生物塑料对地球的危害强于化石塑料
Bioplastics could be "just as bad if not worse" for the planet than fossil-fuel plastics

由专筑网蒋晖，李韧编译

可循环专家Arthur Huang认为，生物塑料对于环境的影响也许会比传统塑料更大。

Huang认为，利用植物所制作的塑料制品虽然代替了化工石油作为原材料，但却需要大量的农田供应原材料，因此可能会影响到人类食物的种植产量。

循环经济工程公司Miniwiz的创始人兼CEO Huang认为，生物塑料在堆肥时会对环境造成损害，使土壤和水的酸性增加，污染陆地和海洋。

他说：“如果我们用对待传统塑料制品的方式对待生物塑料，只会让事情变得更加糟糕。因为在其降解的过程中会改变土壤和水的pH值，损害有价值的食物。”

Huang引用了一份2015年的联合国报告，该报告指出如果公众认为他们所使用的塑料制品可以经过无害地降解，那么他们就会减少对其的重复利用，而这份报告也大大地引发了公众的担忧。

PLA可以堆肥，但不能生物降解

Huang是一名建筑师兼工程师，他开创了塑料的回收技术。2017年，他曾与耐克公司合作设计了一款由回收后的饮料容器所制作而成的运动鞋包装盒。

PLA是一种常见的生物塑料，由提取自玉米、马铃薯或甘蔗等农作物的淀粉发酵后制成，它也可以由藻类的提取物所制成。

Bioplastics could potentially be worse for the environment than conventional plastics, according to recycling expert Arthur Huang.
Switching to plastic made from plants instead of fossil fuels would require vast amounts of farmland, Huang said. This could could cause environmental problems and deprive humans of food.
Huang, founder and CEO of circular-economy engineering company Miniwiz, added that bioplastics can cause damage when they are composted. They make soil and water more acidic, he claimed, potentially polluting both land and ocean.
"If we use them the same way [as conventional plastics] they are just as bad if not worse," he said. "They change the pH value of soil and water as they degrade, and they take away valuable food supplies," he said.
Huang cited a United Nations report from 2015 that raised concerns that the public would recycle less if they thought the plastic they used would harmlessly degrade if discarded.

PLA is compostable, not biodegradable
An architect and engineer, Huang has pioneered techniques for recycling plastic. In 2017 he collaborated with Nike to design sneaker packaging made from recycled drinks containers.
Polylactic Acid (PLA), the most common type of bioplastic, is made from fermented starch extracted from crops such as corn, potatoes or sugar cane. It can also be made from algae.


Huang认为，海洋中的传统塑料制品在很大程度上是“美学问题”／Conventional plastic in soil or the ocean is "largely an aesthetic problem" says Huang

PLA可堆肥，这意味着在适当的条件下，微生物将会在几个月后无害地分解。但是它们不能被生物降解，因此它们会像传统塑料一样在正常的条件下缓慢分解。

Huang介绍说，PLA是一种酸性很高的制品，因此其在降解的过程中会影响到周边环境的酸度。

“这就好像我们把橙汁倒进了海洋或河流的入口。”Huang说。

海洋塑料是“美学问题”

Huang在之前举办的米兰Ro Plastic Prize中发表了他关于生物塑料和传统塑料的相对性的观点。

这次活动的目的是为了鼓励塑料制品的回收与利用，在这期间，为产品、织品和一些发明颁布了奖项。

Huang对“生物塑料本质比传统塑料制品好”这一观点提出了质疑。

他认为，传统塑料对于海洋的影响是美学上的问题，因为它们不会对环境造成很大的影响。同时，它们很可能是一种碳的储存方式，因为其很难释放碳元素。

他认为“它是不能反应的，因此它不会降解，所以无法释放碳元素”。

然而生物塑料却是可以完全降解。那么这就意味着，“你把一个美学问题变成了一个化学问题”。

生物塑料建筑的辩驳

建筑师Arthur Mamou-Mani反驳了Huang的说法,他认为“这是一种非常干净的材料”。这位法国建筑师在上周的米兰设计周中用3D打印技术将PLA作为原材料，为时尚品牌cos建造了一座展馆。

“在碳排放方面，它比传统塑料高出68%。但当涉及到气味时，它的毒性会比传统塑料低50倍。因此在这一点上，当你在办公室做3D打印时就非常重要了。”

PLA is compostable, meaning microbes will break it down harmlessly into biomass and gas within a few months, given the right conditions. They are not biodegradable, since under normal conditions they will break down just as slowly as conventional plastics.
However since PLA is an acid, it will raise the acidity of its surroundings as it composts, according to Huang.
"It's like us dumping lots of orange juice into the ocean, or the mouth of a river," said Huang.

Ocean plastic "an aesthetic problem"
Huang made the comments at the judging of the Ro Plastic Prize in Milan last week, during a jury discussion about the relative merits of bioplastics and fossil-fuel plastics.
The competition, launched to encourage the recycling of plastics, saw prizes awarded for products, fabrics and innovations.
Huang challenged the idea that bioplastics were inherently better than plastics derived from fossil fuels.
Conventional plastic that gets into the soil or the ocean is largely an aesthetic problem, he argued, since it is non-reactive and causes no physical harm to ecosystems. The argument could even be made that plastic waste is an effective method of carbon storage, since it is difficult for conventional plastic to break down enough to release its carbon.
"It's non-reactive; it doesn't break down," he said. "It's solidifying carbon in a way."
However compostable bioplastics do break down completely, meaning "you turn an aesthetic problem into a chemical problem."

Bioplastic architect refutes claims
Architect Arthur Mamou-Mani contested Huang's statements. "It's a very, very clean material," said the French architect, who built a pavilion out of 3D-printed PLA for fashion brand COS as part of Milan design week last week.
"It's 68 per cent more carbon efficient in terms of carbon emissions than conventional plastic. It's 50 times less toxic when it comes to fumes, which is very important when you 3D print it in your office."


Arthur Mamou-Mani为米兰设计周设计了一座PLA的展馆／Arthur Mamou-Mani, who built a PLA pavilion for Milan design week, disagrees

Mamou-Mani为了反驳“PLA会增加土壤酸性”这一观点，他进行了一项实验。他在降解了PLA的土地上种植了生菜，并用其制成沙拉，他声称沙拉的味道非常好。

要降解PLA，“你需要把它放在一个工业堆肥设施中，”Mamou-mani说，“同时你还需要满足60摄氏度和100%的湿度的条件，然后它才会在一个月内分解。当然你也可以把它们放在一个家庭堆肥的设施中，在这种情况下它需要大约6个月的时间来降解。”

再循环优于堆肥

Huang认为，生物塑料最好的归宿是再次回收利用，而不是堆肥。“如果我们能够好好地回收并再利用，而停止一次性的使用，那么可能是一个很好的解决方案。现在用途的单一是所有问题的根源所在。”

去年，策展人JanBoelen告诉Dezeen记者，推广化石燃料塑料回收的举措是“胡说八道”，设计师应该开发生物塑料替代品。

Mamou-Mani disputed the claim that composted PLA lowers the pH value of water or soil, making it more acidic. He cited an experiment where lettuce plants had been grown in PLA compost. "They tested the acidity and the salad was perfectly fine," he said.
To turn PLA into compost, "you need to put it in an industrial composting facility," Mamou-Mani said. "You need 60 degrees Celsius and 100 per cent humidity and then it decomposes within a month. You can put them in a home composter and then it takes about six months as the temperature is a bit lower."

Recycling better than composting
A better solution is to recycle bioplastics instead of composting them, Huang said. "If we switch the name and recycle it seriously and stop single use, that could be a good solution. Single-use is where all the problems begin."
Last year curator Jan Boelen told Dezeen that moves to promote recycling of fossil-fuel plastics were "bullshit" and designers should instead develop bioplastic alternatives.