Bibliography: leaves 256-275. / xx, 275 leaves : ill., map ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

Two municipal sludges, one from a highly industrialized city, Chicago, and another from a lesser industrialized, highly agricultural area, Tucson, are compared for barley production on Pima c 1 (Typic torrifluvent). Both sludges were responsible for highly significant additions of Zn, Cu, Ni, Cd and P to the soil each year at the rates of 100mt/ha single and 20mt/ha for 2 years. Nitrogen responses for barley straw and grain were observed from both sludges. Tucson sludge appears to be attractive as a potential fertilizer, not only as an NPK source, but also for its minimal amounts of heavy metals. The Chicago sludge with high levels of heavy metals, particularly Cd, appears unsuited as a fertilizer because of the plant's tendency to take up toxic levels of heavy metals.

Gold tailings contained in Tailing Storage Facilities (TSFs) contain pyrite which on exposure to air and water becomes a source of acid mine drainage (AMD). AMD has high salinity, elevated levels of heavy metals and low pH, which presents serious threats to surface and groundwater systems. These characteristics in tailings present a hostile environment for plant establishment and growth (Witkowski and Weiersbye 1998a). Therefore, it was hypothesized that organic mulch sourced from sewage sludge and water hyacinth could improve tailings fertility on TSFs in the Highveld gold mines of South Africa. The aim of this study was to develop a greenhouse study to understand how four indigenous plants (Asparagus laricinus Burch. (Asparagaceae), Eragrostis curvula (Schrad.) Nees. (Poaceae), Hyparrhenia hirta (L.) Stapf (Poaceae) and Sutherlandia frutescens (L.) R.Br. (Fabaceae) naturally colonizing the Highveld gold TSFs would survive, grow and accumulate metals from tailings amended using different percentages of water hyacinth and/or sewage sludge, and the susceptibility of the amended tailings to metal leaching. Tailings amended with WH: SS-1.0% proved to be the overall best amendment from the 19 treatments based on the variable tested (e.g. plant growth, plant metal uptake and metal leaching). Amending gold tailings with water hyacinth and/or sewage sludge improved seedling survival, plant survival and growth as compared to non-amended tailings. Tailings amended with dry water hyacinth (WH) created the most favourable plant growing conditions especially at 0.5% of amendment, while those amended only with sewage sludge (SS) presented the most challenging plant growth conditions for all four study species. Amending tailings with water hyacinth and/or sewage sludge showed no significant difference in tailings fertility. However, C (%) and total N decrease significantly after plant growth in all treatments. Hyparrhenia plants grown in tailings amended with WH: SS-1.0% accumulated significantly higher concentrations of Al, Cr, Ni and Zn, while those growing in tailings amended with WH-0.5% accumulated significantly lower concentration of Al, Co, Cr, Fe and Zn as compared to other treatments. Tailings amended with WH-1.0% leached significantly higher concentrations of Mn, while those amended with WH: SS-0.5% and WL-2.0% leached significantly higher concentrations of S as compared to other treatments. All four species accumulated significantly higher concentrations of Al, Co, Cr, Cu, Fe and Ni in the roots than the shoots, except for A. laricinus which accumulated significantly higher concentrations of S, Co, Cr, Mn, Ni and Zn in the shoots than the roots. Sutherlandia frutescens retained all the elements tested in its root biomass. Future field studies in the use of water hyacinth and sewage sludge as organic tailings amendments will be required to get a better understanding of these two potential tailings amendment treatment.

by Ngar, Yuen-ngor. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 186-196). / Chapter Chapter 1 --- Introduction Page / Chapter 1.1 --- Sludge as a waste problem --- p.1 / Chapter 1.2 --- The degraded geological environment of Hong Kong --- p.2 / Chapter 1.3 --- Use of weathered granitic material and sand as planting media --- p.3 / Chapter 1.4 --- Need of soil improvement material --- p.4 / Chapter 1.5 --- Potential for land application of sewage sludge --- p.5 / Chapter 1.6 --- Objectives of study --- p.6 / Chapter 1.7 --- Significance of study --- p.6 / Chapter Chapter 2 --- Literature Review / Chapter 2.1 --- Soil organic amendment for vegetation establishment --- p.9 / Chapter 2.2 --- Types and properties of sewage sludge --- p.10 / Chapter 2.3 --- Guidelines for land application of sludge --- p.12 / Chapter 2.3.1 --- Cation exchange capacity --- p.13 / Chapter 2.3.2 --- Zinc equivalent concept --- p.14 / Chapter 2.4 --- Effects of sludge on soil chemical and physical properties --- p.15 / Chapter 2.4.1 --- Chemical properties --- p.15 / Chapter 2.4.2 --- Physical properties --- p.18 / Chapter 2.5 --- Effects of sludge application on vegetation --- p.19 / Chapter 2.5.1 --- Germination --- p.19 / Chapter 2.5.2 --- Grass growth --- p.20 / Chapter 2.6.1 --- Choice of heavy metals for study --- p.21 / Chapter 2.6.2 --- Factors governing heavy metal availability --- p.25 / Chapter 2.6.3 --- Effects of lime on sludge-amended soil and the heavy metal availability --- p.26 / Chapter 2.6.4 --- Assessing available sludge-borne heavy metals --- p.27 / Chapter Chapter 3 --- Germination and seedling growth of bermudagrass in sludge-amended sand and CDG / Chapter 3 .1 --- Introduction --- p.30 / Chapter 3.2 --- Experimental design --- p.31 / Chapter 3.3 --- Experimental results --- p.34 / Chapter 3.3.1 --- Seed germination --- p.34 / Chapter 3.3.2 --- Seedlings and biomass growth --- p.35 / Chapter 3.3.3 --- DTPA-Extractable heavy metals --- p.39 / Chapter 3.3.4 --- Total heavy metals in plant tissue --- p.44 / Chapter 3.3.5 --- Chemical properties of the soil substrates --- p.49 / Chapter 3.4 --- Discussion --- p.54 / Chapter 3.4.1 --- Germination --- p.54 / Chapter 3.4.2 --- Nutrient effect --- p.56 / Chapter 3.4.3 --- Heavy metal availability from substrates --- p.59 / Chapter 3.4.4 --- Heavy metal uptake by the seedlings --- p.61 / Chapter 3.4.4.1 --- Metal uptake efficiency --- p.61 / Chapter 3.4.4.2 --- Amount of heavy metal uptake --- p.63 / Chapter 3.4.5 --- Textural characteristics --- p.66 / Chapter 3.5 --- Conclusions --- p.67 / Chapter Chapter 4 --- Growth and heavy metal uptake by bermudagrass grown in sludge-amended substrates / Chapter 4.1 --- Introduction --- p.70 / Chapter 4.2 --- Experimental design --- p.71 / Chapter 4.3 --- Results --- p.74 / Chapter 4.3.1 --- Biomass growth --- p.74 / Chapter 4.3.2 --- Heavy metal content of plant tissues --- p.82 / Chapter 4.3.2.1 --- Heavy metal content of the shoot --- p.83 / Chapter 4.3.2.2 --- Heavy metal content of the root --- p.89 / Chapter 4.3.3 --- Comparing the heavy metal levels in the shoot and root portions --- p.93 / Chapter 4.3.4 --- DTPA-extractable heavy metal content in soil substrates --- p.94 / Chapter 4.3.5 --- Chemical properties of the substrates --- p.100 / Chapter 4.4 --- Discussion --- p.103 / Chapter 4.4.1 --- Shoot biomass (First clipping) --- p.104 / Chapter 4.4.2 --- Shoot biomass (Second clipping) --- p.105 / Chapter 4.4.3 --- Shoot biomass ratio between the two clippings --- p.107 / Chapter 4.4.4 --- Total shoot biomass --- p.108 / Chapter 4.4.5 --- Root biomass and root: shoot ratios --- p.112 / Chapter 4.4.5.1 --- Nutrient effect --- p.113 / Chapter 4.4.5.2 --- Heavy metal phytotoxicity --- p.115 / Chapter 4.4.6 --- Total biomass production --- p.117 / Chapter 4.5 --- Conclusions --- p.118 / Chapter Chapter 5 --- Effect of lime on the growth and heavy metal uptake of bermudagrass in sludge-amended substrates / Chapter 5.1 --- Introduction --- p.121 / Chapter 5.2 --- Experimental design --- p.123 / Chapter 5.3 --- Results --- p.125 / Chapter 5.3.1 --- Biomass growth --- p.126 / Chapter 5.3.2 --- DTPA-extractable heavy metals --- p.133 / Chapter 5.3.3 --- Heavy metal uptake by the shoot portion --- p.138 / Chapter 5.3.4 --- Heavy metal uptake by the root portion --- p.147 / Chapter 5.3.5 --- Comparing metal uptake between shoot and root portions --- p.151 / Chapter 5.3.6 --- Chemical properties of substrates --- p.155 / Chapter 5.4 --- Discussion --- p.157 / Chapter 5.4.1 --- Effect of sludge and lime treatments on pH --- p.158 / Chapter 5.4.2 --- Patterns of DTPA-extractable metals and plant uptake --- p.159 / Chapter 5.4.2.1 --- Variation of heavy metal levels with liming rates --- p.160 / Chapter 5.4.2.2 --- Variation of heavy metal levels with sludge loading rates --- p.161 / Chapter 5.4.2.3 --- Bermudagrass as metal accumulator --- p.162 / Chapter 5.4.3 --- Metal uptake by the root and shoot --- p.162 / Chapter 5.4.3.1 --- Antagonistic interactions --- p.163 / Chapter 5.4.3.2 --- Parititioning of heavy metals in shoot and root --- p.163 / Chapter 5.4.4 --- Poor biomass growth --- p.166 / Chapter 5.4.4.1 --- Heavy metal toxicity --- p.166 / Chapter 5.4.4.2 --- Effect of poor soil conditions --- p.167 / Chapter 5.5 --- Conclusions --- p.177 / Chapter Chapter 6 --- Conclusions / Chapter 6.1 --- Summary of findings --- p.179 / Chapter 6.2 --- Implications of the study --- p.180 / Chapter 6.3 --- Limitations --- p.182 / Chapter 6.4 --- Suggestions for further studies --- p.184 / References --- p.186 / Appendix

Thesis (MSc. Agriculture (Soil Science)) -- University of Limpopo, 2014 / Phospho-composts of different mix ratios (5:5, 7:3, 8:2 and 9:1) were produced through thermophilic co-composting of poultry manure (PM) and sewage sludge (SS) with ground phosphate rock (GPR). Composted PM and SS without GPR addition were included as control. Cured phospho-composts were chemically characterised and used for both laboratory incubation and greenhouse studies, respectively for phosphorus (P) mineralisation and bioavailability, over a period of 42 days. Results revealed that Bray-P1 concentration measured in compost amended soils at 14, 21 and 42 DAI differed significantly (P<0.05) and ranged between 5.47 and 11.14 mg kg-1 and between 5.28 and 11.78 mg kg-1 in poultry manure and sewage sludge-based phospho-composts, respectively. The maximum amount of cumulative P mineralised of 16.06 and 9.98 mg kg -1, respectively in PM and SS-based phospho-composts were obtained from the 8:2 mix ratio. The content of the acid detergent fibre of the different phospho-composts showed positive and significant correlation with cellulose, lignin and total organic carbon (TOC). Similarly, cellulose as well as C:P ratio showed significant correlation with both lignin and TOC. The polynomial relationship between cumulative P mineralised and the various GRP and manure mix ratios revealed significant and positive R2- values of 0.731 and 0.613 for PM and SS-based phospho-composts, respectively. The maximum amount of maize tissue P uptake of 0.12 and 0.11 mg pot-1 in PM and SS-based phospho-compost respectively were also obtained from the 8:2 mix ratio while the least amount of 0.04 mg P pot-1 was obtained from GPR and unamended pots. Maize tissue P uptake following the phospho-compost application was significantly affected by the differences in soil type. Tissue P uptake was 0.06 and 0.11 mg P/pot, respectively in low potential and high potential soils with a significantly higher value. The use of the different phospho-composts showed great potential for amelioration of P-deficiency problems in crops while thermophilic cocomposting improved the solubility and bioavailability of P from non-reactive GPR. Keywords: Ground phosphate rock; poultry manure; sewage sludge; phosphocomposts; phosphorus mineralisation; soil fertility management.

The deep row trenching of ventilated improved pit-latrine (VIP) and waste water treatment works (WWTW) sludge is a unique alternative cost effective land application method that will prevent odour and health problems and may permit higher application rates than surface application. The goal of this research is to assess the environmental consequences of employing deep row incorporation of VIP and WWTW sludge to forest plantation lands for the production of Eucalyptus dunnii. The objectives are to monitor, define and quantify the fluxes of nutrients (nitrate and phosphorus) from the buried sludge to the surrounding soils, groundwater and surface water. The WWTW study was conducted on a forestry plantation located near the Shafton Karkloof Falls, about 10 km from Howick in the KwaZulu-Natal province of South Africa. The land for the research is owned by SAPPI, a timber plantation company. The trenching was done with stockpiled secondary sludge from Umgeni WWTW in Howick. VIP sludge trenching was done at the Umlazi E-ponds site in Durban owned by EThekwini Municipality. This site was formally used as a wastewater treatment plant sludge drying bed. The treatment works comprised three oxidation ponds and was operated until 1999, when it was decommissioned after a heavy flood, resulting in damage to the oxidation ponds. The sites were instrumented with wetting front detectors, piezometers and boreholes for collection and analysis of leachate from which were determined subsurface loss of nitrogen and phosphorus. Soil water status and groundwater levels were also monitored. Simulation of the process of water, nitrate and phosphorus transport was performed in order to aid the development of the sustainable management methodologies for land application and the trenching of VIP/WWTW sludge. The study focuses on the entrenched sludge to determine the concentration of pollutants, monitorchanges in concentration over time and to monitor the movement of solutes and any change taking place in the surrounding soil water and groundwater. The results contribute to the development of guidelines and protocols for VIP/WWTW sludge handling and trenching in South Africa. It was demonstrated that the nutrient migration processes can be approximated with the conceptual simplifications of the inputs to the model based on field evidence, soil survey data and applicable literature. In the study, it was found that high concentrations of nutrients were evident in the water infiltrating into and through the sludge in all trench types. The nitrate concentration median values in the trenches were 234mg/l and 36mg/l for SAPPI and Umlazi respectively, while the recorded median value for phosphorus was 1.0mg/l and 3.5mg/l for SAPPI and Umlazi respectively. However the effect of vertical seepage of nutrients, into the deep aquifer in fractured rock has not been observed in the deep borehole with the nitrate concentration median values at 5mg/l and 0.6mg/l for SAPPI and Umlazi respectively, while the phosphorus concentration median values were 0.03mg/l and 0.15mg/l for SAPPI and Umlazi sites respectively. The study revealed significant differences between the sandy alluvial site at Umlazi and the shale dolorite site at the SAPPI forests. Where an unsaturated zone below the entrenched sludge existed at the Umlazi site, nutrient transport was retarded, whereas in the shales of the SAPPI site, preferential delivery flowpaths transported high concentrations of nutrients rapidly from the entrenched sludge to the base of the hillslope. These mechanisms needed to be treated differently in the simulation exercise. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Thesis (M.Sc. (Industrial Ecology and Environment))--Mahidol University, 2007. / LICL has E-Thesis 0023 ; please contact computer services.

No description available.

This study indicated that sewage sludge could be used as an alternative to commercial inorganic fertilizers. It is common practice in South Africa to use agricultural land for disposal of sewage sludge. The disposal of sludge must however be done in a responsible manner to avoid environmental pollution such as nitrate (NO3-) leaching. In South Africa strict guidelines exist regarding sludge disposal, and a maximum of 8 ton ha-1 year-1 (dry mass basis) sludge may be applied. This value was based on possible NO3- leaching, but no equivalent legislation exists for commercial fertilizer that could result in the same harmful effects. In this study the possible pollution hazard in terms of NO3- leaching from sewage sludge was investigated and compared to commercial fertilizer. An incubation trial was done to determine the mineralization rate of sludge and fertilizer. The rate at which inorganic N, NO3- and NH4+ was produced from sewage sludge was measured during this experiment. Sludge was applied at three different loads: 5, 10 and 20 ton dry ha-1. Commercial fertilizer was also applied on three different levels and each level was equivalent to 30% of the N content of the corresponding sludge treatments. It was found that in the sludge treatments the NH4+ levels immediately increased possibly due to microbial activity. The NH4+ levels reached a maximum on day 7, with a production rate of 14, 26 and 60 mg kg-1 NH4+ for the 5, 10 and 20 tondry ha-1 treatment, respectively. After day 7, the production rate decreased while the NO<sub3- production started increasing at the same rate at which the NH4+ levels decreased, as a result of nitrification. The 5, 10 and 20 tondry ha-1 did not show any increases in NO3- production initially, but production started increasing on day 7 and stabilized after 28 days. In the fertilizer treatments the NH4+ levels increased immediately after application. The levels decreased again due to nitrification. Unlike the sludge treatments, and immediate increase in NO3- production was observed. This is because of the inorganic nature of the applied fertilizer. The NO3- content increased over time, and at the same time the NH4+ content decreased. All the inorganic N from the fertilizer is immediately available, while the N in sludge must first be mineralized before the inorganic fraction becomes available. NO3- production from sludge is steady, and after day 28 the total NO3- production from sludge exceeds the total production from fertilizer. Even though more NO3- (mg kg-1) was produced from sludge, the distribution was different and could be utilized more effectively by plants. The risk of NO3- leaching from commercial fertilizer is therefore possibly more than the risk of NO3- leaching from sewage sludge applications. To correlate the above laboratory mineralization values to that of field conditions, a field trail was done. The potential leaching and the effect of plant uptake were also investigated. Two trials were done: one for winter and one for summer conditions. Each trial continued for three months, and soil samples were collected every two weeks on depths of 00-30 cm, 30-60 cm and 60-90 cm. For the winter trial, application levels of 4, 8 and 16 tondry ha-1 sludge were applied. Low mineralization rates and subsequently low NO3- and NH4+ levels were measured that could be attributed to low microbial activity. No NO3- leaching was detected. To obtain better results the application rates were adjusted to 20tondry ha-1 sludge and corresponding fertilizer treatments during the summer trial. Maize was used as a crop to measure the effect of plant uptake on NO3- leaching. No significant differences were obtained between the open blocks and the maize blocks. Significant leaching occurred under fertilizer treatments, but none under sludge treatments. Mineralization was also much slower in the field trial than in the laboratory trial, and after 90 days, there was still NH4+ production in the top horizons. A part of the organic N in sludge was lost through denitrification. These losses could reduce the available inorganic N and subsequently reduce the risk of NO3- leaching. An incubation study was done to measure the gaseous losses of N through N2O and N2. Gas samples were taken and measured on a gas chromatograph. Similar application rates that were used in the previous incubation study were applied, as well as different moisture contents. N2O production from sludge increased immediately after sludge application, after which the production rate steadily decreased until day 14. No significant differences were obtain between 50% and 100% moisture content, and very little N2O production was found from the fertilizer treatments. N kinetics were done on the data obtained from the incubation studies. These values indicate the rate at which sludge could be mineralized and the subsequent rate at which inorganic N, such as NO3- were produced. N balances were also drawn to indicate the quantity of organic N that is mineralized, as well as the change between different inorganic N fractions over time. This study compared the potential N pollution from sewage sludge and commercial fertilizer in agricultural soils. By using all the results mentioned above, a better idea on the dynamics of sewages sludge compared to commercial fertilizer could be obtained. This knowledge could assist to apply sludge as a fertilizer to achieve the maximum benefit from the N content in the sewage sludge, without detrimental environment impact such as groundwater contamination. / Dissertation (MSc)--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (MSc Agric (Pasture Science))--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted