Effects of water acidification on immune responses of the gercacinid, Cardiosoma armatum (Herklots, 1851)

The biological response to chemical pollutants reflects the acid–base status of an aquatic ecosystem. The gercacinid, Cardiosoma armatum (75±0.1 g) was exposed to acidified waters to evaluate the effects on its immune parameters. The crabs were exposed to pH 4.0, 5.0, 6.0 and 7.8 (control) for 28 days. The hematological parameters of control crabs and crabs exposed to varied doses of acidified water indicated a marked reduction. Significant (p<0.05) higher alkaline phosphatase and albumen were obtained in pH 4.0, 5.0 and 6.0 compared to control; other values were mostly similar to control. The highest superoxide dismutase (SOD) (252.61±0.06 min/mg pro) was recorded in control group, while highest CAT activity (2.08±0.16 min/mg protein) was recorded in crabs exposed to pH 4 treatment. Furthermore, the control group's SOD activity was significantly higher than the exposed groups. With a lower pH, the quantities of malondialdehyde increased substantially and were significantly different from the control group. While these findings demonstrate that changes in pH have limited impact on energy use, decreasing immune system conditions show that C. armatum is susceptible to pH variations and may be influenced in aquaculture, where a pH drop is more prominent.

Waste to energy and circular economy: the case of anaerobic digestion

PurposeThis paper highlights how biological waste materials can be used for generating the much needed energy and obtaining nutrient-rich compost for agriculture through anaerobic digestion (AD). The paper further highlights the importance of small and medium enterprises (SMEs) in using AD for converting waste to energy (WTE), leading to many environmental benefits as well as clean energy generation. It would help to reduce pollution, water acidification and carbon emissions that eventually lead to climate change.Design/methodology/approachThe researchers undertook an in-depth study to highlight the role played by an SME in converting WTE and helping towards achieving circularity. An exploratory case-based approach was used to understand value leakage for an AD plant operating on WTE principles in the UK. The plant is still currently active, and it is located in the Midlands, England. Fifteen semi-structured interviews were undertaken with different stakeholders.FindingsThis paper reveals the importance of WTE and the significant role played by AD in converting food waste into useful matter. It reports further into the value leakage issue faced in the AD plants. It demonstrates the importance of technological innovation in SME to capture value leakages in a circular model. Most importantly, it demonstrates how SMEs gain competitive advantage and generate value proposition, while they aim for zero waste to landfill objective.Research limitations/implicationsThe research involves a case study based on an SME, operating on a circular business model. It will be worth investigating how other businesses could gain competitive advantage. For SMEs interested in AD for WTE, this paper introduces further technological innovation to the AD process to leverage further potential for reuse of waste liquid. Any SMEs entering WTE market ought to take into consideration such design implications.Practical implicationsThe paper reveals how the use of waste by SMEs would lead to many environmental benefits as well as clean energy generation. It would help to reduce pollution, water acidification and carbon emissions that eventually lead to climate change. It is useful for addressing the needs of waste food producers and is a cheap raw material for generating energy. The benefits to the public are that it reduces the need for landfill and increases recycling.Social implicationsThe WTE is an effective way of making use of last-stage waste.Originality/valueDespite SMEs being the powerhouse of the European economies, there is limited research investigating how circular economy (CE) could unlock their potential. Moreover, development of AD in the UK has lagged behind other EU countries. We highlight value leakages and argue how technological innovation should be used to close the value chain loop in the WTE production process. This paper, therefore, demonstrates the important role of an AD process, which involves decomposition of biodegradable materials. It shows that AD is an economically viable and environmentally friendly process of obtaining clean energy at low cost.

Water footprint calculation and assessment of viscose textile

Water footprint standards established by the International Standardization Organization (ISO), this paper proposed a newquantitative indicator for water alkalization, and calculated the water footprints involved in viscose textile production. Inaddition, water footprint accounting results were comprehensively evaluated by LCA polygon method which wasdeveloped to interpret LCA results. Results showed that: (1) water scarcity footprint of viscose textile production was60.511 m3H2O eq/ton, of which 85.71% was from the viscose fiber production; (2) water eutrophication footprint ofviscose textile production was 12.439 kg PO43–eq/ton, the major contribution (84.37%) was given by COD and BOD5;(3) water acidification footprint and water alkaline footprint of viscose textile production were 81.453 kg SO2eq/ton and55.675 kg OH–eq/ton, mainly due to H2SO4and NaOH input during the spinning process, respectively; (4) waterecotoxicity footprint of viscose textile production was 3828.169 km3H2O eq/ton, mainly derived from Zn2+in spinningwastewater; (5) LCA polygon analyses showed that environmental load in the spinning was the largest, followed by thepulping and then the dyeing.Keywords:viscose textile, wa