This study was carried out to assess the overall water quality and identify major variables affecting the deep groundwater quality in Kathmandu Valley, Nepal. Forty-two deep wells were sampled during premonsoon and monsoon seasons in 2007 and analyzed for the major physicochemical variables. The water quality variables such as NH ₄ ⁺ -N, Fe, Pb, As, and Cd at most of the sampling locations exceeded the World Health Organization guideline levels for drinking water. Multivariate statistical techniques such as factor analysis and cluster analysis were applied to identify the major factors (variables) corresponding to the different source of variation in deep groundwater quality. Factor analysis indentified six major factors explaining 74.77% of the total variance in water quality; and the major variations are related with the degree of groundwater mineralization, decomposition of organic matter, and reduction of groundwater environment. The water quality of deep groundwater is influenced by the natural hydrogeochemical environment. The wells are broadly divided into two major groups based on the similar groundwater characteristics using cluster analysis. Results show that water quality of deep groundwater does not vary significantly as a function of season.

Despite many efforts for pollution abatement in aquatic ecosystems, there are still some cases of high accumulation of industrial pollutants due to past activities. In Flix reservoir (Ebro River, Spain), there are around 200,000-360,000 tons of industrial pollutants with a high concentration of heavy metals and organochlorides due to the activity of an organochlorine industry during more than half a century. This exceptional amount of pollutants provides a good opportunity (and need) to analyse their effects on fish populations under natural conditions, which is rarely available to ecotoxicologists. We compared the reproductive traits and prevalence of diseases and parasites at this impacted area with a neighbouring upstream reservoir unaffected by the pollution (reference sites) and also to downstream sites. Deformity, eroded fin, lesion and tumour (DELT) anomalies and ectoparasites were clearly more frequent at the impacted area for several fish species (common carp, roach and pumpkinseed). A significant negative impact of Flix reservoir on condition (eviscerated and liver weights, adjusted for fish size with analysis of covariance) and reproductive traits (gonadal weight and number of mature eggs, adjusted for fish size) was also detected for several fish species. The responses to the pollutants were species-specific, and common carp (Cyprinus carpio) was the species with the clearest effects on fitness-related traits at the impacted area, despite also being among the most tolerant to pollution.

We tested the efficacy of matrix-based fertilizers (MBFs) to improve Kentucky bluegrass (Poa pratensis L.) growth while reducing NH, NO3, dissolved reactive phosphorus (DRP), and total phosphorus (TP) compared to commercial slow-release fertilizer (SRF) Polyon®, ESN®, and Avail® in greenhouse column studies. The MBFs covered a range of inorganic N and P in compounds that are relatively loosely bound (MBF6) and more tightly bound compounds (MBF7) with Al(SO4)318H2O and/or Fe2(SO4)33H2O and with high ionic exchange compounds starch, cellulose, and lignin. The total amount of NO3 and NH4 leached was greater from columns receiving Polyon® and ESN® fertilizers than all other treatments. The MBF6+Avail® or MBF7+Avail® fertilizers leached 64–68% less NO3 than Polyon® (43-0-0) and ESN® (46-0-0), and 73–76% less TDP and TP than Avail® (10-34-0). A greater amount of NO3 was leached from the MBF6+Avail® and the MBF7+Avail® treatments than the other MBF fertilizer treatments. Shoot and root biomass were greater when plants received the Avail®, MBF6+Avail®, and MBF7+Avail® fertilizer treatments than the other fertilizer treatments. When combined with small quantities of commercial SRFs, these new MBFs were able to maintain plant growth while reducing N and P leaching. These new MBF formulations do not depend on organic or inorganic coatings to reduce N and P leaching and with further testing and development could be effective commercial fertilizers.

In this work, the determination of moving averages is proposed as a method for quantifying metal, arsenic, and sulfate discharges into a water course undergoing acid mine drainage processes which flows into a public water supply dam in the Iberian Pyrite Belt. The analysis of the results obtained by applying moving averages shows that the highest metal and sulfate concentrations occur in October, coinciding with the first rainfall and the sponging of mine dumps, with November and December being the months when the highest contributions to the Andevalo Dam take place. The discharge of acid mine waters with its corresponding metal load into the Andevalo Dam means, for a single hydrological year, more than 6,000 t of sulfates, almost 600 t of iron, and 1 t of As, of special relevance for the hydrochemical quality of the stored waters. When they arrive at the dam, these metals precipitate, since the water pH is near 7, and remain latent in the bottom sediment as long as the chemical makeup of the dam water does not change.

This study aimed at determining the water quality of River Sirimon and River Kongoni, Ewaso Ng'iro North Basin, Kenya. Water quality analysis of these two rivers was done for a period of 5 months between November 2005 and February 2006. Portable Palintest equipment was used for the chemical analysis. The study established that there were sulphates concentrations of 22 mgL⁻¹ in the Kongoni River water associated with the use of commercial fertilisers as compared to mean values of 7 mgL⁻¹ along Sirimon River; phosphate concentrations were 1.3 mgL⁻¹ in Kongoni and 0.15 mgL⁻¹ in Sirimon and salinity 3 mgL⁻¹ in Kongoni and 0.47 mgL⁻¹ in Sirimon. On average, mean nitrates concentrations of 1.7 mgL⁻¹ were recorded for Kongoni River, which were higher than those recorded for Sirimon River (0.033 mgL⁻¹). These concentration levels were however within the standard levels set by WHO for example 50 mgL⁻¹ for nitrates (WHO 2008). River Kongoni has two major irrigated horticultural farms across it which were likely polluting the river during the time of this study.

Nonpoint source pollution management initiated by the Ministry of Environment (MOE) in Korea resulted to the construction of 25 pilot facilities termed Best Management Practices (BMPs) until 2005. The national nonpoint sources control projects were employed to fulfill the Total Maximum Daily Load programs. The long-term monitoring being conducted at the sites which began in 2006 is providing detailed insight into the performance of the BMPs. The experience and performance data will be used to better understand and implement similar structural BMPs in the future as well as to assist the MOE in developing the design and maintenance guidelines of BMPs. This study presents the results gathered from the monitoring field tests and experiments over 22 rainfall events between the June 2006 and September 2008 period investigating the pollutant removal efficiency of the infiltration trench BMP that is one of the 25 pilot projects of the MOE. In addition, it includes the development of simple linear regression models to estimate constituent event mean concentration. The results reveal high treatment efficiencies for total suspended solids (89%); biochemical oxygen demand, chemical oxygen demand, and dissolved organic carbon (89-93%); oil and grease (100%); cadmium, lead, and zinc (89-93%); total nitrogen (84%); and total phosphorus (82%). The monitoring data and results will represent a step forward to a better prediction of impacts in the environment and to the national development of BMPs for sustainable watershed management in the country.

Water retention and transport in soils is dependent upon the surface tension of the aqueous phase. Surfactants present in aqueous solution reduce the surface tension of aqueous phase. In soil-water systems, this can result in water drainage and reductions in field capacity and hydraulic conductivity. In this investigation, the surface tension of surfactant solutions mixed with soil—in a constant fixed ratio—was measured as a function of surfactant concentration. Two anionic surfactants were used: sodium dodecyl sulphate and sodium bis (2-ethylhexyl) sulfosuccinate. Two soils were also used—a clay soil and a sandy soil. The key observation made by this investigation was that the addition of soil to the surfactant solution provided a further component of surface tension reduction. Neither soil sample reduced the surface tension of water when surfactant was absent from the aqueous phase, though both soils released soil organic matter at low surfactant concentrations as shown by measurement of the chemical oxygen demand of the supernatant solutions. Furthermore, both surfactants were shown to be weakly adsorbed by soil as shown by the use of a methylene blue assay. It is therefore proposed that the additional reduction in surface tension arises from synergistic interactions between the surfactants and dissolved soil organic matter.

The aim was to assess the role of Phragmites australis (Cav.) Trin. ex Steud. in experimental, mature, and temporarily flooded vertical flow wetland filters treating urban runoff rich in organic matter. During the experiment, ammonium chloride was added to sieved concentrated road runoff to simulate primary treated urban runoff contaminated with nitrogen. Five days at 20°C N-allylthiourea biochemical oxygen demand (BOD) and chemical oxygen demand removal efficiencies were relatively lower for planted than unplanted filters. Moreover, there was no significant difference for BOD removal for all filters under fluctuating inflow concentrations of sulfate. The nitrogen removal performances of planted filters were more efficient and stable throughout the seasons compared to those of unplanted filters. A substantial load of nitrogen (approximately 500 mg per filter) was removed by harvesting P. australis. Plant uptake was the main removal mechanism for nitrogen during high concentrations (10 mg/L) of ammonia-nitrogen in the urban runoff.

We present the concentrations and distribution patterns of nine acid leachable trace metals (ALTMs) Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, and Cd in the soil samples from the five century old Pachuca-Mineral de Monte mining district of the Central Mexico. The ALTMs do not show any significant correlation with pH, EC, CaCO₃, and organic carbon. The metal concentration indicates three distinct distribution patterns. Fe, Mn, Cr, Pb, and Zn show enrichment in the high altitude region of the northern and central part of the study area. Likewise, Cu and Cd are enriched in the northern mountainous terrains. Both these groups show strong positive correlation with Mn indicating that they are associated with Mn-bearing minerals. However, we relate the first group of metals to excessive vehicular transportation and second group to mining waste dumps. The third group of ALTMs Co and Ni indicates its direct relationship to ore processing activities. Comparison of ALTMs concentrations from this study and various other studies throughout the world suggests the need to take precautionary measures of surface soil in high altitude areas to avoid metal enrichments and its subsequent environmental problems.

In the present work the kinetics of ferric reduction was investigated using dissimilatory ferric- and sulphate-reducing bacterial cultures. The effect of sulphate reduction on Fe(III) reduction was also studied. The study is an attempt to improve the biological reduction rate of Fe(III) as an alternative biotechnological way to the reduction step in steelmaking processing operations. The results obtained show that the reduction of ferric iron and sulphate took place in a successive way and none synergetic effect was detected. The simultaneous action of both metabolic activities did not enhance the process but slowed down the kinetics of ferric reduction. The reduction process of 3 g/L of soluble ferric and 3 g/L of sulphate lasted 25 days. Ferric iron was the first electron acceptor to be reduced in the first 15 days followed by the sulphate reduction in the following 10 days. That result suggests that ferric reduction is a preferential metabolic process over sulphate reduction when both electron acceptors coexist. None improvement in the kinetics was observed using an electron donor concentration in excess. In contrast, the total reduction of ferric ion (3 g/L) with adapted bacterial cultures was achieved in only 36 h. The presence of sulphate had no effect on the ferric reduction. Finally, an improved culture medium for ferric-reducing bacteria is also proposed.