum treatment, the fungal population was three orders of magnitude higher in alum-treated litter than in nontreated litter (3.5 +/- 0.8 x 10(7) cells g(-1) litter and 5.5 +/- 2.5 x 10(4) cells g(-1) litter, respectively). The decrease in pH produced by alum treatment is believed to inhibit bacterial populations and favor growth of fungi that may be responsible for the mineralization of organic nitrogen in alum-treated litters.

Assessing Natural Organic Matter Treatability Using High Performance Size Exclusion Chromatography

This paper reports the use of high performance size exclusion chromatography (HPSEC) as a tool to assess NOM removal by coagulation. Quantitative information such as percentage removal can be determined after "peak-fitting" the HPSEC molecular weight profile of the source water. A peak-fitting approach was developed based on the molecular weight profile of dissolved organic matter from surface water. A sequential jar testing procedure with five treatment steps was used to characterize organics and to confirm that several NOM components were recalcitrant to coagulation with alum. Despite differences found in both the concentration and character of NOM in three surface waters studied, the final concentrations and characteristics (e.g., molecular weight profile) were very similar after five treatment stages. The molecular weight profiles of the recalcitrant organics were subsequently used to build a peak-fitting technique for NOM removal. The approach was validated by further jar test results of several other water sources, such as ground and river waters, including one found to be very difficult to treat in terms of NOM removal by alum treatment. Predictions of removable and nonremovable organic fractions by coagulation using this peak fitting technique were found to be within 10% of actual values.

Short-term effects of a buffered alum treatment on Green Lake sediment phosphorus speciation

Green Lake, Washington, was treated with a dose of 24 mg Al/L aluminum sulfate (alum) and sodium aluminate during March–April 2004 to reduce dissolved phosphorus concentrations to ameliorate a variety of eutrophication-related problems. Four sediment cores collected six months after the alum treatment in Green Lake were used to examine the short-term effects of alum on sediment phosphorus speciation. Peaks in aluminum bound phosphorus (Al-P) and total aluminum (Tot-Al) were observed in three of the four cores analyzed, resulting in an average ratio of added Al to Al-P formed (Al:Al-P) of 112:1. By comparing this ratio to the average ratio of ~11:1 found in other alum-treated Washington lakes, it can be inferred that approximately 10% of the binding capacity of the added Al had been utilized. Assuming a final ratio of Al:Al-P of 11:1, the added Al has the potential capacity to bind a total of 21.6 g/m2 of P. The amount of sediment inorganic P that supports internal loading (Fe-P and labile-P) in the fall of 2004 was determined to be 2.8 g/m2. Thus the quantity of alum added to Green Lake should be sufficient to inactivate the remaining inorganic mobile-P and to control future P mobilization from the pool of organic sediment P.

Identification of microcystins in waters used for daily life by people who live on Tai Lake during a serious cyanobacteria dominated bloom with risk analysis to human health

Tai Lake is the third largest freshwater lake in China with annual cyanobacteria blooms. Microcystins produced by these blooms have serious health risks for populations surrounding the lake, especially for people living on Tai Lake, because they usually drink raw lake water after a simple alum treatment. This study presents data on the detection and identification of microcystins in waters used for daily life by people living on Tai Lake, during the cyanobacterial blooming in July 2007. The health risks from drinking these microcystin-polluted waters were also calculated. The main microcystins detected by high-performance liquid chromatography-electrospray ionization mass spectrometry in the water samples collected from two parts of Tai Lake (Wuli Lake and Meiliang Bay) were MC-LR (4.33-12.27 microg/L), MC-RR (8.36-16.91 microg/L) and MC-YR (1.41-5.57 microg/L). Risk assessment showed that the drinking water simply treated by alum was not safe. The lowest calculated hazards ratios in all water samples was 6.4, which indicated that the risk of microcystins exposure from drinking water was over six times higher than the tolerable daily intake (TDI) recommended by The World Health Organization (WHO). Further studies should be conducted to elucidate the relationships between the epidemiology of people living on Tai Lake and microcystins exposure from drinking water.

Reducing dissolved phosphorus loading to the Salton Sea with aluminum sulfate

The primary productivity of the Salton Sea. California is excessively high, leading to lowoxygen conditions, low clarity, and odors associated with algal decomposition. Treating the inflow water with aluminum sulfate (alum) to remove soluble phosphorus (P), the limiting nutrient, is being considered to improve water quality. The objective of this study was to evaluate the use of alum to remove dissolved phosphorus from New River water, and the potential for the Al-bound P to be released into the Salton Sea. The New River is dominated by agricultural wastewater and has a salinity somewhat higher than normally encountered for alum treatment (total dissolved solids=2,300 mg l−1), thus, evaluation of alum’s effectiveness is needed. In addition, alum may be dosed directly into the New River and the floc allowed to flow into the Salton Sea if the precipitated P is stable in Salton Sea water. In this study, we evaluated the potential for floc-bound P to be desorbed in Salton Sea water, which has an unusually high salinity (46 g l−1). Aluminum at a 5-mg l−1 dose was effective in removing over 90% of the soluble phosphorus from the New River water. However, when the alum floc was added to Salton Sea water, up to 100% of the Al-bound P was released into the Sea water due to desorption, dissolution, and recrystallization of the alum floc. These results indicate that treatment of agricultural drainage water to reduce P-loading can be effective if the alum floc is settled and not allowed to enter the saline Salton Sea. In addition to alum costs, estimated at US$13 million year−1, settling basin construction and maintenance for floc removal would be required.

다양한 깔짚 첨가제 이용이 단 기간 깔짚내 pH와 수용성 인에 미치는 영향에 관한 연구

The objective of this study was conducted to evaluate the effects of poultry litter amendments on pH and soluble reactive phosphorus (SRP) in poultry litter. Two laboratory studies were conducted for 42 d in Exp. 1 and for 10 d in Exp. 2, respectively. The poultry litter was treated with various amendments which included 4 g fly ash and 4 g <TEX>$AlCl_3\;(AlCl_36H_2O)/100g$</TEX> litter in Exp. 1 and 4 g alum<TEX>$(Al_2(SO_4){_3}\;14H_2O)$</TEX>, 8 g alum, 8.66 g liquid alum, and 17.3 g liquid alum/100 g litter in Exp. 2; untreated litter served as controls. There were no differences in pH between control and T1(4 g fly ash) and SRP contents between T1(4 g fly ash) and T2(4 g <TEX>$AlCl_3$</TEX>) in Exp. 1. A significant difference in pH and SRP contents in Exp. 2 was observed among all treatments(P< 0.05). In experiment 1, T1(4 g fly ash) and T2(4 g <TEX>$AlCl_3$</TEX>) at 42 d decreased SRP in litter by 47.1% and 62.6% of that from litter alone, respectively. In experiment 2, T1(4 g alum), T2(8.66 g liquid alum), T3(8 g alum), and T4(17.3 g liquid alum) treatments at 10 days reduced SRP contents by up to 36.2%, 62.9%, 87.0%, and 83.9%, respectively, when compared with the controls. Decrease in SRP contents was chiefly associated with reduction in litter pH. These results indicate that use of various litter amendments to limit P solubility has potential and should be pursued as a means of reducing soluble reative phosphorus during short term.

Ecological Effects after an Alum Treatment in Spring Lake, Michigan

A whole-lake alum treatment was applied to eutrophic Spring Lake during October and November 2005. Eight months later, an ecological assessment of the lake was performed and compared with data collected in 2003 and 2004. Field measurements showed reduced soluble reactive phosphorus (SRP) and total phosphorus (TP) concentrations in the water column the summer after the alum application, but chlorophyll levels and irradiance profiles were not significantly affected. Total macroinvertebrate density declined significantly in 2006 compared with 2004, with chaoborids and oligochaetes experiencing the greatest reductions. Internal phosphorus release rates, measured using sediment cores incubated in the laboratory, ranged from -0.052 to 0.877 mg TP m(-2) d(-1) under anaerobic conditions. These internal loading rates were significantly lower than those measured in 2003 at three out of four sites. Mean porewater SRP concentrations were lower in 2006 than in 2003, but this difference was statistically significant only under aerobic conditions. The NaOH-extractable SRP fraction in the sediment was also significantly lower in 2006 compared with 2003, whereas the HCl-extractable SRP sediment fraction showed the opposite pattern. Overall, these results indicate that the alum treatment effectively reduced internal P loading in Spring Lake. However, water column phosphorus concentrations remain high in this system, presumably due to high external loading levels, and may account for the high chlorophyll levels. An integrated watershed management approach that includes reducing internal and external inputs of P is necessary to address the cultural eutrophication of Spring Lake.

Particle Characterization and Settling Velocities for a Water Supply Reservoir during a Turbidity Event

Characterization of the particle population for a location in a water supply reservoir, Kensico Reservoir, N.Y., is documented for a high turbidity event, from its onset, through alum treatment and its waning. Supporting in situ measurements included the beam attenuation coefficient at 670nm(c670) and 660nm(c660) [surrogates of turbidity (Tn)], particle concentrations (N) and size distributions (PSDs), and size class specific settling velocities (SVs). Laboratory measurements included chemical and morphometric analyses of individual particles, and routine measurements of Tn. The turbidity is shown to be primarily derived from clay minerals, mostly in the size range of 1.5–6μm. An initial high c670 level (40m−1;Tn∼100NTU) decreased sevenfold in less than 1week in response to alum treatment that largely eliminated the particle size classes responsible for the elevated turbidity. Successful SV experiments, made using a laser in situ scattering and transmissometry (LISST) instrument, for seven particle size classes in the range of 1.25–129μm yielded SV values of 0.17–69.4mday−1. Size classes larger than ∼5μm settled much slower than Stokes law predictions, before alum treatment, indicating that these classes existed as porous flocs or aggregates. Decreases in SVs following treatment suggest changes in floc character consistent with increased porosity. In situ measurements of c670, N, PSDs, and SVs can contribute to the development and testing of a multiple particle size class model to simulate fate, transport, and impacts of suspended particles.

제지슬러지에 대한 alum 처리 및 퇴비화에 따른 인 흡착능 변화

제지슬러지(PMS)는 침전과정에서 alum을 사용함으로 인해 다량의 알루미늄을 함유하며, 그 결과 토양 시용시 종종 작물에 대한 인의 흡수를 제한하는 요인으로 작용한다. 본 연구는 그러한 제지슬러지의 인 흡착 특성을 조사하기 위하여 토양을 대조로 하여 alum을 처리하기 전과 후에 채취한 제지 슬러지 및 제지슬러지 퇴비(PMSC)를 대상으로 인 최대 흡착<TEX>$(X_m)$</TEX>과 흡착에너지 상수 <TEX>$K_f$</TEX>를 조사하였다. 토양의 인 최대흡착량은 800 <TEX>${\mu}g\;g^{-1}$</TEX>인 반면, alum 처리 전 PMS는 47 <TEX>$mg\;g^{-1}$</TEX>, alum처리 후 PMS는 61 <TEX>$mg\;g^{-1}$</TEX>으로서 대조 토양에 비해 PMS의 인 흡착량은 현저하게 높고, alum 처리 후 인흡착능은 약 30% 증가하였다. 또한 퇴비화 후 PMS 퇴비의 최대 인 흡착능은68 <TEX>$mg\;g^{-1}$</TEX>으로서 퇴비화로 인하여 약 11%의 인 흡착능이 증가하였다. 인 흡착 계수인 <TEX>$K_f$</TEX>는 alum 처리 유무 간 큰 차이가 없었으나 퇴비화후에는 크게 증가하는 것으로 나타났다. 인 최대 흡착량<TEX>$(X_m)$</TEX>과 흡착에너지 상수 <TEX>$K_f$</TEX>를 고려한 이러한 결과들은 제지슬러지의 퇴비의 장기 혹은 과량시용이 작물에 대한 인의 흡수를 제한하는 요인으로 작용할 수 있음을 암시한다. Excess application of paper mill sludge (PMS) in field can limit phosphorus uptake by crops because aluminum presented in the sludge can fix or adsorb available phosphorus which is necessary for crop growth. To investigate phosphorus (P) adsorption characteristics of PMS, we examined P adsorption maximum <TEX>$(X_m)$</TEX> using Langmuir isotherm and P adsorption energy constant <TEX>$(K_f)$</TEX> using Freundlich isotherm for PMS without alum, PMS with alum, and composted PMS with alum through a laboratory incubation test. The maximum P adsorption capacities were 800 <TEX>${\mu}g\;g^{-1}$</TEX> in soil, 47 <TEX>$mg\;g^{-1}$</TEX> in PMS without alum and 61 <TEX>$mg\;g^{-1}$</TEX> in PMS with alum. P adsorption capacity with alum treatment for PMS increased by 30%. That of PMS compost was 68 <TEX>$mg\;g^{-1}$</TEX> and showed that composting increases 11% of P adsorption. Freundlich constant <TEX>$K_f$</TEX> was 22 in check soil, while <TEX>$K_f$</TEX> values in PMS without alum and in PMS with alum were 398 and 426, respectively. After composting, <TEX>$K_f$</TEX> value of PMS compost significantly increased as 1,819. In conclusions, p adsorption capacity for PMS were increased by alum treatment or composting and therefore excess or continuous land application of alum-amended or composted PMS can limit P uptake for crops by reducing available P in sell.

Aluminum Hydroxide Adjuvants Activate Caspase-1 and Induce IL-1β and IL-18 Release

Aluminum hydroxide (Alum) is the only adjuvant approved for routine use in humans, although the basis for its adjuvanticity remains poorly understood. In this study, we show that Alum activates caspase-1 and induce secretion of mature IL-1beta and IL-18. Human PBMC or dendritic cells stimulated with pure TLR4 and TLR2 agonists released only traces of IL-1beta or IL-18, despite the fact that the IL-1beta mRNA was readily induced by both TLR agonists. In contrast, cells costimulated with TLR agonists plus Alum released large amount of IL-1beta and IL-18. Alum-induced IL-1beta and IL-18 production was not due to enhancement of TLR signaling but rather reflected caspase-1 activation and in mouse dendritic cells occurred in a MyD88-independent fashion. Secretion of other proinflammatory cytokines such as IL-8 was not affected by Alum treatments. However, TLR-induced production of IL-10 was increased and that of IFN-gamma-inducible protein decreased by Alum cotreatment. Considering the immunostimulatory activities of these cytokines and the ability of IL-1beta to act as adjuvant, our results suggest a mechanism for the adjuvanticity of Alum.

Ultrasound enhancement of microfiltration performance for natural organic matter removal

Sonication of water at 1500 W prior to microfiltration showed that a short time (60 s) gave a reduced flux decline. It is suggested that a less potent, smaller molecular form of the natural organic matter (NOM) was produced by sonication. Longer sonication time diminished this beneficial effect. This may be due to the formation of aggregates or compounds that are more readily adsorbed on to the membrane. Where the sonication was preceded by an alum treatment, the flux loss showed a regular decrease with longer sonication time. It is suggested that the effects of sonication on the alum floc and on the floc/NOM interaction may play a critical role in regulating the flux. Where sand was present during sonication at 800 and 1400 W, the cavitational energy was focussed on adsorbed organic material, resulting in more efficient destruction and the formation of compounds that counteracted the flux enhancement.

A method for comparative evaluation of whole-lake and inflow alum treatment

A method is described to evaluate two methods of phosphorus (P) management in lakes using aluminum sulfate (alum)—in-lake and tributary (inflow) treatment—and compare the resulting in-lake P levels. For in-lake treatment, a technique is described to calculate the optimum alum dose based on measurement of “mobile P” in lake sediments. Mobile P is defined as loosely sorbed and Fe–P, the fraction of sediment P subject to release under anoxic conditions. A linear relationship ( r 2 = 0.90 ) was found between P-release rate and the mobile-P content in sediment cores. Addition of alum to aliquots of sediment showed predictable relationships between (i) alum dose and aluminum-bound P (Al–P) formed and (ii) mobile-P loss and Al–P formation. The decrease in sediment P release that would result from in-lake alum treatment was estimated from the residual mobile P after treatment. A method also is presented to estimate the amount of alum needed to bind potentially mineralizable sediment organic P. For inflow treatment, jar tests with urban runoff in metropolitan St. Paul and Minneapolis, Minnesota (USA) were used to study effects of alum dose on P removal from water. With sufficient mixing, a dose of 8 mg Al L - 1 reduced total P (TP) and soluble reactive P to low levels regardless of pH, TSS, and TOC, but doses ⩽ 4 mg Al L - 1 did not significantly reduce TP compared with settling alone. A modeling approach is described to compare the effects of inflow and in-lake treatment, and a case study is developed to illustrate the approach for typical eutrophic lakes.

UV Inactivation of Bacteria in Raw and Pre-Treated Liquid Swine Manure

The study was conducted to investigate the effectiveness of ultraviolet (UV) irradiation for inactivating coliform bacterial indicators in liquid swine manure samples using a laboratory-scale, low-pressure UV collimated beam apparatus. Raw liquid swine manure was brought from the field and stored at 4 °C for preliminary settling for 24 hours, which was followed by alum treatment in a jar test apparatus. Both pre-settled and alum-treated supernatants were filtered separately through different pore-sized polycarbonate membrane filters. The unfiltered and filtered pre-settled and alum-treated supernatant samples were exposed to a range of UV fluences (i.e., doses) to determine the fluence-response relationship. After preliminary settling, alum treatment, and membrane filtration, UV absorbance values of undiluted swine manure samples at 254 nm varied between 4.0 and 4.2 cm−1 with total suspended solids concentrations of 800 to 1,800 mg 1−1. Total coliforms were reduced by 2 - to 2.5-log10 at UV fluences of 80 to 100 mJ cm&minus2. Relatively small log reductions (< 0.5-log10) were observed at lower fluences (below 20 mJ cm−2) in undiluted manure samples. To reduce the UV absorbance of liquid swine manure, raw manure was diluted 1:50 and 1:10 with deionized water in subsequent experiments. Almost complete inactivation (> 4 to 5 log10) was achieved at UV fluences of 20 mJ cm−2 or higher in the swine manure samples diluted to 1:50. Based on these findings, it was proposed that UV inactivation of coliform in the undiluted liquid swine manure was limited by association of bacterial cells with particulate matter of less than 10 μm in size. Dilution may have disrupted and reduced the association between the bacteria and this fine particulate matter resulting in better dispersion and more complete inactivation by UV.

Tall Fescue Fertilized with Alum-Treated and Untreated Broiler Litter: Runoff, Soil, and Plant Nutrient Content

ABSTRACT Land application of poultry litter as fertilizer may lead to impaired surface and ground water quality. An experiment was conducted at Crossville, AL to study the effects of alum [Al2(SO4)3 · 14H2O] treatment of broiler litter on the yield and nutrient uptake of tall fescue (Festuca arundinaceae) and the nutrient content of runoff water exited from treated plots. Alum was used at the rate of 0, 545 and 1090 kg per 1464 m2 (12 m × 122 m) of the poultry house. The low rate is the one recommended by Natural Resource Conservation Service (NRCS) in Alabama. Soil samples were collected from the research plots at the beginning of the experiment and at the end of each growing season from 0–7.5, 7.6–15, and 16–30 cm depth. Runoff samples were collected from each plot after each rainfall event that caused runoff. Alum treatments had no effect on tall fescue dry matter yield, and the herbage nutrient concentrations were within acceptable limits. We observed significant reductions in the runoff concentrations of NH4-N (28.6 mg L−1 for untreated litter vs. 15.0 mg L−1 for alum-treated litter), total P (11.5 mg L−1 vs. 5.1 mg L−1), soluble reactive P (10.4 mg L−1 vs. 4.7 mg L−1), and particulate P (1.9 mg L−1 vs. 0.8 mg L−1). This practice should receive serious consideration as a method of reducing the adverse environmental impact of broiler chicken production when the litter is applied to pasture land.

Alum Settling and Filtration Treatment of Liquid Swine Manure

A physical/chemical treatment train, which involved preliminary settling for 24 h followed by coagulation/flocculation of supernatant, and filtration, was applied to raw flushed swine manure in bench- and pilot-scale experiments to investigate the effectiveness of the treatment train against the removal of total suspended solids (TSS) and total phosphorus (TP). Alum was used as a coagulant at an average dose of 1600 mg L-1. In the bench-scale experiments, alum treatment was performed using a jar test apparatus, and filtration was achieved by using polycarbonate track-etched membrane filters of pore sizes of 10 and 20 m. At the pilot plant, coagulation, flocculation, and clarification were achieved in a custom-designed sludge blanket clarifier equipped with inclined plate settlers, followed by media filtration in a set of three patented Martin filter columns containing glass beads of different void sizes ranging from 5 to 25 m. Overall percent reductions in TSS and TP were 85% (from 9944 to 1470 mg L-1) and 64% (from 449 to 163 mg L-1) in the bench-scale experiments and were 76% (from 3945 to 936 mg L-1) and 75% (from 164 to 40 mg L-1) in the pilot plant treatment, respectively. Preliminary settling was found to be a very effective step, which removed 53% to 56% and 22% to 28% of TSS and TP, respectively, from the raw liquid swine manure. Moderate reduction in chemical oxygen demand was also observed, while the treatment train had little effect on total Kjeldahl nitrogen and dissolved solids. Particle size distribution analysis showed that most of the phosphorus in the liquid manure was associated with particles <10 m in size and that coagulation and flocculation could enhance the phosphorus removal considerably. At the end of the pilot-scale experiment, approximately 70% and 50% of the initial mass of TSS and TP was removed from the liquid swine manure, respectively, as preliminary settling sludge, whose volume was accounted for approximately 36% of the volume of initial raw manure.

Life-history Responses of Daphnia pulex with Exposure to Aluminum Sulfate

Life table experiments with ten Daphnia clones were conducted to assess responses to three concentrations (0.05 mg 1−1 A1, 0.30 mg 1−1 A1, and 0.50 mg 1−1 A1) of aluminum sulfate (alum), reflecting a general range that might be encountered in lake restoration treatments. Alum is frequently employed for phosphorus inactivation in lake restoration and management applications. Experimental Daphnia clones originated from a lake currently being treated with alum, from a lake treated with alum over twenty years ago, and from a pond with no prior alum additions. When exposed to laboratory alum-conditioned media, clones from the lake with ongoing alum treatment exhibited higher age-specific survivorship, higher fecundity, and faster growth rates compared with clones having less recent or no prior exposure. Our results suggest the possibility that Daphnia may exhibit adaptive strategies that heighten survivorship and fecundity when exposed to sub-lethal chemical stresses. Results also indicate that clone origin and previous exposure to chemicals is an important consideration in Daphnia bioassays.

A case study of treatment performance and organic character

Two South Australian drinking water treatment plants (WTPs), Happy Valley and Myponga, with different source water supplies, were selected for an 18-month natural organic matter (NOM) characterisation case study. During this study (January 2001 to July 2002), the raw water dissolved organic carbon (DOC) concentration increased near the end of 2001; however, the applied alum dose required to maintain treated water DOC concentration decreased for both WTPs. This observation linked well with the results obtained from the rapid fractionation. It was found that the increase in organic carbon at the end of the year was mainly an increase of the very hydrophobic acids (VHA) fraction. This fraction typically has the characteristic of being easily removed by alum treatment. The use of the rapid fractionation technique to study the impact of organic character on disinfection was also very successful. The chlorine demand correlated well with the VHA fraction (r2=0.75 for Happy Valley and Myponga combined) while the r2 values of chlorine demand with DOC and UV were 0.55 and 0.58, respectively.

Laboratory investigation of aluminum solubility and solid-phase properties following alum treatment of lake waters

Water samples from two southern California lakes adversely affected by internal nutrient loading were treated with a 20 mg/L dose of Al 3+ in laboratory studies to examine Al solubility and solid-phase speciation over time. Alum [Al 2(SO 4) 3·18 H 2O] applications to water samples from Big Bear Lake and Lake Elsinore resulted in a rapid initial decrease in pH and alkalinity followed by a gradual recovery in pH over several weeks. Dissolved Al concentrations increased following treatment, reaching a maximum of 2.54 mg/L after 17 days in Lake Elsinore water and 0.91 mg/L after 48 days in Big Bear Lake water; concentrations in both waters then decreased to <0.25 mg/L after 150 days. The solid phase was periodically collected and analyzed using X-ray diffraction (XRD), differential scanning calorimetry-thermogravimetric analysis (DSC-TGA), scanning electron microscopy (SEM), and surface area analyses to investigate the nature of the reaction products and crystallinity development over time. Poorly ordered, X-ray amorphous solid phases transformed over time to relatively well-ordered gibbsite, with strong diffraction peaks at 4.8 and 4.3 Å. XRD also indicated the formation of a second (possibly aluminosilicate) crystalline phase after 150 days in Lake Elsinore water. Surface areas also decreased over time as crystals reordered to form gibbsite/microcrystalline gibbsite species. DSC-TGA results suggested that the initially formed amorphous Al(OH) 3 underwent transformation to >45% gibbsite. These results were supported by geochemical modeling using Visual MINTEQ, with Al solubility putatively controlled by amorphous Al(OH) 3 shortly after treatment and approaching that of microcrystalline gibbsite after about 150 days. These findings indicate that Al(OH) 3 formed after alum treatment undergoes significant chemical and mineralogical changes that may alter its effectiveness as a reactive barrier to phosphorus release from lake sediments.