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Uncontrolled landfill leachate generation portends danger to the environment and aquatic ecosystem, especially without prior treatment before discharge. The application of Al-based coagulants, such as polyaluminum chloride (PACl), has the potential of introducing Al residuals into water bodies. Therefore, an alternative natural coagulant was recommended to reduce the usage of Al-based coagulants. In this study, a coagulation–flocculation process using the combination of PACl as coagulant and Tamarindus indica seed (TiS) as coagulant aid was used in treating the landfill leachate from the Alor Pongsu Landfill Site in Malaysia. Some of the optimum operational conditions determined were the pH and dosage of the coagulant aid, and their effect was considered on parameters, such as suspended solids (SS), color, and COD, using standard jar test procedures. The combination of TiS flocculant reduced the dosage of PACl coagulant from 5,000 mg/L to 2,750 mg/L with removal efficiencies of 99.3%, 97.3%, and 67.4% for SS, color, and COD, respectively.

The main aim of this study is to investigate the simultaneous azo dye removal and bioelectricity production at sulfate reducing conditions in continuously-fed dual-chamber microbial fuel cell (MFC). Initially, optimization of sulfate reduction was performed at different sulfate concentrations (100-900 mg/L) and the constant COD of 1000 mg/L, corresponding to COD/sulfate ratio of 1.11-10, and varying HRT of 12-48h. Optimum COD/sulfate ratio and HRT was found 1.66 and 36h, respectively, corresponding to 96% COD removal, 44% sulfate removal and yielded about 24 W/m2 power density. Further, MFC was fed with azo dye containing (50-1000 mg/L) simulated wastewater to evaluate dye removal performance of sulfate reducing bacteria. Addition of azo dye slightly enhanced the power production to 26 W/m2, the highest value obtained during our study, compared to azo dye lacking study periods. Sulfate and COD removals were adversely affected at azo dye concentrations over 300 mg/L and 150 mg/L, respectively. Additionally, color removal performance of MFC was excellent however, chemical azo dye reduction out-competed with enzymatic reduction at high azo dye levels (>500 mg/L) leading to a poor sulfate (<15%) and COD (<45%) removal and recovery of azo dye reduction efficiency to 91%.

In the present investigation, an attempt for the reduction of six hazardous air Pollutants (HAPs) from diesel exhaust by different blends of diesel and biodiesel has been made. The synthesis of biodiesel has been done from Jetrofa, Linseed Castor and Karanja oils which are commonly used in the Indian market. Blending of diesel with biodiesel was done in different ratios (20 to 40 %) for the estimation of carcinogenic HAPs from the exhaust of a Honda engine (EBK 2010AC Model). The order of HAPs emission from engine exhaust by using diverse blends were Diesel>Jatropha-diesel>Linseed-diesel>Castor-diesel> Karanja-diesel. The maximum reduction of HAPs was established in the following ratio 40% (Biodiesel):60% (Diesel). B(a)P and Chrysene were the two individual aromatic hydrocarbons (AHCs) found in higher concentration in almost all blending fuels, ranging between 50 ng/µl to 101.1 ng/µl. The emission of almost all AHCs reduces by Blending of Diesel with Biodiesel. This was the first comprehensive information which showed the reduction of carcinogenic pollutants from diesel exhaust.

The purpose of this paper is the presentation of the results compiled from self weighing of household food waste and self filling of waste collection diaries that took place in Greece. A diary was compiled and given to 101 urban households in various areas of the country. The participants were asked to weigh and write down in the diary every food item wasted in their households for two full weeks (i.e., 14 days). The total per capita food waste generation in Greece is estimated to be 76.1 (±68.3) kg/inh.y. This figure is divided into the avoided food waste fraction which equals to 25.9 (±34.9) kg/inh.y, and the unavoidable fraction which is estimated to be 50.2 (±47.1) kg/inh.y. The use of diaries for recording food that is thrown away from households is a methodology that underestimates the food wasted in households because households tend to be cautious when they know that they have to weigh and report the amount of food that they throw away. The current research is the first of its kind, presenting actual field data for food waste generation by households in Greece.