有害物質に関する一律排水基準 2001 02 79

 有害物質に関する一律排水基準

「公共下水道や流域下水における下水処理方法」は、有機物の除去を主体とする微生物利用の浄化法が中心で、それ以外の有害化学物質などの多くは処理しきれないことが多い。そのため「下水道法」では、工場や事業所などから排出される産業排水のうち、終末処理場で処理できない物質については、終末処理場の放流水の水質基準とほぼ同等の基準にしてから下水に排水することと定めている。

環境に著しく悪影響を及ぼす物質について「一律基準」を設けている「水質汚濁防止法」は、1970年の制定以来、新たな規制物質の追加、それに伴う特定施設の範囲拡大など年々強化されてきた。企業側としても、近年の工業用水の逼迫や地盤沈下防止のための地下水取水制限、総量規制に伴う放流水量制限などに対応する動きが活発化している。今までは放流水基準値に処理するだけだったものを、さらに脱塩などの高度処理を施し、排水を回収再利用するといった動きが出てきた。結果的に排水や排水中の有価物を再利用することで経費の削減にもつながり、ISO14001に基づく環境マネジメントシステムの一環としても取り組みが進んでいる。

「産業排水に対する規制」は今後も益々強化されることは間違いない。これまで規制対象外だった物質の中には環境ホルモンの疑いのあるものもあり、今後、生物への影響の因果関係が解明されるにつれ、その対応に迫られることになる。

「一律排水基準」

これまで水質汚濁防止法における指定有害物質以外に関する排水規制の対象外だった1日平均排水量が立方メートル未満の小規模事業場。こうした小規模事業は全国の事業所の9割を占め、未処理のまま河川などに放流される排水は大きな問題となっている。しかし近年、すべての都道府県が国の基準よりも厳しい「上乗せ基準」を設けるなど規制強化の方向で進んでいる。2000年10月には中央審議会水質部会排水規制等専門委員会において、フッ素、ホウ素、硝酸・亜硝酸性窒素などの有害物質についての排水基準が定まった。環境省では関連政令を改正して01年春にも施行する意向だ。

「第5次総量規制」

広域的な閉鎖性水域の水質改善を図るためには、その水域に流入する汚濁負荷量の総量を効果的に削減することが重要である。そのため78年の水質汚濁防止法の改正において水質総量規制制度が設けられた。従来の排水規制だけでは環境基準を維持達成することが困難な東京湾・伊勢湾・瀬戸内海を指定水域とし、1979年以来、COD（化学的酸素要求量）を指定項目として、83年度、88年度、93年度、98年度を目標年度とする総量規制が4次にわたって総量規制を実施してきた。環境省の99年度公共用水域水質測定結果でも、カドミウムやシアンなどの有害物質を対象とした健康項目の環境基準達成率は99.5％と、産業部門での排水処理はかなり進んでいるといえる。

しかしCODのみならず窒素・リンの環境基準の達成率」は低く、富栄養化による赤潮などが頻発しているのが現状だ。2000年10月、中央環境審議会水質部会は、この3海域の関係都道府県が独自に決める規制値の目安となる排水濃度基準の範囲を、下水道業や肥料製造業など232業種ごとに定めた答申をまとめた。

この答申は、第5次水質総量規制の目標年次である2004年度までに、新たに窒素・リンを総量規制の対象に加えるとともに、CODについてもパルプ、石油化学、発酵工業などで規制基準を強化するように求めている。答申を受けて環境省は基準範囲を告示する予定で、都道府県が実際に規制を始めるのは2001年度になる見通し。

Uniform effluent standards for hazardous substances 2001 02 79

 Uniform effluent standards for hazardous substances

Sewage treatment methods in public sewage systems and watershed sewage systems" are mainly microorganism-based purification methods that mainly remove organic matter, and many other hazardous chemicals and other substances cannot be treated. For this reason, the Sewerage Law stipulates that industrial wastewater discharged from factories and business establishments that cannot be treated at a final treatment plant must be discharged into the sewage system after being made almost equivalent to the water quality standards of the effluent from the final treatment plant.

Since its enactment in 1970, the Water Pollution Control Law, which sets "uniform standards" for substances that have a significant adverse impact on the environment, has been strengthened year by year through the addition of new regulated substances and the accompanying expansion of the scope of specified facilities. Companies are also increasingly responding to the recent tightness of industrial water supplies, groundwater withdrawal restrictions to prevent land subsidence, and restrictions on the amount of water discharged in accordance with total volume control regulations. What used to be a matter of simply treating wastewater to standard effluent levels is now being replaced by the use of advanced treatment, such as desalinization, to recover and reuse wastewater. As a result, the reuse of wastewater and valuable resources in wastewater has led to cost reductions, and efforts are being made as part of an environmental management system based on ISO 14001.

Regulations on industrial wastewater will no doubt continue to be tightened in the future. Some substances that have not been subject to regulation so far are suspected of being environmental hormones, and as the cause-and-effect relationship of their effects on living organisms is clarified, we will be forced to deal with them in the future.

Uniform Effluent Standards

Small-scale businesses with an average daily wastewater discharge of less than one cubic meter have been exempted from the effluent regulations for non-designated hazardous substances under the Water Pollution Control Law. Such small-scale operations account for 90% of all business establishments in Japan, and untreated wastewater discharged into rivers and other bodies of water has become a major problem. In October 2000, the Special Committee on Wastewater Regulations of the Water Quality Subcommittee of the Central Council established effluent standards for fluorine, boron, nitric acid, nitrite nitrogen, and other toxic substances. The Ministry of the Environment intends to revise the related Cabinet Order and put it into effect in the spring of 2001.

The Fifth Total Emission Regulation

In order to improve the water quality of a wide-area closed water body, it is important to effectively reduce the total amount of pollution load flowing into the water body. For this reason, the 1978 revision of the Water Pollution Control Law established a system of total quantity control of water quality. Since 1979, the total volume control has been implemented four times with COD (chemical oxygen demand) as the designated item and target years of FY83, FY88, FY93, and FY98 as the total volume control. According to the Ministry of the Environment's FY99 public water quality measurement results, the achievement rate of environmental standards for health items targeting cadmium, cyanide, and other toxic substances was 99.5%, indicating that wastewater treatment in the industrial sector has made considerable progress.

In October 2000, the Water Quality Subcommittee of the Central Environment Council issued a report that established a range of effluent concentration standards for each of 232 industries, including the sewerage and fertilizer manufacturing industries, to serve as a guideline for the regulatory values to be determined independently by the prefectures concerned in these three ocean areas. The report was compiled for each of the 232 industries, including the sewage and fertilizer manufacturing industries.

The report calls for the addition of nitrogen and phosphorus to the total volume control by 2004, the target year for the fifth round of water quality total volume control, as well as the strengthening of control standards for COD in the pulp, petrochemical, and fermentation industries. In response to the report, the Ministry of the Environment plans to issue a public notice on the scope of the standards, and it is expected that prefectures will actually begin regulating in FY2001.

Food Waste Recycling and Disposal Act 2001 02 79

 

The 147th Diet session passed the Law for Promotion of Recycling of Food Waste (Food Recycling Law), and preparations are currently underway for its enforcement in April 2001.

Food-related businesses, which are required to reduce the amount of waste they process by 20%, are taking measures such as removing and sorting foreign substances, reviewing food procurement and cooking methods, and installing food waste disposers or outsourcing to recycling companies. The 20% reduction can be achieved not only by recycling, but also by dehydration and shredding. Therefore, it is certain that not a small number of businesses will choose this practical method due to cost considerations, but it is clear that business opportunities have been created for food waste recycling.

As for general waste from business operations, which has an extremely low recycling rate among food wastes, there has not been much progress in technological development and there are almost no recycling facilities. In preparation for the enforcement of the law, there is an urgent need to develop recycling facilities and businesses for business-related general waste generated by supermarkets, convenience stores, and the food service industry.

Under these circumstances, the establishment of food waste recycling systems has already begun in various places, and in conjunction with this, the launch of recycling businesses, technological development, and market introduction are also gaining momentum. At present, the recycling methods envisioned include composting, feed conversion, and biogas conversion. Currently, however, related businesses, whether equipment or reclamation projects, tend to concentrate on composting. In order to recycle the approximately 20 million tons of food waste generated annually, composting alone will naturally lead to an oversupply, and demand will vary throughout the year, depending on the timing of fertilizer application. In terms of business, competition is expected to intensify.

Therefore, there are high expectations for the future development of the business and for the recycling of resources in the feed industry. The effective use of food waste is, of course, also promising, as it is consistent with the government's goal of increasing self-sufficiency, a goal that has been promoted by the government for some time but which has not progressed very far.

Use in Swine Feed

Until recently, it was commonplace to use leftover food scraps as animal feed. This is especially true in pig farming, or what is called "leftover pig farming. Livestock farmers and others collected processed agricultural products, expired foods, and other urban garbage as raw materials for concentrated feed, which they mixed themselves and fed to their pigs. However, around the 1960s, feed manufacturers and agricultural cooperatives began selling formula feed made from corn and soybean meal imported from overseas. In addition, the development of large-scale pig farming operations in conjunction with the increase in consumption of livestock products and the retreat of pig farming operations from urban areas further reduced the use of urban kitchen waste in pig farming operations. Another major factor was the switch to formula feed to save labor due to the aging of workers and other factors.

According to a survey of livestock production conducted by the Ministry of Agriculture, Forestry and Fisheries, the amount of leftover feed per fattening pig decreased from 205.9 kg/year in 1965 to 82.6 kg/year in 1980 and 6.2 kg/year in 1997. Currently, there are approximately 12,500 pig farmers in Japan with approximately 9.9 million head of pigs, but only about 1,000 pig farmers feed their pigs with leftover food, and the number of pigs they feed is about 200,000 head of pigs.

On the other hand, however, food manufacturing by-products such as fish intestine bones, rape seed meal, shochu shochu lees, and squeezed fruit juice lees, which are easily processed in large quantities and of stable freshness and quality, are being processed and used as ingredients for compound feed, and as of 1996, 1.04 million tons had been converted into feed.

As of 1996, 1.04 million tons had been converted to feed. In reality, imported feedstuffs are currently cheaper and of more stable quality. However, it is difficult to imagine that the current feed prices, which are said to be the lowest in the market, will continue at this level. The world has long reached the limit of its ability to increase food production through improvements in agricultural technology, and per capita grain production has been declining by more than 1% every year since its peak in 1984. China has also become a grain-importing country as its meat consumption has increased due to improved living standards. In addition, the effects of abnormal weather conditions worldwide have made agricultural production increasingly unstable.

In addition, Japan's grain self-sufficiency rate is 28%, which is extremely low compared to most countries with populations over 100 million, where the rate exceeds 80%. Despite this, the amount of food waste is one of the highest in the world. Under these circumstances, when the food industry, including production and distribution, takes the opportunity of the Food Recycling Law to seek recycling, the direction of feed conversion will come into focus, not only for industrial waste, but also for general waste from business operations.

Half of all waste can be used.

How much of the food waste can be used as feedstock? According to a trial conducted by the Hokkaido Livestock Experiment Station, "Feed intake, carcass weight, and carcass yield were comparable to those of formula feeds even when 15-30% of the feed was substituted for the formula feed. However, increasing the substitution rate tended to decrease fat brightness, increase the percentage of unsaturated fatty acids, and decrease the melting point. The test results showed that "20% substitution of formula feed is possible in the pre- and mid-fattening period, but in the late fattening period, the substitution rate should be limited to 10% so that the crude fat content of the feed is less than 5%, which is considered a guideline to prevent soft fat pigs from occurring. In other words, based on the high fat content in the feed as a guide, it appears that a 10-20% substitution ratio is possible, although it will vary depending on the stage of growth.

Currently, the annual production of compound feed for swine in Japan is about 6.2 million tons. The main raw materials are corn (2.9 million tons), milo (about 1.1 million tons), and soybean meal (870,000 tons). On the other hand, business-related waste covered by the Food Recycling Law amounts to 6 million tons of general business waste and 3.4 million tons of industrial waste. If all of this were dried and processed, roughly one-fifth, if not impossible, 620,000 tons could be utilized with a 10% blend, and 1.4 million tons with a 20% blend. This figure should be enough to cover the 20% reduction target of the Food Recycling Law.

Dry or Liquid?

There are two major methods of converting food waste into feed. One is the dry method, in which food waste is dried by dry heat or hot water dehydration, and the other is the liquid method, in which food waste is processed in a wet process.

One is the dry feeding method, in which food is dried. The other is the liquid feeding method.

The dry feeding method requires drying, but is relatively easy to transport and store. On the other hand, the liquid feeding method is used in Europe, where a large amount of whey is produced by the dairy industry. There is no cost for drying, but in Japan, where summer temperatures are high, it is necessary to be careful about sanitary control of the vip and feed adjustment layer. Not limited to feed made from food waste, many pig farms in Japan are currently adopting dry feeding systems, and the dry feeding system seems to be more flexible when transportation costs and other factors are taken into account.

For example, Sanzo Organic Recycling built a food waste recycling plant in the Sapporo City Recycling Complex, and since January 1997, under the guidance of the Sapporo City (Mayor: Mr. Nobuo Katsura) Cleaning Department, has been recycling food waste from schools, hotels, restaurants, food processing plants, and other businesses in the city, supplied by the Sapporo City Environmental Service Corporation. The plant is a "oil-temperature, reduced-pressure, and high-temperature" recycling plant.

The plant uses the "oil-temperature decompression dehydration method," which uses the same principle as deep-frying tempura to dehydrate and dry food waste in a sealed, decompressed container. 35 tons of commercial food waste is processed in 10 hours per day, and 7 tons of feed and fertilizer materials are produced per day. After conducting various suitability tests for use as livestock feed, the plant submitted an application to the Distribution and Feed Division of the Livestock Bureau of the Ministry of Agriculture, Forestry, and Fisheries in February 1999, and was approved for provisional values as a feed compounding material. Currently, the company is developing sales of feed compounding materials to feed consumers through compound feed manufacturers, and is also strengthening sales of plants.

Okadora (Yokohama City), an environmental equipment manufacturer, has developed equipment that boils and dries food waste and converts it into animal feed. The company claims that the system can reduce both construction and operating costs by less than half compared to conventional systems by making the drying process more efficient. Construction costs range from 10 to 20 million yen per ton of daily processing volume. The running cost for processing one ton of raw garbage is estimated at 4,000 to 5,000 yen.

In addition, the company plans to develop a distribution network for food waste feed in cooperation with trading companies and feed companies. The food waste is dried in a proprietary boiling dryer, reduced to one-fifth to one-tenth its original weight, and after foreign matter is removed, the food waste is sterilized at high temperatures and the fats and oils are removed in a degreaser before being converted into animal feed. The feed conversion equipment is marketed to supermarkets, restaurants, and other businesses that generate large volumes of food waste. On the other hand, the company intends to sell only the boiling dryer to small-lot customers, including the establishment of a recycling system that takes back the dried products and converts them into feed in bulk.

Building a system through a cooperative

However, as with composting, there are of course many obstacles to overcome when considering feed conversion as a business. In particular, when looking at commercial food waste, there are the issues of sorting out foreign matter and salt, which affect the quality of the feed; ensuring collection volume and lot control; and quality control to comply with the Feed Safety Law. In addition, although the taste of pigs is good, they may receive a low rating. It is difficult for food-related businesses and pig producers, many of which are small to medium in size, to establish their own independent systems.

Therefore, there is a movement to establish a feed conversion system by forming a cooperative. The National Food Recycling Cooperative Association (Nagoya City, Aichi Prefecture) has been working on this concept for the past five years, and it is expected to be realized in FY2001.

The food recycling business conducted by the cooperative is shown in Table 1. In the "flow of things," recyclable food resources are discharged by the discharging company and converted into animal feed at a food recycling plant. The feed then passes through a pig farmer and a food processing company, and finally returns to the emitter in the form of meat. In terms of the "flow of money," the waste-producing companies pay the processing consignment fee, which is then used to convert the waste into animal feed at the food recycling plant. The resulting feed is then supplied to the pig farmer, and the pork produced is returned to the emitting company in the same manner as contract farming. In that case, they are still required to pay for the purchase of meat, but they are provided with pork that is better quality, cheaper, and safer than conventional ones.

In other words, the concept is to create a company with all the parties involved, and to create a recycling system that balances supply and demand and eliminates waste in distribution, sales, and other expenses within the company established by all the parties. As a result of a demonstration test conducted in 1999 with assistance from the Ministry of Agriculture, Forestry and Fisheries (MAFF), we have achieved a certain level of prospect in evaluating the functionality and reliability of the overall system and the quality of recycling. The first bilot model of a practical plant by a PFI corporation is scheduled to be installed in Nagoya in FY2001.

食品廃棄物のリサイクル処理法 2001 02 79

 

「第147回国会」において「食品循環資源の再利用等の促進に関する法律（食品リサイクル法）」が成立し、2001年4月の施行に向けて現在、準備が進められている。

処理量削減目標20％が課せられた食品関連事業者では、異物の除去や分別、食材調達の見直しや調理の工夫といった発生抑制とともに、生ごみ処理機の設置や再生業者への外部委託などの対応を進めている。2割削減であれば必ずしもリサイクルだけでなく、脱水・破砕といった手法でも実現可能だ。そのためコスト面を考慮し、こうした現実的な方法を選択する事業者も少なからずあると思われるが、食品廃棄物の再資源化に向けた事業機会が創出されたことだけは確かだ。

また、食品廃棄物の中でもリサイクル率の極めて低い事業系の一般廃棄物については、これまで技術開発もあまり進んでおらず、リサイクル施設もほとんどないのが現状。法施行に向けて、スーパーやコンビニ、外食産業から排出される事業系一般廃棄物のリサイクル施設、事業の整備も急務だ。

こうした状況の中、すでに各所で食品廃棄物の循環システムの構築が始まっており、それに合わせ、再生事業の立ち上げ、技術開発、市場投入も活発化している。今のところ、想定されている再資源化の手法は堆肥化、飼料化、バイオガス化など。しかしながら現在、装置にしろ、再生事業にしろ、関連事業が堆肥化へと集中している傾向にある。年間2000万トン程度発生する食品廃棄物を再資源化するためには、堆肥化だけでは当然、供給過剰となるのは確実だし、施肥のタイミングもあり年間を通して需要のばらつきもある。事業としてみても競争激化が予想される。

そこで、今後の事業展開、あるいは資源循環の側面から大きな期待を寄せられているのが飼料化だ。食品廃棄物の有効利用は当然のことながら、以前より政府が推し進めているものの、なかなか進展しない自給率の向上という狙いとも一致、有望視される。

「養豚配合飼料での利用」

以前まで残飯は飼料として当たり前に利用されてきた。特に養豚、いわゆる残飯養豚といわれるものだ。農産加工物や賞味期限切れ食品など都市厨芥を、畜産農家などが濃縮飼料原料として集め、各自で配合して豚に与えていた。しかし60年代頃から飼料メーカーや農協などが海外から輸入したトウモロコシや大豆粕を使った配合飼料を販売するようになった。また、畜産物の消費拡大に伴う大規模な養豚経営展開、養豚経営の都市圏からの後退で、さらに養豚経営での都市厨芥利用が減少した。就業者の高齢化などにより、省力化を図るため配合飼料への切替を進めたのも大きな要因だ。

農水省の畜産生産調査によると、肥育豚1頭当たりの残飯給餌量は、1965年に205.9kg／年だったものが80年には82.6kg／年、97年には6.2kg／年と減少している。また現在、国内には約1万2500戸の養豚農家があり、飼養頭数は約990万頭だが、残飯給餌による養豚農家は約1000戸、飼養頭数は約20万頭となっている。

しかしながらその一方で、多量かつ鮮度・品質が安定、処理しやすい食品製造副産物、たとえば魚腸骨やなたねかす、焼酎かす、果汁絞りかすなどは加工され、配合飼料原料としての利用が進んでおり、96年時点で104万トンが飼料化されている。

現実的には、今のところ輸入飼料原料のほうが価格が安く、品質も安定している。しかし、現在の市場最安値ともいわれる飼料価格がこのまま続くとは考えにくい。世界的に農業技術の向上による食料増産はとっくに限界に来ており、1人当たりの穀物生産量は84年をピークに毎年1％以上減少している。中国でも生活向上で食肉消費が増加し、穀物輸入国となっている。さらに、世界的な異常気象の影響により、ますます農産物生産の不安定要素は高まっている。

また、日本の穀物自給率は28％と、人口1億人以上の国のほとんどが80％を超える中では極端に低い。にもかかわらず食品廃棄物量の多さは世界でもトップクラス。こうした状況下で、食品リサイクル法を機に、生産、流通も含めた食品業界が再資源化を模索する場合に、産業廃棄物はもとより、事業系一般廃棄物においても飼料化という方向性がクローズアップされてくる。

「廃棄物全量の半分は利用可能」

食品廃棄物をもとにした飼料原料はどれぐらいの量が利用可能なのだろうか。北海道立滝川畜産試験場が実施した都市厨芥飼料化製品の給与試験によると、「配合飼料に15～30％代替して給与しても飼料摂取量、枝肉重量、枝肉歩留まりなどの成績は配合飼料と比べて何ら遜色はない。ただし、代替率を上げることで、脂肪の明るさの低下、不飽和脂肪酸割合の増加、融点低下の傾向が見られた。肥育前・中期は配合飼料の20％代替が可能だが、肥育後期では飼料の粗脂肪含有比率を軟脂肪豚発生防止のための目安とされる5％以下となるよう、代替率を10％までとする」という試験結果を出している。つまり飼料中の高脂肪含有量を目安として、成育段階で違ってくるものの、10～20％の配合が可能なようだ。

現在、国内での養豚用配合飼料の年間生産量は約620万トン。その原料の主なものは、トウモロコシ（290万トン）、マイロ（約110万トン）、大豆粕（87万トン）となっている。一方、食品リサイクル法で対象となっている事業系の廃棄物は事業系一般廃棄物が600万トン、産業廃棄物が340万トン。これを全量乾燥加工したとすると大体5分の1、無理にしても、10％配合で62万トン、20％で140万トンの利用可能性がある。食品リサイクル法の削減目標20%分ならば十分まかなえる数字だろう。

「ドライかリキッドか」

食品廃棄物の飼料化では大きく分けて2つの方法がある。ひとつは乾熱や湯温脱水で乾燥処理を行うドライ方式、もうひとつは湿式処理を行うリキッド方式だ。

「乾燥させるドライ給与方式」。もうひとつが「リキッド給与方式」だ。

ドライ給与方式は乾燥させるコストがあるものの、輸送や保存が比較的容易というのが特徴。一方、リキッド方式は、醸造、乳製品加工、大豆加工、果物加工などの工場から高水分のまま養豚場に搬入し、養豚場で飼料調整を行い給与するというもので、乳業界からホエイが多く出る欧州などで行われている。乾燥させるコストはないが、夏季高温の日本では、バイプや飼料調整層の衛生管理に気を使う必要がある。食品廃棄物を原料にした飼料に限らず、今のところ国内ではドライの給餌システムを取り入れている養豚場が多く、輸送コストなども考慮に入れると、ドライ給与方式の方が融通性はありそうだ。

例えば、三造有機リサイクルは、札幌市リサイクル団地内に生ごみリサイクルプラントを建設し、97年1月より札幌市（市長：桂信雄氏）清掃部の指導のもと、札幌市環境事業公社から市内の学校、ホテル、レストラン、食品加工工場などから排出される残飯・厨芥などの事業系生ごみの供給を受け、リサイクル事業を行っている。

同プラントは「油温減圧脱水法」と呼ばれる方式で、天ぷらを揚げるのと同じ原理を利用して密閉減圧容器の中で脱水・乾燥させるもの。1日当たり10時間で35トンの事業系生ごみを処理し、飼・肥材料を7トン／日生産する。本プラントで作られる生ごみ再生品は、家畜飼料としての各種適性試験を行った後、99年2月に農林水産省・畜産局流通飼料課に申請書を提出し、飼料配合材としての暫定値を認定された。現在、飼料配合材を配合飼料メーカーを通じて飼料消費者への販売を展開しているほか、プラントの販売も強化している。

また環境装置メーカーのオカドラ（横浜市）は、生ごみを煮沸乾燥、飼料化する装置を開発している。乾燥工程の効率化で、従来方式に比べ建設費、運転費ともに半分以下で済むという。1日処理能力は2トン～400トンまで対応。建設費は1日処理量1トン当たり1000万～2000万円。生ごみ1トンを処理するランニングコストは4000～5000円としている。

さらに同社では今後、商社や飼料会社などと連携し、生ごみ飼料の流通網を整備する方針。独自開発した煮沸乾燥機で生ごみを乾燥し、5分の1～10分の1に減量、異物を除去した後に高温殺菌、脱脂機で油脂分を取り除き飼料化する。飼料化装置はスーパーやレストランなど大量の生ごみを排出する事業者に売り込む。一方、小口の顧客には煮沸乾燥機だけを販売し、できた乾燥品を引き取り一括して飼料化するリサイクル体制構築も含め、展開していきたい考えだ。

「協同組合化でシステムを構築」

とはいえ、飼料化を事業として捉えた場合、堆肥化と同様にさまざまな障害ももちろん多い。特に事業系の食品廃棄物を視野に入れると、飼料の品質を左右する異物や塩分などの分別、回収量の確保とロット管理、飼料安全法をクリアする品質管理などが挙げられる。また豚について食味は良好であるものの、格付け評価が低く出ることなどもある。中小規模の事業者も多い食品関連事業者や養豚事業者がそれぞれ単独でシステムを構築するのは難しい面がある。

そこで、協同組合化することによって、飼料化のシステムを構築しようという動きも出てきた。全国食品リサイクル事業協同組合（愛知県名古屋市）が5年前から進めてきた構想が2001年度にも実現しそうだ。

同組合が行う食品循環資源再生事業は、表1のように行われる。「ものの流れ」は排出企業から食品循環資源が出され、食品リサイクル工場で飼料化される。その後、飼料が養豚事業者、食品加工事業者を経て、最終的に肉の形で排出企業に戻ってくる仕組みだ。「金の流れ」については、排出企業から処理委託費を負担してもらって、それを元に食品リサイクル工場で飼料化。できた飼料を養豚事業者に支給し、生産された豚肉は契約栽培と同じ考え方で、最終的に排出企業に戻す。その際も食肉購入費を出してもらうが、従来のものより品質が良くて安い、安全な豚肉を提供する。

つまり、関係者全体でひとつの企業体を作るといった考え方で、皆で設立した会社内で需給バランスをとりつつ流通・営業その他の経費などの無駄を排した循環システムを作り上げる構想。参画した全員が、個々にやったのでは得られないメリットが得られる。99年に農水省の補助を得て、実証試験を行った結果、全体のシステムの機能や信頼性の評価、リサイクルの品質評価である程度の見通しを付けた。収支見通し（表3）も良好だ。PFI法人による実用プラント第1号バイロットモデルを2001年度、名古屋に設置する予定だ。