High Sulfate Concentrations Research Articles

Experimental Study on Microstructure and Erosion Mechanisms of Solid Waste Cemented Paste Backfill under the Combined Action of Dry-Wet Cycles and Sulphate Erosion.

Solid waste cemented paste backfill (SWCPB) meets the needs of coal mining area management. SWCPB is a cementitious paste backfill material without added cement and is made only from oil shale residue (OSR), steel slag (SS), soda residue (SR) and water. In this study, mine water characteristics were simulated by combining dry–wet cycling experiments with sulphate erosion experiments. SWCPB was assessed regarding appearance, mass loss, and unconfined compressive strength (UCS), and the erosion products were microscopically analysed with X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The mechanism for erosion of the SWCPB by sulphate-rich mine water was comprehensively analysed and revealed. Research showed that the erosion mechanism was divided into two parts: chemical and physical erosion. Low concentrations of sodium sulphate promoted hydration, thereby contributing to the increased mass and strength of SWCPB. At high sodium sulphate concentrations, the erosion mainly consumed Ca(OH)2 within the material, and the main generated erosion products were gypsum and ettringite (AFt). This was accompanied by the destructive effects of Na2SO4 crystal expansion, which resulted in damage and the reduced workability of the SWCPB. The whole erosion process was continuous, mainly due to transformations of pits, pores and cracks. The conclusions of this study may provide appropriate guidance for application of SWCPB materials in the treatment of coal mine backfills. In addition, the corresponding theoretical analysis of the erosion mechanism for SWCPB materials is provided.

Evaluating the oxidation inhibition of sulfide in urban sewers using a novel quantitative method

Sulfide inhibition is a critical task for the secure operation of sewer systems, and oxidation is usually utilised to achieve this purpose. However, the effects and mechanism of oxidation during the transformation of sulfur-associated pollutants in gas-liquid-solid phases of sewers have not been extensively evaluated. In this study, a method for quantifying sulfur-associated pollutant exchange pathways in gas-liquid-solid phases of sewers was established. The results showed that although the concentration of sulfide decreased under different oxidation conditions, the consumption of sulfate in sewers clearly increased. The transformation strength of elemental sulfur was high (18.65 mg/L, 35.52% of sulfate from the influent) and the accumulation of sulfate in sediment was obvious (3.49 mg/L, 6.65% of sulfate from the influent). Higher concentrations of sulfate in the influent promoted the generation of sulfide in sediment (8.98 mg/L, 17.10%). Thus, the oxidation process led to the generation of more absolute sulfide. In addition, promoting the metabolism of sulfate-reducing bacteria enhanced the loss of organic carbon in sewers, which might weaken the efficacy of nitrogen and phosphorus removal in wastewater treatment plants. Based on the evaluation of the exchange pathways of sulfur-associated pollutants in sewers, further studies into sulfide inhibition in sewers should consider the above issues to enhance the safe management of urban sewers.

Anion-type modulates the effect of salt stress on saline lake bacteria

Beside sodium chloride, inland saline aquatic systems often contain other anions than chloride such as hydrogen carbonate and sulfate. Our understanding of the biological effects of salt composition diversity is limited; therefore, the aim of this study was to examine the effect of different anions on the growth of halophilic bacteria. Accordingly, the salt composition and concentration preference of 172 strains isolated from saline and soda lakes that differed in ionic composition was tested using media containing either carbonate, chloride or sulfate as anion in concentration values ranging from 0 to 0.40 mol/L. Differences in salt-type preference among bacterial strains were observed in relationship to the salt composition of the natural habitat they were isolated from indicating specific salt-type adaptation. Sodium carbonate represented the strongest selective force, while majority of strains was well-adapted to growth even at high concentrations of sodium sulfate. Salt preference was to some extent associated with taxonomy, although variations even within the same bacterial species were also identified. Our results suggest that the extent of the effect of dissolved salts in saline lakes is not limited to their concentration but the type of anion also substantially impacts the growth and survival of individual microorganisms.

Comparative analysis of microbial communities from different full-scale haloalkaline biodesulfurization systems

In biodesulfurization (BD) at haloalkaline and dO2-limited conditions, sulfide-oxidizing bacteria (SOB) effectively convert sulfide into elemental sulfur that can be used in agriculture as a fertilizer and fungicide. Here we show which bacteria are present in this biotechnological process. 16S rRNA gene amplicon sequencing of biomass from ten reactors sampled in 2018 indicated the presence of 444 bacterial Amplicon Sequence Variants (ASVs). A core microbiome represented by 30 ASVs was found in all ten reactors, with Thioalkalivibrio sulfidiphilus as the most dominant species. The majority of these ASVs are phylogenetically related to bacteria previously identified in haloalkaline BD processes and in natural haloalkaline ecosystems. The source and composition of the feed gas had a great impact on the microbial community composition followed by alkalinity, sulfate, and thiosulfate concentrations. The halophilic SOB of the genus Guyparkeria (formerly known as Halothiobacillus) and heterotrophic SOB of the genus Halomonas were identified as potential indicator organisms of sulfate and thiosulfate accumulation in the BD process.Key points• Biodesulfurization (BD) reactors share a core microbiome• The source and composition of the feed gas affects the microbial composition in the BD reactors• Guyparkeria and Halomonas indicate high concentrations of sulfate and thiosulfate in the BD process

Repurposing anaerobic digestate for economical biomanufacturing and water recovery.

Due to mounting impacts of climate change, particularly increased incidence of drought, hence water scarcity, it has become imperative to develop new technologies for recovering water from nutrient-rich, water-replete effluents other than sewage. Notably, anaerobic digestate could be harnessed for the purpose of water recovery by repurposing digestate-borne minerals as nutrients in fermentative processes. The high concentrations of ammonium, phosphate, sulfate, and metals in anaerobic digestate are veritable microbial nutrients that could be harnessed for bio-production of bulk and specialty chemicals. Tethering nutrient sequestration from anaerobic digestate to bio-product accumulation offers promise for concomitant water recovery, bio-chemical production, and possible phosphate recovery. In this review, we explore the potential of anaerobic digestate as a nutrient source and as a buffering agent in fermentative production of glutamine, glutamate, fumarate, lactate, and succinate. Additionally, we discuss the potential of synthetic biology as a tool for enhancing nutrient removal from anaerobic digestate and for expanding the range of products derivable from digestate-based fermentations. Strategies that harness the nutrients in anaerobic digestate with bio-product accumulation and water recovery could have far-reaching implications on sustainable management of nutrient-rich manure, tannery, and fish processing effluents that also contain high amounts of water. KEY POINTS: • Anaerobic digestate may serve as a source of nutrients in fermentation. • Use of digestate in fermentation would lead to the recovery of valuable water.

Geochemistry and Utilization of Water from Thermal Springs of Tawang and West Kameng Districts, Arunachal Pradesh

ABSTRACT The hydrogeochemical studies provide insights about reservoir conditions of geothermal springs along with utilization of thermal waters for domestic, livestock and irrigation purposes. Most of the hot springs of Tawang and West Kameng districts of Arunachal Pradesh emanated through garnet bearing high grade gneissmigmatite-schist-quartzite sequence of the Se La Group, except for Dirang hot springs which emanate from river terrace deposits lying on the footwall of deformed quartzite-phyllite. The thermal waters are of mixed Na-Ca-HCO3-SO4-Cl type, meteoric in origin and at the same time immature in nature, moving sluggishly towards mineral-fluid equilibration zone with slow rock-water interactions. Chemical geothermometry showed wide variation in estimation of sub-surface reservoir temperature and quartz geothermometry model fits prominently to provide the most reliable reservoir temperature varying within 90±40°C. The studies recorded highest reservoir temperature of Thingbu hot spring with 133°C with very high fluoride concentration in all the hot springs except Bishum and Phudung as per BIS (2012) IS: 10500 specifications. High fluoride and sulfate concentration in thermal spring waters make it unsuitable for drinking purpose. The applicability of thermal waters for irrigation is predicted through sodium adsorption ratio (SAR) calculations which showed that waters of Dirang-2, Sorbe and Kitpi-1&2 are not suitable for irrigation purpose due to high salinity and SAR values.

Evidence for high-elevation salar recharge and interbasin groundwater flow in the Western Cordillera of the Peruvian Andes

Abstract. Improving our understanding of hydrogeological processes on the western flank of the central Andes is critical to communities living in this arid region. Groundwater emerging as springs at low elevations provides water for drinking, agriculture, and baseflow. However, the high-elevation sources of recharge and groundwater flow paths that convey groundwater to lower elevations where the springs emerge remain poorly quantified in the volcanic mountain terrain of southern Peru. In this study, we identified recharge zones and groundwater flow paths supporting springs east of the city of Arequipa and the potential for recharge within the high-elevation closed-basin Lagunas Salinas salar. We used general chemistry and isotopic tracers (δ18O, δ2H, and 3H) in springs, surface waters (rivers and the salar), and precipitation (rain and snow) sampled from March 2019 through February 2020 to investigate these processes. We obtained monthly samples from six springs, bimonthly samples from four rivers, and various samples from high-elevation springs during the dry season. The monthly isotopic composition of spring water was invariable seasonally in this study and compared to published values from a decade prior, suggesting that the source of recharge and groundwater flow paths that support spring flow is relatively stable with time. The chemistry of springs in the low-elevations and mid-elevations (2500 to 2900 m a.s.l.) point towards a mix of recharge from the salar basin (4300 m a.s.l.) and mountain-block recharge (MBR) in or above a queñuales forest ecosystem at ∼4000 m a.s.l. on the adjacent Pichu Pichu volcano. Springs that clustered along the Río Andamayo, including those at 2900 m a.s.l., had higher chloride concentrations, indicating higher proportions of interbasin groundwater flow from the salar basin likely facilitated by a high degree of faulting along the Río Andamayo valley compared to springs further away from that fault network. A separate groundwater flow path was identified by higher sulfate concentrations (and lower Cl-/SO4-2 ratios) within the Pichu Pichu volcanic mountain range separating the city from the salar. We conclude that the salar basin is not a hydrologic dead end. Instead, it is a local topographic low where surface runoff during the wet season, groundwater from springs, and subsurface groundwater flow paths from the surrounding mountains converge in the basin, and some mixture of this water supports groundwater flow out of the salar basin via interbasin groundwater flow. In this arid location, high-elevation forests and the closed-basin salar are important sources of recharge supporting low-elevation springs. These features should be carefully managed to prevent impacts on the down-valley water quality and quantity.

Effects of organic carbon and sulfide on the anammox reaction in the anoxic column in the SRDAPN process for treating high-strength wastewater

Low energy consumption treatment of high-strength wastewater is crucial in controlling groundwater pollution and eutrophication in closed waterbodies. In this study, the sulfate reduction, denitrification/anammox, and partial nitrification (SRDAPN) process, which is an effective organic carbon and nitrogen removal process with low energy consumption for low strength wastewater, was applied to treat livestock wastewater with high COD and sulfate concentration, and microbial reaction and community were examined using an anaerobic–anoxic biological filter reactor that simulates circulation from an aerobic reactor. At a total organic carbon loading rate of 2.7–5.8 kgC/m3·day, sulfate reduction and methane production occurred simultaneously in the anaerobic column of the reactor. Specifically, sulfate reduction resulted in organic matter removal rates of 38 and 26% at ambient temperature and 25 °C, respectively. Furthermore, both heterotrophic and autotrophic denitrification occurred in the anoxic column, and when the organic loading rate in the anoxic reactor was below 0.2 kgC/m3·day, 33%–37% of ammonium and 33%–34% of nitrite were removed by the anammox reaction. Heterotrophic denitrification bacteria (Thauera, Comamonas, and Denitratisoma) and sulfur denitrification bacteria (Sulfurimonas denitrificans) grew in the lower and middle parts of the anoxic column, whereas anammox bacteria (2.5% of Candidatus Brocadia at ambient temperature and 9.4% of Candidatus Kuenenia at 25 °C) grew in the upper part of the anoxic column. These results indicate that the SRDAPN process based on sulfur cycle and anammox is useful for treatment of high strength wastewater with low energy consumption.

Morphological Phenotypes, Cell Division, and Gene Expression of Escherichia coli under High Concentration of Sodium Sulfate

Sodium and sulfate ions are among the suggested abundant ions on Europa, a moon of Jupiter. In order to investigate the potential habitability of Europa, we study the effects of sodium sulfate (Na2SO4) on a non-halophilic bacterium by subjecting Escherichia coli (E. coli) to a wide range of Na2SO4 concentrations (0–1.0 m). We discover that, as the concentration of sodium sulfate increases, the biomass doubling time increases and the cell growth is completely inhibited at m Na2SO4. Furthermore, we find that E. coli exhibits three distinct morphological phenotypes—(i) shortened, (ii) normal, and (iii) elongated/filamented cells at m and m Na2SO4. We have examined the expression of different genes involved in sodium and sulfate transport (nhaA, nhaB, cysZ, sbp), osmotically driven transport of water (aqpZ), sulfate metabolism (cysN), fatty acid production (fabA), and a global transcriptional regulator (osmZ). Our results suggest that the expression of these genes is not affected significantly at high concentrations of sodium sulfate in the exponential growth phase. Using our experimental data and the existing data in the literature, we show that the osmotic pressure difference may play a major role in determining the growth inhibition of E. coli and B. subtilis at high concentrations of salt.

Deciphering the fate of sulfate in one- and two-chamber bioelectrochemical systems

Treatment of wastewaters with high concentration of sulfate before discharge is an environmental imperative. However, current technologies are often highly energy- and chemical-demanding. Recently, microbial electrochemical technologies (MET) have been proposed as an alternative and more sustainable approach for the treatment of wastewaters rich in sulfate. Here we compare the sulfate reduction performance of one- and two-chamber reactors. In two-chamber reactors, sulfate reduction to sulfide was achieved with high electron recovery efficiency (83.9 ± 1.3%) at a sulfate reduction rate of 9.7 ± 2.6 mg SO42− L−1 d−1 cm−2, whereas in one-chamber reactors apparently no sulfate reduction took place. Non-electrochemical microcosm experiments suggested that sulfate reduction in two-chamber reactors was driven by the availability of cathodically produced H2. In one-chamber reactors, the presence of anodically produced O2 presumably resulted in chemical short circuit including aerobic hydrogen oxidation, abiotic and biotic re-oxidation of sulfide to sulfate. Microbial community analysis demonstrated that sulfate reduction was mainly performed by sulfate reducing prokaryotes (SRP) belonging to the genera Desulfomicrobium and Desulfovibrio, whereas sulfide oxidizing bacteria (SOB) (mainly Acinetobacter and Sulfuricurvum) could be responsible for re-oxidation of sulfide. Thus, fundamental and application-oriented research on microbial electrochemical sulfate reduction ought to be studied in two-chamber reactors for avoiding a potential bias of results by anodic reactions.

Characteristics of secondary organic aerosols tracers in PM2.5 in three central cities of the Yangtze river delta, China

Secondary organic aerosols (SOA) are important atmospheric pollutants that affect air quality, radiation, and human health. In this study, 14 typical SOA tracers were measured in PM2.5 collected from three central cities of the Yangtze River Delta (YRD) region in the winter of 2014 and the summer of 2015. Among the determined SOA tracers, α/β-pinene SOA tracers contributed 55.9%, followed by isoprene SOA tracers (33.7%), anthropogenic benzene SOA tracer (6.4%) and β-caryophyllene SOA tracer (4.0%). There was no significant difference in the concentration of individual SOA tracers among the three cities (p > 0.05), indicating a high degree of regional consistency. The concentrations of isoprene, α/β-pinene, and toluene SOA tracers were significantly higher in summer than in winter. A correlation of SOA tracers with temperature implies that the isoprene and α/β-pinene SOA tracers in summer were greatly boosted by plant emissions and the high DHOPA in summer could be attributed to evaporation of paint and solvent. In contrast, the elevated β-caryophyllene SOA tracer in winter was likely associated with active biomass burning. Furthermore, we observed a close correlation of summer isoprene and α/β-pinene SOA tracers with sulfate only in Shanghai, which verifies that biogenic SOA formation was facilitated by high concentration of sulfate. The ratios of MGA/MTLs and P/M were applied to reveal the impact of NOx on SOA formation and the aging degree of SOA, respectively. The MGA/MTLs ratios were comparable for the three cities, but much higher than the background value of this region as expected. The P/M ratios suggest that the aging degree of SOA in the YRD region was generally low, but the winter SOA were fresher than the summer SOA. Our research helps to understand pollution characteristics of SOA tracers in the urban agglomeration.

Inhibition of sulfate-reducing bacteria with formate.

Despite hostile environmental conditions, microbial communities have been found in µL-sized water droplets enclosed in heavy oil of the Pitch Lake, Trinidad. Some droplets showed high sulfate concentrations and surprisingly low relative abundances of sulfate-reducing bacteria in a previous study. Hence, we investigated here whether sulfate reduction might be inhibited naturally. Ion chromatography revealed very high formate concentrations around 2.37 mM in 21 out of 43 examined droplets. Since these concentrations were unexpectedly high, we performed growth experiments with the three sulfate-reducing type strains Desulfovibrio vulgaris, Desulfobacter curvatus, and Desulfococcus multivorans, and tested the effects of 2.5, 8, or 10 mM formate on sulfate reduction. Experiments demonstrated that 8 or 10 mM formate slowed down the growth rate of D. vulgaris and D. curvatus and the sulfate reduction rate of D. curvatus and D. multivorans. Increasing formate concentrations delayed the onsets of growth and sulfate reduction of D. multivorans, which were even inhibited completely while formate was added constantly. Contrary to previous studies, D. multivorans was the only organism capable of formate consumption. Our study suggests that formate accumulates in the natural environment of the water droplets dispersed in oil and that such levels are very likely inhibiting sulfate-reducing microorganisms.

The changing face of SDS denaturation: Complexes of Thermomyces lanuginosus lipase with SDS at pH 4.0, 6.0 and 8.0

HypothesisLipases are widely used in the detergent industry and must withstand harsh conditions involving both anionic and zwitterionic surfactants at alkaline pH. Thermomyces lanuginosus lipase (TlL) is often used and stays active at high concentrations of the anionic surfactant sodium dodecyl sulfate (SDS) at pH 8.0, but is sensitive to SDS at pH 6.0 and below. We propose that enhanced stability at pH 8.0 results from a structurally distinct complex formation with SDS. ExperimentsWe use small-angle X-ray scattering (SAXS) to elucidate structures of TlL:SDS at pH 4.0, 6.0, and 8.0 and further investigate the complexes at pH 8.0 using hydrogen/deuterium exchange mass spectrometry (HDX-MS). FindingsAt pH 4.0, large dense aggregates are formed at low [SDS], which become gradually less dense at higher [SDS], resulting in a core–shell structure. At pH 6.0, SDS induces a TlL dimer and forms a hemi-micelle along the side of the dimer. At higher [SDS], TlL adopts a core–shell structure. At pH 8.0, TlL forms a dimer with a SDS hemi-micelle but avoids a core–shell structure and maintains activity. Three helices are identified as SDS anchor points. This study provides important structural insight into the stability of TlL towards SDS under alkaline conditions.

Salt weathering of sandstone under dehydration and moisture absorption cycles: An experimental study on the sandstone from Dazu rock carvings

AbstractSalt crystallization and phase change in porous media cause significant deterioration of cultural heritage made of stones and bricks. In this study, laboratory experiments on salt weathering of sandstone from the Dazu rock carvings (DRC) in Chongqing, southwest China, were carried out by exposing them to cycles of temperature and humidity change. Mirabilite, the main component of the salts in DRC that readily undergoes phase change, was utilized for the study. Three groups of Dazu sandstone (DS) samples with high (2.4 mol/L), moderate (1.5 mol/L) and low concentrations (1.0 mol/L) of sodium sulphate were prepared; and two conditions, high‐temperature with low‐humidity and low‐temperature with high‐humidity, were designed to simulate the fluctuations of temperature and humidity in the Dazu area. After several cycles, the dehydration and moisture absorption of DS under these two conditions forces the phase change of sodium sulphate between thenardite (Na2SO4) and mirabilite (Na2SO4·10H2O), causing different levels of damage. A combination results of sample length, weight, microstructure, and mechanical property variations show that the damage effect of the thenardite formed during dehydration is more significant than that of mirabilite in moisture absorption. During these cycles, there is noticeable salt migration and the local concentration of salts is influenced by the microstructure of the stone and the distribution of clay minerals. Samples with high salt content show disintegration of the stone into powder, while those with moderate salt concentration show flaking and salt accumulation on the surface. These types of damage correspond with observations of natural weathering in the field. The experiment shows that no obvious damage takes place when the salt content is lower than 0.67%. These results contribute to a better understanding of the effects of salt weathering on sandstone and provide references for choosing correct prevention and protection measures for the world heritage site DRC.

Water decontamination under high salinity using the TiO2 NT/PbO2–Cu electrochemical oxidation system: kinetics mechanism and DFT studies

In this study, a facile and cost-effective PbO2 layer coated TiO2 nanotubes (NTs) electrode was fabricated to serve as an anode to degrade a model contaminant under the condition of high sulfate concentration.

First Report of Culicoides Biting Midges (Diptera: Ceratopogonidae) Attacking People in Italy, With the Description of Extreme Larval Breeding Sites and Diurnal Activity of Culicoides riethi.

Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) play a paramount role in medical and veterinary entomology worldwide, particularly as vectors of pathogens which cause animal diseases. Biting midges are also infamous for the nuisance they provoke to people involved in outdoor activities. Nonetheless, attacks to man by midges from any Culicoides species have not been reported in Italy. An entomological investigation was performed following repeated attacks to man in a nature park near Rome (central Italy). The study area is a natural degassing zone, characterized by widespread hazardous gas emissions of CO2 and H2S, with several water bodies including permanent lakes, ponds, and pools. The biting midge C. riethi Kieffer, 1914 was very active during daytime in the period April–June. The species has been identified as responsible for attacks on people in the area. An in-depth analysis of the extreme environmental conditions revealed the ability of larvae to thrive in several water bodies, characterized by an extremely low pH and a high concentration of sulfates.

Lipid Production by Yarrowia lipolytica B9 Using Crude Glycerol as Carbon Source

The present study was carried out to optimize some culture conditions to increase lipid production from Yarrowia lipolytica B9 in crude glycerol-based medium. The experiments displayed that too high concentrations of ammonium sulfate, KH2PO4, and MgSO4 increased cell growth but inhibited lipid synthesis. In contrast, more synthesis of lipids was determined to be achived at high concentrations of NaCl. The optimum concentrations of glycerol, ammonium sulfate, KH2PO4, MgSO4, and NaCl for lipid synthesis were determined as 50, 3, 1.5, 1 and 5 g/L, respectively. The optimal incubation time for lipid synthesis was found to be 6 days. Lipid concentration of 2.69 g/L and lipid content of 60.1%, were reached under optimal culture conditions.

Risk Assessment of Gypsum Amendment on Agricultural Fields: Effects of Sulfate on Riverine Biota.

Gypsum (CaSO4∙2H2O) amendment is a promising way of decreasing the phosphorus loading of arable lands, and thus preventing aquatic eutrophication. However, in freshwaters with low sulfate concentrations, gypsum‐released sulfate may pose a threat to the biota. To assess such risks, we performed a series of sulfate toxicity tests in the laboratory and conducted field surveys. These field surveys were associated with a large‐scale pilot exercise involving spreading gypsum on agricultural fields covering 18% of the Savijoki River (Finland) catchment area. The gypsum amendment in such fields resulted in approximately a four‐fold increase in the mean sulfate concentration for a 2‐month period, and a transient, early peak reaching approximately 220 mg/L. The sulfate concentration gradually decreased almost to the pregypsum level after 3 years. Laboratory experiments with Unio crassus mussels and gypsum‐spiked river water showed significant effects on foot movement activity, which was more intense with the highest sulfate concentration (1100 mg/L) than with the control. Survival of the glochidia after 24 and 48 h of exposure was not significantly affected by sulfate concentrations up to 1000 mg/L, nor was the length growth of the moss Fontinalis antipyretica affected. The field studies on benthic algal biomass accrual, mussel and fish density, and Salmo trutta embryo survival did not show gypsum amendment effects. Gypsum treatment did not raise the sulfate concentrations even to a level just close to critical for the biota studied. However, because the effects of sulfate are dependent on both the spatial and the temporal contexts, we advocate water quality and biota monitoring with proper temporal and spatial control in rivers within gypsum treatment areas. Environ Toxicol Chem 2022;41:108–121. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Biological Desulfurization of Tannery Effluent Using Hybrid Linear Flow Channel Reactors

The tanning process generates a saline effluent with high residual organics, sulfate and sulfide concentrations. The transition from a linear to circular economy requires reimagining of waste streams as potential resources. The organics in tannery effluent have the potential to be converted to renewable energy in the form of biogas if inhibitors to anaerobic digestion are removed. Hybrid linear flow channel reactors inoculated with culture-enriched halophilic sulfate reducing bacteria from saline environments were evaluated as a novel pretreatment step prior to anaerobic digestion for the concurrent removal of sulfur species and resource recovery (elemental sulfur and biogas). During continuous operation of a 4-day hydraulic retention time, the reactors were capable of near-complete sulfide oxidation (>97%) and a sulfate reduction efficiency of 60–80% with the formation of a floating sulfur biofilm containing elemental sulfur. Batch anaerobic digestion tests showed no activity on untreated tannery effluent, while the pretreated effluent yielded 130 mL methane per gram COD consumed.

Lysosomal storage diseases. Mucopolysaccharidosis type III, sanfilippo syndrome

The review describes the clinical, biochemical and molecular genetic characteristics of autosomal recessive mucopolysaccharidosis type III, or Sanfilippo syndrome. This is a genetically heterogeneous group of rare, but similar in nature, diseases caused by a deficiency of one of the four lysosomal enzymes involved in the degradation of heparan sulfate. All types of mucopolysaccharidosis III are characterized by severe degeneration of the central nervous system in combination with mild somatic manifestations, which is explained by the accumulation of high concentrations of heparan sulfate in the lysosomes of various cells, including the central nervous system. The primary biochemical defect in the most common type of mucopolysaccharidosis IIIA, occurring with a frequency of 1 : 105 and presented in 60% of all cases of the disease, is heparan-N-sulfatase, or sulfamidase deficiency. Mucopolysaccharidosis IIIB type occurs twice less often and accounts for about 30% of all cases of Sanfilippo syndrome. It is caused by the presence of inactivating mutations in the lysosomal -N-acetylglucosaminidase gene. Mucopolysaccharidosis IIIC and IIID are 4% and 6%, and occur at frequencies of 0.7 and 1.0 : 106. Mucopolysaccharidosis IIIC is caused by inactivating mutations in the gene of membrane-bound lysosomal acetyl-CoA:-glucosaminid-N-acetyltransferase, or N-acetyltransferase. Mucopolysaccharidosis IIID is based on the deficiency of lysosomal N-acetylglucosamine-6-sulfatase. The role of experimental models in the study of the biochemical basis of the pathogenesis of Sanfilippo syndrome and the development of various therapeutic approaches are discussed. The possibility of neonatal screening, early diagnosis, prevention and pathogenetic therapy of these severe lysosomal diseases are considered. As an example, a clinical case of diagnosis and treatment of a child with type IIIB mucopolysaccharidosis is presented.