Novel approach of phosphate-reclamation as struvite from sewage sludge by utilising hydrothermal carbonization.

Hydrothermal carbonization (HTC) showed promising performance as an alternative sewage sludge treatment already, as the draining ability of sludge is improved while fuel properties of the yielded hydrochar are superior to native sludge. On the other hand, the sole combustion of sewage sludge and its corresponding hydrochars are a waste in terms of nutrients like phosphorus and nitrogen. Therefore, a combination of HTC and a nutrient recycling strategy via the precipitation of phosphate and nitrogen as struvite (magnesium ammonium phosphate) are introduced in this research. We used an anaerobically digested sewage sludge with high loads of aluminium- and ironsalts. Phosphate release cannot be reached by HTC alone, as phosphate is heavily bound in stable iron- and aluminium-associations. An acid leaching step removes it from the hydrochar (58.5-94.8% P), while the process liquid arising from HTC is used as ammonium source (107-291 mmol l-1NH4). After adjusting pH and addition of a magnesium source, struvite is rapidly precipitated in high purity. Nitric acid is used as a "catalyst" in HTC to improve the degree of carbonization on one hand but also improve the phosphate recovery on the other hand by increasing the amount of ammonium available for struvite formation in the process liquid. The highest total recovery rate of phosphate from sludge was 82.5 wt.% and therefore this approach showed to be a serious alternative to other P-recovery techniques.

[Hyperparathyroidism--new aspects]. / Neue Aspekte bei Hyperparathyreoidismus.

Hyperparathyroidism is generally classified into a primary and secondary form. The primary form is caused by an autonomous adenomatous hypertrophy and/or hyperplasia of parythyroideal glands without known cause in most of the patients. Resulting elevated levels of parathyroid hormone cause elevation of serum calcium, subsequently followed by cerebral symptoms, fatigue and calcinosis of vessels and kidneys. The mainstay of secondary HPT is the initial vitamin D deficiency such as associated with kidney failure. Via an increased PTH secretion, calcium homeostasis will be maintained together with ongoing hyperplasia of the parathyroidea. Therapeutic approaches are related to pathophysiological mechanisms. While surgical removal of adenomatous glands is the mainstay of therapy in primary and late secondary forms, during the still regulated initial period of secondary HPT supplementation of vitamin D and/or sensitation of parathyroideal Calcium-sensing-receptors are therapy of choice.

[Colorectal neoplasms. Study of the attitudes among Danish gastroenterologists]. / Kolorektale neoplasmer. En holdningsundersøgelse blandt danske gastroenterologer.

The results of a questionnaire concerning colorectal neoplasms are discussed with reference to the relevant literature. Coloscopy is the examination of first choice in the diagnosis and follow-up of colorectal neoplasms but double-contrast barium enema (DCBE) is still justified, particularly in cases where coloscopy proves difficult. In the light of present knowledge, the replies to the questionnaire appear to attach too much importance to frequent early control examinations of patients with cancer and adenomata at the expense of more relevant long-term control. Before a control programme for colorectal neoplasm is commenced, a clean colon should be ensured. Patients attending control examinations should be informed about the symptoms of interval cancer.

Food-stimulated cholescintigraphy as a supplement to ERC in patients with suspected bile flow obstruction. A preliminary study.

Cholescintigraphy after food stimulation was carried out in 40 patients (13 patients with biliary enteric bypass, 14 patients with bile duct stenosis, demonstrated by ERC, 5 patients with endoprothesis and 8 patients with clinically suspected post-cholecystectomy syndrome. Biliary-bowel transit time of one hour or less was considered to be normal. In patients with biliary enteric bypass 11 had a normal transit time; however, one with a concomitant anastomotic leakage, and 2 patients had prolonged transit time and a significant obstruction by the anastomosis. All 14 patients with demonstrated biliary stricture had normal transit time. In 5 patients with endoprothesis, 2 had prolonged transit time in spite of patent endoprothesis. Finally, in the 8 patients with suspected post-cholecystectomy syndrome, 4 had normal sphincter of Oddi manometry and normal transit time, and 4 had abnormal sphincter of Oddi manometry, but only one with prolonged transit time. It is concluded that in patients with biliary enteric bypass (hepatico-jejunostomia) or biliary strictures a biliary-bowel transit time of one hour will be discriminatory between normal and abnormal conditions. This is in contrast to patients with endoprothesis and suspected sphincter of Oddi dysmotility, where a transit time of one hour only will have limited predictive value.