Global and regional potential of wastewater as a water,nutrient and energy source

There is a proactive interest in recovering water, nutrients and energy from waste streams with the increase in municipal wastewater volumes and innovations in resource recovery. Based on the synthesis of wastewater data, this study provides insights into the global and regional “potential” of wastewater as water, nutrient and energy sources while acknowledging the limitations of current resource recovery opportunities and promoting efforts to fast-track high-efficiency returns. The study estimates suggest that, currently, 380 billion m³ (m³ = 1,000 L) of wastewater are produced annually across the world which is a volume five-fold the volume of water passing through Niagara Falls annually. Wastewater production globally is expected to increase by 24% by 2030 and 51% by 2050 over the current level. Among major nutrients, 16.6 Tg (Tg = million metric ton) of nitrogen are embedded in wastewater produced worldwide annually; phosphorus stands at 3.0 Tg and potassium at 6.3 Tg. The full nutrient recovery from wastewater would offset 13.4% of the global demand for these nutrients in agriculture. Beyond nutrient recovery and economic gains, there are critical environmental benefits, such as minimizing eutrophication. At the energy front, the energy embedded in wastewater would be enough to provide electricity to 158 million households. These estimates and projections are based on the maximum theoretical amounts of water, nutrients and energy that exist in the reported municipal wastewater produced worldwide annually. Supporting resource recovery from wastewater will need a step-wise approach to address a range of constraints to deliver a high rate of return in direct support of Sustainable Development Goals (SDG) 6, 7 and 12, but also other Goals, including adaptation to climate change and efforts in advancing “net-zero” energy processes towards a green economy.     

Assessment of antimicrobial activity of Catechu and its dyed substrate

The present study was undertaken to evaluate the antimicrobial activity of catechu in solution and % microbial reduction of dyed wool samples against Escherichia coli MTCC 443, Staphylococcus aureus MTCC 902, Candida albicans ATCC 10261 and Candida tropicalis ATCC 750, by using micro-broth dilution method, disc diffusion assay and growth curve studies. The dye showed the maximum antimicrobial activity at 20% w/v, inhibiting the microbial growth by more than 90%. In the next set of the experiments the antimicrobial activity of the dye was compared on woollen yarn alone and on pre-mordanted samples. The reduction in antimicrobial activity was observed when mordanted samples were examined. K/S, CIELab values and fastness properties of the dyed samples were assessed. The structural morphology of woollen yarn was also evaluated using scanning electron microscopy (SEM). Haemolytic activity on human erythrocytes was studied to exclude possibility of further associated cytotoxicity. The observed antimicrobial characteristics and negligible cytoxicity of catechu indicate that the dye might be a promising antimicrobial agent for developing bioactive textile materials and clothing.     

Lead availability and phytoextraction in the rhizosphere of Pelargonium species

Environmental Science and Pollution Research - Availability of lead (Pb) in soil is a major factor controlling the phytoremediation efficiency of plants. This study was focused on investigating the...     

Role of non-timber forest products in sustaining forest-based livelihoods and rural households' resilience capacity in and around protected area: a Bangladesh study†

People in the developing world derive a significant part of their livelihoods from various forest products, particularly non-timber forest products (NTFPs). This article attempts to explore the contribution of NTFPs in sustaining forest-based rural livelihood in and around a protected area (PA) of Bangladesh, and their potential role in enhancing households' resilience capacity. Based on empirical investigation, our study revealed that local communities gather a substantial amount of NTFPs from national park despite the official restrictions. Twenty seven percent households (HHs) of the area received at least some cash benefit from the collection, processing and selling of NTFPs, and NTFPs contribute to HHs' primary, supplementary and emergency sources of income. NTFPs also constituted an estimated 19% of HHs' net annual income, and were the primary occupation for about 18% of the HHs. HHs' dependency on nearby forests for various NTFPs varied vis-à-vis their socio-economic condition, as well as with their location from the park. Based on our case study, the article also offers some clues for improving the situation in PA.     

Investigating the potential of Morris algorithm for improving the computational constraints of global sensitivity analysis

Environmental Science and Pollution Research - Sensitivity analysis (SA) is widely acknowledged as advantageous and worthwhile in recognizing parameters for model calibration and optimization,...     

Employing sensitivity analysis to catchments having scanty data

Environmental Science and Pollution Research - Sensitivity analysis (SA) is generally desirable for parameter optimization, mapping, and calibration in hydrological models, yet the implementation...     

Spatial variations in selected metal contents and particle size distribution in an urban and rural atmosphere of Islamabad, Pakistan

Spatial variations in total suspended particulate matter (TSP) were investigated for distribution of metals and particle size fractions in the urban and rural atmosphere of Islamabad, Pakistan. The metals Na, K, Fe, Mn, Pb, Cd, Cr, Zn, Ni and Co, and the particle fractions <2.5, 2.5-10, 10-100 and >100 microm were included in the study. TSP samples were trapped on glass fibre filters using high volume samplers and quantification of metals was done using Atomic Absorption Spectrometry employing HNO(3) based wet digestion. At the urban site, Na was dominant at 2.384 microg/m(3) followed by K, Fe and Zn with 0.778, 0.667 and 0.567 microg/m(3) as mean concentrations, respectively. The metal levels for the rural site ranged from 0.002 microg/m(3) for Cd to 1.077 microg/m(3) for Na. However, compared with the urban site, mean Pb concentration showed an almost two-fold enhancement, i.e., 0.163 Vs. 0.327 microg/m(3). Metals and particle size source identification was done using Principal Component Analysis and Cluster Analysis. Five sources were traced out for the urban site: industrial, soil, automobile emissions, metallurgical industries and excavation activities. For the rural site, four sources were recorded: agricultural, automotive emissions, excavation activities and metallurgical units. Collectively, for both the sites, PM(10-100) emerged as a major contributor to TSP, followed by PM(2.5-10), PM(<2.5) and PM(>100) in that order. The metals showed in general positive relationship with fine particulate fractions (PM(2.5-10), PM(<2.5)), and negative correlation with coarse fractions (PM(10-100), PM(>100)). Comparison with the corresponding data from various Asian sites revealed that the levels of Na, K, Fe, Mn, Co and Ni for the present study were lower than those reported for grossly polluted cities of the world.     

Pinning down social vulnerability in Sindh Province,Pakistan: from narratives to numbers,and back again

This paper reflects critically on the results of a vulnerability assessment process at the household and community scale using a quantitative vulnerabilities and capacities index. It validates a methodology for a social vulnerability assessment at the local scale in 62 villages across four agro‐ecological/livelihood zones in Sindh Province, Pakistan. The study finds that the move from vulnerability narratives to numbers improves the comparability and communicational strength of the concept. The depth and nuance of vulnerability, however, can be realised only by a return to narrative. Caution is needed, therefore: the index can be used in conjunction with qualitative assessments, but not instead of them. More substantively, the results show that vulnerability is more a function of historico‐political economic factors and cultural ethos than any biophysical changes wrought by climate. The emerging gendered vulnerability picture revealed extremes of poverty and a lack of capacity to cope with contemporary environmental and social stresses.     

Integrating livelihoods and conservation in protected areas: understanding the role and stakeholder views on prospects for non-timber forest products,a Bangladesh case study

Protected areas (PAs) represent a key global strategy in biodiversity conservation. In tropical developing countries, the management of PAs is a great challenge as many contain resources on which local communities rely. Collection and trading of non-timber forest products (NTFPs) is a well-established forest-based livelihood strategy, which has been promoted as a potential means for enhanced conservation and improved rural livelihoods in recent years, even though the sustainability or ecological implications have rarely been tested. We conducted an exploratory survey to understand the role and stakeholder views on conservation prospects and perceived ecological feasibility of NTFPs and harvesting schemes in a northeastern PA of Bangladesh, namely the Satchari National Park. Households (n?=?101) were interviewed from three different forest dependency categories, adopting a stratified random sampling approach and using a semi-structured questionnaire. The study identified 13 locally important NTFPs, with five being critically important to supporting local livelihoods. Our study suggests that collection, processing and trading in NTFPs constitutes the primary occupation for about 18% of local inhabitants and account for an estimated 19% of their cash annual income. The household consensus on issues relating to NTFPs and their prospective role in conservation was surprisingly high, with 48% of respondents believing that promotion of NTFPs in the PA could have positive conservation value. The majority (71%) of households also had some understanding of the ecological implications of NTFP harvesting, sustainability (53%) and possible management and monitoring regimes (100%). With little known about their real application in the field, our study suggests further investigations are required to understand the ecological compatibility of traditional NTFP harvesting patterns and management.     

Effect of green marketing mix,green customer value,and attitude on green purchase intention: evidence from the USA

Environmental Science and Pollution Research - The undertaken research examines the impact of green attitude, green customer value (e.g., environmental image and perceived value), and green...