Sludge Materials Research Articles

The granular sludge membrane bioreactor: A new tool to enhance Anammox performance and alleviate membrane fouling

Anammox process has be widely concerned as a novel biological nitrogen removal technology because of reduced operating costs and environmental friendliness. However, the long start-up time and operational instability of Anammox process has hindered its wide applications. A new-type hybrid granular sludge membrane bioreactor (GSMBR) combining sludge granulation with membrane filtration was developed for accelerating start-up of Anammox process and stabilizing its operation as well as alleviating the membrane fouling. Anammox start-up period was shortened to 43 days, the maximum nitrogen removing rate and efficiency reached 0.83 kg N m−3 d−1 and 97 % respectively on 115 d. Moreover, the membrane fouling is relatively light. The maximum transmembrane pressure only reached 32 kPa on 115 d, when there were still several visible micropores and channels on the fouled membrane surface. The mature brownish-red Anammox granular sludge mostly sized at 0.5–1.0 mm. The specific population shift from norank Alphaproteobacteria to Candidatus Brocadia was found. Three Anammox species were present in the mature sludge and uncultured Candidatus Brocadia sp. was the predominated bacteria. GSMBR was proven to be a robust reactor for enhancing Anammox performance. This study was helpful to promote the engineering applications of Anammox process in treating the high-strength nitrogenous wastewaters.

Biofuel production by co-pyrolysis of sewage sludge and other materials: a review

Biofuel production by co-pyrolysis of sewage sludge and other materials: a review

Selective recovery of high-grade rare earth, Al, and Co-Mn from acid mine drainage treatment sludge material

Rare earth elements (REEs) and critical elements (CEs) have been in the spotlight recently due to their vital role in high-tech applications and green energy initiatives. Due to the scarcity of mineral resources for the majority of these elements, there has been significant interest in the recovery of these elements from secondary resources. Among the secondary resources, acid mine drainage (AMD) and associated sludge materials have been found to be viable sources of multiple critical elements, including REEs, Al, Co, and Mn. AMD and sludge samples from 3 AMD treatment sites in Pennsylvania were characterized for elemental content and contained value evaluation. A novel purification process based on a previously developed 3-stage AMD treatment process was designed to recover high-grade Al, REE, Co, and Mn products from the sludge materials through aqueous processing with multiple cleaner steps and precise control of the process parameters. The final products of the three stages of this purification process are boehmite and dawsonite in Stage I, adamsite-(REE) in Stage II, and cobalt oxide and ramsdellite in Stage III. Recoveries of > 99 % for the target elements were achieved with the design of a recycling load. Through the proposed purification process, 92.8 % aluminum minerals in Stage I, 88.5 % mixed-REE-carbonate in Stage II, 68 % ramsdellite, and 6.9 % cobalt oxide in Stage III were produced.

Tailoring waste-derived materials for Calcium-Looping application in thermochemical energy storage systems

The integration of the Ca-looping (CaL) process in concentrated solar power systems (CSP) has been identified as an interesting approach for thermochemical energy storage (TCES) systems, since the TCES material regeneration can use clean and unlimited solar energy. The CaL cyclic stability of CaCO3 is an important parameter for the large-scale implementation of this technology, but in literature little attention has been paid to the absorptivity of natural CaO precursors such as limestone and other CaCO3-based materials. The CaCO3/CaO particles are usually white, and their absorptivity is relatively low at the wavelengths that correspond to solar radiation, limiting their use in directly irradiated reactors. In this work, the heat storage density (HSD) and absorptivity of different waste resources and natural Portuguese geological materials were assessed and improved after doping with 10 or 20 wt% of “dark” inert additives. A sludge and SiC were used to increase the CaL-TCES materials absorptivity at the wavelengths of solar visible radiation and to hinder the material sintering. It is found that the doping of the CaL-TCES materials with sludge hinders the sintering of the CaO particles, and after 20 carbonation-calcination cycles the HSD of the doped material is two times higher than the corresponding value for undoped material (400–408 vs 203 kJ/kg CaCO3). However, the sludge additive has a minimal impact on the solar absorptivity of the TCES material. On the other hand, the SiC addition to a waste of marble powder (WMP-Galrão) has a positive impact with an increase of 13 % on the absorptivity of the TCES material but does not improve the HSD. The absorptivity of CaL-TCES materials is a relevant property that can be improved through the use of “dark” inert additives. These new results show that TCES materials with improved HSD can be obtained through the tailoring of marble and sludge waste-derived materials, but sludges from other sources, with higher solar absorptivity need to be evaluated. The use of wastes is relevant for the circular economy goals, and it is environmentally friendly.

Mechanical Strength, Water Seepage and Microstructure of a Novel Landfill Solidified Sludge Liner Material

In order to prepare a novel landfill liner material, we used industrial calcium-containing waste (slag, fly ash, and desulfurized gypsum) to solidify municipal sludge. The mechanical and permeability properties of the solidified sludge material (SSM) were evaluated using straight shear, uniaxial compression, and permeability tests. The hydration products, microscopic morphology, and elemental composition of the SSM after the wet and dry cycles were analyzed using a combination of scanning electron microscopy (SEM + EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The SSM has high strength and low hydraulic conductivity. The values of cohesion c and internal friction angle φ reached 0.45–3.31 MPa and 6.52–36.28°. The SSM exhibited a compressive strength of 0.93–11.67 MPa and hydraulic conductivity of 4.80 × 10−9–1.34 × 10−7 cm/s. Analysis shows that SiO2, Al2O3, and CaO in industrial calcium-containing solid wastes and sludges produce dense bulk and agglomerated C-S-H and C-A-S-H gels under alkali excitation. The optimum ratio of sludge, desulfurized gypsum, fly ash, and slag in the solidified sludge was 1:0.61:0.62:0.54, whereas the optimum exciter was Ca(OH)2. The SSM may be used as a good barrier material to prevent water seepage in landfills.

Determination of pharmaceuticals and metabolites in sludge and hydrochar after hydrothermal carbonization using sonication-QuEChERS extraction method and UHPLC LTQ/Orbitrap MS.

Pharmaceuticals (PhACs) are an important group of emerging contaminants that are released continuously in the environment from wastewater treatments plants (WWTPs). They can produce biological effects even though at very low concentrations. Conventional WWTPs are not able to remove or degrade completely emerging pollutants resulting in the presence of PhACs in sewage sludge after wastewater treatment. PhACs are found in sludge at low ppb-ppt levels, and their analysis and detection is a difficult task due to the complexity of sewage sludge matrices. Hydrothermal carbonization is currently being proposed as a suitable conversion technology for sewage sludge management to recover valuable products and to be used for soil amendment. In this work, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methodology with a dispersive solid-phase extraction (d-SPE) clean-up followed by ultra-high-performance liquid chromatography coupled with high-resolution linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ/Orbitrap MS), operated in positive ionization mode, was adopted to investigate 33 multiclass pharmaceuticals in sewage sludge and in hydrochar produced after hydrothermal carbonization. The analytical method was first optimized studying various extraction parameters and finally validated in terms of linearity, recovery, intra and inter-day precisions, expanded uncertainty (%U)/Horrat ratio at three spiking levels, matrix-effects (ME), process efficiency (PE), and limits of detection and quantification. The developed methodology fulfilled all analytical requirements and was finally applied to sludge samples from the WWTP of Ioannina city where a group of antibiotics was detected at concentrations up to 15ngg-1 and psychiatric drugs such as amisulpride, clozapine, and citalopram were detected at higher concentration levels up to 205, 87.4 and 63.2ngg-1, respectively. The method was also applied to hydrothermally treated sludge sample under different reaction conditions. Most of the antibiotic compounds were not detected, and several psychiatric drugs such as mirtazapine, bupropion, valsartan, diazepam, and caffeine were found at concentrations below the LOQ.

Triple action of FeCl3-assisted hydrothermal treatment of digested sludge for deep dewatering

In this study, a FeCl3-assisted hydrothermal treatment (HTT) process under mild conditions (90 °C–130 °C) was developed for deep dewatering of anaerobically digested sludge. HTT of sludge at 90 °C–130 °C with 4%–6% Fe3+ ions loading based on total sludge solids followed by mechanical dewatering reduced sludge water content from 82% to 38%–53% and sludge weight by 62%–72%. The treatment increased the flowability of sludge through reduction of apparent viscosity and disintegration of colloidal forces between sludge particles. This study unveiled that FeCl3-assisted HTT process had three mechanisms for improving sludge dewaterability and flowability. The treatment hydrolysed sludge flocs in the presence of Lewis acid FeCl3 and high temperature (90–130 °C). Fe3+ ions also improved dewaterability through the formation of double electric layers and neutralisation of surface negative charges, leading to flocculation of sludge flocs. More importantly, the hydrolysed sludge components produced during HTT process acted as reducing agents and led to in-situ generation of iron oxyhydroxide nanoparticles through reduction-oxidation reactions, further enhancing flocculation/co-precipitation of sludge flocs. The treatment reduced EPS content and changed conformational structures of EPS proteins by breaking down hydrogen bond-maintaining α-helix which led to a loose EPS protein structure and enhanced hydrophobicity and flocculability. Furthermore, the FeCl3-assisted treatment promoted immobilisation of the majority of heavy metals in the sludge matrix through co-precipitation/complexation reactions with iron species and organic/inorganic matters. This indicates that the FeCl3-assisted treatment reduced direct toxicity/bioavailability of the majority of heavy metals and the treated sludge may be suitable for land application. Overall, this study provides new insights into mechanism of FeCl3-assisted HTT process for dewaterability of anaerobically digested sludge and immobilisation of heavy metals.

Utilization of sludge-based alginate beads for the application of rare earth elements (REEs) recovery from wastewater: A waste to resource approach

The main purposes of this research work were to realize the potential of sludge valorization by converting the sludge into adsorbents and to investigate the performance of sludge-based adsorbents for rare earth elements (REEs) recovery from dilute aqueous solutions. Hydrochloric acid and Fenton reagents were employed as pretreatment procedures to enhance the surface area and adsorption yield. Following this, sludge-based alginate beads were prepared by using HCl treated (HT) and Fenton treated (FT) sludge materials. The chemical composition and surface chemistry of sludge-based adsorbent beads were thoroughly analyzed by state-of-the-art analytical techniques, such as Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) analysis. The prepared beads were then investigated for the recovery of REEs. The batch adsorption studies revealed that the FT sludge beads performed better in comparison to the HT sludge beads. Among REEs, the HT- and FT-sludge beads demonstrated higher affinity towards Sm 3+ ions, displaying the maximum adsorption capacities of 2.83 mg/g and 4.16 mg/g, respectively, in a multi-component system (C o = 25 ppm of each REE; pH = 5, t = 24 h and dosage = 5 g/L). In conclusion, the results from this work showed that the prepared sludge-based alginate beads can be used for REEs recovery from diluted waste streams and the tested sludge treatment options were also found effective in converting the waste to resource i.e., sludge to adsorbent for REEs recovery. • Hydrochloric acid and Fenton reagents were used in the pre-treatment of sludge. • Treated sludge was transformed into beads to recover REEs from wastewater. • Sorption capacity of beads were investigated at pH (2–5) and pH 5 became optimal point. • Max. adsorption capacities of Sm 3+ , 2.83 mg/g (HCl treated) and 4.16 mg/g (Fenton treated).

Metal-free catalysis for organic micropollutant degradation in waste activated sludge via poly(3-hydroxybutyrate) biopolymers using Cupriavidus sp. L7L coupled with peroxymonosulfate

This study employed a novel and environment-friendly biopolymer/oxidant catalytic system, viz., poly(3-hydroxybutyrate)/peroxymonosulfate (PHB/PMS), for pretreating wastewater sludge for the first time. Under optimal conditions, i.e., 3.1 × 10−4 M of PMS and 3.3 g/L of PHB at pH = 6.0, the PAHs in the sludge matrix was decreased by 79 % in 12 h. Increase in salinity (75 % synthetic seawater) achieved 83 % of PAHs degradation. Functional groups (CO) of the biopolymer matrix were active centers for biopolymer-mediated electron transfer that produced reactive oxygen species (SO4−, HO, and 1O2) for adsorption and catalytic oxidation of PAHs in the sludge. Functional metagenomic analysis revealed the main genus, Conexibacter (phylum, Actinobacteria) exhibited PAH-degrading function with high efficiency in the biodegradation of PAHs from sludge pretreated with PHB/PMS. Coupling chemical oxidation and biostimulation using bacterial polymer-based biomaterials is effective and beneficial for pretreating wastewater sludge toward circular bioeconomy.

Research on valorisation of spent garnets as addition in cementitious materials – preliminary experimental evaluation

Abrasive waterjet (AWJ) material processing represents a relatively new and extremely efficient method in the specific industries, implying various applicability areas, attributed to different materials, with different properties and domains of use. Besides numerous advantages of the AWJ cutting and generally of the material processing techniques, they also involve the waste generation: the abrasive sands are converted into sludge material, collected into recipients and further on, after natural drying, they become waste dumps randomly deserted. The enlargement of the AWJ techniques in the latest years determines the corresponding increase of the associated Garnet wastes (Spent Garnets, SG), thus leading towards the clear need of identifying opportunities for their recycling and valorisation. Aggregates are basic raw materials in the production of concrete, mortar and plasters, composite cementitious and/or cement-free materials (geopolymer concrete) in the building materials and generally, in the construction industry. The rapid growth of the population, recorded mainly in urban areas, determines an increasing demand on housing facilities and consequently, on concrete production and aggregates consumption. Aggregates and sand, mainly exploited from riverbeds or quarries, represent exhaustible natural resource for which substitution solutions need to be found, in order to control and reduce their extraction from the natural landscape. Considering the superposition of this independent cause and effect situations, the rapid growth of Spent Garnets (SG) landfills, generated by AWJ processes, and, on the other hand, the need to substitute the natural aggregate in construction industry, a reliable solution could emerge from the potential valorisation of SG wastes as partial or even complete substitution of sands / aggregates in the composition of construction materials. The present paper offers a preliminary overview regarding the possibility of incorporating SG wastes of local production in usual cement-based materials, as partial substitute of the aggregate, for the double purpose of waste management implementation and natural resources protection, on the transition path towards the implementing the Circular Economy (CE) concept in the Romanian industry.

Investigation of the process of desalination of the concentrate of reverse osmosis plants by energy waste

PURPOSE. To investigate the cleaning process of the reverse osmosis water filtration system (ROWFS) concentrate with energy waste, to obtain and determine its quality indicators, to study the mechanism of sulfate and chloride ions adsorption by sorption material on the basis of energy waste, to consider the process of sulfate and chloride ion adsorption by this sorption material under static and dynamic conditions.METHODS. The method of variable weights was used to determine the adsorption capacity of the sorption material. Methods of titrimetric and photocolorimetric analysis were used during determining of water quality indicators.RESULTS. In this paper the technology of desalination of the ROP concentrate by the adsorption method was studied. Under static conditions the adsorption isotherm has been constructed. On the basis of ground sludge the granular sorption material has been developed. The possibility of using ionexchange filters with granular loading has been considered, the adsorption curve under dynamic conditions has been constructed.CONCLUSION. The sorption based on energy waste - carbonate sludge material for the purification of ROWFS concentrate has been developed. Adsorption isotherms of sulfate and chloride ions were constructed on the basis of experimental data. For investigation the purification of the ROWFS concentrate under dynamic conditions the granular sorption material was obtained. The adsorption technology of ROWFS concentrate purification from sulfate and chloride ions by energy waste is presented.

Antimicrobial PCMX facilitates the volatile fatty acids production during sludge anaerobic fermentation: Insights of the interactive principles, microbial metabolic profiles and adaptation mechanisms

Para-chloro-meta-xylenol (PCMX), as a massively used antimicrobial agent, exhibited dose-dependent effects on the sludge fermentation for volatile fatty acids (VFAs). The presence of PMCX at environmental levels (10–20 mg/g TSS) promoted the VFAs production by 2.5–3.0 folds but caused evident inhibition at high level (100 mg/g TSS). PCMX synchronously promoted the sludge solubilization, hydrolysis, and acidification but inhibited methanogenesis. Mechanistic investigations revealed that PCMX could interact with the extracellular polymeric substances (EPS) in sludge and cause the release of biodegradable substrates (especially proteins) by altering the WAS structures. Moreover, the functional fermentative bacteria (i.e., Firmicutes and Chloroflexi) were enriched while those VFAs consumers (i.e., Methanothrix and Methanomassiliicoccus) were reduced with low level of PCMX exposure. The microbial enzymatic activities (i.e., protease) and critical genes relevant to the substrates transport (i.e., gluC and lhpN) and metabolisms (especially the proteins, i.e., pckA), and VFAs biosynthesis (i.e., fabG) were all upregulated with the low PCMX stimulus. The microbial response and adaptation to PCMX toxicity were mainly attributed to the regulation of two-component and quorum sensing systems. Overall, PCMX contributed to the VFAs accumulation during sludge fermentation by mainly interacting and disrupting the sludge structures, and improving the microbial metabolic function traits. This work provided new insights into exogenous pollutants’ interactions, potential influences, and reaction mechanisms in the complicated sludge matrix.

Optimised reduction of total solids and organic matter of sewage sludge matrix for an improved extraction of microplastics

The extraction of microplastics from complex environmental matrices, such as sewage sludge, has proven challenging because of their high organic content. A common procedure for the extraction of microplastics from sludge involves conducting a chemical digestion to reduce the amount of organic matter in the sample, followed by a density separation of microplastics. In order to increase the reliability of the density-based separation, an optimisation of the chemical digestion is needed. The aim of this study was to maximise the total solids and carbon content reduction of sludge by optimising the sodium dodecyl sulphate (SDS) pretreatment and the duration of H2O2 digestion. A reduction in total solids by 95.6% and in carbon content by 98.1% were achieved with the optimised digestion method, which involved an application of 1% SDS and a 2-day H2O2 treatment in the first digestion step. The inclusion of the SDS pretreatment significantly increased the reduction of total solids and carbon content. The optimised digestion process had no significant visible effects on tested reference microplastics and provided an extraction efficiency of 84% for 150 μm reference microspheres and 72% for 650 μm long microfibres. To enable the application of the optimised digestion process to other types of sludges, the consumption of SDS and H2O2 were also presented as per grams of organic matter in the untreated sludge.

Enhanced aerobic granular sludge formation by applying Phanerochaete chrysosporium pellets as induced nucleus.

The long start-up period is a major challenging issue for the widespread application of aerobic granular sludge (AGS). In this study, a novel rapid start-up strategy was developed by inoculating Phanerochaete chrysosporium (P. chrysosporium) pellets as the induced nucleus in a sequencing batch airlift reactor (SBAR) to enhance activated sludge granulation. The results demonstrated that P. chrysosporium pellets could effectively shorten the aerobic granulation time from 32 to 20days. The AGS promoted by P. chrysosporium pellets had a larger average diameter (2.60-2.74mm) than that without P. chrysosporium pellets (1.78-1.88mm) and had better biomass retention capacity and sedimentation properties; its mixed liquor suspended solids (MLSS) and sludge volume index (SVI30) reached approximately 5.2g/L and 45mL/g, respectively. The addition of P. chrysosporium pellets promoted the secretion of extracellular polymeric substances (EPS), especially protein (PN). The removal efficiencies of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN), and total phosphorus (TP) in P. chrysosporium pellets reactor were 98.91%, 89.17%, 64.73%, and 94.42%, respectively, which were higher than those in the reactor without P. chrysosporium pellets (88.73%, 82.09%, 55.75%, and 88.92%). High throughput sequencing analysis indicated that several functional genera that were responsible for the formation of aerobic granules and the removal of pollutants, such as Acinetobacter, Pseudomonas, Janthinobacterium, and Enterobacter, were found to be predominant in the mature sludge granules promoted by P. chrysosporium pellets.

Rheological behavior of oil sludge from Algerian refinery storage tanks

The consumption and demand for petroleum are increasing dramatically with the rapid development of industry and energy sector. As a result, petroleum refineries produce the greatest amount of oily sludge formed at the bottom of storage tanks during oil storage operations, which has a severely negative impact on the storage capacity and the operational safety of the storage tank. The present study focuses on the rheology of this complex fluid from Algerian crude oil storage tanks. Rheological measurements were performed at different temperatures under steady shear and dynamic oscillometry using AR-2000 Rheometer. The results obtained show that the sludge exhibits yield-pseudoplastic flow behavior at low shear rates, which is adequately described by the Herschel Bulkley model based on the standard error and correlation coefficient values. However, quasi-Newtonian flow behavior occurs at very high shear rates. The increase in temperature had positive effects on the rheological properties of the sludge, including dynamic viscosity, shear stress, yield stress, complex modulus, elastic modulus and viscous modulus. The dynamic rheology studies have shown that the sludge material behaves more like a solid than a liquid under all experimental conditions studied.

Converting the cigarette butts into valuable products using the pyrolysis process

More than 5.5 trillion cigarettes are manufactured, and approximately 4.5 trillion cigarette butts are being scattered across the globe per year. These cigarette butts are considered as one of the most hazardous wastes and environmental threats in the world. Thermochemical techniques can be used to turn biomass and solid wastes into valuable final products. Pyrolysis is a comfortable thermochemical technique for turning biomass into biochars, biofuels, briquette solid fuels, and further valuable products such as activated carbons, carbon black, and printing ink. In this study, it was attempted to review the available researches about pyrolysis of cigarette butts with an emphasis on transforming them into carbonated solid and liquid products. It was found that, in addition to the process variables, the type of cigarette butts treatment has a significant effect on the yield and quality of the finished goods. Further studies on the pyrolysis of cigarette butts, especially microwave-assisted pyrolysis and hybrid waste pyrolysis, seemed to be necessary. Solving the technical issues associated with the pyrolysis of cigarette butts to produce the value-added goods would contribute to their application in waste disposal and recycling of other resources. Future studies should focus on the separation methods with the help of gas products to provide the heat required in the reactor. Moreover, mixing the sewage sludge material, as a feed, with cigarette butts and application of appropriate models and experiments to attain the products with specific properties are recommended. The results of this study can be used to eliminate the hazards of the cigarette butts scattered in the environment and create the added value for the pyrolysis process.

Antibiotic-metal complexes in wastewaters: fate and treatment trajectory.

Unregulated usage, improper disposal, and leakage from pharmaceutical use and manufacturing sites have led to high detection levels of antibiotic residues in wastewater and surface water. The existing water treatment technologies are insufficient for removing trace antibiotics and these residual antibiotics tend to interact with co-existing metal ions and form antibiotic-metal complexes (AMCs) with altered bioactivity profile and physicochemical properties. Typically, antibiotics, including tetracyclines, fluoroquinolones, and sulphonamides, interact with heavy metals such as Fe2+, Co2+, Cu2+, Ni2+, to form AMCs which are more persistent and toxic than parent compounds. Although many studies have reported antibiotics detection, determination, distribution and risks associated with their environmental persistence, very few investigations are published on understanding the chemistry of these complexes in the wastewater and sludge matrix. This review, therefore, summarizes the structural features of both antibiotics and metals that facilitate complexation in wastewater. Further, this work critically appraises the treatment methods employed for antibiotic removal, individually and combined with metals, highlights the knowledge gaps, and delineates future perspectives for their treatment.

Chronic Cholecystitis of Dogs: Clinicopathologic Features and Relationship with Liver

Simple SummaryThis study on the gallbladders and livers of 219 client-owned dogs provides a benchmark for future studies on chronic canine cholecystitis. The statistical evaluation of clinical data; histopathology; histochemistry; and immunohistochemistry in this report provides insight into the etiology of chronic cholecystitis in dogs(1) Background: Chronic cholecystitis of dogs has not been vigorously investigated histopathologically. In addition, the relationship between gallbladder and liver diseases is not known. (2) Methods: We aimed to provide a hallmark for canine chronic cholecystitis using clinical data, histopathology, histochemistry, immunohistochemistry, and statistical analysis. (3) Results: Our investigation of 219 ultrasonographically abnormal surgically resected canine gallbladders revealed 189 cases (86.3%) of mucosal lymphoplasmacytic infiltration (chronic cholecystitis). Sludge, a gravity-dependent or nondependent fine granular hyperechoic material, was more prevalent (105/219, 47.9%) than mucocele (51/219, 23.2%) in this cohort. Mucosal lymphoid follicles were detected in 68/219 cases (31%), suggesting the influence of long-standing antigenic stimulation. Bacteria were histochemically detected in 41/60 (68.3%) of heavily inflamed gallbladders, 18/129 (14%) of lightly inflamed, and 3/18 (16.7%) of uninflamed gallbladders, suggesting a possible relationship between bacteria and chronic cholecystitis. Simultaneous liver biopsies revealed mild or no inflammation, changes consistent with primary portal vein hypoplasia, and mild hepatocellular degeneration. (4) Conclusions: Based on the results of our statistical analysis, we conclude that canine chronic cholecystitis is a long-standing inflammatory process of unknown (but possibly bacterial) etiology and that liver pathology is unlikely the cause of chronic cholecystitis in dogs.

Managing Non-Sewered Human Waste Using Thermochemical Waste Treatment Technologies: A Review

The utilisation of micro-scale thermal treatment technologies for non-sewered applications has been emerging as a prominent route for the safe treatment and disposal of high water content hazardous feedstock. This study provides a comprehensive review of the technological concepts practiced up to date in commercial/pilot and small scales for various types of solid fuels. The respective challenges are critically described and discussed to aid in the selection of promising technology for on-site sanitary applications. Furthermore, the challenges observed with the nominated (pyrolysis) technology are discussed in detail and addressed. This study suggests rapid energy recovery from by-products primarily made up of the highest yield of syngas with a desirable calorific value. The optimum operating ranges are discussed to ensure a reliable thermal conversion of sludge materials considering the application constraints and technology drawbacks. However, further studies are needed to investigate the uncertainties regarding emissions, energy consumption and overall associated costs.

Biodegradation mechanism of naphthalene using marine sponge symbiotic bacteria

Generally, all petroleum processing industries produce oil sludge or sludge. Polycy-clic Aromatic Hydrocarbons (PAH), one of the components contained in sludge, are hazardous and toxic waste material with toxic, carcinogenic and mutagenic properties. The research objective was to understand the biodegradation mechanism of naphthalene by utilizing a marine sponge symbiotic bacterial isolate. Partial bacteria Bacillus Sp strain AB353f (BC), sponge isolate Neopetrosia sp and Acinetobacter Calcoaceticus strain PHCDB14 (AC) isolate sponge Callyspongia (Aerizusa) as biomaterial for PAH degradation. Biodegradation method integrates bacterial suspension with 10,000 ppm naphthalene for 25 days. Every 5 days, the bio-degradation indicators were observed and the products of the destruction of naphthalene components were measured using FTIR and GC-MS. The results showed that BC isolates and AC isolates from sponge symbionts could degrade naphthalene. The biodegradation performance of BC bacteria tended to be more dominant than AC against naphthalene. Based on the functional groups resulting from FTIR, three types of biodegradation products were identified, namely: alcohol, aldehyde and carboxylic acid and one transition product in the form of a cate-chol. Maximum naphthalene bio-degradation occurs at an interaction period of 20 - 25 days.