The water quality of a stream affected by miningactivities was investigated on the basis of a mineralogical studyfor the related solids, and their subsequent changes weremonitored for a year, so as to clarify the impact of the acidmine drainage (AMD) to the stream. The mine-affected stream wasclassified into Ca–Mg and sulfate type, and the concentrations ofits major constituents ranged from tens to hundreds times higherthan those of the background stream. This was most likely due toacid-generating reactions involving the oxidation of sulfides inthe mineralized zone, and subsequent neutralizations involvingcalcite and chlorite as possible sources of Ca and Mg,respectively. This interpretation is consistent with thethermodynamic and mass-balance calculations. The concentrationsof the dissolved constituents changed seasonally, dependinglargely on rainfall in the mine-affected stream. However, thedramatic decrease in the ratio of Mg/Ca, independent of rainfall,indicates that some changes did occur in sources, including theheterogeneous distribution of main source materials, the changein chemical conditions, especially in pH, pe(Eh), and PCO ₂,in the reacting fluid, and the consequential solubility changesin sources. In spite of the limitations of short-term monitoring,it does provide some meaningful information in order to constructa long-term monitoring program.

The starch manufacturing industrial units, such as sago mills,both in medium and large scale, suffer from inadequate treatment and disposal problems due to high concentration of suspended solids present in the sludge. A laboratory scale study was conducted to investigate the viability of anaerobic treatment of sago waste sludge, enriched in particulate organicmatter, using a fluidized bed reactor. The start-up of the reactor was carried out using a mixture of digested supernatantsewage sludge and cow dung slurry in different proportions. The effect of operating variables such as COD of the effluent, bed expansion, minimum fluidization velocity on efficiency oftreatment and recovery of biogas was investigated. The maximum efficiency of treatment was found to be 82% and the nitrogen enriched digested sludge was recommended for agricultural use. A kinetic model was developed for the degradation of particulate organic matter using the general kinetic equation [dS/dt = K HC SXC] which allowed for a more accurate mathematical representation of the hydrolysis process. Analysing data from a series of batch tests, the best fit value of C was found to be in the range 0.43 to 0.62.

Although confined animal production generates enormous per-unit-area quantities of waste, wastewater from dairy and swine operations has been successfully treated in constructed wetlands. However, solids removal prior to wetland treatment is essential for long-term functionality. Plants are an integral part of wetlands; cattails and bulrushes are commonly used in constructed wetlands for nutrient uptake, surface area, and oxygen transport to sediment. Improved oxidation and nitrification may also be obtained by the use of the open water of marsh-pond-marsh designed wetlands. Wetlands normally have sufficient denitrifying population to produce enzymes, carbon to provide microbial energy, and anaerobic conditions to promote denitrification. However, the anaerobic conditions of wetland sediments limit the rate of nitrification. Thus, denitrification of animal wastewaters in wetlands is generally nitrate-limited. Wetlands are also helpful in reducing pathogen microorganisms. On the other hand, phosphorus removal is somewhat limited by the anaerobic conditions of wetlands. Therefore, when very high mass removals of nitrogen and phosphorus are required, pre- or in-wetland procedures that promote oxidation are needed to increase treatment efficiency. Such procedures offer potential for enhanced constructed wetland treatment of animal wastewater.