Chemical Engineering

 Bio-oil production from non-conventional Parinari polyandra pyrolysis process.  Bio-oils were obtained using a fixed bed reactor within a temperature range of 375 -550 o C.  The presence of valuable compounds suggests high potentials for industrial applications. The presence of acetic acids in bio-oil suggests the need to upgrade the oil before utilization as a fuel.    GRAPHICAL ABSTRACT ARTICLE INFO ABSTRACT Article history:

HIGHLIGHTS  Bio-oil production from non-conventional Parinari polyandra pyrolysis process.  Bio-oils were obtained using a fixed bed reactor within a temperature range of 375-550 o C.  The presence of valuable compounds suggests high potentials for industrial applications. The presence of acetic acids in bio-oil suggests the need to upgrade the oil before utilization as a fuel.

This study reports the comparative studies and microbial risk assessment of different frozen seasfoods processed in Ijora-olopa, Lagos State, Nigeria. Different varieties of popularly consumed frozen sea-foods bought from different processing shops in Ijora-olopa, Lagos were microbiologically analyzed for the presence of microorganisms. Total plate counts, enterobacteriaceae counts and Salmonella-Shigella (SS) counts were enumerated using Plate Count Agar (PCA), Eosin Methylene Blue (EMB) Agar and Salmonella-Shigella Agar (SSA), respectively. The total counts for all the processed frozen seafood products ranged between 1.08 x 10 2 to 2.86 x 10 4 CFU/ml. These were generally high exceeding the limit of 1.0 x 10 2 CFU/ml. The coliform count ranged between 0.76 x 10 2 and 1.36 x 10 4 cells. The Salmonella-Shigella (SS) count ranged between 0.26 x 10 2 and 0.96 x 10 4 cells. Seventeen (17) isolates were characterized from the samples on PCA with percentage of occurrence of different microorganisms characterized as follows: Bacillus cereus (29.4%), Enterobacter aerogenes (29.4%), Salmonella sp. (17.6%), Flavobacterium sp. (11.8%), Micrococcus sp. (5.9%), and Staphylococcus auerus (5.9%). Consumption of some of this water and the seafood product processed with these water samples available in the market should be discouraged.

This study reports the comparative studies and microbial risk assessment of different frozen seasfoods processed in Ijora-olopa, Lagos State, Nigeria. Different varieties of popularly consumed frozen sea-foods bought from different processing shops in Ijora-olopa, Lagos were microbiologically analyzed for the presence of microorganisms. Total plate counts, enterobacteriaceae counts and Salmonella-Shigella (SS) counts were enumerated using Plate Count Agar (PCA), Eosin Methylene Blue (EMB) Agar and Salmonella-Shigella Agar (SSA), respectively. The total counts for all the processed frozen seafood products ranged between 1.08 x 10 2 to 2.86 x 10 4 CFU/ml. These were generally high exceeding the limit of 1.0 x 10 2 CFU/ml. The coliform count ranged between 0.76 x 10 2 and 1.36 x 10 4 cells. The Salmonella-Shigella (SS) count ranged between 0.26 x 10 2 and 0.96 x 10 4 cells. Seventeen (17) isolates were characterized from the samples on PCA with percentage of occurrence of different microorganisms characterized as follows: Bacillus cereus (29.4%), Enterobacter aerogenes (29.4%), Salmonella sp. (17.6%), Flavobacterium sp. (11.8%), Micrococcus sp. (5.9%), and Staphylococcus auerus (5.9%). Consumption of some of this water and the seafood product processed with these water samples available in the market should be discouraged.

Uncontrolled emission of greenhouse gases (GHGs) to the atmosphere leads to climate change. One of the key contributors in GHG emission is municipal solid waste. Increasing population and rapid urbanisation in Malaysia directly influence MSW generation that has increased from 5.6 million tonnes in 1997 to more than 8 million tonnes in 2010 with a projection of more than 9 million tonnes by 2020. There are 6 operational sanitary landfills out of the 104 in operation in Peninsular Malaysia with five of them recovering methane. With a biodegradable component of more than 60%, MSW landfills are potential sources of cheaper and cleaner landfill gas (LFG). 310,225 t of methane were emitted from the MSW landfills in 2010 with carbon credit potential of US$85.93 million and can yield 2.20 Â 10 9 kW h of electricity valued at US$219.50 million. Emission projections were made for the years 2015 and 2020. The analysis points to a very promising and viable resource utilisation potential that will be of economic and environmental benefits. It will also create job opportunities for the local community. The use of this LFG will provide the means for overall GHG reductions and boost the efforts to achieve sustainable development.

Tanneries have gained negative image in the society because of the high polluting nature of their effluents. A typical tanning company consumes as much as 400 kg sodium sulphide; 250 kg ammonium sulphate; 820 kg sodium chloride; 80 kg sulphuric acid; 740 and 40 kg of lime and sodium carbonate per production day and with about 32 of such companies in Kano, the tanning process is simply the most environmentally polluting industry because of the enormous discharge into the water bodies such as the Challawa and Jakara rivers. Effluent from the tanneries is 225 m3/day and 12 tons of solid waste per day amounting to gross pollution of the environment all year round. The effluent from tannery industries in Kano were collected and characterized in the course of this study. Because of the expensive nature of conventional treatment, biological methods were considered for the treatability of the waste through the use of microorganisms. Hence, the bioremediative potentials of microorganisms iso...

The use of recycled sewage sludge ash (SSA) in Portland cement and concrete has attracted a lot of global interest due the increase in sludge production and the limitation of land availability where it is used as a soil conditioner. These are in addition to rising environmental concerns. The major components of SSA are SiO2, CaO, Al2O3, Fe2O3, MgO and P2O5. These compounds, in theory, make SSA a good pozzolanic material because when finely ground, SSA is found to be cementitious. Thus it can be used as cement replacement in Portland cement and concrete. Some of the advantages include reduction in waste disposal costs, provision of excellent sustainable practices, conservation of the environment provision of partial solution to land limitation problem for landfill. Some of its disadvantages are in terms of pozzolanic activity and strength coupled with high water demand which could be solved by adequate modification and treatment. This paper reviews the various use of SSA and summarises the progress made in the development of SSA as a partial replacement for Portland cement and concrete brought to you by CORE View metadata, citation and similar papers at core.ac.uk

The views of the public on solid waste bound to be generated in Johor Bahru Malaysia are presented and appraised. This is because of the massive development currently going on to transform the city to an international standing by the year 2025. For this reason, attempts to raise stakeholder awareness on the need to embrace on how best to manage the current problem with reduced impacts to the environment currently and in the future was attempted. Data were collected through contacts and questionnaire survey. Analytical hierarchy process (AHP) technique was used to structure and assess the views and judgments of stakeholders on the environmental impacts of solid waste disposal. SuperDecision software was used to generate and compute results of stakeholder's judgments. The assessment revealed that fauna and flora, habitat depletion and land use among the criteria are most critical environmental impacts. Landfilling, recycling, incineration and composting were evaluated in terms of the environmental impacts. The choice of incineration is perceived to improve environmental visibility, preserves fauna and flora as well as stream ecology, improves environmental air quality and optimizes land use. Similarly, recycling of waste, is perceived to preserves fauna and flora, stream ecology, habitat depletion, improves air quality as well as land use. Composting is perceived to be the best option in terms of preservation of stream ecology, habitat depletion and land use practice. Landfill generates less noise and vibration but found to be responsible for more than 50% of the environmental impacts created by solid waste in this area. Composting and recycling are mostly preferred to landfilling and incineration and the reason why this is so was provided. The study also identified challenges ahead and highlights that benefits attached to some vital disposal options (such as incineration) are yet to be fully implemented.

The global threat caused by increasing surface temperature has led to negative climate changes. One of the greenhouse gases responsible for this global warming is methane. It is emitted naturally and anthropogenically from different sources and its concentration in the atmosphere has assumed alarming proportions. Its devastating consequences on climate change and atmospheric chemistry have made it to be a focus of intense scrutiny and study. The anthropogenic sources of its emissions are generally grouped under three sectors of agriculture, energy and waste. The past emission trends of methane from these sectors are investigated through their sources while mitigation and abatement strategies are suggested. It is observed that the agricultural sector emits the highest amount of methane, followed by the energy and waste sectors, respectively.

This study assessed concentration levels of particulate matter (PM) in the ambient environment of Ilorin metropolis, Nigeria, during haze episodes. Meteorological data (wind speed and direction, rainfall data, sunshine data, relative humidity and temperature) were obtained. Aerocet 531S particle counter (MetOne Instruments, USA) was used to measure four mass concentration ranges of PM (PM1.0, PM2.5, PM10 and the total suspended particles (TSP)) in 10 locations taking into consideration land use patterns. Surfer® version 8 (Golden Software LLC, USA) was used to model the spatial variation of particulate matter concentration levels using kriging interpolation griding method. Human exposure assessment was done using the total respiratory deposition dose (TRDD) estimates and statutory limit breach (SLB) approaches. The appearance of dominating weak southern atmospheric wind flow was observed as wind speed ranged from 0 to 6.811 m/s while solar radiation periods ranged from 0.3 to 3.5 h/...

Environmental contaminations by polycyclic aromatic hydrocarbons (PAHs) especially from incinerators occur subtly, and PAH contribution from this source is underestimated. However, as environmental PAH concentrations build up, this may be a serious concern around the incinerator vicinity due to the potential consequences of PAHs on ecosystems and human health. Thus, the contribution of selected (12) PAHs from the Obafemi Awolowo University Teaching Hospital medical waste incinerator (or source, HWI_0) was determined by sampling stack gas and ambient air around incinerator vicinity from June 2014 to May 2015. Results showed that the 12 PAH source (HWI_0) concentrations were in the range of NA (for phenanthrene, pyrene, anthracene, benz[e]acephenanthrylene, and indeno[2,1-b]chromene) to 10.9 ng/m3 (pyrelene) and generally higher than the receptor points (hospital waste incinerators (HWIs)). The average total PAH concentrations per month at HWI_0 and the receptors-HWI_1, HWI_2, HWI_3, ...

Cement manufacturing contributes to the elevation of air pollutants in the atmosphere and thus impact on the nearby communities. This study assessed air quality in a major Cement Plant in Ibese Ogun State, Nigeria, through an ambient air quality monitoring and air emission dispersion modelling. Particulate Matter (PM) and gaseous pollutants were measured using portable samplers and AERMOD View was used for the emission dispersion modelling. Combustion products including SO 2 , NO, NO 2 , CO and VOCs were the gaseous pollutants detected along the complex fenceline and in the receptor environments. Pollutants measurements were undertaken at 23 locations within the fence line and receptor locations. The daily SO 2 and NO 2 Federal Ministry of Environment-Nigeria (FMEnv) limits were exceeded in ten (10) and five (5) locations along the fenceline, respectively. Particulates were detected in all the locations along the fenceline and in the communities. The cumulative gaseous pollutants resulting from simultaneous operations of all the identified plant air emission point sources are 0.01-276.13% of their respective 24-h limits along the fenceline, with 1-h SO 2 within the threshold limit at all fenceline locations, but 1-h NO X exceeds the threshold limit at all locations 16-21 times. The 24-h CO and VOCs are within their limits at all fenceline locations; however the 24-h SO 2 and NO X are breaching the limits at some locations 30-34 times (0.34-0.39% of the investigation period) and 44-87 times, respectively. Daily and Annual averaging concentrations of PM 10 was 14.32-31.54% and 4.90-52.60% of their respective limits. Process facilities are the major point sources of atmospheric emissions identified in the factory. Several fugitive emission sources were also identified during the field work. Comprehensive evaluation of the fugitive emission sources should be carried out in the cement plant for immediate attention.