坏境 means "environment" and 周围 means "surroundings." Just as in English, you use "environment" to describe the physical and non-physical attributes of a place. You use "surroundings" to describe the immediate area around a place. For example: 这家餐馆环境很好 OK This restaurant is in a good environment. 这家餐馆周围很好 NOT OK This restaurant has good surroundings ... sounds funny even in English. Instead, you use 周围 to describe the physical surroundings of the restaurant: 这家餐馆周围有很多店家 There are many stores in vicinity (in the "surrounding") of this restaurant.

In terms of part of speech: 环境is a noun: 环境正在恶化。the environment is deteriorating. Or a noun adjective:环境问题正越来越受到重视。environmental issues are receiving more and more attention. 周围is a positional noun:在我家的周围有很多流浪汉。there are a lot of vagrants near (in the vicinity of) my house. Or an adverb：房子很漂亮。周围环境也很好。the house is very pretty. In the vicinity the environment is also very good. In terms of semantics: 环境is an ecological concept while 周围is a geographical concept. You can use them in the same sentence: 我家周围环境很好. In the vicinity of my house the environment is pretty good. ---------------------------- Hope this helps. :)

I agree with the previous answers and I think 环境 is environment, but not exactly the eco one. You can say: 学英语最好有一个好的环境 （A good environment is important for English learning), so here 环境 is like you are more exposed to English like you have English friends, you are in an English speaking country and things like that.