Resource conservation through land treatment of municipal wastewater

Industrialization and urbanization have been causing tremendous pressure on the water resources. In turn, to maintain the pace of development, it has become necessary to search for alternative sources of water. Conventional wastewater-treatment technologies are cost-intensive and often pose financial constraint in developing countries. Therefore, considerable attention has been directed towards design and development of low-cost wastewater management technologies coupled with recycle and reuse benefits. High Rate Transpiration System (HRTS) is one such technology which can be implemented for domestic effluent disposal and reuse. This hypothesis was examined in field and laboratory experiments conducted by the National Environmental Engineering Research Institute (NEERI), Nagpur, India. This communication highlights the use of HRTS for the removal of pollutants like BOD, nitrogen and phosphorus from primary treated wastewater. The low-tech and low-cost wastewater treatment HRTS shows good performance for reduction of pollutants with minimal soil and plant contamination

Pulp and papermill wasterwater: can it solve the irrigation water scarcity problem

Changes in physico-chemical properties of soils and crops grown with pulp and paper mill wastewater in field lysimeters were carried out for three years at the integrated pulp and paper mill, madhya pradesh (india). lysimeters were prepared by excavating pits of 5 m x 2 m x 2 m, lined with polyethylene sheet and filled with sandy loam, clay and loamy sand soils and provided with percolate collection system. treated wastewater was used for crop irrigation containing high salinity and specific ion toxicity. with respect to sodium adsorption ration (sar), it was categorized under group `no restriction on use’. sandy loam & loamy sand soils in lysimeter i and iii percolate was 17% and 20% of irrigation while clay soil in lysimeter ii it was only 15%. sandy loam & loamy sand soils respectively showed 97 & 96% removal of chemical oxygen demand (cod) while clay soil removed 99% of cod and the color removal in both cases was 100%. percolate initially showed leaching of calcium and magnesium and retention of sodium, which got adsorbed in soil matrix. Application of wastewater resulted in increase in water holding capacity, ph (0.6 - 1.3 units), electrical conductivity of saturated extract (ece - 0.6 - 2.1 ms cm-1) and exchangeable sodium percent (esp - 8.1 - 11.6). organic carbon and available nitrogen, phosphorus and potash content of soils were also increasing. however, there was decrease in bulk density. the results showed that the application of wastewater increased the grain and straw yield of jowar, wheat and moong as compared to plain water respectively. there was slight variation in micro and macro nutrient content of grains of crop irrigated with wastewater, but it did not affect the nutrient quality and there was no accumulation of toxic heavy metals in the food grain. we measured nutrient input by wastewater and output by leaching and harvest export on unfertilized crop. a semi quantitative nutrient balance showed that all lysimeters had negative balance of micronutrients, indicating open nutrient cycles on these soils. these results showed that the pulp and paper mill wastewater might be successfully utilized for crop productio

Land Capability Classification for Agro-economic Evaluation of Mahadayi Dam, Karnataka, India

This paper examines the socio-economic impact of proposed dam on cropland productivity of Mahadayi project, Karnataka, India. Systematic appraisal of dam and their designing by categories of classes on the basis of physical and chemical characteristics of soil has been done in favour of development of agronomic conditions for the study of proposed dam sites in Karnataka. The study is aimed at the effective utilization of land according to their classes. Documentation on the land capability classification is a versatile component in formulation effective land use planning before the construction of dam. Thus an attempt was made to evaluate dominantly occurring soils on four class’s viz. soil depth, soil texture, soil drainage and soil erosion. The study was focused on the evaluation of economics of crop production based on agro climatic condition of the study area and existing cropping pattern. This study is important as it explores how an input of water and nutrient would respond under variable climatic conditions. In addition,interactions of water supplies with fertilizer rates at optimizing these resources need have been investigated. This paper identifies key challenges and solutions for carrying out project-level economic analysis of adaptation to climate change, both stand-alone and integrated into broader development projects. Very few projects addressing adaptation thus far have been subject to in-depth and rigorous economic analysis for a variety of reasons, including a lack of guidance on how to deal with assessments of the impacts of climate change, as well as with estimating costs and benefits of adaptation under uncertainty. Our focus is on the agricultural sector, where the impacts of climate change have the potential to disrupt the livelihoods of rural populations in many regions and where adaptation must be given urgent consideration. Nevertheless, some of the approaches discussed are suitable to projects in other sectors

Effect of gypsum on moisture availability in vertisols under soybean gram sequence.

A field experiment entitled, effect of gypsum on moisture availability in Vertisols in under soybean–gram sequence was conducted during season of 2008-2009 at extra assistant director (EAD) farm, College of Agriculture, Nagpur. The field experiment was laid out in randomized block design (RBD) with seven treatments replicated thrice. Highest yield and moisture use efficiency in soybean were obtained 3 t gypsum ha-1 whereas 1.5 t gypsum ha-1 also increased yield and MUE of soybean over control. Increasing level of gypsum also increased the yield and MUE efficiency of gram. Reduction in water dispersible clay, ESP, pH, exchangeable sodium, Mg. Improvement in HC, exchangeable Ca and Ca/Mg ratio was found with higher level of gypsum but low level of gypsum i.e. 1.5 t ha-1 was also sufficient to give better result over control (no gypsum). Favourable changes in soil physical and chemical properties were mostly found in surface soil (0-30 cm) and in sub-soil (30-60 cm) effect was not significant. Increased in moisture storage in sub soil observed in gypsum applied plots over control. Result revealed that 1.5 t gypsum ha-1 was found sufficient to maintain enough electrolyte concentration and maintaining Ca/Mg ratio for improving H.C. and other physical properties resulted in better storage of moisture and increased in yield of soybean and gram

The role of sand, marble chips and Typha latifolia in domestic wastewater treatment – a column study on constructed wetlands

The relative importance of sand, marble chips and wetland plant Typha latifolia is evaluated in constructed wetlands (CWs) for the treatment of domestic wastewater intended for reuse in agriculture. The prototype CWs for the experiments are realized in polyvinyl chloride columns, which are grouped into four treatments, viz. sand (<2 mm) + Typha latifolia (cattail), sand, marble chips (5–20 mm) + cattail and marble chips. The removal percentage of organic and nutritional pollutants from the wastewater is measured at varying hydraulic retention time in the columns. The statistical analysis suggests that the main effects of sand and cattail are found to be significant (p < .05) for the removal of biological oxygen demand and chemical oxygen demand from the wastewater. The presence of cattail significantly (p < .01) contributes to the conversion of total nitrogen in wastewater into NO− 3 by fostering the growth of favorable microbes for the nitrification. The removal of PO3− 4 and turbidity from the wastewater is significantly (p < .01) influenced by sand than the presence of cattail. The maximum PO3 4− adsorption capacity of the sand is estimated to be 2.5 mg/g. Marble chips have significantly (p < .01) influenced the removal of SO2− 4 and its maximum removal capacity is estimated to be 9.3 mg/g. The negative correlation between the filter media biofilm and column hydraulic conductivity is also reported for all the treatments. Thus, the findings of this study elucidate the role of low-cost and easily available filter media and it will guide the environmental practitioners in designing cost-effective CWs for wastewater treatment

Examination of Lead and Cadmium in Water-based Paints Marketed in Nigeria

Background. In spite of the availability of substitutes for lead and cadmium compounds in paints, manufacturers continue to produce paints with high levels of these metals. As the population continues to grow and there is a continued shift from oil-based to water-based paints, the sales and use of these paints will increase the exposure of humans and the environment to these metals. Objectives. We measured the levels of lead (Pb) and cadmium (Cd) in 174 paint samples marketed in Lagos and Ibadan, Nigeria. Paint samples from different manufacturers registered with and without Standards Organization of Nigeria (SON) were considered. Methods. Samples were acid digested using a microwave digester and the levels of the elements were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Discussion. The levels of Cd and Pb (dry weight) in all samples ranged from 98–1999 μg/g and 170–3231 μg/g, respectively. All the samples were above the permissible limits of 90 ppm of the US Consumer Product Safety Commission and 100 ppm limit of the European Union (EU) for Pb and Cd in paint. Conclusions. We concluded that water-based paints marketed in Nigeria still contain substantial amounts of lead and cadmium which are detrimental to human health and the entire ecosystem. These metals are among the EU priority metals due to the increased risk of occupational exposure to humans and vulnerable groups such as children. Competing Interests. The authors declare no competing financial interests

Developmental strategies for sustainable ecosystem on mine spoil dumps: a case of study

An important goal of ecological rehabilitation is to accelerate natural successional processes to increase biological productivity, soil fertility and biotic control over biogeochemical fluxes within the recovering ecosystems. A new approach called Microbe Assisted Green Technology (MAGT) is an integrated biotechnological approach developed at National Environmental Engineering Research Institute (NEERI) through exhaustive laboratory as well as field studies and serve as a model for land reclamation and development of lush green vegetation on mine overburdens. One year old seedlings of native tree species were planted on 6.3 ha area of manganese mine overburden at Gumgaon under Manganese Ore India Ltd., Maharashtra, India. Continuous efforts resulted in nutrient rich soil with high N, P, K and organic carbon; well developed biodiversity, including bacteria, fungi, higher plants (more than 350 species) and different classes of animals. Planted trees accumulated 698 t ha−1 above ground biomass and 143 t ha−1 below ground mass. This was achieved in 18 years by MAGT, which otherwise takes hundreds of years