John Jackson worked in the Witham-based criminal justice mental health team when concerns were raised about his internet use in 2013.
A Health and Care Professions Council panel heard 40% of his work internet use between May 2012 and May 2013 involved "adult pornographic material".
Mr Jackson admitted the findings of the investigation, the panel was told.
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An investigation into Mr Jackson's internet use found he had viewed pornography on 1,296 occasions.
The panel also heard how Mr Jackson, who was employed by Essex County Council but seconded to the North Essex Partnership NHS Foundation Trust as a senior practitioner, "no longer wished to work as a social worker".
Mr Jackson was dismissed following an internal disciplinary hearing in August 2013. His appeal against that dismissal was dismissed.
Essex County Council has yet to comment on the case.

Guineans are expected to celebrate the landmark with concerts and fireworks.
The disease killed more than 2,500 people in the country and a further 9,000 in Sierra Leone and Liberia.
Sierra Leone was declared free of Ebola in November, but new cases have emerged in Liberia, which had been declared Ebola-free in September.
A country is considered free of human-to-human transmission once two 21-day incubation periods have passed since the last known case tested negative for a second time.
The disease has had an enormous social and economic impact on Guinea, the BBC's Ibrahima Diane in Conakry says.
According to the UN, 6,220 Guinean children have lost one or both parents to Ebola.
More than 100 health workers also lost their lives in the fight against the disease.
Meanwhile, survivors are still living in fear of the stigma and long-term side effects associated with the virus, our correspondent adds.
The fight against Ebola was particularly difficult in Guinea, he says.
Some communities initially did not believe there was an epidemic, while others blamed it on Western countries and the Guinean authorities.
The government has blamed the virus for poor economic performance and says it has also caused people to distrust the country's health services.
President Alpha Conde has doubled the health budget since winning re-election in November.

Gilmartin, 30, has signed an undisclosed-length deal after leaving the Hornets, where he failed to play a first-team game in three years.
His most recent senior match in England came for Plymouth in January 2013.
Keeper Brill, 31, joined Colchester in January on a short-term deal and rejected the offer of a new contract.
The former Luton, Barnet and Oldham player found himself as number two to Sam Walker, who played every league game last season.
Gilmartin will coach keepers Walker and Dillon Barnes, with Ademola Bankole leaving the role after more than nine years at the club.
Find all the latest football transfers on our dedicated page.

The head of Queen's, Prof Patrick Johnston, told the BBC's Inside Business programme a rise in tuition fees, or a return to public funding, was required to bridge a Â£100m gap.
"We have some very critical decisions as a society to make very, very quickly, because we're already in trouble" he said.
"We're bringing corporation tax in in 2018, we actually today don't have the graduates to fill those jobs.
"We have to either come up with a number of solutions, one of which might be the public purse begins to fund the full investment in higher education that is needed, either fees or we have to get back to public funding."
Inside Business is on BBC Radio Ulster and Radio Foyle at 13:30 BST on Sunday.
A senior social worker who viewed adult pornography more than 1,000 times using a work computer has been struck off.
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Guinea is to be declared free of Ebola by the World Health Organization (WHO), two years after the epidemic began there.
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Colchester have signed goalkeeper Rene Gilmartin as a player-coach after his release by Watford, and confirmed Dean Brill will not be returning.
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The vice-chancellors of Queen's University and Ulster University have said serious decisions need to be taken over the future funding of higher education in Northern Ireland.