Applicability of agricultural waste and by-products for adsorptive removal of heavy metals from wastewater.

Assessing river water quality using water quality index in Lake Taihu Basin, China.

The concept of indexing water with a numerical value to express its quality, based on physical, chemical and biological measurements, was developed in 1965 by US based National Sanitation Foundation (NSF). In NSFWQI, the selection of parameters is based on Delphi method and these models were formulated in additive and multiplicative forms. The models were implemented across various states in the US while being continually refined. One refined form is known as Oregon Water Quality Index (OWQI). The index enjoys the advantage of being free from the arbitration in weighting the parameters and employs the concept of harmonic averaging. Another model of WQI from Europe (Spain) is that of Bascaron (Bol. Inf. Medio Ambient. 9:30–51, 1979), which is based on the normalization of the concentrations of the water quality parameters and then aggregating them through an additive model with suitable weights attached to the parameters involved. The major differences in various WQIs are based on the mannerism of statistical integration and interpretation of parameter values. A totally different approach was adopted in the Canadian Water Quality Index also known as Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI). CCME WQI and is also being used by many countries all over the world and has also been endorsed by United Nations Environmental Program (UNEP) in 2007 as a model for Global Drinking Water Quality Index (GDWQI). The most commonly used parameters are dissolved oxygen, pH, turbidity, total dissolved solids, nitrates, phosphates, metals among others. All indices have one or other limitation and the search for a perfect one is still a challenge.

https://link.springer.com/content/pdf/10.1007%2Fs12403-011-0040-0.pdf

A Review of Genesis and Evolution of Water Quality Index (WQI) and Some Future Directions

The use of water quality indices (WQIs) as a tool to evaluate the status of water quality in rivers has been introduced since the 1960s. The WQI transforms selected water quality parameters into a dimensionless number so that changes in river water quality at any particular location and time could be presented in a simple and easily understandable manner. Although many WQIs have been developed, there is no worldwide accepted method for implementing the steps used for developing a WQI. Thus, there is a continuing interest to develop accurate WQIs that suit a local or regional area. This paper aimed to provide significant contribution to the development of future river WQIs through a review of 30 existing WQIs based on the four steps needed to develop a WQI. These steps are the selection of parameters, the generation of sub-indices, the generation of parameter weights and the aggregation process to compute the final index value. From the 30 reviewed WQIs, 7 were identified as most important based on their wider use and they were discussed in detail. It was observed that a major factor that influences wider use of a WQI is the support provided by the government and authorities to implement a WQI as the main tool to evaluate the status of rivers. Since there is a lot of subjectivity and uncertainty involved in the steps for developing and applying a WQI, it is recommended that the opinion of local water quality experts is taken, especially in the first three steps (through techniques like Delphi method). It was also observed that uncertainty and sensitivity analysis was rarely undertaken to reduce uncertainty, and hence such an analysis is recommended for future studies.

/pdf/development-of-river-water-quality-indices-a-review-21n1hpr2bw.pdf

Development of river water quality indices-a review

Assessment of eutrophication and water quality in the estuarine area of Lake Wuli, Lake Taihu, China.

Water quality index as a simple indicator of aquaculture effects on aquatic bodies

The natural cotton fiber was used to synthesize an anion exchange, containing ZrO 2 film on its surface, NCFZC (natural cotton fiber/ZrO 2 composite). This anion exchanger was produced by the reaction of the zirconium oxychloride and hydroxyl groups on surface of the natural cotton fiber. The material was used for Cr(VI) ions adsorption studies. Adsorption equilibrium time and optimum pH for Cr(VI) adsorption were found to be 6 h and 4.0, respectively. The Langmuir and Temkin isotherms were used to models adsorption equilibrium data. The adsorption capacity of NCFZC was found to be 1.33 mmol/g. Kinetic studies showed that the rate of adsorption of Cr(VI) on NCFZC obeyed a pseudo-second-order kinetic model.

Cotton Fiber/ZrO2, A New Material for Adsorption of Cr(VI) Ions in Water

Monte Carlo simulation (MCS) methodology has been applied to explain the variability of parameters for pollutant transport and fate modeling. In this study, the MCS method was used to evaluate the transport and fate of copper in the sediment of the Tibagi River sub-basin tributaries, Southern Brazil. The statistical distribution of the variables was described by a dataset obtained for copper concentration using sequential extraction, organic matter (OM) amount, and pH. The proposed stochastic spatial model for the copper transport in the river sediment was discussed and implemented by the MCS technique using the MatLab 7.3™ mathematical software tool. In order to test some hypotheses, the sediment and the water column in the river ecosystem were considered as compartments. The proposed stochastic spatial model makes it possible to predict copper mobility and associated risks as a function of the organic matter input into aquatic systems. The metal mobility can increase with the OM posing a rising environmental risk.

/pdf/monte-carlo-method-applied-to-modeling-copper-transport-in-4veh496h4b.pdf

Monte Carlo method applied to modeling copper transport in river sediments

Residual CuSO4 was incorporated into the mass utilized for cement preparation. To a cement mass with 1:0.5:5 of cement, lime and sand to 0.25, 0.50, 0.75 and 1.00% of residual CuSO4 were added. The sulfate was mixed separately with lime and water to induce metal precipitation. The hardened test bodies were submerged in Milli-Q water for three months. No Cu was detected in the water by Atomic Absorption Spectrometry. The best proportion for mechanical resistance and porosity is 0.50%. The cement is adequate for non-structural objects.

/pdf/incorporacao-de-cuso-4-residual-em-argamassa-como-metodo-de-5dry7u1eat.pdf

INCORPORAÇÃO DE CuSO 4 RESIDUAL EM ARGAMASSA, COMO MÉTODO DE DISPOSIÇÃO FINAL

Agronomy students generally lack interest in chemistry. The objective of this work was to modify the analytical chemistry curriculum to increase student interest. Samples of soils and plants prepared by students were introduced. Soil was treated with molasses residue, organic matter (chicken manure and humus obtained from goat excrement), and lime. The response of plants to the different soil treatments increased student interest in chemical analyses. Evaluation of several chemical and physicochemical parameters of samples demonstrated in a clear way the application of the theoretical and practical concepts of chemistry.

Sonia Maria Nobre Gimenez

Papers

Water quality index as a simple indicator of aquaculture effects on aquatic bodies

Cotton Fiber/ZrO2, A New Material for Adsorption of Cr(VI) Ions in Water

Monte Carlo method applied to modeling copper transport in river sediments

INCORPORAÇÃO DE CuSO 4 RESIDUAL EM ARGAMASSA, COMO MÉTODO DE DISPOSIÇÃO FINAL

Linking the Lab Experience with Everyday Life: An Analytical Chemistry Experiment for Agronomy Students