Unfiltered Samples Research Articles

To what extent can portable fluorescence spectroscopy be used in the real-time assessment of microbial water quality?

The intrinsic fluorescence of aquatic organic matter emitted at 350nm when excited at 280nm correlates widely with water quality parameters such as biochemical oxygen demand. Hence, in sewage-impacted rivers and groundwater, it might be expected that fluorescence at these wavelengths will also correlate with the microbial water quality. In this paper we use a portable fluorimeter to assess the relationship between fluorescence intensity at this wavelength pair and Escherichia coli enumeration in contrasting river catchments of poor water quality: in KwaZulu-Natal, S. Africa and the West Midlands, UK. Across all catchments we demonstrate a log correlation (r=0.74) between fluorescence intensity and E. coli over a seven-log range in E. coli enumerations on non-perturbed (unfiltered) samples. Within specific catchments, the relationship between fluorescence intensity and E. coli is more variable, demonstrating the importance of catchment-specific interference. Our research demonstrates the potential of using a portable fluorimeter as an initial screening tool for indicative microbial water quality, and one that is ideally suited to simple pollution scenarios such as assessing the impact of faecal contamination in river or groundwater at specific sites.

Evaluation of preconcentration methods in the analysis of synthetic musks in whole‐water samples

According to the European Water Framework Directive, environmental assessment of organic compounds should be made in whole-water samples, but due to their hydrophobicity and strong attraction to organic content these compounds can be found bound to suspended particle matter or in the dissolved fraction. In this work, the extraction of musk compounds was studied in whole-water samples exhibiting different amounts of dissolved organic carbon and suspended particulate matter using polyethersulfone preconcentration technique. Matrix effects in estuarine and wastewater (both influent and effluent) were evaluated for filtered and unfiltered samples. For unfiltered samples, estuarine water exhibited matrix effects <20%, while for effluent it was up to 48% and for influent ranged from 85 to 99%. To compensate matrix effects and determine total concentrations in unfiltered samples, different quantification approaches were tested: the use of deuterated analogues and standard additions. Standard additions provided the best results for unfiltered samples. Finally, filtered and unfiltered samples were analyzed using both polyethersulfone preconcentration and membrane-assisted solvent extraction and results showed a good agreement between the two methods. In both cases unfiltered samples provided concentrations 1.5-2.6 times higher than filtered samples.

Continuous underway measurements of dimethyl sulfide in seawater by purge and trap gas chromatography coupled with pulsed flame photometric detection

In this study, a conventional purge and trap (PT) system was modified with gas chromatography coupled with pulsed flame photometric detection (GC-PFPD) to achieve long-term continuous shipboard underway measurements of trace-level dimethyl sulfide (DMS) in unfiltered seawater. This PT system is automated, time-efficient and electronically temperature controlled. A complete analytical cycle for each sample only requires 8.5min. The critical aspects of the PT-GC-PFPD system were evaluated, and sharp peaks were observed for nanomolar levels of DMS with a low limit of detection (LOD) of 0.05nmolL−1. Unfiltered seawater samples were continuously supplied to the system because small deviations were observed in the responses between filtered and unfiltered seawater samples (ranging from 0.7% to 4.7%). Moreover, during 9days of continuous in-situ observations, a 6% deviation in the standards was observed, indicating that this system is reliable and stable. The successful application of this system in a field study suggested that the proposed DMS analysis method would significantly facilitate data collection in the field. In addition, dimethylsulfoniopropionate (DMSP) was also detected by this system after conversion to DMS. The required modifications are affordable and can be easily performed by laboratories that have traditional, non-commercial, purge and trap systems.

Temporal variability of reactive iron over the Gulf of Alaska shelf

The Gulf of Alaska (GoA) shelf is a highly productive regime bordering the nitrate-rich, iron (Fe)-limited waters of the central GoA. The exchange between nitrate-limited, Fe-replete coastal waters and nitrate-rich, Fe-deplete offshore waters, amplified by mesoscale eddies, is key to the productivity of the region. Previous summer field studies have observed the partitioning of Fe in the coastal GoA as being heavily dominated by the particulate phase due to the high suspended particulate loads carried by glacial rivers into these coastal waters. Here we present new physico-chemical iron data and nutrient data from the continental shelf of the GoA during spring and late summer 2011. The late summer data along the Seward Line showed variable surface dissolved iron (DFe) concentrations (0.052nM offshore to 4.87nM inshore), within the range of previous observations. Relative to available surface nitrate, DFe was in excess (at Fe:C=50μmol:mol) inshore, and deficient (at Fe:C=20μmol:mol) offshore. Summer surface total dissolvable iron (TDFe, acidified unfiltered samples) was dominated by the acid-labile particulate fraction over the shelf (with a median contribution of only 3% by DFe), supporting previously observed Fe partitioning in the GoA. In contrast, our spring data from southeast GoA showed TDFe differently partitioned, with surface DFe (0.28–4.91nM) accounting on average for a much higher fraction (~25%) of the TDFe pool. Spring surface DFe was insufficient relative to available nitrate over much of the surveyed region (at Fe:C=50μmol:mol). Organic Fe-binding ligand data reveal excess concentrations of ligands in both spring and summer, indicating incomplete titration by Fe. Excess concentrations of an especially strong-binding ligand class in spring surface waters may reflect in-situ ligand production. Due to anomalous spring conditions in 2011, river flow and phytoplankton biomass during our spring sampling were lower than the expected May average. We argue our samples are likely more representative of early spring pre-bloom conditions, providing an idea of the possible physico-chemical partitioning of Fe in coastal GoA waters relevant to initial spring bloom dynamics.

Pillar cuvettes: capillary-filled, microliter quartz cuvettes with microscale path lengths for optical spectroscopy.

The goal of most analytical techniques is to reduce the lower limit of detection; however, it is sometimes necessary to do the opposite. High sample concentrations or samples with high molar absorptivity (e.g., dyes and metal complexes) often require multiple dilution steps or laborious sample preparation prior to spectroscopic analysis. Here, we demonstrate dilution-free, one-step UV-vis spectroscopic analysis of high concentrations of platinum(IV) hexachloride in a micropillar array, that is, "pillar cuvette". The cuvette is spontaneously filled by wicking of the liquid sample into the micropillar array. The pillar height (thus, the film thickness) defines the optical path length, which was reduced to between 10 and 20 μm in this study (3 orders of magnitude smaller than in a typical cuvette). Only one small droplet (∼2 μL) of sample is required, and the dispensed volume need not be precise or even known to the analyst for accurate spectroscopy measurements. For opaque pillars, we show that absorbance is linearly related to platinum concentration (the Beer-Lambert Law). For fully transparent or semitransparent pillars, the measured absorbance was successfully corrected for the fractional surface coverage of the pillars and the transmittance of the pillars and reference. Thus, both opaque and transparent pillars can be applied to absorbance spectroscopy of high absorptivity, microliter samples. It is also shown here that the pillar array has a useful secondary function as an integrated (in-cuvette) filter for particulates. For pillar cuvette measurements of platinum solutions spiked with 6 μm diameter polystyrene spheres, filtered and unfiltered samples gave identical spectra.

Transparent exopolymer particles (TEP) and Coomassie stainable particles (CSP): Differences between their origin and vertical distributions in the ocean

The discovery of ubiquitous, abundant and transparent gel-like particles, such as the polysaccharide-containing transparent exopolymer particles (TEP) and protein-containing Coomassie stainable particles (CSP) has changed our conception of particle–organism interaction and created new questions about the origin, composition, and role of these particles in aquatic systems. Using both standard and novel staining methods, we studied these gel-like particles to determine whether CSP and TEP are sub-units of the same particle, are distinct particles with different characteristics and behaviors, or are both. Our seawater mesocosm results show that phytoplankton produce both TEP and CSP; however, their highest abundances occur at differences phases in the phytoplankton bloom. We developed a new technique for visualizing stained transparent material in unfiltered aqueous samples with the FlowCAM; this technique allows in-situ visualization and imaging of TEP and CSP in parallel stained samples. Visual examination of stained and unstained TEP and CSP from seawater microcosms, marine algal cultures, and freshwater showed that TEP and CSP have different shape, size and particle-association behavior. In a diatom-dominated microcosm, TEP concentrations were higher than CSP concentrations and unlike CSP, TEP were usually associated with diatom cells or aggregates. The cyanobacteria culture, however, showed higher CSP than TEP concentrations and aggregates of those cells appeared to be CSP-rich. Vertical and seasonal distributions of TEP and CSP in the Sargasso Sea were different. Even though both types of particles were most abundant in the upper 100m of the water column, CSP closely followed fluorescence and total particle concentration, while the highest TEP concentration was always in the shallowest sample collected. Thus, we conclude that TEP and CSP are different particles, produced by different species at different growth phases and rates. They have different roles and are affected by different processes according to the community composition and environmental conditions.

Long-term monitoring of arsenic, copper, selenium, and other elements in Great Salt Lake (Utah, USA) surface water, brine shrimp, and brine flies.

This paper presents long-term monitoring data for 19 elements with a focus on arsenic (As), copper (Cu), and selenium (Se), in surface water (2002-2011), brine shrimp (2001-2011), and brine flies (1995-1996) collected from Great Salt Lake (GSL, Utah, USA). In open surface waters, mean (±standard deviation [SD]; range; n) As concentrations were 112 (±22.1; 54.0-169; 47) and 112 μg/L (±35.6; 5.1-175; 68) in filtered and unfiltered surface water samples, respectively, and 16.3 μg/g (±5.6; 5.1-35.2; 62) dry weight (dw) in brine shrimp. Mean (±SD; range; n) Cu concentrations were 4.2 (±2.1; 1.3-12.5; 47) and 6.9 μg/L (±6.6; 1.9-38.1; 68) in filtered and unfiltered surface water samples, respectively, and 20.6 μg/g (±18.4; 5.4-126; 62) dw in brine shrimp. Finally, mean (±SD; range; n) dissolved and total recoverable Se concentrations were 0.6 (±0.1; 0.4-1.2; 61) and 0.9 μg/L (±0.7; 0.5-3.6; 89), respectively, and 3.6 μg/g (±2.2; 1.1-14.9; 98) dw in brine shrimp. Thus, Se in open lake surface waters was most often in the range of 0.5-1 μg/L, and concentrations in both surface water and brine shrimp were comparable to concentrations measured in other monitoring programs for the GSL. Temporally, the statistical significance of differences in mean dissolved or total recoverable As, Cu, and Se concentrations between years was highly variable depending which test statistic was used, and there was no clear evidence of increasing or decreasing trends. In brine shrimp, significant differences in annual mean concentrations of As, Cu, and Se were observed using both parametric and nonparametric statistical approaches, but, as for water, there did not appear to be a consistent increase or decrease in concentrations of these elements over time.

Effects of transparent exopolymer particles and suspended particles on the survival of Salmonella enterica serovar Typhimurium in seawater.

The bacterium Salmonella enterica can infect marine mammals and has been increasingly implicated in seafood-borne disease outbreaks in humans. Despite the risk this zoonotic agent poses to animals and people, little is known regarding the environmental factors that affect its persistence in the sea. The goal of this study was to evaluate the impact of two constituents on the survival of Salmonella in the marine environment: transparent exopolymer particles (TEP) and suspended particles. A decay experiment was conducted by spiking Salmonella into bottles containing seawater, seawater with alginic acid as a source of TEP, filtered seawater or filtered seawater with alginic acid. Survival of Salmonella was monitored using culture followed by enrichment assays to evaluate if the bacteria entered a viable but non-cultivable (VBNC) state. Salmonella cell counts dropped significantly faster (P ≤ 0.05) in the unfiltered seawater samples with and without TEP. The slowest decay occurred in filtered seawater containing alginic acid, with VBNC Salmonella persisting for 17 months. These findings suggest that TEP may favor Salmonella survival while suspended particles facilitate its decay. Insight on the survival of allochthonous, zoonotic pathogens in seawater can guide monitoring, management and policy decisions relevant to wildlife and human public health.

PBDEs versus NBFR in wastewater treatment plants: occurrence and partitioning in water and sludge

This study evaluates the occurrence of flame retardants (FR) in five wastewater treatment plants (WWTPs) located close to Barcelona (NE Spain), an area with high urban and industrial pressures. Compounds studied include eight polybromodiphenyl ethers (PBDEs) and eight New Brominated Flame Retardants (NBFRs), for which little information regarding their presence, partitioning and fate within the WWTPs is available. In unfiltered influent samples, PBDEs were not detected and bis(2-ethyl-1-hexyl)tetrabromophthalate was the only NBFR detected, and all WWTPs were efficient in eliminating this compound as no residues were found in the effluents. However, primary sludge contained from 279 to 2299 ng/g dry weight of ΣFR and the concentration increased in secondary (biological) sludge. NBFRs accounted for the main FR detected in sludge, representing a 63-97% of the total load, and among PBDEs, BDE-209 was the most ubiquitous congener. Considering the amount of sludge generated in each WWTP, it was estimated that 0.34-17.2 kg of FR are released annually through the sludge, which can have negative environmental and health implications if sludge is used as biosolid in agriculture. Overall, this study provides a sampling design and analytical protocol to be used to determine the evolution of FR in WWTPs and compares the levels detected, considering that PBDEs are being phased out to be substituted by other compounds which also have high accumulative and recalcitrant properties.

A summarized review of procedures for the optimization of preliming

Procedures noted herein will result in relatively optimal prelimer control and performance. Through the application of the procedures and control methods noted, it is possible to maintain relatively optimal preliming performance over a relatively wide range of operating conditions and beet quality. Certain severe adverse conditions affecting 1st carbonatation slurry filtration performance may require somewhat higher final preliming alkalinity than indicated by the test for determination of the optimum endpoint. Such conditions may be indicated by an abnormal flattening of the minimum point of the optimum alkalinity determination plot of transmittance difference between filtered and unfiltered sample aliquots.

Effects of chlorination operating conditions on trihalomethane formation potential in polyaluminum chloride-polymer coagulated effluent

In this study, coagulation performance of polyaluminum chloride (PAC) and PAC-lignin acrylamide (PAC+LAM) in reservoir water treatment was contrastively analyzed. Effects of operating conditions including chlorine dose, contact time and pH on the formation potential of trihalomethanes (THMs) during chlorination in coagulated effluent were also investigated. Comparing with PAC, PAC+LAM achieved higher efficiency in the removal of THMs precursors. TTHM yield in unfiltered water samples (UW) was greater than that of filtered water (FW) due to the residual dissolved organic matter (DOM) in the suspended particles or micro flocs. Meanwhile, operating conditions during chlorination had a significant influence on THMs formation potential. With chlorine dose rising, mass ratio of CHCl3 to TTHM increased, whereas that of CHBr2Cl decreased due to higher Cl2/Br− molar ratio. TTHM and CHCl3 levels rose with the increase of pH. Under a given chlorination condition, there was a minor effect of contact time on THM speciation.

Trace element behaviour at cold seeps and the potential export of dissolved iron to the ocean

Seawater samples were collected by submersible above methane seeps in the Gulf of Guinea (Regab and Baboon pockmarks) in order to investigate the behaviour of iron (Fe), manganese (Mn) and rare earth elements (REE) during fluid seepage. Our aim was to determine whether cold seeps may represent potential sources of dissolved chemical species to the ocean. Dissolved (<0.45 μm filtered samples) and total dissolvable (unfiltered samples) concentrations were determined over ∼50 m long vertical transects above the seafloor and at various discrete locations within the pockmarks.We show that substantial amounts of Fe and Mn are released into seawater during seepage of methane-rich fluids. Mn is exported almost quantitatively in the dissolved form (more than 90% of total Mn; mean MnDISS∼12±11 nmol/kg). Although a significant fraction of Fe is bound to particulate phases, the dissolved iron pool still accounts on average for approximately 20 percent of total iron flux at vent sites (mean FeDISS∼22±11 nmol/kg). This dissolved Fe fraction also appears to remain stable in the water column. In contrast, there was no evidence for any significant benthic fluxes of pore water REE associated with fluid seepage at the studied sites.Overall, our results point towards distinct trace element behaviour during fluid seepage, with potential implications for the marine geochemical budget. The absence of any dissolved REE enrichments in bottom waters clearly indicates effective removal in sub-surface sediments. Most likely, precipitation of authigenic mineral phases at cold seeps (i.e. carbonates) represents a net sink for these elements. While Mn appears to behave near-conservatively during fluid seepage, the observed relative stability of dissolved Fe in the water column above seepage sites could be explained by complexation with strong organic ligands and/or the presence of Fe-bearing sulfide nanoparticles, as reported previously for submarine hydrothermal systems. Considering the ubiquitous occurrence of methane vents at ocean margins, cold seeps could represent a previously unsuspected source of dissolved Fe to the deep ocean.

N-nitrosodimethylamine formation upon ozonation and identification of precursors source in a municipal wastewater treatment plant.

Ozone doses normalized to the dissolved organic carbon concentration were applied to the primary influent, primary effluent, and secondary effluent of a wastewater treatment plant producing water destined for potable reuse. Results showed the most N-Nitrosodimethylamine (NDMA) production from primary effluent, and the recycle streams entering the primary clarifiers were identified as the main source of NDMA precursors. The degradation of aminomethylated polyacrylamide (Mannich) polymer used for sludge treatment was a significant cause of precursor occurrence. A strong correlation between NDMA formation and ammonia concentration was found suggesting an important role of ammonia oxidation on NDMA production. During ozonation tests in DI water using dimethylamine (DMA) as model precursor, the NDMA yield significantly increased in the presence of ammonia and bromide due to the formation of hydroxylamine and brominated nitrogenous oxidants. In addition, NDMA formation during ozonation of dimethylformamide (DMF), the other model precursor used in this study, occurred only in the presence of ammonia, and it was attributable to the oxidation of DMF by hydroxyl radicals. Filtered wastewater samples (0.7 μm) produced more NDMA than unfiltered samples, suggesting that ozone reacted with dissolved precursors and supporting the hypothesis of polymer degradation. Particularly, the total suspended solids content similarly affected NDMA formation and the UV absorbance decrease during ozonation due to the different ozone demand created in filtered and unfiltered samples.

Size and composition analyses of colloids in deep granitic groundwater using microfiltration/ultrafiltration while maintaining in situ hydrochemical conditions

In studies of colloids in deep groundwater, a serious problem exists because the properties of the colloids are influenced by changes in the chemistry of groundwater upon exposure to the atmosphere and pressure release during sampling. To collect and analyze colloids in deep groundwater without significantly changing the groundwater chemistry, a microfiltration/ultrafiltration technique, while maintaining in situ hydrochemical conditions (mainly hydraulic pressure and anaerobic condition), was developed. The size distributions and compositions of colloids in granitic groundwater obtained at a depth of 300m at the Mizunami Underground Research Laboratory (MIU) in Japan were studied using the microfiltration/ultrafiltration technique. The shapes and compositions of the fractionated colloids collected on the membrane filter were determined by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and attenuated total reflection infrared spectroscopy. Additionally, partitioning of rare earth elements (REEs) based on colloid size was compared with REE concentrations in the filtered and unfiltered groundwater samples using inductively coupled plasma mass spectrometry. Different types of colloids consisting of inorganic and organic substances were observed and complex formation between the colloids and REEs was suggested. Furthermore, characteristic partitioning of REEs depending on colloids size was observed in complex natural environments without chemical disturbance. The current findings are useful for understanding migration of radionuclides.

Iron isotope composition of the bulk waters and sediments from the Amazon River Basin

The present study provides iron concentrations and isotopic compositions determined by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), along with key chemical, mineralogical and physical properties of 35 representative bulk (unfiltered) waters and bulk sediments from the Amazon River Basin. These samples from the Amazon River, five of its main tributaries (the Solimões, Negro, Madeira, Tapajós and Trombetas rivers) and four sub-tributaries (the Purus, Jaú, Ucayali and Napo rivers) were essentially collected during seven field missions conducted for over two years. These encompassed the centennial flood of May 2009 and the exceptional low water stage of September–October 2010, thereby providing the most extreme hydrological situations that have been recorded over the last hundred years. While the data confirmed massive losses of iron (up to ~19000tons/day, ca. 50% of the Amazon River bulk water budget) in the Solimões and Negro rivers mixing zone, the Fe isotope signatures of these bulk waters behaved conservatively. This property allows the use of bulk water Fe isotope signature to track iron sources and explain such isotopic signature in terms of simple mixing. Unfiltered samples from the organic-rich black water rivers present light δ57Fe relative to the average continental crust composition. This contrasts with the composition of the bulk white waters carrying a high mineral suspended load that have δ57Fe values undistinguishable from the crustal isotopic signature (~0.1‰ relative to IRMM-14). This observation indicates that the Fe isotopic composition represents a reliable direct tracer of the iron speciation and, therefore, of the host phases of iron in its sources. Specifically, the white water δ57Fe most likely trace the signatures of igneous and sedimentary sources, as well as of their lateritic soil minerals, while the bulk black water δ57Fe track a preferential release of Fe that has gone through a reduction step in the organic-rich horizons of tropical podzols as a result of the biological activity. This study shows that the total iron transferred by the Amazon River represents between 5 and 30% of the world's ocean Fe input by rivers, and this Amazon bulk water iron displays an isotopic composition indistinguishable from that of the average continental crust.

A population search filter for hard-to-reach populations increased search efficiency for a systematic review

ObjectivesThis article discusses how hard-to-reach population groups were conceptualized into a search filter. The objectives of this article were to (1) discuss how the authors designed a multistranded population search filter and (2) retrospectively test the effectiveness of the search filter in capturing all relevant populations (eg, homeless people, immigrants, substance misusers) in a public health systematic review. Study Design and SettingSystematic and retrospective analysis via a case study. Retrospective analysis of the search filter was conducted by comparing the MEDLINE search results retrieved without using the search filter against those retrieved with the search filter. A total of 5,465 additional results from the unfiltered search were screened to the same criteria as the filtered search. ResultsNo additional populations were identified in the unfiltered sample. The search filter reduced the volume of MEDLINE hits to screen by 64%, with no impact on inclusion of populations. ConclusionsThe results demonstrate the effectiveness of the filter in capturing all relevant UK populations for the review. This suggests that well-planned search filters can be written for reviews that analyze imprecisely defined population groups. This filter could be used in topic areas of associated comorbidities, for rapid clinical searches, or for investigating hard-to-reach populations.

Physical and remineralization processes govern the cobalt distribution in the deep western Atlantic Ocean

Abstract. The distributions of the bio-essential trace element dissolved cobalt (DCo) and the apparent particulate Co (PCo) are presented along the GEOTRACES-A02 deep section from 64° N to 50° S in the western Atlantic Ocean (longest section of international GEOTRACES marine environment program). PCo was determined as the difference between total cobalt (TCo, unfiltered samples) and DCo. DCo concentrations ranged from 14.7 pM to 94.3 pM, and PCo concentrations from undetectable values to 18.8 pM. The lowest DCo concentrations were observed in the subtropical domains, and the highest in the low-oxygenated Atlantic Central Waters (ACW), which appears to be the major reservoir of DCo in the western Atlantic. In the Antarctic Bottom Waters, the enrichment in DCo with aging of the water mass can be related to suspension and redissolution of bottom sediments a well as diffusion of DCo from abyssal sediments. Mixing and dilution of deep water masses, rather than scavenging of DCo onto settling particles, generated the meridional decrease of DCo along the southward large-scale circulation in the deep western Atlantic. Furthermore, the apparent scavenged profile of DCo observed in the deep waters likely resulted from the persistence of relatively high concentrations in intermediate waters and low DCo concentrations in underlaying bottom waters. We suggest that the 2010 Icelandic volcanic eruption could have been a source of DCo that could have been transported into the core of the Northeast Atlantic Deep Waters. At intermediate depths, the high concentrations of DCo recorded in the ACW linearly correlated with the apparent utilization of oxygen (AOU), indicating that remineralization of DCo could be significant (representing up to 37% of the DCo present). Furthermore, the preferential remineralization of phosphate (P) compared to Co in these low-oxygenated waters suggests a decoupling between the deep cycles of P and Co. The vertical diffusion of DCo from the ACW appears to be a significant source of DCo into the surface waters of the equatorial domain. Summarizing, the dilution due to mixing processes rather than scavenging of DCo and the above-mentioned remineralization could be the two major pathways controlling the cycling of DCo into the intermediate and deep western Atlantic.

Effect of filtration on colour, antioxidant activity and total phenolics of honey

82 Honey samples harvested in 2009 and 2010 flowering seasons were investigated in order to examine the influence of filtration on colour, antioxidant activity and total phenolics content. In unfiltered honey samples the total phenolics content varied between 40.5 and 177 mgGAE/100 g. The average antioxidant activity ranged from 47.2 to 83.4% when measured with DPPH and from 6 to 79% once measured with ABTS+. The results indicated that filtration had no significant effect on the above-mentioned parameters, however they were found to depend on the types of honey.

The Biofiltration Potentials of a Brewery Effluent Using Two Saprophytic Fungi Species

Aims: This research attempts to investigate the effect of a biologically mediated filtration technique {using the mycelia from two saprophytic filamentous fungi – Aspergillus flavus (A. flavus) and Aspergillus niger (A. niger), isolated from the soil} on the physicochemical indices of an Industrial (Brewery) effluent. Study Design: The experiment was conducted in a Completely Randomized Design (CRD). In all cases, the value for each data was the mean from 3 replicates. Data were subjected to a one way analysis of variance – ANOVA, while the separation of the means (post Hoc Test) was done using the independent sample T-Test at 1% level of significance. Place of Study: The Study was conducted at different Institutional Laboratories (such as the Federal Institute of Industrial Research, Oshodi; Environmental Biology Lab., Yaba College of Technology and Chemistry Lab., University of Lagos) in Lagos, Nigeria. Methodology: The effluent samples were analyzed for various physical parameters such as pH, temperature, turbidity, conductivity and Total Dissolved Solids and chemical parameters such as Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Phosphates, Sulphates, Chlorides, Hardness, Alkalinity and Nitrates using standard Original Research Article Annual Research & Review in Biology, 4(24): 4004-4022, 2014 4005 laboratory techniques and equipment. Results: The results obtained from this work showed that both fungal species were able to bring about a significant (p≤0.01) improvement in most of the physicochemical parameters considered in this Brewery effluent when compared to the unfiltered (Control) effluent samples, as well as against approved benchmarks as provided by some statutory regulatory bodies in Nigeria such as the Lagos State Environmental Protection Agency (LASEPA) and now defunct Federal Environmental Protection Agency (FEPA). Conclusion: The results from this study shows that A. niger and A. flavus (that were used in this experiment) has some promise at improving some important physicochemical indicators of a poorly treated brewery effluent.

Assessment of the Antimicrobial Efficiency of Moringa oleifera Seed Extracts in the Treatment of Grey Water

The antimicrobial efficiency of Moringa oleifera seed extracts in the treatment of grey water was investigated in this study. The Moringa oleifera seeds were collected, prepared and used to treat both filtered and unfiltered grey water at different concentrations. Physical parameters like Biochemical Oxygen Demand (BOD), Turbidity, Electrical conductivity (EC) and Total dissolved solids (TDS) of the raw, filtered and treated grey water samples were conducted. The result revealed 65.7%, 67.1% and 80.1% BOD removal for the 50mg/l, 100mg/l and 150mg/l Moringa treatment respectively. An average of 97.4% turbidity removal was achieved for the filtered grew water sample after treatment with 150mg/l of Moringa seed extract. For the Electrical conductivity, a 27.3% removal was achieved for the unfiltered sample while for the Total dissolved solids, a 91.52% removal was recorded for the filtered grew water sample using 150mg/l of seed extract. The analysis of the total coliforms and pH conducted showed that 50mg/l, 100mg/l and 150mg/l of Moringa oleifera seed extracts solution respectively achieved 68.33%, 85.00% and 97.50% removal for the filtered grey water with pH values of 6.37, Original Research Article British Journal of Applied Science & Technology, 4(3): 558-567, 2014 559 5.88 and 5.83 respectively. It was calculated that the optimum dosage of Moringa seed powder required to maintain minimum crop pH requirement of (6.5) was 32.89mg/l (44.95%). It was concluded that the seed extract of Moringa oleifera acts as a natural coagulant, flocculent and absorbent for the treatment of grew water. The presence of indicator organisms shows that the water samples are faecally contaminated and is only safe for irrigation purposes after the treatment.