Sustainable deployment of environmental management systems for higher education institutions:challenges and limitations

Higher education institutions (HEIs) face unique barriers to implementation of environmental management systems (EMSs) compared to the private sector, where formal EMS approaches such as ISO 14001 are widely used. HEIs across the world have tended to adopt structured EMSs through less formal methods or apply bespoke approaches based on institutional drivers for implementation. This chapter explores organizational factors specific to HEIs that impact on their ability to implement and sustain formal EMS approaches. An in-depth review was undertaken examining key organization barriers to EMS adoption, and organizational factors specific to HEIs that can affect the successful implementation and sustainability of EMS approaches. The study finds that considerations of the key actors, existing organizational structures, governance and leadership, and resistance to change are important areas to consider in the implementation of an EMS within an HEI. UK HEIs are used as a case study to examine the relationship between EMS uptake and performance, and identify trends toward the adoption of various types of systems. We find that a trend toward the adoption of more formalized EMS approaches among UK HEIs contradicts the suggestion from the literature that less-formal approaches may be more suitable. The study challenges the assumption that formal approaches to environmental management such as ISO 14001 and Eco-Management and Audit Scheme (EMAS) provide the gold standard EMS, suggesting that alternative standards may be more suitable in the context of the unique organizational structures and key barriers to EMS implementation faced by HEIs

Potential benefits and disbenefits of the application of water treatment residuals from drinking water treatment processes to land in Scotland:development of a decision support tool

Water Treatment Residuals (WTRs) are a by-product of the addition of chemical coagulants to water during the water treatment process and are a mixture of water and organic and inorganic matter that coagulates during the treatment process. WTRs often contain metals such as iron, aluminium, and manganese that have been oxidised as part of the process or are constituents of the coagulation chemicals used. The metals within WTRs are of interest with regard to applying these sludges to agricultural land. WTRs can also contain beneficial organic matter and nutrients (primarily nitrogen). The nature of the benefits delivered is largely dependent on the quality of the raw water and these beneficial components are generally found in much smaller quantities in WTRs than are found in sewage sludge produced from wastewater. However, WTRs can still be used to enhance the physical properties of soils. As urban populations increase in size, it is anticipated that the tonnage of WTRs will increase significantly in the future. At present, the majority of WTRs are disposed of in landfills; however, landfill charges are increasing significantly, making disposal of an increasing tonnage of WTRs financially unviable. In terms of a circular economy, the procedure of reusing WTRs for alternative applications satisfies the Scottish Government’s goals in terms of waste prevention and reducing the amount of material being sent to landfill as set out in the Proposals for Legislation in 2019. Given the potential benefits in terms of cost savings and compliance with government legislation, and the complexities of understanding where and when WTRs can be used in land applications, we developed a Decision Support Tool (DST) that uses data obtained from an extensive review of approaches in other countries to assist in decision making. We also conducted a pre-application analysis and provided guidance on when and where WTRs can be used in land applications and when they are not suitable, presented in a simplified format that requires few inputs from the user in order to simplify the process and removes the requirement for a specialist operator during pre-application analyses

Flume study on the effects of microbial induced calcium carbonate precipitation (MICP) on the erosional behaviour of fine sand

Tangential flow-induced interface erosion poses a major threat to a wide variety of engineering structures, such as earth-filled embankment dams, and oil- and gas-producing wells. This study explores the applicability of microbial induced calcium carbonate (CaCO3) precipitation (MICP) by way of the ureolytic soil bacterium Sporosarcina pasteurii as a method for enhancing the surface erosion resistance of fine sand. Specimens were treated with cementation solution concentrations between 0·02 and 0·1 M, and the erosional behaviour examined in a flume under surface-parallel flow and increasing shear stress. Photographs, cumulative height eroded-time series and erosion rates were obtained as a function of specimen height, MICP treatment formulation and calcium carbonate content. Results showed that while untreated specimens eroded primarily in particulate and mass form, MICP-treated specimens were characterised by a block erosion mechanism. Further, erodibility was found to depend on the calcium carbonate content and the cementation solution concentration. To understand this, a systematic study of the calcium carbonate crystal sizes and distributions was undertaken through X-ray computed tomography. Fundamentally, the effectiveness of MICP for erosion control was found to be dominated both by the precipitated calcium carbonate content and microstructural features, with higher contents and larger crystals yielding lower erodibility values. Additionally, crystal growth mechanisms varied depending on the cementation solution concentration.</p

Removal of atmospheric CO₂ by engineered soils in infrastructure projects

The use of crushed basic igneous rock and crushed concrete for enhanced rock weathering and to facilitate pedogenic carbonate precipitation provides a promising method of carbon sequestration. However, many of the controls on precipitation and subsequent effects on soil properties remain poorly understood. In this study, engineered soil plots, with different ratios of concrete or dolerite combined with sand, have been used to investigate relationships between sequestered inorganic carbon and geotechnical properties, over a two-year period. Cone penetration tests with porewater pressure measurements (CPTu) were conducted to determine changes in tip resistance and pore pressure. C and O isotope analysis was carried out to confirm the pedogenic origin of carbonate minerals. TIC analysis shows greater precipitation of pedogenic carbonate in plots containing concrete than those with dolerite, with the highest sequestration values of plots containing each material being equivalent to 33.7 t C ha−1 yr−1 and 17.5 t C ha−1 yr−1, respectively, calculated from extrapolation of results derived from the TIC analysis. TIC content showed reduction or remained unchanged for the top 0.1 m of soil; at a depth of 0.2 m however, for dolerite plots, a pattern of seasonal accumulation and loss of TIC emerged. CPTu tip resistance measurements showed that the presence of carbonates had no observable effect on penetration resistance, and in the case of porewater pressure measurements, carbonate precipitation does not change the permeability of the substrate, and so does not affect drainage. The results of this study indicate that both the addition of dolerite and concrete serve to enhance CO2 removal in soils, that soil temperature appears to be a control on TIC precipitation, and that mineral carbonation in constructed soils does not lead to reduced drainage or an increased risk of flooding

Sequestering atmospheric CO₂ inorganically:a solution for Malaysia's CO₂ emission

Malaysia is anticipating an increase of 68.86% in CO2 emission in 2020, compared with the 2000 baseline, reaching 285.73 million tonnes. A major contributor to Malaysia's CO2 emissions is coal-fired electricity power plants, responsible for 43.4% of the overall emissions. Malaysia's forest soil offers organic sequestration of 15 tonnes of CO2 ha(-1) year(-1). Unlike organic CO2 sequestration in soil, inorganic sequestration of CO2 through mineral carbonation, once formed, is considered as a permanent sink. Inorganic CO2 sequestration in Malaysia has not been extensively studied, and the country's potential for using the technique for atmospheric CO2 removal is undefined. In addition, Malaysia produces a significant amount of solid waste annually and, of that, demolition concrete waste, basalt quarry fine, and fly and bottom ashes are calcium-rich materials suitable for inorganic CO2 sequestration. This project introduces a potential solution for sequestering atmospheric CO2 inorganically for Malaysia. If lands associated to future developments in Malaysia are designed for inorganic CO2 sequestration using demolition concrete waste, basalt quarry fine, and fly and bottom ashes, 597,465 tonnes of CO2 can be captured annually adding a potential annual economic benefit of (sic)4,700,000.</p

Cow urine as a source of nutrients for Microbial-Induced Calcite Precipitation in sandy soil

Microbial Induced Calcite Precipitation (MICP) via biostimulation of urea hydrolysis is a biogeochemical process in which soil indigenous ureolytic microorganisms catalyse the decomposition of urea into ammonium and carbonate ions which, in the presence of calcium, precipitate as calcium carbonate minerals. The environmental conditions created by urine in soil resemble those induced by MICP via urea hydrolysis. Thus, this study assesses the suitability of a waste product, cow urine, as a source of nutrients for MICP. Urea stability in fresh and sterilised urine were monitored for a month to cover the length of a potential MICP intervention. An experimental soil column set up was used to compare the soil response to the repeated application of fresh and sterilised cow urine, within pH of 7 and 9, and the chemical-based solution. Urea hydrolysis and the carbonate content in solution were monitored to assess the suitability of the proposed alternative. In addition, the nitrification process was monitored. Key findings indicated i) urea concentration and stability in fresh and sterilised cow urine are suitable for MICP application; ii) the soil response to treatments of cow urine within pH of 7 and 9 are similar to the chemical-based solution; and iii) increasing solution pH results in a faster activation of ureolytic microorganisms and higher carbonate content in solution. These results demonstrate that cow urine is a suitable substitute of the chemical-based MICP application

Dissolution experiments on dolerite quarry fines at low liquid to solid ratio:a source of calcium for MICP

Microbially induced calcite precipitation (MICP) is an emerging soil stabilisation technique consisting of the precipitation of the mineral calcite in the soil matrix. The components required for MICP are currently industry end products. In this study, the calcium release and reusability of calcium-rich silicate quarry fines, dolerite, were investigated in closed (batch reactor) and open (permeability test) systems at liquid-to-solid (L/S) mass ratios ≤ 1·5 for MICP applications. The large specific surface area and reactive surface area accelerated calcium release, achieving calcium concentrations between 10 and 23 mM for different settings. Dissolution in the batch reactor resulted in increased silt (&lt;0·006 mm) and clay fractions. X-ray fluorescence analysis indicated no significant depletion of calcium in the dolerite after dissolution. The study showed that dolerite quarry fines dissolution in distilled water at low L/S ratios is a rich source of calcium for MICP applications.</p

Dolerite fines used as a calcium source for microbially induced calcite precipitation reduce the environmental carbon cost in sandy soil

Microbial-Induced Calcite Precipitation (MICP) stimulates soil microbiota to induce a cementation of the soil matrix. Urea, calcium and simple carbon nutrients are supplied to produce carbonates via urea hydrolysis and induce the precipitation of the mineral calcite. Calcium chloride (CaCl2) is typically used as a source for calcium, but silicate rocks and other materials have been investigated as alternatives. Weathering of calcium-rich silicate rocks (e.g. basalt and dolerite) releases calcium, magnesium and iron; this process is associated with sequestration of atmospheric CO2 and formation of pedogenic carbonates. We investigated atmospheric carbon fluxes of a MICP treated sandy soil using CaCl2 and dolerite fines applied on the soil surface as sources for calcium. Soil-atmosphere carbon fluxes were monitored over two months and determined with an infrared gas analyser connected to a soil chamber. Soil inorganic carbon content and isotopic composition were determined with isotope-ratio mass spectrometry. In addition, soil-atmosphere CO2 fluxes during chemical weathering of dolerite fines were investigated in incubation experiments with gas chromatography. Larger CO2 emissions resulted from the application of dolerite fines (116 g CO2-C m-2) compared to CaCl2 (79 g CO2-C m-2) but larger inorganic carbon precipitation also occurred (172.8 g C m-2 and 76.9 g C m-2, respectively). Normalising to the emitted carbon to precipitated carbon, the environmental carbon cost was reduced with dolerite fines (0.67) compared to the traditional MICP treatment (1.01). The carbon isotopic signature indicated pedogenic carbonates (δ13Cav = 8.2±5.0‰) formed when dolerite was applied and carbon originating from urea (δ13Cav = 46.4±1.0‰) precipitated when CaCl2 was used. Dolerite fines had a large but short-lived (&lt;2 d) carbon sequestration potential, and results indicated peak CO2 emissions during MICP could be balanced optimizing the application of dolerite fines

Passive CO₂ removal in urban soils:evidence from brownfield sites

Management of urban brownfield land can contribute to significant removal of atmospheric CO2 through the development of soil carbonate minerals. However, the potential magnitude and stability of this carbon sink is poorly quantified as previous studies address a limited range of conditions and short durations. Furthermore, the suitability of carbonate-sequestering soils for construction has not been investigated. To address these issues we measured total inorganic carbon, permeability and ground strength in the top 20 cm of soil at 20 brownfield sites in northern England, between 2015 and 2017. Across all sites accumulation occurred at a rate of 1–16 t C ha−1 yr−1, as calcite (CaCO3), corresponding to removal of approximately 4–59 t CO2 ha−1 yr−1, with the highest rate in the first 15 years after demolition. C and O stable isotope analysis of calcite confirms the atmospheric origin of the measured inorganic carbon. Statistical modelling found that pH and the content of fine materials (combined silt and clay content) were the best predictors of the total inorganic carbon content of the samples. Measurement of permeability shows that sites with carbonated soils possess a similar risk of run-off or flooding to sandy soils. Soil strength, measured as in-situ bearing capacity, increased with carbonation. These results demonstrate that the management of urban brownfield land to retain fine material derived from concrete crushing on site following demolition will promote calcite precipitation in soils, and so offers an additional CO2 removal mechanism, with no detrimental effect on drainage and possible improvements in strength. Given the large area of brownfield land that is available for development, the contribution of this process to CO2 removal by urban soils needs to be recognised in CO2 mitigation policies

Recent advances on palm oil mill effluent (POME) pretreatment and anaerobic reactor for sustainable biogas production

Palm oil is one of the leading agricultural crops in the world, as it dominates 34% of the global vegetable oil market, with approximately 64.6*103 million kgs of production in 2017. However, along with its breakthrough, the generation of palm oil mill effluent (POME) as uncontrolled waste has become a serious matter and requires proper management to reduce its negative effects on the environment. Subsequently, the high organic content of POME makes it possible to convert waste into value-added products, such as biogas. A ratio of 0.5 for biological oxygen demand to chemical oxygen demand (BOD/COD) indicates a high possibility for biological treatment. Recently, the utilisation of POME as a cheap source for biogas production has gained an extraordinary amount of attention, and intensive research has been conducted on the upstream to downstream process. Finding the most suitable and efficient pretreatment technique and reactor configuration are vital parameters for the treatment and conversion of POME to biogas. This review describes existing pretreatment processes for POME and recommends recently manufactured high-rate anaerobic reactors as the most suitable and efficient pretreatment technique for maximising the extraction of biogas from POME