Novel membrane bioreactors and constructed wetlands for treatment of pre-processed animal rendering plant wastewater in Scotland

The performance of a novel industrial membrane bioreactor (MBR) comprising denitrification, nitrification and ultrafiltration for the secondary treatment of primary treated animal rendering wastewater has been compared with an experimental, low-cost and novel vertical-flow constructed treatment wetland planted with Typha latifolia L. The process wastewater followed pre-treatment by dissolved air flotation (DAF). The DAF effluent gave highly variable chemical oxygen demand (COD) and ammonia of 5200 (± 2050) and 490 (± 270) mg/l, respectively. The MBR effluent for COD and ammonia was 45 and 63 mg/l, respectively. The treatment performance of the constructed wetland for COD, ammonia and suspended solids was 167, 63 and 15 mg/l, respectively

Case study: design, operation and water quality management of a combined wet and dry pond system

Pond structures as cost-effective water treatment, storage and “source control” drainage techniques can be applied in order to reduce wastewater treatment costs, produce water for subsequent recycling and reduce the risk of downstream flooding. However, there is a need for detailed design, operation and maintenance data. The purpose of this study was to optimise design and operation guidelines, and to assess the water treatment potential of stormwater pond systems. Performance data (15 months) for a stormwater pond pilot plant were collected. The system is based on a combined silt trap, attenuation wet pond and dry pond system applied for drainage of roof water run-off from a single domestic property. United Kingdom Building Research Establishment and Construction Industry Research and Information Association, and German Association for Water, Wastewater and Waste design guidelines were tested. These design guidelines were insufficient because they do not consider local hydrological and soil conditions. The infiltration function for the dry pond is logarithmic and depends on the season. Furthermore, biochemical and physical algal control techniques were successfully applied, and passive water treatment of rainwater run-off with a wet pond was found to be sufficient. However, seasonal and diurnal variations of biochemical oxygen demand, dissolved oxygen and pH were recorded. Finally, capital and labour costs for small ponds are high

A note on the double dividend hypothesis

This paper tries to clear the confusion in the literature about the potential of environmental tax reforms to yield a double dividend. In opposition to a number of recent papers it is found that the possibility for a double dividend depends largely on the substitutabllity characteristics of taxed commodities and not on the uncompensated elasticities. It is found that a double dividend is possible, if the following conditions are met. First, the initial tax system has to be inefficient from a non-environmental point of view. Second, it is possible to raise the tax on the externality creating commodity and in exchange to reduce the tax on a commodity that is a gross substitute for the externality creating commodity. Third, under the existing distortionary tax system the commodity whose tax is reduced is relatively difficult to substitute through other taxed commodities and hence, easier to substitute through the untaxed numeraire.

Environmental regulation and its impact on welfare and international competitiveness in a Heckscher-Ohlin framework

This paper discusses the issue of competitiveness and environmental regulation from the viewpoint of Heckscher-Ohlin models. It demonstrates that the impact of unilateral environmental regulations does not necessarily lead to a decrease in international competitiveness. Important is the measure of international competitiveness and the industry under consideration. Furthermore, this paper shows that in contrast to other theoretical work on this subject, unilateral environmental regulation does not necessarily lead to capital flight. It is also possible that the economy under consideration attracts more internationally mobile capital.

Search for nearby stars among proper motion stars selected by optical-to-infrared photometry. II. Two late M dwarfs within 10 pc

We have identified two late M dwarfs within 10 parsecs of the Sun, by cross-correlating the Luyten NLTT catalogue of stars with proper motions larger than 0.18 arcsec/yr, with objects lacking optical identification in the 2MASS data base. The 2MASS photometry was then combined with improved optical photometry obtained from the SuperCOSMOS Sky Surveys. The two objects (LP775-31 and LP655-48) have extremely red optical-to-infrared colours ((R-K)~7) and very bright infrared magnitudes (K_s<10): follow-up optical spectroscopy with the ESO 3.6-m telescope gave spectral types of M8.0 and M7.5 dwarfs, respectively. Comparison of their near-infrared magnitudes with the absolute magnitudes of known M8 and M7.5 dwarfs with measured trigonometric parallaxes yields spectroscopic distance estimates of 6.4+/-1.4 parsecs and 8.0+/-1.6 parsecs for LP775-31 and LP655-48, respectively. In contrast, Cruz & Reid (2002) recently determined spectral types of M6 for both objects, and commensurately larger distances of 11.3+/-1.3 parsecs and 15.3+/-2.6 parsecs. LP655-48 is also a bright X-ray source (1RXS J044022.8-053020). With only a few late M dwarfs previously known within 10 parsecs, these two objects represent an important addition to the census of the Solar neighbourhood.Comment: Astronomy & Astrophysics (Letters), in press; 5 pages, 1 figure, uses aa.cls version 5.

Constructed wetlands: Treatment of concentrated storm water runoff (part A)

The aim of this research was to assess the treatment efficiencies for gully pot liquor of experimental vertical- flow constructed wetland filters containing Phragmites australis (Cav.) Trin. ex Steud. (common reed) and filter media of different adsorption capacities. Six out of 12 filters received inflow water spiked with metals. For 2 years, hydrated nickel and copper nitrate were added to sieved gully pot liquor to simulate contaminated primary treated storm runoff. For those six constructed wetland filters receiving heavy metals, an obvious breakthrough of dissolved nickel was recorded after road salting during the first winter. However, a breakthrough of nickel was not observed, since the inflow pH was raised to eight after the first year of operation. High pH facilitated the formation of particulate metal compounds such as nickel hydroxide. During the second year, reduction efficiencies of heavy metal, 5-days at 20°C N-Allylthiourea biochemical oxygen demand (BOD) and suspended solids (SS) improved considerably. Concentrations of BOD were frequently �20 mg/L. However, concentrations for SS were frequently �30 mg/L. These are the two international thresholds for secondary wastewater treatment. The BOD removal increased over time due to biomass maturation, and the increase of pH. An analysis of the findings with case-based reasoning can be found in the corresponding follow-up paper (Part B)

The Glasgow sustainable urban drainage system management project: Case studies (Belvidere hospital and Celtic FC stadium areas)

The Glasgow Sustainable Urban Drainage System (SUDS) Management Project satisfies the first phase of the Glasgow Surface Water Management Project. This is Glasgow City Council’s contribution to the Transformation of Rural and Urban Spatial Structure (TRUST) project, one of the European Union’s (EU) interregional (INTERREG IIIB) funded research projects. The remit of this EU project comprises also other representative regions in Europe. The project shows also how SUDS can contribute to the overall catchment dynamics of cities such as Glasgow, ultimately relieving stress on the current predominantly combined sewer system. Fifty-seven sites within 46 areas of Glasgow were identified for investigation. A detailed soil chemistry analysis, a preliminary SUDS feasibility assessment and a desk study relating to historical planning issues that may be relevant for subsequent future development and regeneration options were undertaken. Detailed design and management guidelines were then drafted for selected representative demonstration areas (Belvidere Hospital and Celtic FC Stadium Areas) of high public and property developers interest, and education value. A combination of infiltration trenches or swales with ponds or underground storage were the most likely SUDS options for the majority of the demonstration areas. Soil contamination issues were considered when selecting SUDS because heavy metals such as lead and zinc can cause environmental health problems

Phytoremediation performance of floating treatment wetlands with pelletized mine water sludge for synthetic greywater treatment

Buckets containing floating reed ( ) simulated floating treatment wetlands (FTWs) and were used to improve the remediation performance of synthetic greywater (SGW). The aim of the study was to investigate the behaviour of FTWs for treatment of key contaminants within artificial greywater. Pelletized ochre based on acid mine water sludge was introduced to selected FTWs, because of its capability in sequestration phosphorus and other trace elements. The impact of the following four operational variables were tested in the experimental set-ups of the FTWs (four replicates each): pollutant strength (high- (HC) and low- (LC) concentrations), treatment time (2- or 7-days of hydraulic retention time (HRT)), presence or absence of macrophytes ( ) and cement-ochre pellets. The results showed that 5 - day biochemical oxygen demand (BOD) and chemical oxygen demands (COD) were significantly (  < 0.05) reduced in all wetlands. Nitrate-nitrogen (NO -N) concentrations were significantly (  < 0.05) higher, and those measurements for PO -P were significantly (p < 0.05) lower than the corresponding ones determined for the influent. The existence of ochre pellets with significantly (  < 0.05) decreased B, Cd, Cr, Cu, Mg, Ni and Zn concentrations, but increased Al, Ca, Fe and K concentrations in the effluent, with the exception of sodium (Na). The FTW performances can be improved by utilising ochre-cement pellets to increase the pH of greywater. The presence of acts as a buffer to neutralise the pH of SGW. Rhizomes and biofilms mitigate increases in turbidity, TSS and colour values. [Abstract copyright: © The Author(s) 2019.

The Glasgow sustainable urban drainage system management project: Case studies (Belvidere hospital and Celtic FC stadium areas)

The Glasgow Sustainable Urban Drainage System (SUDS) Management Project satisfies the first phase of the Glasgow Surface Water Management Project. This is Glasgow City Council’s contribution to the Transformation of Rural and Urban Spatial Structure (TRUST) project, one of the European Union’s (EU) interregional (INTERREG IIIB) funded research projects. The remit of this EU project comprises also other representative regions in Europe. The project shows also how SUDS can contribute to the overall catchment dynamics of cities such as Glasgow, ultimately relieving stress on the current predominantly combined sewer system. Fifty-seven sites within 46 areas of Glasgow were identified for investigation. A detailed soil chemistry analysis, a preliminary SUDS feasibility assessment and a desk study relating to historical planning issues that may be relevant for subsequent future development and regeneration options were undertaken. Detailed design and management guidelines were then drafted for selected representative demonstration areas (Belvidere Hospital and Celtic FC Stadium Areas) of high public and property developers interest, and education value. A combination of infiltration trenches or swales with ponds or underground storage were the most likely SUDS options for the majority of the demonstration areas. Soil contamination issues were considered when selecting SUDS because heavy metals such as lead and zinc can cause environmental health problems