Groundwater pollution is a worldwide phenomenon with potentially disastrous consequences. Prevention of pollution is the ideal approach. However, in practice groundwater quality monitoring is the main tool for timely detection of pollutants and protection of groundwater resources. Monitoring groundwater quality is a specialised task for a hydrogeologist and a water quality monitoring expert. Although general prescriptions for waste management facilities exist these may not be applicable in all cases. In the literature, divergent approaches have identified various sets of pollutants and pollution indicators. This paper discusses international and local trends in groundwater monitoring for baseline studies and ongoing pollution detection monitoring for a variety of situations. Cemeteries, a pollution source for which no local monitoring requirements exist, are also included. The effectiveness of some commonly prescribed monitoring parameters is considered, as well as the use of "bulk parameters" for reducing the number of analyses and the associated costs, while still achieving the optimum result. Although not considered in detail in this paper, cost-effective groundwater quality monitoring should be a key part of the design of a monitoring programme.
Batch experiments were performed to denitrify groundwater using sawdust as a carbon source at Marydale, South Africa. Alkalinity, pH, electrical conductivity, nitrate, nitrite, ammonia, SO 4 2−
With the increasing demand on limited resources, groundwater will have to serve more people in southern Africa, especially in remote rural areas. The situation is becoming more precarious with the projected change in rainfall and climate patterns. Concurrently, nitrate pollution of groundwater would seem to be on the increase. This makes the remediation of high nitrate groundwater by low cost and robust methods a much-needed intervention.Three methods that have shown potential for full-scale application are reverse osmosis, ion exchange, and biological denitrification. Biological denitrification is specific in the removal of nitrate and is thus the most versatile approach being studied. In situ denitrification, i.e. within the aquifer, is an attractive alternative due to relative simplicity and low investment and maintenance costs.Research needs identified include minimisation of nitrite accumulation, optimisation of reaction conditions, inhibitory effects of reaction intermediates and by-products, and optimisation of measuring and control systems. This work presents a laboratory model set up using a 2200 x 350 x 350 mm column for denitrifying high nitrate groundwater. The column contains seven ports which stretch along the entire column like observation boreholes and can be used either for sampling or injecting during the experiment. The sampling/injecting ports are at 300, 500, 700, 1000, 1200, 1500, and 1700 mm distance respectively. Hence the reactions can be studied over the total length of the column. An unconfined primary aquifer will be simulated. Flow, pH, EC and initial conditions will be as close as possible to field conditions. Monitoring will include nitrogen species microbiological species (e.g. heterotrophic plate count). Hydraulic properties and (organic N, NO2-, NO3-and NH4+), pH, EC, Eh, as well as indicator flow rate will also be monitored with time. Modelling using PHREEQC and an excel based model will be done using the data from the experiment.Results describe the comparison between Phreeqc modelling and batch experiments for in-situ groundwater denitrification using sawdust as an electron donor and carbon source with respect to changes in system performance with time.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.