Landfill leachate treatment by electrochemical oxidation

This study investigated the electrochemical oxidation of stabilized leachate from Pulau Burung semi-aerobic sanitary landfill by conducting laboratory experiments with sodium sulfate Na₂SO₄ (as electrolyte) and graphite carbon electrodes. The control parameters were influent COD, current density and reaction time, while the responses were BOD removal, COD removal, BOD:COD ratio, color and pH. Na₂SO₄ concentration was 1 g/L. Experiments were conducted based on a three-level factorial design and response surface methodology (RSM) was used to analyze the results. The optimum conditions were obtained as 1414 mg/L influent COD concentration, 79.9 mA/cm² current density and 4 h reaction time. This resulted in 70% BOD removal, 68% COD removal, 84% color removal, 0.04 BOD/COD ratio and 9.1 pH. Electrochemical treatment using graphite carbon electrode was found to be effective in BOD, COD and color removal but was not effective in increasing the BOD/COD ratio or enhancing biodegradability of the leachate. The color intensity of the treated samples increased at low influent COD and high current density due to corrosion of electrode material.     

The impact of Local Authorities’ interventions on household waste collection: A case study approach using time series modelling

At a local Government level there have been many interventions and changes made to household waste collection services to meet new regulatory requirements. These changes include separate collection of recyclable and organic materials. This paper has used a time series model to quantify the success of interventions introduced by a LA.The case study was a medium sized UK LA, Charnwood Borough Council (CBC), the research analyses monthly data of quantities of recyclates, garden waste for composting and residual waste for landfill disposal. The time series model was validated with a five year data set and used to measure the impacts of the various changes to identify which intervention was the most successful, while controlling for season and number of working days. The results show the interventions analysed both had abrupt and permanent positive impacts on the yield of recyclable materials, and a corresponding negative impact on the residual waste.The model could be added to the National data base to help LAs to compare interventions and to understand which schemes encourage householder participation and improve recycling performance.     

An Experimental and Metamodeling Approach to Tensile Properties of Natural Fibers Composites

Journal of Polymers and the Environment - The present work presents an analysis of the tensile properties of Palm as well as Luffa natural fiber composites (NFC) in high density polyethylene...     

A Case-study of ISO 14001-based Environmental Management System Implementation in the People's Republic of China

The ISO 14001 implementation process among certified firms in China was examined by conducting a questionnaire survey distributed to all certified firms as of December 1998. Results showed that the ISO 14001-based environmental management system (EMS) has a significant effect on firms' daily environmental activities and performance. Recycling, natural resource consumption and released pollutants have been managed in a better way and, in some cases, pollutants have been reduced. The study showed that firms' main targets for adopting the system were to: enhance the firm's public image; enhance employees' environmental awareness; improve the EMS inside the firm; improve the environmental aspects and performance inside the firm; and improve relations with government offices and local citizens. ISO 1400-based EMS implementation showed that it is a promising tool for helping build a better partnership between three main stakeholders, government, local citizens and enterprises. The system has enabled firms to consider the role of the local people in a more effective way. For example, special consideration is given to involving local citizens in health and emergency preparedness during firms' daily environmental activities. Moreover, enhancing environmental awareness among the local citizens and giving more consideration to co-operation with other firms from the same industrial groups are reported by certified firms. Finally, there are strong demands for government support to build more reliable information systems, ISO 14001-related research, more incentives for eco-labelling and tax exemptions.     

Assessing vulnerability to invasion by nonnative plant species at multiple spatial scales

Basic information on where nonnative plant species have successfully invaded is lacking. We assessed the vulnerability of 22 vegetation types (25 sets of four plots in nine study areas) to nonnative plant invasions in the north–central United States. In general, habitats with high native species richness were more heavily invaded than species-poor habitats, low-elevation areas were more invaded than high-elevation areas, and riparian zones were more invaded than nearby upland sites. For the 100 1000-m² plots (across all vegetation types), 50% of the variation in nonnative species richness was explained by longitude, latitude, native plant species richness, soil total percentage nitrogen, and mean maximum July temperature (n = 100 plots; P < 0.001). At the vegetation-type scale (n = 25 sets of four 1000-m² plots/type), 64% of the variation in nonnative species richness was explained by native plant species richness, elevation, and October to June precipitation (P < 0.001). The foliar cover of nonnative species (log) was strongly positively correlated with the nonnative species richness at the plot scale (r = 0.77, P < 0.001) and vegetation-type scale (r = 0.83, P < 0.001). We concluded that, at the vegetation-type and regional scales in the north–central United States, (1) vegetation types rich in native species are often highly vulnerable to invasion by nonnative plant species; (2) where several nonnative species become established, nonnative species cover can substantially increase; (3) the attributes that maintain high native plant species richness (high light, water, nitrogen, and temperatures) also help maintain nonnative plant species richness; and (4) more care must be taken to preserve native species diversity in highly vulnerable habitats.     

Environmental planning and management for the Assarawat highland region of south-western Saudi Arabia: the traditional versus the professional approach

The environmental planning and management of the Assarawat highlands of south-western Saudi Arabia are currently confronted by difficult problems. Deforestation is caused either by natural or intentional forces. Natural factors are limited to lightning fire and drought, while intentional forces include vandalism caused by the burning or cutting of preserved forests. Such vandalism continues despite the tremendous efforts of afforestation and preservation by several government agencies, especially the Ministry of Agriculture and Water, the National Commission for Wildlife Conservation and Development and by the municipalities of the cities and towns in the region. For centuries, local inhabitants of the Assarawat highlands have successfully established environmental planning and management strategies which balanced the settlements' growth and natural resource uses according to Islamic laws, and the tribal self-government of each settlement and tribal region. Following the establishment of the Kingdom of Saudi Arabia in 1932, the land management system started to change from tribal-based, where every tribe used to manage its local territory, to State authority. The creation of the State witnessed the unification of various fragmented tribes of Saudi Arabia into one government. This meant that environmental planning and management moved from local/regional towards a national control. This investigation proposes that the local/regional planning and management practised by the tribes could be viably utilized today. As in the past, the implementation of these practices could protect the natural environment of the locality and region and regularize their exploitation rationally, as long as vernacular people implement them. Today environmental planning and management need to be based on strategies of local requirements that enable the indigenous people to plan and manage the use of the resources.     

Antiviral Effects of Lactococcus lactis on Feline Calicivirus,A Human Norovirus Surrogate

Foodborne viruses, particularly human norovirus (NV) and hepatitis virus type A, are a cause of concern for public health making it necessary to explore novel and effective techniques for prevention of foodborne viral contamination, especially in minimally processed and ready-to-eat foods. This study aimed to determine the antiviral activity of a probiotic lactic acid bacterium (LAB) against feline calicivirus (FCV), a surrogate of human NV. Bacterial growth medium filtrate (BGMF) of Lactococcus lactis subsp. lactis LM0230 and its bacterial cell suspension (BCS) were evaluated separately for their antiviral activity against FCV grown in Crandell–Reese feline kidney (CRFK) cells. No significant antiviral effect was seen when CRFK cells were pre-treated with either BGMF (raw or pH 7-adjusted BGMF) or BCS. However, pre-treatment of FCV with BGMF and BCS resulted in a reduction in virus titers of 1.3 log₁₀ tissue culture infectious dose (TCID)₅₀ and 1.8 log₁₀ TCID₅₀, respectively. The highest reductions in FCV infectivity were obtained when CRFK cells were co-treated with FCV and pH 7-adjusted BGMF or with FCV and BCS (7.5 log₁₀ TCID₅₀ and 6.0 log₁₀ TCID₅₀, respectively). These preliminary results are encouraging and indicate the need for continued studies on the role of probiotics and LAB on inactivation of viruses in various types of foods.