Laguna de Bay is the largest freshwater body in the Philippines with multiple-use. The primary use of the lake is to serve as the future domestic water supply at Metro Manila. The biota of the lake consists of 25 species of fish, 24 species of zooplankton, two species of shrimps, 6 species of mollusks, 42 species of aquatic macrophytes and 154 species of algae. A total of 60 mesophilic anaerobic and facultative anaereobic bacteria and 453 bacterial strains belonging to 22 genera have been identified. A review of 12 papers dealing with biological studies on Laguna de Bay in relation to aquatic pollution is presented. Studies on the impact of heavy metal, pesticide and thermal pollution on the biota of the lake have been sporadic and cursory. There is need for a more comprehensive and systematic monitoring of the lake's pollutants to provide time-series for pollution abatement

A series of experiments on biological nutrient removal using suspended growth bioreactor with a various reactor configuration have been conducted during the last five years. The first configuration applied a contact stabilization flowed by a denitrification processes in two sludge system. The two sludge systems mean that the aerobic sludge is recirculated in the aerobic circuit, and the anaerobic sludge is recirculated in the anaerobic circuit. The second configuration was conducted in a contact stabilization and denitrification processes in a one sludge system. The one sludge system meant that there are no separation between aerobic and anaerobic sludge; the aerobic and anaerobic processes are in the same circuit and all sludge are recirculated in the same circuit. The third configuration was performed in anaerobic-aerobic-anaerobic reactors and ended by the clarifier to clarify the biosludge before recirculated to the head of the circuit. This configuration was also using a one sludge system. In those three configurations, the hydraulic detention time in the reactors were varied from 2 to 6 hours, and the sludge age from 2 to 15 days. The results showed that the first configuration gave a very high performance in carbon and nitrogen removal. In terms of TOC [total oxygen concentration], the carbon removal achieved up to 92 percent or in terms of total COD [carbon oxygen demand] up to 80 percent, and 97 percent for total nitrogen removal. On the other hand, the phosphorus removal was only limited to the amount required for cells metabolism. More carbon removal were observed in the second configuration (94 percent of total COD) but less total nitrogen were removed (93), however, phosphorus were removed significantly (up to five times of the cells metabolism requirement). The best results in those three nutrients removal was achieved in the third configuration. No less than 95 percent of total COD and 96 percent of nitrogen removal were noticed, and phosphorus were removed at the level of more than six times of the cells metabolism requirement. The experiments concluded that the phosphorus removal was conducted by the aerobic microorganisms which are alternately treated in aerobic-anaerobic conditions. The degree of removal depended on how long the microorganisms were put in the aerobic and anerobic conditions. If the anaerobic condition was too long, the microorganisms would die, and no phosphorus removal took place. If it was too short, the removal would be less. For carbon and nitrogen removals in the system, the hydraulic detention time in the reactors and sludge appeared as the essential parameters in the process

Technology options involving the use of natural and accelerated bioremediation systems to treat complex mixtures of aromatic wastes would be a useful addition to current remediation strategies. The approach outlined in this paper would focus on harnessing the potential of a key detoxification enzyme, glutathione-S-transferase (GST) as part of an accelerated phytoremediation system to detoxify aromatic pollutants in soil and ground water. Major efforts will include the clarification of GST detoxification activity by characterizing the enzyme in a series of phenolic and azo-dye-tolerant phytoremediation candidates (e.g. elite clones of thyme), and the development of methods to manipulate the GST detoxification pathway in elite plant clones to accelerate the detoxification of aromatic pollutants. The information provided by the GST characterization studies could be used to develop significant new phytoremediation systems based on manipulated GST biotransformation pathways in elite plant clonal systems tolerant to highly polluted environments. One major advantage of the new phytoremediation systems would be their potential to perform in highly contaminated environments by providing a favorable rhizophere zone for microbial degradation of aromatics along with an enhanced GST-linked detoxification pathway

Macro-porous cellulose carrier (AQUACEL) was applied for immobilization of denitrifying bacteria to develop a practical nitrogen removal system with high performance. When the immobilized cell was applied to denitrification under high nitrogen loading rate, flotation of carriers caused by the evolution of nitrogen gas resulted. To counter the problem of carrier flotation, new reactors using hydrodynamic jet flow and centrifugal force were developed. These new reactors distributed homogeneously the floating carriers, and complete denitrification was obtained even at high loading rate of 20 kg N/cu m-carrier/d. This AQUACEL system was effectively applied to denitrification of wastewater discharged from an eletroplating factory

Wood cores were taken at breast height of mature sugar maple (Acer Saccharum Marsh.) trees of approximately the same age from four sites in Ontario, Canada differing in soil characteristics and general tree health. The soils of two of the sites were acidic (podzols), while the soils of the other two sites were calcareous (brunisols). Selected elemental analyses using Neutron Activation Analysis were conducted on the soils and the xylem wood of the sugar maple trees, and the results were compared relative to tree health. Aluminum in stem xylem was found to be significantly higher in declining trees (mean 7.7 ppm) relative to the healthy trees (mean 4.0) from the acidic sites, where aluminum was freely available in the soil. Soil extractable aluminum was also significantly higher in the soil adjacent to the declining trees (mean 5.10) compared to the healthy trees (mean 3.20). These results show that xylem aluminum contents reflect the increased availability of aluminum in acidifying soils and provide additional evidence that dendrochemistry may be used as a proxy environmental monitoring tool.

A field study was performed on the effects of acid mine leachate from slate mine tailings seeping into a small river passing through the tailings. Before entering the tailings the river water has high alkalinity which neutralizes acidity upon mixing with leachate within the tailings. Donwstreams of the tailings the pH of the river water ranges about pH = 8, the water contains high concentrations of sulfate (≈1500 μmol/1 and particulate bound aluminium (≈80 μmol/I), but low concentrations of dissolved aluminium (≈3 μmol/1). It is therefore assumed that AI(OH)₃ colloids are precipitated during the neutralisation process and transported out of the tailings. The concentration of particulate bound aluminium along the river shows a strong correlation with the concentration of sulfate, which indicates that particulate bound aluminium is conservative. It therefore seems that under dry weather conditions (under most of the sampling was performed) no chemical retention mechanism exists which confines the distribution of aluminium to a restricted part of the catchment area. In contrast, the white river sediment is rich in both aluminium and sulfate, which suggests the temporary formation of aluminium hydroxosulfate minerals. Favorable (i.e. acidic) conditions may prevail at high discharges where the acidity accumulated in the tailings is flushed into the river with its subsequent acidification.

Allium test has already been used to determine cytotoxicity of waste drilling fluids. In the present work the cytotoxicity of four pure chemicals (Defoamex, Idthin 400, Magco Thin and Slick Pipe) was investigated. Those chemicals are components of drilling fluids, therefore, they are usually constituents of oil and gas industry waste waters. The tested chemicals were prepared in 1:9 dilution and cytotoxic effects on root-tip meristem ofAllium ascalonicum were analysed after 24-, 48- and 72-hour-treatments. All samples showed cytotoxicity which was proved by cytogenetic parameters such as inhibition of mitotic activity and increase of mitotic abnormalities and chromosomal aberrations in comparison with the control. Almost all mitotic abnormalities induced by four chemicals tested were the result of disturbed spindle mechanisms accompanied with stickiness. Slick Pipe revealed the most prominent mitodepressive effect and induced a high number of abnormalities. It caused a significant decrease of mitotic activity and increase of mitotic abnormalities after all three treatment durations, while chemicals Defoamex and Magco Thin showed a significant decrease of mitotic activity only after 72-hour-treatment. Chemicals Defoamex, Idthin 400 and Magco Thin revealed a significant increase of mitotic abnormalities after 48- and 72-hour-treatments.