This week on Dezeen, the impact of plastic on the environment was yet again a talking point, as the London Marathon gave out drinks in edible seaweed capsules and a study revealed the truth behind biodegradable bags.

On Sunday, over 30,000 biodegradable Ooho capsules were handed out to runners at the London Marathon, marking the largest ever trial of the drinks pods.

Designed to reduce plastic waste, the pods are made from a seaweed-based substance and can be filled with water or other beverages. The wrappers can be consumed or dropped on the ground, as they naturally decompose in under six weeks.

Meanwhile the University of Plymouth revealed the results of its study that found "biodegradable" plastic bags remain intact and useable three years after being dropped in the sea or buried underground.

Five types of plastic carrier bag were used for the experiment, which was conducted over three years in soil and marine environments. The biodegradable bag, the oxo-biodegradable bag and the standard plastic bag all remained fully functional.

In architecture news this week, Studio Gang's 40-storey Mira tower topped out in San Francisco, as shown in photos released by developer Tishman Speyer.

BIG also unveiled plans for a tower in Ecuador's capital Quito, which will comprise two curved blocks covered in earthy coloured tiles.

Notre-Dame continued to hit headlines, as Studio NAB proposed replacing its gothic roof with a public greenhouse and Dezeen deputy editor Tom Ravenscroft argued that a new, modern spire should be welcomed.

Over 1,000 architecture and heritage experts also called on the French president to abandon his five-year deadline for its rebuild, saying it should be carried out "without haste".

In design, Chinese e-commerce giant Alibaba unveiled a new custom typeface that its partners, sellers and consumers can use for their own brand identities.

Facebook launched its "modern" site redesign, which aims to puts privacy at the forefront and features a "cleaner", all-white design. Users will see these updates in the Facebook app immediately.

Following years of extreme land subsidence, the president of Indonesia announced plans to relocate the nation's sinking capital away from Jakarta. The new capital will be close to the geographic centre of the country.

Indonesia also featured on the shortlist for the Aga Khan Award, announced this week. A community library built by Indonesian studio Shau using ice cream tubs features on the 20-strong shortlist, alongside a courtyard home in Beijing and a fish market in Oman.

Create Streets founder Nicholas Boys Smith was named interim chair of the UK's Building Better, Building Beautiful Commission, following Roger Scruton's removal in April.

Meanwhile in the US, Airbnb's offshoot design studio Samara hired Apple industrial designer Miklu Silvanto to join the company's housebuilding initiative, Backyard, which plans to roll out housing designs later this year.

The unpaid internships saga continued this week, when recent architecture graduate Urvashi Vasishtha spoke to Dezeen about her experience of "exploitative internships" in India.

In contrast, we rounded up five of the best paid internships available on Dezeen Jobs right now, including opportunities in London, Hong Kong and the Netherlands.

Projects that sparked readers' imaginations this week included a lavender-topped writer's study in Ireland, Sutherland & Co's self-designed studio in Scotland and the revival of a mid-century house in Upstate New York.