An assessment of Environmental Conditions and the Benthic Fauna of the Odaw River Basin

The Odaw River is formed from several streams running from the Aburi Mountains in the Eastern Region of Ghana and ending up in the Korle Lagoon in Accra. Human activities have modified the course of this channel resulting in changes in water quality. This study was therefore conducted to investigate the extent of impact on macro-fauna communities by comparing the results with similar studies carried out in previous years. Faunal abundance and the similarity of macro-fauna among sampling stations for each season were respectively investigated by one-way analysis of similarity (ANOSIM) and cluster analysis all based on Bray-Curtis similarity index of species abundance. The Odaw River was found to be highly polluted, showing a pollution gradient from upstream to downstream, the upstream being the least polluted. Shannon-Wiener diversity index upstream was 0.53–2.00, midstream 0.64–1.41 and downstream had the least ranging from 0–0.04. Sensitive taxa of Dytiscidae, Hydropsychidae and Libellulidae were found only upstream from Obommirem to Buade. The mid portion of the Odaw catchment area were dominated by Oligochaeta, Naedidae and Lymnaea while the lower portion was dominated by the Chironomidae. There was no seasonal variation in the physico-chemical parameters analysed except for phosphate which showed significantly higher concentrations in the dry season than in the rainy season. The distribution of invertebrates did not also show seasonal variation in abundance between sampling stations suggesting good adaptation of prevailing species to small changes in water quality. Midstream and lower stream portions of the catchment area showed increased pollution over the years when previous studies were compared. This study shows that prevailing macro-fauna can be used to characterize sites of differing water qualities

Sustainable gold mining wastewater treatment by sorption using low-cost materials; Proefschrift Wageningen en UNESCO-IHE Institute for Water Education Delft.

Among the various wastewater treatment technologies, the sorption process is considered better because of lower cost, simple design and easy operation. Sorption technique was employed to remove heavy metals from gold mining effluent using natural and plant materials. An assessment of the effluent quality of a gold mining company in Ghana indicated that arsenic, copper and cyanide were the major pollutants in the process effluent. The research showed that coconut shell (CS) can be an important low-cost sorbent for Cu(II) removal from inorganic wastewater. However, arsenic removal was only possible with iron-oxide-coated sand (IOCS). The removal of Cu(II) was mainly through an ion exchange mechanism. The sequential sorption-desorption characteristics of Cu(II) on CS and IOCS showed that both sorbents are good for Cu(II); but cyclic sorption and desorption using 0.05 M HCl was only feasible with CS. The intraparticle diffusion controls the rate of sorption in this study. Arsenic and copper were successfully removed from the effluent by the studied materials. The research showed that the down-flow fixed-bed treatment configuration is an ideal system for the simultaneous removal of copper and arsenic from low concentration gold mining effluent, in addition to other heavy metals present in very low concentrations

Product design for a functional non-alcoholic drink

Product design is the procedure by which customer needs are translated into commercial products. The non-alcoholic drink sector has seen a tremendous growth of new products in recent times. Many of the new innovations include light versions of juices with lower calorie and carbohydrate content and an increase in the variety of juices that are used. In recent trends, consumers seek beverages or drinks that help improve on their health status due to the increasing rate of diseases and sicknesses hence most non-alcoholic drinks on the market have an additional value of health benefits. The aim of this work was to design a non-alcoholic drink product with functional properties to satisfy customer needs, ensuring that all safety, environmental and industrial regulations were taken into consideration. Customer needs in relation to functional fruit drink was identified through survey. These needs were translated into product specifications and various product concepts generated and the best selected using a selection matrix. From assessing the needs of customers and with the help of the selection matrix, prekese functional non-alcoholic drink was chosen as a better functional fruit drink relative to most drinks on the market. The prekese functional non-alcoholic drink had an antioxidant capacity of 24–28 μmol Fe2+/L which is greater than that of the benchmark and most drinks on the local market. Keywords: Product specifications, Tetrapleura tetraptera fruit, Antioxidant activity, Customer needs, Benchmar

Towards an adaptive model for simulating growth of marine mesozooplankton: A macromolecular perspective

Ultimately, the structure and functioning of marine ecosystems is defined by the transfer of autotrophic production to higher trophic levels and selective consumption of these autotrophs by predators. Hence, feeding regulation via modification of grazing and food incorporation by predators is critical for understanding and predicting the dynamics of ecosystems. In marine ecosystem and biogeochemical models, feeding regulation by consumers is assumed to be mainly dictated by food quality (Q), which is determined using food quality modules (FQMs) that mimic a consumers’ ability to anticipate fitness consequences for feeding on specific prey items. Current FQMs are based on frameworks that a priori identify specific food components, usually nitrogen (N), and/or phosphorus, as limiting. This negates the importance of consumer physiology, and ignores biochemical constrains on the limiting role of chemical elements in animal production. To help address these problems, we propose a new adaptive approach that bases Q on consumers’ capacity for food uptake and metabolic physiology. Uniquely, it (i) has separate pathways for the utilisation of carbon (C) associated with proteins, lipids and carbohydrates, (ii) considers stage-specific structural biochemical requirement of animals, and (iii) does not treat consumers’ structural demand for carbon as a “unitary requirement” but discriminates among the required biochemical forms of carbon. The approach is applicable to all heterotrophs. In the example given here the model has been configured to represent the calanoid copepod Acartia tonsa. Consistent with experimental observation, but unlike previous models, our model predicts the relationship between Q and food C:N to be unimodal with a maximum Q only at the threshold C:N for biomass production. Results suggest that prey C:N ratios may be irrelevant for food quality due to macromolecular biochemical constrains on the utilisation of chemical elements. This result emphasizes the importance of biochemical substances in animal nutrition and production as well as the necessity of developing food quality models able to adapt to the biochemical needs of the consumer