Policies and regulations for Brazil’s artisanal gold mining sector: analysis and recommendations

In Brazil, artisanal and small-scale gold mining (ASGM) produces in the range of 6 tonnes of gold (Au) per annum, and employs approximately 200,000 people. Most of this mining activity is in the Amazon region, where miners have been extracting gold for more than 40 years. In the Tapajos River Basin, assessments indicate that around 99% of miners operate without the environmental and mining permits required by law. This is a result of a combination of unrealistic or lack of proper policies and regulations, lack of political will, lack of infra-structure to enforce the existing regulations and lack of incentives to miners to comply with legal requirements.In this article, we analyze a group of 20 laws, decrees and resolutions in Brazil, focusing on how idiosyncrasies in these regulations reveal gaps between policy and reality in ASGM areas. Artisanal miners operate in vast and remote areas and the government lacks the resources (personnel, vehicles, information and materials) to enforce the laws. Our analysis emphasizes the need for creating new government commitments and identifying priority areas where government agents can focus their efforts.There is no single solution for the environmental, health, technical and socio-economic problems associated with ASGM. However, a realistic approach should consider improving the level of education of miners, creating government programs to provide technical assistance in the field, simplifying administrative procedures and ensuring adequate measures for enforcement.     

Monitoring dissolved organic carbon in surface and drinking waters

The presence of natural organic matter (NOM) strongly impacts drinking water treatment, water quality, and water behavior during distribution. Dissolved organic carbon (DOC) concentrations were determined daily over a 22 month period in river water before and after conventional drinking water treatment using an on-line total organic carbon (TOC) analyzer. Quantitative and qualitative variations in organic matter were related to precipitation and runoff, seasons and operating conditions. Following a rainfall event, DOC levels could increase by 3.5 fold over baseflow concentrations, while color, UV absorbance values and turbidity increased by a factor of 8, 12 and 300, respectively. Treated water DOC levels were closely related to the source water quality, with an average organic matter removal of 42% after treatment.     

WATER QUALITY MODELING FOR THE FEITSUI RESERVOIR IN NORTHERN TAIWAN1

ABSTRACT: Field data collected from the Feitsui Reservoir in Taiwan indicate that the water is at a stage between mesotrophic and eutrophic. Recent measurements such as total phosphorus, chlorophyll a and Secchi depth levels suggest that the water quality has been declining. A two‐dimensional, laterally averaged, finite difference hydrodynamic and water quality model was used to simulate the water quality in the Feitsui Reservoir in an effort to determine sound water quality management strategies. The model was calibrated and verified using data collected in 1996 and 1997. The calibrated model was used to simulate algal biomass (in terms of chlorophyll a) levels under various wasteload reduction scenarios. Model results show that 50 percent reduction of the total phosphorus load will improve the existing water quality, shifting the trophic status from eutrophic/mesotrophic to oligotrophic. The modeling effort has yielded valuable information that can be used by decision makers for the evaluation of different management strategies of reducing watershed nutrient loads.     

PLANNITG INDIANA'S WATER INFRASTRUCTURE FROM A COMPETITIVE PERSPECTIVE1

ABSTRACT: Indiana has embarked on a program to assess the condition of its infrastructure and to plan for its future. The perspective of this planning differs from the traditional “master plan” approach — instead, the focus is on competitiveness for economic development. The initial work on the water and sewerage competitiveness of the infrastructure includes: (1) a comparative analysis of the water resources and infrastructure of Indiana and its industrial midwestern neighbors; (2) a technology scan to identify possible technological opportunities that may be important for Indiana; and (3) a set of recommendations for future planning. This work is preliminary in nature but should serve as a starting point for continued strategic planning over the next decade for positioning of Indiana's water and sewerage infrastructure as a key element in the economic growth equation.     

Vitrification for reclaiming spent alkaline batteries

The object of this study is to stabilize spent alkaline batteries and to recover useful metals. A blend of dolomite, limestone, and cullet was added to act as a reductant and a glass matrix former in vitrification. Specimens were vitrified using an electrical heating furnace at 1400 °C and the output products included slag, ingot, flue gas, and fly ash. The major constituents of the slag were Ca, Mn, and Si, and the results of the toxicity leaching characteristics met the standards in Taiwan. The ingot was a good material for use in production of stainless steel, due to being mainly composed of Fe and Mn. For the fly ash, the high level of Zn makes it economical to recover. The distribution of metals indicated that most of Co, Cr, Cu, Fe, Mn, and Ni moved to the ingot, while Al, Ca, Mg, and Si stayed in the slag; Hg vaporized as gas phase into the flue gas; and Cd, Pb, and Zn were predominately in the fly ash. Recovery efficiency for Fe and Zn was >90% and the results show that vitrification is a promising technology for reclaiming spent alkaline batteries.     

Characteristics of mercury desorption from sorbents at elevated temperatures

This study investigated the dynamic desorption characteristics of mercury during the thermal treatment of mercury-loaded sorbents at elevated temperatures under fixed-bed operations. Experiments were carried out in a 25.4 mm ID quartz bed enclosed in an electric furnace. Elemental mercury and mercuric chloride were tested with activated carbon and bauxite. The experimental results indicated that mercury desoption from sorbents was strongly affected by the desorption temperature and the mercury–sorbent pair. Elemental mercury was observed to desorb faster than mercuric chloride and activated carbon appeared to have higher desorption limits than bauxite at low temperatures. A kinetic model considering the mechanisms of surface equilibrium, pore diffusion and external mass transfer was proposed to simulate the observed desorption profiles. The model was found to describe reasonably well the experimental results.     

Characteristics of heavy metal absorption of river bed sludge components

Chronic inhalation of aerosols of different Cd compounds by rats gave sufficient evidence that inhaled Cd is a lung carcinogen in rats. In contrast, the evidence in humans has been termed limited that inhaled Cd causes lung cancer in occupationally exposed humans. In order to assess the carcinogenic potential of ambient air concentrations of Cd, the accumulated dose of Cd in lung tissue from a rat inhalation study was modelled taking into account deposition and retention of Cd in the lung. A lung Cd—cancer incidence relationship could then be established, and an equivalent human exposure could be calculated using man specific pulmonary Cd retention and deposition data for Cd containing particle sizes in the ambient air. Linear interpolation to low doses showed that the pulmonary carcinogenic risk from inhalation of environmental airborne Cd is generally very low, but may reach about 1 × 10^‐4 in polluted industrialized areas. Combined exposures to Cd plus other carcinogens or air pollutants may increase the risk considerably. Cd in cigarette mainstream smoke was estimated to contribute less than 5 % of the total lung cancer risk from smoking cigarettes. However, the influence of co‐exposure to other compounds in cigarette smoke is not known and should be taken into account.     

Assessing carbon footprint in the life cycle of accommodation services: the case of an international tourist hotel

The accommodation sector is the most demanding energy consumer among all building stock categories. This study quantifies an international tourist hotel in Taiwan to holistically estimate the greenhouse gas emissions of hotel accommodation services through a complete life cycle inventory. The study also investigates the difference between the carbon emissions of the baseline and reduction years to understand the effects of carbon emission reduction on the hotel industry. Results show that energy consumption is the main source of carbon footprint. However, the carbon emissions of other activities, such as the production and transportation of hotel amenities and laundry services, are 15.90% for the baseline year and 16.03% for the reduction year. These values are larger than the 5% cutoff rule according to PAS 2050. Thus, these factors should also be considered in assessing the carbon emissions of accommodation services. Hotel occupancy rate significantly affects carbon emissions during a one-night stay in a standard room as the functional unit. The selection of the functional unit should be considered in the hotel strategy. Although this case study involves an international tourist hotel in Taiwan, the findings and recommendations for improvements can be applied elsewhere.