Ключевые слова: above, aerial, aerial view, background, biology, building, circle, clean, cleaning, dirty, drone view, ecology, ecosystem, effluent, environment, environmental, facility, factory, flow, green, industrial, industry, plant, pollution, process, purification, purified, purify, purity, recycle, recycling, reservoir, separation, sewage, sewage treatment, sewer, sewerage, sludge, storage, system, tank, technology, treatment, urban, view, waste, wastewater, wastewater treatment plant, water, water pollution,