Reassessing the role of sulfur geochemistry on arsenic speciation in reducing environments

Recent evidence suggests that the oxidation of arsenite by zero-valent sulfur (S(0)) may produce stable aqueous arsenate species under highly reducing conditions. The speciation of arsenic (As) in reducing soils, sediments and aquifers may therefore be far more complex than previously thought. We illustrate this by presenting updated E(h)-pH diagrams of As speciation in sulfidic waters that include the most recently reported formation constants for sulfide complexes of As(III) and As(V). The results show that the stability fields of As(III) and As(V) (oxy)thioanions cover a large pH range, from pH 5 to 10. In particular, As(V)-S(-II) complexes significantly enhance the predicted solubility of As under reducing conditions. Equilibrium calculations further show that, under conditions representative of sulfidic pore waters and in the presence of solid-phase elemental sulfur, the S(0)((aq))/HS(-) couple yields a redox potential (E(h))～ 0.1 V higher than the SO(4)(2-)/HS(-) couple. S(0) may thus help stabilize aqueous As(V) not only by providing an electron acceptor for As(III) but also by contributing to a more oxidizing redox state.     

Tracer studies for evaluation of in situ air sparging and in-well aeration system performance at a gasoline-contaminated site

Field-scale tracer studies were conducted at a gasoline-contaminated site in order to evaluate the effectiveness of in situ air sparging (IAS) and in-well aeration (IWA) in controlling the movement of soil gas and groundwater in the subsurface. The field site was comprised of silty sand (SM) and silty clay (CL), underlain by a clay layer at approximately 7.6 m. Depth to groundwater ranged from 2.4 to 3 m. Soil permeability and the natural hydraulic gradient were both low. Helium was used to trace the movement of soil gas in the unsaturated zone during the IAS field study, and successfully confirmed short-circuit pathways for injected air and demonstrated the limited distribution of injected gases at this site. Fluorescein, bromide, and rhodamine were used to trace the movement of groundwater during the IWA system field study, and successfully documented the inability of the IWA system to recirculate enough groundwater to enhance subsurface dissolved oxygen levels or to remediate groundwater by air stripping at this site. The inability of the systems to remediate the site was likely due to site conditions which consist of low-permeability soils and decreasing permeability with depth. As a result, relatively impermeable layers exist at the depth of the IAS screen and the lower IWA screen. These site conditions are not conducive to successful performance of either remediation system.     

A Crystalline, 2D Polyarylimide Cathode for Ultrastable and Ultrafast Li Storage

Organic electrode materials are of long‐standing interest for next‐generation sustainable lithium‐ion batteries (LIBs). As a promising cathode candidate, imide compounds have attracted extensive attention due to their low cost, high theoretical capacity, high working voltage, and fast redox reaction. However, the redox active site utilization of imide electrodes remains challenging for them to fulfill their potential applications. Herein, the synthesis of a highly stable, crystalline 2D polyarylimide (2D‐PAI) integrated with carbon nanotube (CNT) is demonstrated for the use as cathode material in LIBs. The synthesized polyarylimide hybrid (2D‐PAI@CNT) is featured with abundant π‐conjugated redox‐active naphthalene diimide units, a robust cyclic imide linkage, high surface area, and well‐defined accessible pores, which render the efficient utilization of redox active sites (82.9%), excellent structural stability, and fast ion diffusion. As a consequence, high rate capability and ultrastable cycle stability (100% capacity retention after 8000 cycles) are achieved in the 2D‐PAI@CNT cathode, which far exceeds the state‐of‐the‐art polyimide electrodes. This work may inspire the development of novel organic electrodes for sustainable and durable rechargeable batteries.     

Effects of rice straw ash amendment on Cu solubility and distribution in flooded rice paddy soils

Rice straw burning is a common post-harvest practice on rice paddy land, and it leads to the accumulation of rice straw ash (RSA) in paddy soil. To understand the role of RSA in determining the mobility and bioavailability of metal contaminants, this study investigated the effects of RSA amendment on the solubility and distribution of Cu in contaminated rice paddy soils with flooding incubation. The addition of RSA to the soils suppressed the release of Cu into the soil solutions, which was primarily attributed to the metal-binding capacity of the RSA. Additionally, after the soils were flooded, the increase in soil pH and decrease in redox potential resulted in the transformation of Cu into less soluble forms. The RSA amendment appeared to enhance the changes in pH and redox potential of the flooded soils and, consequently, the immobilization of Cu in the soils. The results suggest that the RSA can retard the bioavailability and movement of the metal in contaminated soils and, thus, lower the potential environmental risk of Cu toxicity.     

Natural radioactivity and radiation protection in use of phosphogypsum waste product samples

Phosphogypsum material is the phosphate fertilizer by-product usually used for soil fertility. This material contains high activity concentration of uranium (²³⁸U) and radium (²²⁶Ra and ²²⁸Ra) radionuclides. Addition of phosphate fertilizers to soils leads to accumulation of radium nuclides with other elements on soil. These nuclides can diffuse through soil layers and dissolve in groundwater components. Risks may be evolved from using groundwater for drinking purposes. The risks associated with radium nuclides and the exposure dose rate for soils and groundwater samples are assessed. Sand mineral is found to be a good adsorbent that can be used as a natural ion exchanger for the removal of radium and phosphate ions from aqueous solutions.     

Hazardous concentrations of selenium in soil and groundwater in North-West India

Soil and groundwater samples were collected for bulk elemental analyses in particular for selenium (Se) concentrations from six agricultural sites located in states of Punjab and Haryana in North-West India. Toxic concentrations of Se (45-341 μg L(-1)) were present in groundwater (76 m deep) of Jainpur and Barwa villages in Punjab. Selenium enrichments were also found in top soil layers (0-15 cm) of Jainpur (2.3-11.6 mg kg(-1)) and Barwa (3.1 mg kg(-1)). Mineralogical analyses confirmed silicates and phyllosilicates as main components of these soils, also reflected by the high content of SiO(2) (40-62 wt.%), Al(2)O(3) (9-21 wt.%) and K(2)O (2.2-3.2 wt.%). Prevailing intensive irrigation practices in Punjab with Se enriched groundwater may be the cause of Se accumulation in soils. Sequential extraction revealed >50% Se bioavailability in Jainpur soils. Appearance of selenite was observed in some of the batch assays with soil slurries under reducing conditions. Although safe Se concentrations were found in Hisar, Haryana, yet high levels of As, Mo and U present in groundwater indicated its unsuitability for drinking purposes. Detailed biogeochemical studies of Se in sediments or groundwater of Punjab are not available so far; intensive investigations should be started for better understanding of the problem of Se toxicity.     

Attenuation mechanisms of N-nitrosodimethylamine at an operating intercept and treat groundwater remediation system

The North Boundary Containment System (NBCS), an intercept-and-treat system, was established at Rocky Mountain Arsenal (RMA), Commerce City, CO, to remove low-level organic contaminants from a groundwater plume exiting RMA to the north and northwest. N-nitrosodimethylamine (NDMA) was detected in groundwater collected from the dewatering and recharge zones of the NBCS system. Concern over the fate of NDMA, in terms of potentially exiting the boundaries of the arsenal, prompted an investigation to evaluate potential attenuation mechanisms for NDMA within the alluvial aquifer system and within the NBCS itself. Groundwater, soil, and granular activated carbon (GAC) samples were taken from key locations in the NBCS system. Soil and GAC samples were assayed for sorption kinetics and for adsorption and desorption properties using 14C-labeled NDMA. NDMA biodegradation experiments were conducted by following 14CO(2) evolution from 14C-labeled NDMA in soils and GAC samples under aerobic and anaerobic conditions. The sorptive capacity of the site soils for NDMA was insignificant. Furthermore, the adsorption of the NDMA by the soil was almost completely reversible. Evaluation of the degradation potential of the native microbial consortia indicated a high level of NDMA mineralization when measured using bench-scale microcosms. The native consortia had capability to mineralize the NDMA under both aerobic and anaerobic incubations, indicating facultative characteristics. Testing of the local groundwater chemistry revealed that the area of the aquifer of interest was microaerobic and neutral in pH. These conditions were optimal for NDMA removal. While sorption was insignificant, degradation was a significant attenuation mechanism, which may be the reason that no NDMA has migrated off-site. This gives rise to the potential of a long-term sink for attenuating NDMA within the recharge zone of the treatment system.     

Influence of soil components on adsorption-desorption of hazardous organics-development of low cost technology for reclamation of hazardous waste dumpsites

The waste disposal practices on land frequently lead to the deposition of hazardous waste at geologically/hydrogeologically unsuitable locations, resulting in surface and groundwater contamination. The movement of chemicals through soil is not only dependent on the physical, chemical and biological properties of the waste but also on the characteristics of the soil of the disposal site. In this paper the authors report their results on the influence of soil components on adsorption-desorption of certain industrially widely used hazardous organics like phenol, p-nitrophenol, 4-chloro-2-nitrophenol and 2,4-dichlorophenol on typical soils of Patancheru industrial area (Hyderabad, AP, India). The data on nature of organics, soil organic matters, clay, free iron and aluminum oxides of soils are known to influence the adsorption-desorption process are presented. There was reduction up to 67.5% (organic matter removed), 53.8% (clay removed) and 24.2% (iron and aluminum oxides removed) in the adsorption capacity of the soils when compared to untreated soils indicating the role played by these soil components in adsorption process. Desorption isotherms of soil adsorbed hazardous organics exhibited hysteresis at higher initial concentration indicating the degree of irreversibility of adsorption-desorption process. Mixed microbial cultures were developed which can degrade the hazardous organics to complete mineralisation by utilizing them as sole source of carbon and their corresponding biokinetic constants were evaluated. Preparation of dumpsites with suitable soil surface having high holding capacity for organics and their in situ biodegradation by mixing with specific microbial cultures can be exploited as a cost effective technology for reclamation of hazardous waste dumpsites.     

Risk-based monitored natural attenuation--a case study

The term "monitored natural attenuation" (MNA) refers to a reliance on natural attenuation (NA) processes for remediation through the careful monitoring of the behavior of a contaminant source in time and space domains. In recent years, policymakers are shifting to a risk-based approach where site characteristics are measured against the potential risk to human health and the environment, and site management strategies are prioritized to be commensurate with that risk. Risk-based corrective action (RBCA), a concept developed by the American Society for Testing Materials (ASTM), was the first indication of how this approach could be used in the development of remediation strategies.This paper, which links ASTM's RBCA approach with MNA, develops a systematic working methodology for a risk-based site evaluation and remediation through NA. The methodology is comprised of seven steps, with the first five steps intended to evaluate site characteristics and the feasibility of NA. If NA is effective, then the last two steps will guide the development of a long-term monitoring plan and approval for a site closure. This methodology is used to evaluate a site contaminated with oil from a pipeline spill. The case study concluded that the site has the requisite characteristics for NA, but it would take more than 80 years for attenuation of xylene and ethylbenzene, as these chemicals appear in the pure phase. If fast remediation is sought, then efforts should be made to remove the contaminant from the soil. Initially, the site posed a serious risk to both on-site and off-site receptors, but it becomes acceptable after 20 years, as the plume is diluted and drifts from its source of origin.     

Pentachlorophenol contaminated groundwater bioremediation using immobilized Sphingomonas cells inoculation in the bioreactor system

Pentachlorophenol (PCP) has been used as a wood preservative for more than 100 years. The extensive use of PCP has widely contaminated soil and groundwater. PCP is toxic to living organisms. The main objective of this research was to inoculate the pure PCP-degrading bacterium strain Sphingomonas chlorophenolica PCP-1, isolated from PCP-contaminated soils, into PCP-contaminated groundwater for remediation purposes. The factors that influenced the bioremediation were explored with batch experiments using the inoculated immobilized and suspended cells as inoculation. A biological treatment system inoculated with immobilized cells was set up to estimate the microbial capability to degrade PCP. The results indicated that the suspended and immobilized cells could be inoculated into PCP-contaminated groundwater without adding other supplementary nitrogen and phosphate sources in batch conditions. Moreover, PCP decomposition was accompanied with released Cl- and decreasing pH value. The optimum HRT in the bioreactor system was 12.6h. PCP removal in the bioreactor remained stable and PCP removal efficiency was higher than 92% at this phase. Furthermore, PCP concentration in the biotreatment system effluent remained undetectable. It is possible to bioremediate PCP-contaminated groundwater using immobilized S. chlorophenolica PCP-1 cells in a bioreactor system. The proposed biological treatment system could be maintained for at least for 2 months.     

Distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans in the landfill site for solidified monoliths of fly ash

One landfill site, which co-treated solidified monoliths of fly ash and bottom ash, was investigated comprehensively to characterize its PCDD/F distribution. The solidified monoliths, soil, banyan leaves, groundwater in the monitoring wells and the treated landfill leachates in this landfill site for solidified monoliths of fly ash were all sampled to clarify their PCDD/F characteristics. Although the PCDD/F leaching concentrations were extremely lower than the Taiwan PCDD/F TCLP regulation of solidified monoliths, the PCDD/F contents in the surface soils of the landfill site are 460 times higher than that of urban soils and the highest value is 2.8 times higher than the Taiwan soil regulation (1000 ngI-TEQkg(-1)). The elevated PCDD/F contents in the soil reveal their potential for causing adverse health risk for humans, including the pathway of resuspension of soil particles and volatilization of PCDD/Fs from soil. The PCDD/F concentrations in the groundwater and the treated landfill leachates of the landfill site for solidified monoliths were both higher than that in the control samples, suggesting its potential to be a PCDD/F source of nearby water environment. Without proper control and management, landfill sites for solidified monoliths of fly ash can seriously hazard the surrounding environment, therefore, are important to consider.     

Membrane-based hybrid processes for high water recovery and selective inorganic pollutant separation

The removal of heavy metals (e.g. Pb(II), Cd(II), Cu(II), etc.) and oxyanions (e.g. nitrate, As(III, V), Cr(VI), etc.) is of immense interest for treatment of groundwater and other dilute aqueous systems. However, the presence of non-toxic components, such as hardness (Ca, Mg) and sulfate, can interfere with the separation of toxic species. For example, pressure-driven membrane processes, such as reverse osmosis (RO), have been limited for water treatment due to problems that these extraneous components cause with water recovery and ionic strength (osmotic pressure) of the retentate. In addition, nitrate rejection by RO is considerably lower than NaCl rejection, resulting in permeate concentrations that may be too high for groundwater recharging. Other separation systems that rely solely on sorption of toxic species (e.g. ion exchange resins) may not have sufficient selectivity for efficient use in the presence of competing ions. Hence, implementation of pressure-driven membrane separations and high capacity sorbents in hybrid processes shows much promise for remedying these difficulties. For example, selective separation of nitrate may be achieved by combining nanofiltration (NF) for sulfate removal, followed by RO or ion exchange for nitrate removal (see example 1). When small concentrations of toxic metals are present, the large retentate volumes of RO processes may be reduced by selective removal of toxic species with a high capacity sorbent, thus permitting disposal of a lower volume, non-toxic stream (see example 2). The use of microfiltration membrane-based sorbents containing multiple polymeric functional groups is a novel technique to achieve high metal sorption capacity under convective flow conditions. These sorbents are formed by the attachment of various polyamino acids (MW: 2500-10,000), such as polyaspartic acid (cation sorption), polyarginine (oxyanion sorption), and polycysteine (chelation exchange), directly on the membrane pore surfaces. Since these sorbents have also been found to have high selectivity over non-toxic metals, such as calcium, they are ideal candidates for hybrid processing with RO/NF.     

Removal of arsenic from water using Fe-exchanged natural zeolite

An elevated arsenic (As) content in groundwater imposes a great threat to people worldwide. Thus, developing new and cost-effective methods to remove As from groundwater and drinking water becomes a priority. Using iron/aluminum hydroxide to remove As from water is a proven technology. However, separation of As-bearing fine particles from treated water presented a challenge. An alternative method was to use coarse-grained sorbents to increase the flow rate and throughput. In this research, a natural zeolite (clinoptilolite) was exchanged with iron(III) to enhance its As removal. Batch test results showed a Fe(III) sorption capacity of 144 mmol/kg on the zeolite. The As sorption on the Fe-exchanged zeolite (Fe-eZ) could reach up to 100mg/kg. Columns packed with Fe-eZ were tested for As removal from water collected from acid mine drainage (AMD) and groundwater containing high natural organic matter and high As(III). With an initial concentration of 147 μg/L in the AMD water, a complete As removal was achieved up to 40 pore volumes. However, the Fe-eZ was not effective to remove As from Chia-Nan Plain groundwater due to its high initial As concentration (511 μg/L), high amounts of natural organic matter, as well as its low oxidation-reduction potential, under which the As was in reduced As(III) form.     

Unlockable Nanocomplexes with Self‐Accelerating Nucleic Acid Release for Effective Staged Gene Therapy of Cardiovascular Diseases

Nucleic acid (NA)‐based therapy is proposed to address serious diseases such as cardiovascular diseases (CVDs). Powerful NA delivery vehicles are essential for effective gene therapy. Herein, a novel type of delivery vehicle, an unlockable core–shell nanocomplex (Hep@PGEA) with self‐accelerating NA release, is structurally designed. Hep@PGEA is composed of disulfide‐bridged heparin nanoparticle (HepNP) core and low‐toxicity PGEA cationic shell. In comparison with NA, heparin, a negatively charged polysaccharide macromolecule, exhibits stronger interactions with cationic species. Upon the breakdown of redox‐responsive HepNP cores, unlocked heparin would interact with the outer cationic shells and replace the condensed NA to facilitate NA release. Such unique Hep@PGEA is successfully explored for effective miRNA–pDNA staged gene therapy of myocardial infarction (MI), one of the most serious CVDs. With the progression of MI, glutathione amounts in heart tissues increase. MiR‐499 (for the inhibition of cardiomyocyte apoptosis) and plasmid encoding vascular endothelial growth factor (for the promotion of angiogenesis) are sequentially delivered for systemic treatment of MI. Such treatment produces impressive results in restoring heart function and suppressing cardiac hypertrophy. Due to the wide existence of redox agents in cells, the proposed unlockable delivery nanovehicle and staged therapy strategy can provide new methods to effectively treat different serious diseases.     

A fully coupled finite element analysis of water‐table fluctuation and land deformation in partially saturated soils due to surface loading

A fully coupled numerical model is presented for the water‐table fluctuation and land deformation in partially saturated soils due to surface loading. This numerical model is developed based on the poroelastic governing equations for groundwater flow in deforming variably saturated porous media and the Galerkin finite element method. The numerical model is verified and validated against a one‐dimensional consolidation problem concerning surface loading on a soil column which has six different initial water‐table elevations. The numerical model is then applied to a two‐dimensional consolidation problem of surface loading on a partially saturated soil at a construction site. Results from the numerical simulations of both problems show that the water table fluctuates in the partially saturated soils, and the unsaturated zone above the water table has significant effects on the consolidation behaviour of the partially saturated soils under surface loading. Such effects are caused by the permanent absorption of a portion of the mechanical loading stress and the weak hydromechanical coupling between the solid skeleton deformation field and the groundwater flow field in the unsaturated zone due to its partial saturation. Copyright © 2000 John Wiley & Sons, Ltd.     

Surface studies of aminoferrocene derivatives on gold: electrochemical sensors for chemical warfare agents

The cystamine conjugate [(BocNH)Fc(CO)CSA]2 was prepared by coupling cystamine with the N-protected ferrocene amino acid derivative BocHN-Fc-COOH and was fully characterized by spectroscopic methods and by single-crystal X-ray diffraction. The cystamine conjugate forms films on gold substrates, which upon deprotection of the amino group, react with chemical warfare agent (CWA) mimics, upon which the redox properties of the Fc group are affected significantly. Cyclic voltammetry shows 50(5) mV anodic shifts of the Fc redox potentials after exposure to EtSCH2CH2Cl, a simulant for sulfur mustard HD (MA), and (NC)(EtO)2P(O), a simulant for nerve agent Tabun (NA). Exposure to MA and NA causes an increase in 2.3 and 4.5 ng mass, respectively, in QCM which indicates ca. 70% efficiency in Boc-deprotection. Ellipsometry measured a film thickness increase from 6(+/-1) A for the deprotected film to 10(+/-4) A for the film modified with MA and to 7(+/-2) A for the film modified with NA. AFM measurements show changes in the thickness and morphology of the film after reaction with MA and NA. The surfaces were analyzed by X-ray photoelectron spectroscopy (XPS) and clearly show the attachment of the cystamine conjugate on the surface and its reaction with CWA mimics.     

Investigation of the transport and fate of Pb, Cd, Cr(VI) and As(V) in soil zones derived from moderately contaminated farmland in Northeast, China

Some farmland in Shenyang had been irrigated with industrial wastewater since 1962. Although wastewater irrigation was ceased in 1992, soil had been heavily polluted by heavy metals, especially by Cd. For better understanding processes of soil-heavy metal interactions, in particular, the mobility and retention mechanism of heavy metal in soil, a study on the transport and fate of heavy metals in soil zones from Shenyang suburb was carried out by column leaching tests in laboratory. Breakthrough curves of Pb, Cd, Cr(VI) and As(V) fitted by Thomas model and Yoon–Nelson model. The results of fitted breakthrough curves showed that transport rates of the four heavy metals in the soil zones followed the order: Cr(VI) > As(V) > Cd > Pb, which indicated that Cr(VI) was much more mobile, and Pb was comparatively unmovable. Cr in effluents and As were almost entirely Cr(VI) and As(V), respectively, and no Cr(III) and As(III) was ever detected during the leaching tests. The contents of Pb, Cd, Cr and As in leached soils decreased in the order of Pb > Cd > Cr > As, which suggested that adsorption ability of soil to Pb was greatest and to As was least. The methods of selective sequential extraction and solvent extraction were used to determine the fractions of Pb, Cd, Cr, As and the valent states of Cr, As [Cr(VI) or Cr(III), As(V) or As(III)] in original soils and in leached soils. After leaching tests, the relative and absolute concentrations of exchangeable, carbonate, Fe–Mn oxide and organic fraction of each element were all increased, which enhanced the potential mobility and risk of Pb, Cd, Cr and As to soil/groundwater system. The relative concentrations of Cr(III) and As(III) in different depth of the soil zones after leaching tests were increased by about 6.0% and 5.6%, respectively. Cr(III) and As(III) tended to be adsorbed by soils, which reduced the mobility of them into groundwater.     

In situ stabilisation/solidification: project lifecycle

The successful application of any remedial technology, including stabilisation/solidification, begins with the site investigation. Following a review of the data collected during the site investigation, a treatability study (TS) and pilot study (PS) are prerequisites to full-scale implementation as they show the effects and delivery of binders to the soils, the geochemistry of the soils, and binder dosages necessary for the existing geology. Further, evaluating the data gathered during the TS and PS can help in accurately estimating and executing full-scale operations. Invariably, deviations from the TS and PS regarding soil characteristics and soil chemistry may exist, but the experience gained via the TS and PS aids in making decisions when faced with new and unexpected conditions in the field. This paper will discuss the execution of typical TS and PS applications and their implementation for full-scale treatment. Because the long-term performance durability of design mixes and technology applications are not generally addressed in remediation, post-remediation monitoring and sampling data must be made available to the public to advance the science and art of stabilisation/solidification. As a first step in advancing this technology, this paper follows the lifecycle of stabilisation/ solidification projects from the site investigation through the completion of full-scale work. A 10-year post-remediation sampling event also evidences the long-term viability of the technology.     

Speciation of selenium in groundwater: seasonal variations and redox transformations

Speciation of selenium in groundwater is essential from the viewpoint of toxicity to organisms and biogeochemical cycling. Selenium speciation in groundwater is controlled by aquifer redox conditions, microbial transformations, dissolved oxygen (DO) and other redox couples. A suburban area of Chennai city in India, where improper waste disposal measures have been practiced is selected for this study. Se(IV), Se(VI) and other hydrochemical parameters were monitored in shallow ground water during pre- and post-monsoon seasons for a period of three years. The objective of the study was to investigate the effect of groundwater recharge on selenium speciation. The concentration of Se(IV), and Se(VI) ranged between 0.15-0.43 μg L⁻¹ and 0.16-4.73 μg L⁻¹, respectively. During post-monsoon period the concentration of Se(IV), and Se(VI) ranged between 0.15-1.25 μg L⁻¹ and 0.58-10.37 μg L⁻¹, respectively. Se(VI) was the dominant species of selenium during the pre- and post-monsoon periods. During the post-monsoon periods, leaching of selenium from soil was more effective due to the increased oxidizing nature of the groundwater as indicated by the DO and redox potential (Eh) measurements. This finding has important implications on the behavior of selenium in groundwater, and also on the health of people consuming groundwater from seleniferous areas.     

Extension of the conditions for application of the simplified calculation methods according to DIN EN 1996‐3/NA for the design of unreinforced masonry walls

Dedicated to University Prof. Dr.‐Ing. Carl‐Alexander Graubner for his 60th birthday The simplified calculation methods for unreinforced masonry structures given in DIN EN 1996‐3/NA are an easily applicable design standard for an efficient and fast verification of the resistance of mainly vertically loaded masonry walls. However, the design rules are not based on mechanical models. Instead, they are empirical approaches for a simplified estimation of the load bearing capacity. For this reason, the range of application of DIN EN 1996‐3/NA is limited by several conditions to ensure a sufficient safety of this design procedure. With regard to extending the conditions for application, extensive comparative calculations were carried out. Thereby, considering clearly defined boundary conditions, the load bearing capacity according to DIN EN 1996‐3/NA was compared to that according to DIN EN 1996‐1‐1/NA. It was the aim of this comparison to identify load bearing reserves of the simplified calculation methods to point out potential for an extension regarding the maximum permissible clear wall height and the slab span. As a result, it can be stated, that an increase of the maximum wall height up to 6.0 m and the maximum slab span of 7.0 m is possible in certain cases.