Sustainability of Water Quality and Ecology最新文献

Suitability study of groundwater for domestic and irrigation purposes was carried out in the middle Subarnarekha river basin, Jharkhand. Collected samples were analysed for physicochemical parameters such as conductivity, total dissolved solids (TDS), pH, and heavy metals. After the physicochemical analysis groundwater samples were categorised for simplicity, accordingly, it shows that 52.6% samples fall in Ca-Cl₂, 33.3% in Ca-HCO₃, 10.5% in Ca-SO₄, and 1.7% samples in Mg-HCO₃ and rest were Na-Cl type. Interpretation of hydro-geochemical data suggests that leaching of ions followed by weathering and anthropogenic impact (mainly mining and agricultural activities) control the chemistry of groundwater in the study area. The TDS concentration at Govindpur site varies from 2677 mg L⁻¹ in the pre-monsoon to 2545 mg L⁻¹ in the post-monsoon season that is higher than the BIS (2004-05) maximum permissible limit (2000 mg L⁻¹). The elevated concentration of NO₃⁻ was identified at Govindpur, Hatia Bridge, Kandra, Musabani, Saraikela, Mango and Tatanagar. The higher NO₃⁻ concentration was due to the action of leaching and anthropogenic activities. At most of sampling locations, the concentration of Cd, Pb, and Ni were found higher than the prescribed limits defined by BIS and WHO. Groundwater suitability for drinking purpose was also evaluated by the synthetic pollution index (SPI), it suggests that 74%, 95%, and 21% samples fall in seriously polluted category during pre-monsoon, monsoon, and post-monsoon season, respectively. The calculated values of SAR, Na%, RSC, PI, and MH have shown that except at few locations, most of groundwater samples are suitable for irrigation purposes.

The Water Framework Directive (WFD), implemented in 2000, is the major policy instrument for water quality in the European Union. Its main aim is to homogenise and standardise water quality assessments in all Member States, stimulate water quality improvement and contribute to the management of transboundary water problems. Surface water quality descriptions are a crucial part of the WFD. The first WFD assessment was presented in 2009 and in 2014 a second set of results were available, allowing comparison of the status between both years. The main issue for policymakers is whether the quality has changed over the past years. In this study, two methods are evaluated to examine the differences in surface water quality. The WFD method uses the differences in the percentage of water bodies with a good quality for comparing between both assessments. The time-series method uses the WFD metrics to calculate water quality with all available monitoring data, aggregated to grid cells. The conclusion concerning the WFD method is that the two assessment reports of 2009 and 2014 are too dissimilar in method and standards and therefore not suitable to evaluate changes over time. The time-series method showed a small improvement for phytoplankton and macrophytes and no improvement for benthic invertebrates.

The technologic resilience of water and wastewater service options was compared for a coastal community. Options included a centralized, conventional system; decentralized wastewater options such as composting and urine diversion toilets paired with a centralized drinking water system; and centralized drinking water with on-site graywater and rainwater reuse along with a centralized blackwater pressure sewer and digester. Four characteristics of resilience were reviewed based on literature for each option: the robustness, adaptive capacity, rapidity, and resourcefulness. Each system was evaluated for a cold weather event, storm event, power outage, short-term drought, wildfire, and predicted climate changes. Across all events, the service options utilizing graywater reuse and a blackwater pressure sewer and digester were considered the most robust. This was due to the potential advantages of water savings during drought and less environmental contamination during storms, assuming the addition of a backup generator at the household level; however, responsible management of the on-site components of these systems was important for resourcefulness. A scenario with multiple storm, wildfire, and drought events was constructed to quantitatively compare the resilience of the options with respect to water and wastewater service over a 100-year service life. Overall, no one system was the clear resilient choice given the selected events and assumptions, and resilience based on past event frequency over-predicted performance compared to the projected frequency given climate change. Key uncertainties include the duration of event failure, the frequency of future events, and the possible impact of water saving technology on the availability of source water.

Knowledge of rainwater quality is critical for safeguarding public health. The review investigated rainwater quality, and public health risks associated with its consumption. Land use practices, roof material, weather patterns and their interactions influence rainwater quality. Contrary to the notion that roof water is safe, data point to physico-chemical and microbial contamination of rainwater via atmospheric deposition, leaching and weathering of roof materials, storage/conveyance utilities and faecal contamination. However, epidemiological studies linking consumption of rainwater to public health risks are scarce especially in developing countries. This reflects the lack of epidemiological research and confounding factors such as high disease burden. To minimize the public health risks, we recommend the implementation of risk assessment framework integrating laboratory analytical results and sanitary inspection risk analysis. Such a framework will enable proper prioritization and targeting of engineering/technological interventions, public education and housekeeping programmes.

Storm water run-off from urban developments need to be controlled to minimize its impacts on the quality and hydrodynamics of receiving waters. Holistic management strategies and treatment at the source have been introduced in Australia to mitigate the effects of run-off from urban developments on waterways. The adoption of conventional storm water quality and quantity controls and Water Sensitive Urban Design (WSUD) principles by councils, developers, industry and catchment managers assist in mitigating this impact.

Pending on local council requirements, lot scale (re)development may include a combination of a rainwater tank, an On Site Detention (OSD) system and possibly an infiltration or bio-retention system, with overflows discharging to the existing drainage systems. It is argued in this paper that designing these systems independently may result in over-design, increasing development costs. This paper considers the effect of rainwater tanks on water quantity discharges on a lot scale, and how this can affect the design of OSD systems.

This major research study, conducted in Western Sydney, indicated that where planning development controls require that storm water management be implemented to ensure run-off flow rates do not increase as a result of the development, a reduction can be applied to the OSD design, if a rainwater tank is installed on the same site as the OSD and is connected to multiple end-uses. This combination of systems can contain up to the 1-year Average Recurrence Interval (ARI) runoff in the rainwater tanks, thereby significantly reducing the OSD volume and orifice size.

Knowing that the fog harvesting is a non-conventional method for the production of freshwater, the sustainability of a fog collection project is studied. Sustainability and feasibility of fog harvesting collection projects is the focus of this Paper. A sustainable operation of fog harvesting projects which provides numerous sites worldwide with sufficient amounts of fresh water worldwide is presented. The key characteristics of fog harvesting system are considered including the physical process; the fog collectors; and the mesh types.

Sustainability aspects of fog collection projects are investigated including fog water quantity and quality. The feasibility of fog harvesting collection projects is evaluated, compared with other sources for freshwater supply including the corresponding infrastructure; the cost of water; the operational costs; and the amortization periods for expenses. The vision of implementing a fog collection project including the decision-making criteria is presented as a logical process. The community involvement analysis and the social impact are analyzed in the light of the existing freshwater resources and needs. The most important environmental factors that affect the volume and the frequency of water are evaluated. The Paper concludes that prior to implementing a fog water harvesting program; a pilot-scale assessment of the collection system should be executed.

It is predicated that algal blooms will become an increasing problem under changing climatic conditions. This is particularly concerning for the potable water treatment industry since algogenic organic matter (AOM) in surface waters supplying water treatment works (WTWs) can cause a number of treatment issues. However, whilst previous studies have shown that AOM is distinct from terrigenous, humic-dominated organic matter, limited information exists relating to changes in the character of AOM during different algal growth phases. In this study, reservoir water containing dissolved organic carbon (DOC) dominated by humic material was enriched with nutrient medium to create an algal bloom. Over the course of the algal bloom, DOC was characterised using XAD-fractionation and UV absorbance measurements. In addition, the reactivity of DOC with chlorine both before and after XAD-fractionation was assessed using trihalomethane formation potential (THMFP) and bromine incorporation measurements to monitor whether THM yield and speciation varied between different growth phases. Characterisation of DOC during the algal bloom indicated a shift towards more hydrophilic, aliphatic (low specific UV absorbance; SUVA) DOC with the release of extracellular organic matter (EOM) and later intracellular organic matter (IOM) during cell lysis. XAD-fractionation results suggest that algae produce predominantly hydrophilic neutral (HPIN) DOC. In contrast to some existing research, our study shows a marked change in DOC reactivity over time with a reduction in standardised THMFP (STHMFP) and the initial rate of THM formation observed as the algal bloom progressed. However, bromine incorporation increased with culture age.