Optimising of Scenedesmus sp. biomass production in chicken slaughterhouse wastewater using response surface methodology and potential utilisation as fish feeds

Production of Scenedesmus sp. biomass in chicken slaughterhouse wastewater (CSWW) is a promising alternative technique for commercial culture medium due to the high nutritional content of the generated biomass to be used as fish feeds. The current work deals with optimising of biomass production in CSWW using response surface methodology (RSM) as a function of two independent variables, namely temperature (10–30 °C) and photoperiod (6–24 h). The potential application of biomass yield as fish feeds was evaluated based on carbohydrate, protein and lipid contents. The results revealed that the best operating parameters for Scenedesmus sp. biomass production with high contents of carbohydrates, proteins and lipids were determined at 30 °C and after 24 h. The actual and predicted values were 2.47 vs. 3.09 g, 1.44 vs. 1.27 μg/mL, 29.9 vs. 31.60% and 25.75 vs. 28.44%, respectively. Moreover, the produced biomass has a high concentration of fatty acid methyl ester (FAME) as follows: 35.91% of C15:1; 17.58% of C24:1 and 14.11% of C18:1N9T. The biomass yields have 7.98% of eicosapentaenoic acid (EPA, C20:5N3) which is more appropriate as fish feeds. The Fourier transform infrared (FTIR) analysis of biomass revealed that the main functional groups included hydroxyl (OH), aldehyde (=C–H), alkanes and acyl chain groups. Scanning electron micrograph (SEM) and energy-dispersive X-ray spectroscopic analysis (EDS) indicated that the surface morphology and element distribution in biomass produced in BBM and CSWW were varied. The findings have indicated that the biomass produced in CSWW has high potential as fish feeds.

     

Practising interdisciplinarity in the interplay between disciplines: experiences of established researchers

This paper focuses on the practice of interdisciplinary research and its relationship with disciplines within the context of sustainability research. Disciplines are defined as institutions, i.e. conventions, norms or formally sanctioned rules that coordinate human action [Vatn, A., 2005. Institutions and the Environment. Edward Elgar Publishing, Cheltenham, UK). These institutions coordinate the practice of research. The central claim of this study is that interdisciplinary research occurs at the interplay between disciplinary institutions. These ideas are developed through the analysis of nine qualitative interviews conducted with established researchers who share an interest in studying issues of environmental sustainability. Specifically, this analysis identifies the motives of researchers who engage in interdisciplinary research and discusses the key characteristics of interdisciplinary research practice. The findings suggest that interdisciplinary research practice relies on disciplinary institutions as points of theoretical and methodological reference. Yet, the paper points at tensions that occur between the practice of interdisciplinary research and the practice of more traditional disciplinary research.     

Glutathione antioxidant status of frozen meat samples

Lipid oxidation is a process, which results in rancidity and deterioration of fats posing a major problem in food industry. Antioxidants are of interest, which presumably protects food from oxidative deterioration during storage. The glutathione antioxidant system of different meat samples were noticed for six months under refrigerated storage. Activity of glutathione reductase (GR) and level of glutathione (GSH) decreased during six months storage in all the four meat samples. The glutathione peroxidase (GSH-Px) and glutathione-S-transferase (GST) activity increased gradually during storage. It seems possible that glutathione antioxidant system protected the meat samples against quality loss during its storage.     

Economic evaluation of measles catch-up and follow-up campaigns in Afghanistan in 2002 and 2003

This paper assesses the cost-effectiveness of, and the return on the investment in, the 2002 catch-up and the 2003 follow-up measles campaigns in Afghanistan from the perspective of the donor. The catch-up campaign targeted nearly 12 million children aged between six months and 12 years, while the follow-up campaign targeted over five million children aged between 9 and 59 months. Both campaigns successfully vaccinated approximately 96 per cent of the respective target populations, and are expected to avert an estimated 301,000 measles deaths over the next 10 years. The average cost per dose of measles vaccine delivered was USD 0.40. The cost per death prevented is USD 23.6, assuming a case fatality rate of 10 per cent and a discount rate of three per cent. With more than 42,000 measles deaths avoided for every one million US dollars spent, the campaigns are an excellent public health investment for precluding childhood mortality in a country affected by a complex emergency.     

Removal of acutely hazardous pharmaceuticals from water using multi-template imprinted polymer adsorbent

Molecularly imprinted polymer adsorbent has been prepared to remove a group of recalcitrant and acutely hazardous (p-type) chemicals from water and wastewaters. The polymer adsorbent exhibited twofold higher adsorption capacity than the commercially used polystyrene divinylbenzene resin (XAD) and powdered activated carbon adsorbents. Higher adsorption capacity of the polymer adsorbent was explained on the basis of high specific surface area formed during molecular imprinting process. Freundlich isotherms drawn showed that the adsorption of p-type chemicals onto polymer adsorbent was kinetically faster than the other reference adsorbents. Matrix effect on adsorption of p-type chemicals was minimal, and also polymer adsorbent was amenable to regeneration by washing with water/methanol (3:1, v/v) solution. The polymer adsorbent was unaltered in its adsorption capacity up to 10 cycles of adsorption and desorption, which will be more desirable in cost reduction of treatment compared with single-time-use activated carbon.     

Vermistabilization and nutrient enhancement of anaerobic digestate through earthworm species Perionyx excavatus and Perionyx sansibaricus

The aim of the study was to examine safe reuse and recycling of organic waste digestate obtained from a biogas plant (5 % total solid) with enhanced nutrient value through vermitechnology. Two indigenous epigeic earthworm species Perionyx excavates and Perionyx sansibaricus were tried individually for this purpose. The results clearly show a significant increase in pH values from 6.5–7.4, electrical conductivity (21.3–21.7 %), total N (84.5–94.6 %), total P (35.9–47.1 %), total K (49.8–52.6 %), Ca (41.9–41.9 %) and a significant decrease in total organic C (17.1–22.4 %), C/N ratio (7.2–6.9), C/P ratio (20.3–20.6), COD (51.9–55.7 %), BOD (85.5–91.2 %). Similarly, indicator organisms (fecal coliforms and fecal streptococci) showed decrement at the end of the composting period (60 days). Fecal Coliforms reduce to nil, while in fecal streptococci a 6 log reduction was observed. Oxygen uptake rate dropped to 67.4–70 % for vermireactors. Overall, the aforementioned findings highlighted that the indigenous earthworm species could enhance the nutrient value of the anaerobic digestate, which could be utilized as an efficient soil conditioner.     

Inhalation exposure to volatile organic compounds in the printing industry

ABSTRACT

This study reports on the occupational inhalation exposure to VOCs of workers in the Kuwaiti printing industry. Using the evacuated canister methodology, we targeted 72 VOCs in three printeries and compared the concentrations to previous reports and relevant occupational exposure levels (OELs). We found that recent efforts in the printing industry to reduce VOC usage had been successful, as concentrations of key hazardous VOCs were substantially lower than anticipated. On the other hand, nearly all target VOCs were found. Non-production areas were sampled along with the offset printing areas, another strength of this study, and revealed exposures to hazardous VOCs among administers and digital printer and CTP operators. Exposure to ototoxic VOCs amounted to 1–3% of the OEL, consisting mostly of ethylbenzene, which was likely in use in two of the study printeries. Exposure to carcinogenic or probably carcinogenic VOCs was 15–20% of the OEL at four locations across the three printeries, consisting mostly of vinyl chloride and benzyl chloride. Vinyl chloride VOC was partially sourced from outdoors, but was also likely used inside the study printeries. Interestingly, concentrations of vinyl chloride were similar in most sampling locations to that of CFC-114, a CFC banned by the Montreal Protocol and not commonly used as a refrigerant. This unexpected finding suggests further study is warranted to identify the use of these VOCs in printeries. Exposure to hazardous VOCs up to nearly 50% of the OEL, consisting largely of bromoform and vinyl chloride. Bromoform was found in all the study printeries, sourced partially from outdoor air. The higher concentrations found inside the study printeries likely resulted from the use of the desalinated water for washing. This finding raises of emissions from sources other than blanket washes, and inks, etc. adding to the total VOC load in printery indoor air.

Implications: Results from this study indicate that efforts to reduce worker exposure to VOCs particularly dangerous to human health in recent years have been successful, but there is still much to be done to protect workers. Exposures to ototoxic and carcinogenic VOCs were identified, among both production and non-production workers. Unexpected findings included the apparent use in printing activities of the carcinogen vinyl chloride and CFC-114, banned under the Montreal Protocol. Observed lapses in safety procedures included failure to utilize ventilation systems and closing doors between work areas, indicating management and worker education should remain a priority.     

Arsenic(V) removal from aqueous solutions using an anion exchanger derived from coconut coir pith and its recovery

The performance of a new anion exchanger (AE) prepared from coconut coir pith (CP), for the removal of arsenic(V) [As(V)] from aqueous solutions was evaluated in this study. The adsorbent (CP-AE) carrying dimethylaminohydroxypropyl weak base functional group was synthesized by the reaction of CP with epichlorohydrin and dimethylamine followed by treatment of hydrochloric acid. IR spectroscopy results confirm the presence of -NH(+)(CH(3))(2)Cl(-) group in the adsorbent. XRD studies confirm the decrease of crystallinity in CP-AE compared to CP, and it favours the protrusion of the functional group into the aqueous medium. Batch experiments were conducted to examine the efficiency of the adsorbent on As(V) removal. Maximum removal of 99.2% was obtained for an initial concentration of 1 mgl(-1) As(V) at pH 7.0 and an adsorbent dose of 2 gl(-1). The kinetics of sorption of As(V) onto CP-AE was described using the pseudo-second-order model. The equilibrium isotherms were determined for different temperatures and the results were analysed using the Langmuir equation. The temperature dependence indicates an exothermic process. Utility of the adsorbent was tested by removing As(V) from simulated groundwater. Regeneration studies were performed using 0.1N HCl. Batch adsorption-desorption studies illustrate that CP-AE could be used to remove As(V) from ground water and other industrial effluents.     

Integral assessment of climate impact on the transboundary Mesta River flow formation in Bulgaria

The present work considers the section of the Mesta River on Bulgarian territory using the integral method for evaluation of climate and anthropogenic impact on the river flow. The level of this impact is determined by the index K _i (flow module), the coefficient C _i for the deviation of the average annual water volume Q _i from the flow norm Q _o and the index h _i for the deviation of the average annual rainfall volume H _i from the average multi-annual rainfall volume H _o . The dynamics of the average annual flow Q _i at two typical hydrometric stations – Yakoruda and Khadzhidimovo, as well as the dynamics of the average annual rainfall for the Yakoruda station was examined for the period 1955–2003. The data for the considered period 1955–2003 exhibit a decreasing trend of the average annual water volumes dynamics for both stations due to the impact of climate changes in the Mesta River catchment.     

Agro-potentiality of distillery effluent on soil and agronomical characteristics of Abelmoschus esculentus L. (okra)

The present study showed that irrigation of soil with different effluent concentrations (10, 25, 50, 75, and 100 %) of distillery effluent (DE) for 60 days resulted in significant (P?<?0.001) changes in moisture content; electrical conductivity (EC), pH, chlorides (Cl^?), total organic carbon (TOC), exchangeable sodium (Na⁺), available potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), iron (Fe²⁺), total Kjeldahl nitrogen (TKN), available phosphorus (P), and sulfate (SO₄ ^2?) of soil. The non-significant (P?>?0.05) changes were observed for water-holding capacity and bulk density of the soil. Among various concentrations of DE irrigation, irrigation with 100 % effluent concentration increased moisture content, (24.85 %), EC (77.88 %), Cl^? (285.95 %), TOC (3,171.42 %), exchangeable Na⁺ (241.04 %), available K⁺ (52.49 %), Ca²⁺ (990.37 %), Mg²⁺ (1,751.72 %), TKN (1,417.00 %), available P (305.00 %), and SO₄ ^2? (75.32 %) in the soil and decreased pH (?20.22 %). The more stimulation in agronomical parameters such as shoot length, root length, number of leaves, flowers, pods, dry weight, fresh weight, chlorophyll content, leaf area index, and crop yield of A. esculentus were observed to be inversely proportional to the concentration of effluent water, with the best results being obtained at a dilution of 25 % of DE concentration.