The digital ecosystem is used extensively by people worldwide for various services such as social media, banking, healthcare, insurance, etc. Every coin has two sides similarly digital usage also has its advantages and disadvantages from the user’s perspective. One of the disadvantages is the sharing of personal and sensitive data over the digital medium without understanding the hazards. This personal identification information (PII) is used not only for providing personalized services to the users but also for profiling the users for the gain of the service providers. The importance of user rights over their data is easily neglected. Privacy Preservation plays an important role in the digital ecosystem to control the security and privacy of the users PII. This includes achieving User Anonymity, Data Confidentiality and Access Control. Researchers have provided various methods and solutions to ensure privacy and security of digital data using centralized methods including cloud services. Security challenges exist in such approaches due to their centralized nature. Eventually, researchers are exploring the decentralized approach using blockchain technology. Blockchain technology paves the way for many applications that need a distributed and trustful way of data management. This paper presents a systematic review of research work done to satisfy the privacy preservation challenges in decentralized, non-financial applications such as Healthcare, Social media, Identity management, etc., on a public blockchain i.e. Ethereum, and further identifies the gaps amongst them. The authors conclude by suggesting a combined approach to solve the existing gaps for efficient privacy protection of digital data on Dapps.