The supply of nutrients from domestic wastewater encourages the practice of reuse in agricultural production, but the presence of heavy metals, even at low concentrations, can cause environmental problems in the long term. This study analyzed the effects of the application of domestic wastewater and well water on heavy metal levels in a cambisoil cultivated with chili peppers. Thus, an experimental area of 744 m² was established in Milagres rural community, Apodi-RN. This area is comprised of a sewage treatment station and drip irrigation system. The treatments were T1 - 100% of treated domestic wastewater (ART) and 0% of well water (AP), T2 - 75% of ART and 25% of AP, T3 - 50% of ART and 50% of AP, T4 - 25% of ART and 75% of AP and T5 - ART 0% of ART and 100% of AP. During the experimental period we chemically analyzed ART and AP, while soil samples were collected in the layers 0 to 0.20 m, 0.20 to 0.40 m and 0.40 to 0.60 m for determination of pH and the content of copper, zinc, iron and manganese. The results indicated that the levels of copper, zinc, iron and manganese on cambisoil were not influenced by the proportions of domestic treated wastewater and well water; however, the soil pH decreased as the proportions of domestic treated wastewater increased as compared to well water. | O aporte de nutrientes das águas residuárias doméstica estimula a prática do reuso na produção agrícola, porém a presença de metais pesados, mesmo que em baixas concentrações, pode acarretar problemas ambientais no longo prazo. O presente trabalho objetivou analisar os efeitos da aplicação da água residuária doméstica e água de poço na alteração dos teores de metais pesados em um cambissolo cultivado com pimenta malagueta. Para isso, uma área experimental de 744 m² foi montada no assentamento Milagres em Apodi-RN. Essa área é composta de estação de tratamento de esgoto e de sistema de irrigação por gotejamento. Os tratamentos utilizados foram T1 - 100% de aplicação água residuária doméstica tratada (ART) e 0% de água de poço (AP), T2 - 75% de ART e 25% de AP, T3 - 50% de ART e 50% de AP, T4 - 25% de ART e 75% de AP e T5 - 0% de ART e 100% de AP. No período experimental foram realizadas análises químicas da ART e AP, enquanto do solo foram coletadas amostras nas camadas de 0 a 0,20 m, 0,20 a 0,40 m e 0,40 a 0,60 m para determinação dos valores de pH e do conteúdo de cobre, zinco, ferro e manganês. Os resultados indicaram que os teores de cobre, zinco, ferro e manganês do cambissolo não foram influenciados pelas proporções de água residuária doméstica tratada e de água de poço. Os valores de pH do solo apresentaram tendência de redução nas proporções com mais água residuária doméstica tratada em relação a água de poço.

Esta pesquisa foi norteada pelo objetivo de determinar as concentrações dos níveis de cádmio (Cd) no solo e na água de consumo do município de Buriticupu-MA, comparando os teores de cádmio encontrado no solo e nas diferentes fontes de abastecimentos de água de consumo com os níveis estabelecidos pela legislação nacional e internacional. Buscou-se, também, analisar as concentrações de cádmio encontradas em áreas próximas à BR 222 e aos lixões da cidade. Foram coletadas 50 amostras de solo e 30 de água. As coletas ocorreram em março de 2015, sendo que os procedimentos de coleta do solo seguiram as recomendações protocoladas pela USEPA (1989 e 1991) e Byrnes (1994). As análises da água foram realizadas no Centro de Estudos da Saúde do Trabalhador e Ecologia Humana (CESTEH), da Escola Nacional de Saúde Pública Sergio Arouca (ENSP/Fiocruz), seguindo o protocolo já estabelecido pelo laboratório, que utilizou a espectrometria de absorção atômica eletrotérmica. Os procedimentos para a digestão de cádmio na água seguiram o método EPA 3020A. Os procedimentos para determinação de cádmio no solo, seguiram o método USEPA 3050B, da Agência de Proteção Ambiental dos EUA (USEPA, 1998a), no Laboratório de Solos da Universidade Estadual do Maranhão (UEMA), mediante espectrometria de emissão atômica com plasma acoplado indutivamente (ICP-OES). Os níveis de cádmio encontrados na água variaram entre ≤ 0,04 µg L-1 e 0,22 µg L-1 , sendo que 77% dos valores ficaram abaixo do limite de detecção (0,04 µg L-1 ), com uma média de 0,053 µg L-1 . Não houve diferença entre os teores de cádmio nas diferentes fontes analisadas de abastecimento de água para consumo. Os níveis de cádmio encontrados no solo variaram entre ≤ 0,14 mg Kg -1 e 4,089 mg kg-1 , com uma média geral de 0,705 mg Kg-1 . Quase metade das amostras (44%) se encontravam em pH ácido (4,5-5,5) e, em 20%, a concentração de cádmio estava acima de 1,3 mg kg-1 . Constatouse variação nos níveis de cádmio entre os bairros e dentro deles, como também nos pontos próximos à BR 222 e lixões da cidade. Os resultados encontrados para os níveis de cádmio na água de consumo analisada, neste estudo, apresentaram níveis abaixo daqueles estabelecidos pela legislação nacional e internacional, não incorrendo, portanto, em riscos à saúde da população local. Contudo, para as concentrações de cádmio no solo, observou-se algumas áreas com a nítida perturbação antropogênica, sobretudo nas proximidades dos lixões. | The aim of this research was to determine the cadmium (Cd) levels in soil and drinking water in the city of Buriticupu located in the state of Maranhão, comparing the cadmium content found in the soil and different sources of water supply for consumption with levels established by national and international laws. This study also aimed to determine cadmium concentration in the surroundings areas of the Brazilian highway 222 and landfills of the cited city. Fifty soil samples and thirty of water were collected. The sampling occurred March of 2015, and the sampling procedures for soil followed recommendations of US EPA (1989 e 1991) and Byrnes (1994). The analysis of water was conducted in the Center for Studies on Workers’ Health and Human Ecology (CESTEH), from the National School of Public Health Sergio Arouca (ENSP/Fiocruz), following a protocol previously established by the laboratory, which used the electrothermal atomic absorption spectrometry. The procedures to digest cadmium in water followed the method EPA3020A. The soil digestion followed the US EPA 3050B in the Soil Laboratory of the State University of Maranhão (UEMA), and cadmium was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). cadmium levels found in water ranged from ≤ 0.04 µg L-1 to 0.22 µg L-1 , wherein 77% of the values were below the limit of detection (0.04 µg L-1 ), averaging 0.053µg L-1 . There were not differences among cadmium content in different sources analyzed of water supply for consumption. Cadmium levels in soil found varied between ≤ 0.14 mg Kg-1 and 4.089 mg kg-1 with a general average of 0.705 mg Kg-1 . Almost half of the samples (44%) was in an acid pH (4.5- 5.5) and, in 20% of them, the cadmium concentration was over 1.3 mg kg-1 . A variation in cadmium levels was found between neighborhoods and within them as well as in the surroundings of the Brazilian highway 222 and landfills in the city. The results for cadmium levels in drinking water revealed levels below those set by national and international laws and shall not pose, therefore, a risk to the health of local people. However, related to cadmium concentrations in soil, there are some areas with distinct anthropogenic disturbance especially in the vicinity of landfills.

2 3 . No município de Castelo existem corpos hídricos em áreas agrossilvipastoris, utilizados para irrigação de lavouras, dessedentação animal e consumo humano. Objetivou-se, com esse estudo, avaliar a qualidade da água e do sedimento de fundo de oito córregos do município de Castelo, com base em variáveis físico-químicas. A temperatura, o oxigênio dissolvido (OD) e o pH da água foram medidos por meio de sonda. As amostras de sedimento de fundo foram coletadas com uma pá de ponta chata, com volume de 2,565 dm³ e, depois de secas, foram homogeneizadas e encaminhadas para o laboratório, onde foram determinados o pH, os teores de fósforo, potássio, cálcio, magnésio, alumínio, ferro, cobre, zinco, manganês, boro, sódio, carbono e matéria orgânica, a acidez potencial, a capacidade de troca catiônica, a soma de bases trocáveis e os índices de saturação de bases, de alumínio e de sódio. Verificou-se que o OD está abaixo do limite recomendado pelo CONAMA, na maioria dos pontos amostrados, mas o pH está dentro dos limites recomendados. No sedimento de fundo, os teores de ferro são altos, o que é uma característica dos solos da região. Com exceção do ferro e do manganês, os teores de minerais são baixos ou médios, na maioria dos pontos. A porcentagem de matéria orgânica é menor que 10% do peso seco, caracterizando o sedimento de fundo como mineral, em todos os pontos. O alto teor de areia indica pouca afinidade dos metais pelo sedimento de fundo. Essa condição, associada à acidez do sedimento de fundo, favorece a liberação dos minerais para a coluna de água, constatando-se o risco de contaminação ambiental. = In Castelo city, there are water bodies in agroforestry areas, used for irrigating crops, watering animals and human consumption. This study aimed to evaluate the water and bottom sediment quality of eight streams in Castelo city, based on physico-chemical variables. Temperature, dissolved oxygen (DO) and pH were measured by a probe. 2,565 dm³ volume sediment samples were collected with a flathead shovel, dried, homogenized, and sent to the laboratory for analysis. pH, the contents of phosphorus, potassium, calcium, magnesium, aluminum, iron, copper, zinc, manganese, boron, sodium, carbon and organic matter, acidity potential, cation exchange capacity, sum of exchangeable bases and the saturation index of bases, aluminum, and sodium were determined. It was found that the OD was below the recommended limits set by CONAMA in most sites, but the pH was within recommended limits at all points. In the bottom sediment, the iron content was high, which is characteristic of soils of the region. With the exception of iron and manganese, the mineral content was either low or medium, in most points. The percentage of organic matter was less than 10% by dry weight, characterizing the sediment as mineral at all points. The high content of sand indicates low affinity of metals by sediment. This condition, associated with the acidity of the sediment, favors the leaching of minerals into the water column. This is a potential environmental contamination risk.

The Agua Negra drainage system (30 12'S, 69 50' W), in the Argentine Andes holds several ice- and rock-glaciers, which are distributed from 4200 up to 6300 m a.s.l. The geochemical study of meltwaters reveals that ice-glaciers deliver a HCO₃⁻----Ca²⁺ solution and rock-glaciers a SO₄²⁻----HCO₃⁻----Ca²⁺ solution. The site is presumably strongly influenced by sublimation and dry deposition. The main processes supplying solutes to meltwater are sulphide oxidation (i.e. abundant hydrothermal manifestations), and hydrolysis and dissolution of carbonates and silicates. Marine aerosols are the main source of NaCl. The fine-grained products of glacial comminution play a significant role in the control of dissolved minor and trace elements: transition metals (e.g. Mn, Zr, Cu, and Co) appear to be selectively removed from solution, whereas some LIL (large ion lithophile) elements, such as Sr, Cs, and major cations, are more concentrated in the lowermost reach. Daily concentration variation of dissolved rare earth elements (REE) tends to increase with discharge. Through PHREEQC inverse modelling, it is shown that gypsum dissolution (i.e. sulphide oxidation) is the most important geochemical mechanism delivering solutes to the Agua Negra drainage system, particularly in rock-glaciers. At the lowermost reach, the chemical signature appears to change depending on the relative significance of different meltwater sources: silicate weathering seems to be more important when meltwater has a longer residence time, and calcite and gypsum dissolution is more conspicuous in recently melted waters. A comparison with a non-glacierized semiarid drainage of comparable size shows that the glacierized basin has a higher specific denudation, but it is mostly accounted for by relatively soluble phases (i.e. gypsum and calcite). Meltwater chemistry in glacierized arid areas appears strongly influenced by sublimation/evaporation, in contrast with its humid counterparts.

Shallow groundwater is the main source for drinking water in Kabul, Afghanistan. It comes from a multitude of shallow hand-pumped wells spread over the whole city area. The groundwater is characterised by slightly oxic redox conditions. Interactions with aquifer carbonates lead to near-neutral pH and high degrees of hardness. The mostly negative water budget of the Kabul Basin is the result of strong evaporation which leads to an increase in salt and also of some undesirable constituents, e.g. borate. Several years of drought have aggravated this problem. The shallow groundwater in the city has received tremendous amounts of pollution due to a lack of proper waste disposal and sewage treatment. Common indicators are elevated concentrations of nutrients such as nitrate and faecal bacteria. The high infant mortality can at least partially be attributed to the insufficient water hygiene. Acid generated during the mineralisation of the wastewater is hidden due to the strong pH buffering capacity of the groundwater system. Redox and pH conditions preclude significant mobilisation of trace metals and metalloids.

More than 99% of water use in Denmark is based on groundwater. Denmark has had a comprehensive national groundwater-monitoring programme since 1988 based on 74 well catchment areas and six small agricultural catchments with more than 1,500 screens at different depths for regular, mostly annual, water quality sampling. In addition, water samples from 10,000 abstraction wells are analysed every 3–5 years. The water is analysed for main components, inorganic trace elements, organic micro pollutants, and pesticides and their metabolites. A unique feature is the 20-year time-series data of inorganic pollutants. Groundwater modelling supports traditional monitoring to improve the conceptual geological understanding and to assess the quantitative status and the interaction between groundwater and surface water. The programme has been continuously adjusted to incorporate new knowledge from research programmes and meet new policy demands, currently the European Union Water Framework Directive, particularly with respect to an increased focus on quantitative aspects and on the groundwater/surface water interaction. The strengths and weaknesses of the Danish programme are assessed and compared with other national groundwater-monitoring programmes. Issues discussed include: strategic considerations for monitoring design, the link between research and monitoring, and adoption of responses to climate changes.

Geochemical and isotopic characterization of groundwater and lake-water samples were combined with water and total dissolved solids balances to evaluate sources of groundwater quality deterioration in eastern Hetao Basin, Inner Mongolia, China. Groundwater quality is poor; 11 of 13 wells exceed drinking-water guidelines for at least one health-based parameter and all wells exceed aesthetic guidelines. The well water is largely derived from Yellow River irrigation water. Notably high uranium concentrations in the Yellow River, relative to world rivers, suggest groundwater uranium and other trace elements may originate in the river-derived irrigation water. Complex hydrostratigraphy and spatial variation in groundwater recharge result in spatially complex groundwater flow and geochemistry. Evapotranspiration of irrigation water causes chloride concentration increases of up to two orders of magnitude in the basin, notably in shallow groundwater around Wuliangsuhai Lake. In addition to evapotranspiration, groundwater quality is affected by mineral precipitation and dissolution, silicate weathering, and redox processes. The lake-water and TDS balances suggest that a small amount of discharge to groundwater (but associated with very high solute concentrations) contributes to groundwater salinization in this region. Increasing salinity in the groundwater and Wuliangsuhai Lake will continue to deteriorate water quality unless irrigation management practices improve.