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Reducing pulpmill effluent toxicity
Volume21/Number 1/January 1990 mature otters to San Nicolas this year, with the hope that the otters will raise young there. They are hoping that pups weaned at the island will consider it home. After assessment of the success of this year's operations, the scientists will decide whether to continue the project.
Reducing Pulpmill Effluent Toxicity The Western Forest Products Ltd. Pulpmill at Woodfibre on Howe Sound, British Columbia, has launched a pilot project costing nearly $1 million to reduce the toxicity of its effluent by accelerated biological treatment. This is one of the two Howe Sound pulpmills in the vicinity of which the fisheries for crabs, prawns, and shrimps were closed indefinitely on 30 November, 1988 owing to the high levels of dioxins in those crustaceans. The pulpmills at Woodfibre, because it is hemmed in by the sea in front and the mountains behind, has limited space for treatment facilities, such as a biological treatment pond. Therefore, a system of intensive treatment in a confined area is needed. The pilot project involves the use of 'turbocharged' micro-organisms to digest contaminants in the pulpmill effluent. The microorganisms, similar to those that occur naturally, are combined in one tank with pure oxygen and in another with air. Temperature, nutrients, pH, oxygen and air levels and contact time are all controlled, allowing the micro-organisms to consume various contaminants in the mill effluent faster than they would under uncontrolled natural conditions. A similar treatment process has been used by various pulpmills in the USA. It has been found to reduce biodegradable organic matter by 90%, toxic compounds such as resin acids by 100%, and chlorinated organics by 30-50%. Reduction of dioxins and furans, however, can only be achieved through substitution for the chlorine used in bleaching with another agent such as chlorine dioxide or oxygen. The pilot project is intended to determine whether pure oxygen or air would be most effective in reducing pollution from the pulpmill. At present, it processes about 1% of the mill's effluent. When scaled up to full production, it will cost $50 million to build and $2 million per year to operate. It will be part of the $70 million pollution abatement programme being carried out by the mill, which is expected to be ready by 31 December 1992. M. W A L D I C H U K
Destruction of Dioxins in Pulpmill Boilers A Canadian federal-provincial study suggests that pulpmill boilers are capable of destroying dioxins in dioxincontaminated wood waste, which is burned in pulpmills to produce power. Some of the wood may sometimes contain chlorophenols used for treating lumber against mould fungi and sapstain. Chlorophenol wood preserv-
atives may also be contaminated with dioxins and furans. Temperatures in pulpmill boilers exceed 900°C. Tests were conducted at the Northwood Pulpmill in Prince George, British Columbia. The test burn used the same chlorophenol solutions that sawmills use on lumber. About 12 I. were put into the burner during the first test and 60 1. in the second. The boiler destroyed more than 99.99% of the chlorophenols. It also destroyed the dioxins and furans. Laboratory tests showed that the dioxins were just above the limit of detection. M. W A L D I C H U K
High Mercury Level in Dead Whale A killer whale, Orcinus orca, found dead on Long Beach on the west coast of Vancouver Island in April 1989, exhibited 1 272 ppm mercury in its liver. This animal was 15 or 16 yr old when it died apparently of an intestinal infection. It was known to scientists as L-14, a member of the L-pod, which migrates between Campbell River, British Columbia, and Puget Sound, Washington. There are known to be about 350 killer whales in a number of distinctive pods in coastal waters of British Columbia. The reason for the high mercury concentration in the liver of this animal is unknown. It was almost double the previous mercury level record found in a false killer whale beached on the British Coast in 1988. The high mercury level in the killer whale, determined by a provincial veterinary laboratory in Abbotsford, British Columbia, was reported on 2 October 1989 by Pare Steacy of the Stranded Whale and Dolphin Programme of British Columbia. M. W A L D I C H U K
Round-the-World News Taiwan A recent report by the Taiwanese Council of Economic Planning and Development (CEPD) attributes the problem of land subsidence to increasing activity by the island's fish and shrimp farmers. According to the CPD report, land in the Taipei basin has sunk by at least 2.2 m in the last 30 years and is continuing to sink at an annual rate of 2-3 cm. In other areas of Taiwan even greater rates of sinkage are reported. This subsidence has been attributed to the large increase in number of wells drilled (more than 2000 in the last 10 yr). Seventy percent of water from the island's wells is used for pond culture by fish and shrimp farmers. Although drilling of new wells is illegal it is apparently still on the increase. In a recent case, the government is faced with spending US $58 million in an effort to drain seawater from a 300 ha site which flooded after subsidence due to illegal well drilling.
Reducing Pulpmill Effluent Toxicity The Western Forest Products Ltd. Pulpmill at Woodfibre on Howe Sound, British Columbia, has launched a pilot project costing nearly $1 million to reduce the toxicity of its effluent by accelerated biological treatment. This is one of the two Howe Sound pulpmills in the vicinity of which the fisheries for crabs, prawns, and shrimps were closed indefinitely on 30 November, 1988 owing to the high levels of dioxins in those crustaceans. The pulpmills at Woodfibre, because it is hemmed in by the sea in front and the mountains behind, has limited space for treatment facilities, such as a biological treatment pond. Therefore, a system of intensive treatment in a confined area is needed. The pilot project involves the use of 'turbocharged' micro-organisms to digest contaminants in the pulpmill effluent. The microorganisms, similar to those that occur naturally, are combined in one tank with pure oxygen and in another with air. Temperature, nutrients, pH, oxygen and air levels and contact time are all controlled, allowing the micro-organisms to consume various contaminants in the mill effluent faster than they would under uncontrolled natural conditions. A similar treatment process has been used by various pulpmills in the USA. It has been found to reduce biodegradable organic matter by 90%, toxic compounds such as resin acids by 100%, and chlorinated organics by 30-50%. Reduction of dioxins and furans, however, can only be achieved through substitution for the chlorine used in bleaching with another agent such as chlorine dioxide or oxygen. The pilot project is intended to determine whether pure oxygen or air would be most effective in reducing pollution from the pulpmill. At present, it processes about 1% of the mill's effluent. When scaled up to full production, it will cost $50 million to build and $2 million per year to operate. It will be part of the $70 million pollution abatement programme being carried out by the mill, which is expected to be ready by 31 December 1992. M. W A L D I C H U K
Destruction of Dioxins in Pulpmill Boilers A Canadian federal-provincial study suggests that pulpmill boilers are capable of destroying dioxins in dioxincontaminated wood waste, which is burned in pulpmills to produce power. Some of the wood may sometimes contain chlorophenols used for treating lumber against mould fungi and sapstain. Chlorophenol wood preserv-
atives may also be contaminated with dioxins and furans. Temperatures in pulpmill boilers exceed 900°C. Tests were conducted at the Northwood Pulpmill in Prince George, British Columbia. The test burn used the same chlorophenol solutions that sawmills use on lumber. About 12 I. were put into the burner during the first test and 60 1. in the second. The boiler destroyed more than 99.99% of the chlorophenols. It also destroyed the dioxins and furans. Laboratory tests showed that the dioxins were just above the limit of detection. M. W A L D I C H U K
High Mercury Level in Dead Whale A killer whale, Orcinus orca, found dead on Long Beach on the west coast of Vancouver Island in April 1989, exhibited 1 272 ppm mercury in its liver. This animal was 15 or 16 yr old when it died apparently of an intestinal infection. It was known to scientists as L-14, a member of the L-pod, which migrates between Campbell River, British Columbia, and Puget Sound, Washington. There are known to be about 350 killer whales in a number of distinctive pods in coastal waters of British Columbia. The reason for the high mercury concentration in the liver of this animal is unknown. It was almost double the previous mercury level record found in a false killer whale beached on the British Coast in 1988. The high mercury level in the killer whale, determined by a provincial veterinary laboratory in Abbotsford, British Columbia, was reported on 2 October 1989 by Pare Steacy of the Stranded Whale and Dolphin Programme of British Columbia. M. W A L D I C H U K
Round-the-World News Taiwan A recent report by the Taiwanese Council of Economic Planning and Development (CEPD) attributes the problem of land subsidence to increasing activity by the island's fish and shrimp farmers. According to the CPD report, land in the Taipei basin has sunk by at least 2.2 m in the last 30 years and is continuing to sink at an annual rate of 2-3 cm. In other areas of Taiwan even greater rates of sinkage are reported. This subsidence has been attributed to the large increase in number of wells drilled (more than 2000 in the last 10 yr). Seventy percent of water from the island's wells is used for pond culture by fish and shrimp farmers. Although drilling of new wells is illegal it is apparently still on the increase. In a recent case, the government is faced with spending US $58 million in an effort to drain seawater from a 300 ha site which flooded after subsidence due to illegal well drilling.