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In this work, chitin (CTN), chitosan (CTS) and activated carbon (AC) were used as adsorbents to recover valuable metals from leachates of mobile phone wastes. The mobile phone wastes (contactors) were collected and characterized. The valuable metals were extracted by thiourea leaching. The adsorption of valuable metals from leachates was studied according to the kinetic and equilibrium viewpoints. It was found that the contactors were composed by Au, Ni, Cu and Sn. The thiourea leaching provided extraction percentages of 68.6% for Au, 22.1% for Ni and 2.8% for Cu. Sn was not extracted. The leachate presented 17.5 mg L -1 of Au, 324.9 mg L -1 of Ni and 573.1 mg L -1 of Cu. The adsorption was fast, being the equilibrium attained within 120 min. The adsorption of Au, Ni and Cu onto CTN and AC followed the Langmuir model, while, the adsorption of these metals onto CTS, followed the Freundlich model. Removal percentages higher than 95% were obtained for all metals, depending of the type and amount of adsorbent. It was demonstrated that the adsorption onto chitin, chitosan and activated carbon can be an alternative to recover valuable metals from leachates of mobile phone wastes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Waste management in large urban centers is one of the main challenges for public administration. Two of the most abundant wastes in cities are waste solid and municipal wastewater (MWW). Their management can be optimized if they are treated together. This work analyzed an anaerobic–aerobic system for the treatment of fruit and vegetable wastes (FVWs) and MWW. Firstly, FVWs were collected and characterized; once in the laboratory, they were placed in a tank with the MWW, aiming at transferring to the water those solids with a particle size below 105 µm; then, they were separated by sieving. The mixture of MWW and FVWs with a particle size below 105 µm was fed into an up-flow anaerobic sludge reactor (UASB); in the latter, dissolved and suspended organic matter was transformed into methane and carbon dioxide. The water that left the UASB was sent to be post-treated in an activated sludge reactor (ASR). The chemical oxygen demand (COD) was used as an evaluation parameter of the anaerobic–aerobic system; a removal efficiency higher than 80% was achieved, whereas it was 60% in the ASR. Another evaluation parameter was methane (CH4) productivity, with an average of 3.0 LCH4 L−1 d−1. VWF leaching achieved an average COD extraction of 7.68 kg∙m−3. The UASB efficiency was on average 70% for the assayed loads (2–8 kg COD·L−1·d−1). The energy potential calculated for the anaerobic–aerobic system was 510.2 kW∙h∙d−1 [ABSTRACT FROM AUTHOR]

There is currently a dearth of information on the determination, occurrence and ecotoxicological risk of antibiotics in dumpsite leachates and hospital wastewater in Africa. A quick, easy, cheap, effective, rugged and safe (QuEChERS) protocol which combines extraction and clean-up in one step was optimized for the determination of antibiotics sulfadoxine, sulfamethazine and trimethoprim in dumpsite leachates and hospital wastewater. The occurrence and ecotoxicological risk of target antibiotics were investigated in wastewater from two hospitals, effluent receiving water and leachates from three dumpsites in Ibadan, Nigeria. Recoveries in hospital wastewater ranged from 53 to 116% while recoveries ranged from 50 to 89% in leachates. Method limits of quantification ranged from 0.7 to 12.1 µg L−1 in hospital wastewater and from 6.2 to 38.8 µg L−1 in leachates. Intra-day precisions (% RSD) were ≤ 21%. High concentrations of target antibiotics were measured: up to 475 µg L−1 for sulfamethazine in leachates, 118 µg L−1 for trimethoprim in hospital wastewater and 117 µg L−1 for sulfadoxine in effluent receiving water. Sulfadoxine presented high risk to algae, daphnid and fish in hospital wastewater, effluent receiving water and leachates. This work highlights the need for adequate and sound management of wastes containing pharmaceuticals in Nigeria. [ABSTRACT FROM AUTHOR]

For safe disposal of wastes in landfills, compacted bentonite is recommended as bottom liners due to their significant cation exchange (CEC) and swelling capacity, low permeability and large specific surface area (SSA). The present investigation carried out various experimental studies determining the compressibility behaviour and unconfined compressive strength (UCS) of two different compacted bentonites in the presence of municipal solid waste (MSW) and synthetic MSW leachates. Various examinations were conducted determining alterations in consolidation parameters like the coefficient of consolidation (cv), time taken for 90% consolidation (t90) and compression index (Cc) with both leachates. The outcomes reveal that Cc and t90 values of both bentonites declined; however, cv value rose. Results also indicated that under any given consolidation pressure, a lesser void ratio was achieved for leachates. UCS of both bentonites reduced with leachates' interaction yet, lying within the recommended a value higher than 200 kPa. A comparative assessment of the two bentonites displayed that bentonite having higher CEC and swelling capacity, and SSA unveiled more excellent Cc and t90 values and a reduction in the UCS. A higher variation in behaviour of bentonites was perceived in the existence of MSW leachate in comparison to synthetic MSW leachate. [ABSTRACT FROM AUTHOR]

The proper management of municipal waste is critical for resource recovery, sustainability and health. Lebanon main approach for managing its municipal waste consisted of landfill disposal with minimal recycling capacity. This approach contributed to exceeding the holding capacity of existing landfills leading eventually to their closures. The closure of a major landfill (Naameh landfill) servicing Beirut and Mount Lebanon areas led to municipal wastes piling in the streets and forests for more than a year in 2016. The main problem identified in the municipal wastes consisted of untreated leachates (from regulated and unregulated dumpsites) going straight into the Mediterranean Sea. Therefore leachate samples were collected and subjected to chemical characterization followed by biological assessment. The chemical characterization and profiling of the Lebanese leachates were compared to results reported in Lebanon, Europe and United States as well as to the toxicity reference values (TRV). The biological assessment was conducted in vitro using human derived immortalized cell cultures. This strategy revealed significant alarming cellular organelles and DNA damages using in vitro cytotoxicity assays (MTS and comet assay). The significant damages observed at the cellular level prompted further animal model investigations using BALB/c mice. The animal data pointed to significant upregulation of liver activity enzymes coupled with significant damage expression in liver spleen and bone marrow DNA. The presented research clearly indicated that there is an urgent need for development of national waste strategies for proper treatment and disposal of municipal waste leachates in Lebanon. [ABSTRACT FROM AUTHOR]

Inefficient management of landfills and dumpsites for waste disposal is a major problem in Nigeria. Leachates and pollutants from these dumpsites have been known to contribute to the pollution of groundwater systems. The extents of pollution however are poorly quantified since the flow of pollutants continues below earth surface. The use of GIS mapping enabled the evaluation of spatial characteristic of pollutants in the groundwater systems. Thirty (30) hand dug well within 10 - 100m were sampled around two poorly managed dumpsites in Ibadan. Twenty-three (23) physico-chemical and heavy metals water quality indicators were analyzed following Standard Methods. The result were subjected toT- test of mean compared with WHO (2005) drinking water standard (p<0.05). Using GIS Inverse Distance Weighted Interpolation, the maps of the pollutants were produced and the spatial distribution shown. Elevation, topography and slope were major determinants in the distribution of level of pollutant revealed in the generated maps. Although, pH CI-, K+, Fe, Cr and Pb were not significantly different from the Maximum Allowable Limits (MAL) TSS, TDS, Total Hardness, NO3-, SO42-, Ca, Mg, Na, Cu, Zn, are all lower while CO32-, Mn, Cd, and BOD5 are higher than MAL. The DO is good since it's averagely higher than minimum required for water drinking. The GIS maps will guide in groundwater prospecting in the area and aid decision on enforcement of environmental standard in siting of residences and groundwater wells. [ABSTRACT FROM AUTHOR]